High frequency bandpass high power electromagnetic pulse protector

Abstract

This invention discloses a high-frequency bandpass strong electromagnetic pulse protector. The protector is fixed inside a shielding box. A PCB board has a microstrip filter for signal passband transmission within the high-frequency communication band. A transient suppression diode is soldered to the PCB board and located at the device end to limit residual voltage and current entering the protected communication equipment. A gas discharge tube is soldered to the PCB board and located at the cable end to discharge current when a strong electromagnetic pulse overvoltage occurs. A matching circuit is connected to the gas discharge tube and the transient suppression diode, respectively, and is designed based on their parasitic parameters to ensure that the protector does not affect the insertion loss and return loss of the communication signal under normal conditions. A connector assembly is located in the shielding box and connected to the PCB board to connect the protector in series in the communication link.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic pulse protection technology, and in particular, a high-frequency bandpass strong electromagnetic pulse protector. Background Technology

[0002] In the field of high electromagnetic pulse (HEP) protection technology, the protection of communication equipment from the rapid rise, high power, and wide coverage of HEPs is a significant issue. Common protection methods include shielding, grounding, transient suppression, and filtering. However, shielding is not suitable for communication equipment due to its communication requirements; grounding offers limited suppression of HEPs; transient suppression devices are generally ineffective in protecting communication equipment due to parasitic parameters, residual voltage, and response time; and high-power, high-frequency filters are difficult to design and extremely expensive.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art in this country. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention proposes a high-frequency bandpass strong electromagnetic pulse protector. It utilizes the time delay characteristics and high isolation of a filter to compensate for the insufficient response time and poor isolation of transient devices. Simultaneously, the high transient power provided by the transient suppression device reduces the design difficulty and cost of the filter. Simply connecting the protector in series before the communication equipment provides a certain level of protection without affecting the normal operation of the equipment. It protects against overvoltage and overcurrent generated by strong electromagnetic pulse coupling and can withstand transient overcurrents with peak values ​​in the hundreds of amperes.

[0005] The objective of this invention is achieved through the following technical solution: a high-frequency bandpass electromagnetic pulse protector includes:

[0006] Shielding box,

[0007] The protector, which is fixed inside the shielding box, includes,

[0008] The PCB board incorporates a microstrip filter for signal passband transmission within the high-frequency communication band.

[0009] Transient voltage suppressor diodes, soldered to the PCB board and located at the device end, limit residual voltage and current entering the protected communication equipment.

[0010] A gas discharge tube, soldered to a PCB board and located at the cable end, is used to discharge current in the event of a strong electromagnetic pulse overvoltage.

[0011] The matching circuit is connected to the gas discharge tube and the transient suppression diode respectively, and is designed based on their parasitic parameters to ensure that the protector does not affect the insertion loss and return loss of the communication signal under normal conditions.

[0012] A connector assembly, which is located in the shielding box and connected to the PCB board, to connect the protector in series in the communication link.

[0013] In the high-frequency bandpass strong electromagnetic pulse protector, the gas discharge tube, microstrip filter and transient suppression diode are connected in series to form a multi-level protection structure against strong electromagnetic pulses to suppress transient overcurrents in the hundreds of amperes.

[0014] In the high-frequency bandpass electromagnetic pulse protector, the microstrip filter (5) is a hairpin type or parallel coupled microstrip line structure with a center frequency of 1MHz~6GHz, an in-band insertion loss of <2dB and an out-of-band rejection capability of >30dB.

[0015] In the aforementioned high-frequency bandpass strong electromagnetic pulse protector, the breakdown voltage of the gas discharge tube is 100V~500V, the response time is less than 100ns, and it conducts discharge to ground under the action of strong electromagnetic pulse.

[0016] In the high-frequency bandpass electromagnetic pulse protector, the clamping voltage of the transient suppression diode is 5V~40V, and the maximum current carrying capacity is greater than 50A.

[0017] In the aforementioned high-frequency bandpass electromagnetic pulse protector, the matching circuit includes capacitors and inductors to simulate the parasitic parameters of a gas discharge tube and a transient suppression diode under normal conditions.

[0018] In the aforementioned high-frequency bandpass electromagnetic pulse protector, under an IEC standard electromagnetic pulse with an injection current peak of 48A, the peak current flowing into the protected equipment after protection is less than 0.6A, the insertion loss is less than 2dB, and the return loss is greater than 20dB.

[0019] In the aforementioned high-frequency bandpass electromagnetic pulse protector, the gas discharge tube is replaced with a varistor or a semiconductor discharge tube; the transient suppression diode is replaced with a thyristor or a bidirectional transient suppression device.

[0020] In the aforementioned high-frequency bandpass electromagnetic pulse protector, the microstrip filter is replaced by an LC filter, a ceramic filter, or a dielectric filter.

[0021] In the aforementioned high-frequency bandpass electromagnetic pulse protector, the connector assembly includes an SMA and a BNC that connect the protector in series with the communication link.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] This invention utilizes the low parasitic parameters of microstrip line filters to solve the problem of large design errors and difficult debugging caused by the parasitic parameters of LC components at high frequencies. Attached Figure Description

[0024] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0025] In the attached diagram:

[0026] Fig. 1 This is the circuit schematic diagram of the present invention;

[0027] Fig. 2 This is a 3D view of the shielded box design of the present invention;

[0028] Fig. 3 This is a physical image of the present invention without a shielding box;

[0029] In the diagram, 1. Protector, 2. Screw, 3. Connector assembly, 4. Shielding box, 5. Microstrip filter, 6. Transient suppression diode, 7. Gas discharge tube.

[0030] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0031] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0032] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0033] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0034] To better understand, such as Figs. 1-3 As shown, the high-frequency bandpass electromagnetic pulse protector includes,

[0035] Shielding box 4,

[0036] Protector 1, which is fixed inside the shielding box 4, includes,

[0037] The PCB board includes a microstrip filter 5 for signal passband transmission within the high-frequency communication band.

[0038] Transient voltage suppressor diode 6, soldered to the PCB board and located at the device end, limits residual voltage and current entering the protected communication equipment.

[0039] Gas discharge tube 7, which is soldered to the PCB board and located at the cable end, is used to discharge current when a strong electromagnetic pulse overvoltage occurs.

[0040] The matching circuit is connected to the gas discharge tube 7 and the transient suppression diode 6 respectively, and is designed based on their parasitic parameters to ensure that the protector does not affect the insertion loss and return loss of the communication signal under normal conditions.

[0041] Connector assembly 3, located in the shielding box 4 and connected to the PCB board, connects the protector in series in the communication link. The filter and transient suppressor, after modularization, can be integrated on the same circuit board. The corresponding communication connector can be selected as needed to connect to the front end of the device requiring protection, thus protecting the communication equipment. This overcomes the shortcomings of transient suppressors, such as parasitic parameters and slow response time, and avoids the problem of insufficient power in high-frequency filtering devices.

[0042] Furthermore, this invention allows for adjustment of filter parameters, transient suppression module parameters, and insulation design, enabling it to operate at various voltage levels and communication frequencies. It ensures economic efficiency under lower overvoltages and guarantees electrical performance under higher overvoltages. By using multiple transient suppression devices and filters, it addresses the issues of insufficient response speed and isolation of transient suppression devices, while also resolving the problem of insufficient filter discharge capacity, thus avoiding interference to communication caused by the addition of transient suppression devices under normal conditions. Experimental verification shows that these designs do not affect the response and current-carrying capacity of transient suppression devices, resulting in excellent performance in both protection and communication. This invention offers high flexibility; it can be integrated into the circuit as a protection module during electronic device design, or installed as an expansion device on existing electronic devices via corresponding connectors, providing plug-and-play functionality and adapting to various communication devices with different connectors. In addition, this invention can meet the mechanical strength and grounding requirements of different usage scenarios through the design of different shielding boxes, ensuring that the invention is simple to use, convenient to transport, lightweight, and easy to disassemble and install.

[0043] In a preferred embodiment of the high-frequency bandpass strong electromagnetic pulse protector, the gas discharge tube 7, the microstrip filter 5, and the transient suppression diode 6 are connected in series to form a multi-level protection structure against strong electromagnetic pulses to suppress transient overcurrents in the hundreds of amperes.

[0044] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, the microstrip filter 5 is a hairpin-type or parallel-coupled microstrip line structure, and its center frequency can be designed to be between 1MHz and 6GHz as needed, with in-band insertion loss <2dB and out-of-band rejection capability >30dB.

[0045] In a preferred embodiment of the high-frequency bandpass strong electromagnetic pulse protector, the breakdown voltage of the gas discharge tube 7 is 100V~500V, the response time is less than 100ns, and it conducts discharge to ground under the action of strong electromagnetic pulse.

[0046] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, the clamping voltage of the transient suppression diode 6 is 5V~40V, and the maximum current carrying capacity is greater than 50A.

[0047] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, the matching circuit includes capacitors and inductors to simulate the parasitic parameters of a gas discharge tube and a transient suppression diode under normal conditions.

[0048] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, under an IEC standard electromagnetic pulse with an injection current peak of 48A, the protector 1 results in a peak current flowing into the protected device of less than 0.6A, an insertion loss of less than 2dB, and a return loss of greater than 20dB. This means that the present invention has good protection performance; for an IEC standard injection current waveform of 48A, the current after protection is approximately 0.6A, effectively protecting vulnerable downstream electronic equipment.

[0049] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, the gas discharge tube 7 is replaced by a varistor or a semiconductor discharge tube; and the transient suppression diode 6 is replaced by a thyristor or a bidirectional transient suppression device.

[0050] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, the microstrip filter 5 is replaced by an LC filter, a ceramic filter, or a dielectric filter.

[0051] In a preferred embodiment of the high-frequency bandpass electromagnetic pulse protector, the connector assembly includes an SMA and a BNC that connect the protector in series with the communication link.

[0052] In one embodiment, the protector 1 is fixed to the shielding box by screws 2 and is arranged horizontally.

[0053] In one embodiment, a microstrip filter is used, relying on the electromagnetic coupling principle between current-carrying conductors for filtering. Compared to LC filters, it is less affected by stray parameters at high frequencies, and its design is closer to the actual electrical performance. Furthermore, the filter provides good isolation and a certain time delay characteristic, ensuring that transient suppression diodes at different protection levels can cooperate in operation. Using gas discharge tubes and transient suppression diodes solves the problem of discharging strong electromagnetic pulse overvoltages. Filters alone are insufficient for overvoltage discharge, leading to filter breakdown and reduced isolation, resulting in protection failure. Adding a gas discharge tube at the filter front end effectively suppresses overvoltages, allowing the protector to withstand higher voltages without breakdown while maintaining the same insulation design. Adding a transient suppression diode at the filter rear end limits the voltage and current entering electronic equipment, while cooperating with the gas discharge tube to ensure smooth response of the protector at different voltage levels. Replacing the gas discharge tube and transient suppression diode with their parasitic parameters under normal conditions and designing corresponding circuits based on these parameters modularizes the protector structure, avoids interference from parasitic parameters to communication, and ensures that parameters such as insertion loss and return loss are within required ranges. Furthermore, the circuit design has sufficient redundancy, enabling it to withstand significant parameter errors without degrading filtering or communication performance. With a characteristic impedance of 50 Ω, it supports various connectors including SMA and BNC and can match the impedance of most communication devices. The protector can be integrated into the circuit design as a module or externally connected to equipment as an extended protection module, offering flexible usage and convenient expansion. It also supports cascading multiple protectors for better protection.

[0054] The gas discharge tube is connected to the cable end, and the transient suppression diode is connected to the equipment end. Overvoltage is discharged through the common ground, and the microstrip filter plays an isolation role to prevent residual voltage from entering the equipment side.

[0055] Combination Figs. 2-3 The main installation process of one embodiment of the present invention is as follows: First, the gas discharge tube 7, the transient suppression diode 6, and their matching circuit are soldered onto a PCB board with a hairpin-type microstrip filter 5 to form a protector 1. If no shielding box is required for mechanical strength, BNC / SMA connectors can be directly soldered onto the PCB board for use. If the mechanical strength of the shielding box is required, the protector 1 is fixed to the shielding box 4 using screws 2 according to the design. BNC / SMA connectors with square plate flanges are fixed to the shielding box with screws, and the inside of the connectors is soldered to the protector 1. The connector near the gas discharge tube 7 is connected to the communication cable side, and the connector near the transient suppression diode 6 is connected to the electronic device side. Actual tests have confirmed that, after proper matching design, the present invention embodiment causes almost no interference to the communication of the communication equipment and can effectively protect against strong electromagnetic pulse waveform injection current with a peak value of approximately 48A.

[0056] Furthermore, the microstrip filter of this invention enables high-frequency signal passband transmission, providing high isolation and time delay characteristics. The microstrip filter has minimal impact from parasitic parameters in the high-frequency band, exhibiting excellent bandpass characteristics and out-of-band rejection capabilities, effectively isolating transient interference signals and preventing them from entering communication equipment. Its time delay characteristics facilitate timing coordination of transient suppression devices, enhancing protection synergy. The gas discharge tube rapidly discharges overvoltage, providing the first level of high-energy protection. It has a high current-carrying capacity (up to hundreds of amperes), and although its response time is slower than a TVS, it can withstand greater energy, making it suitable for the initial discharge of strong electromagnetic pulses and preventing overload damage to subsequent devices. The transient suppression diode precisely clamps residual voltage, providing the second level of fine protection. The TVS has a fast response speed (nanosecond level) and low clamping voltage, effectively limiting residual voltage and current entering the equipment and protecting sensitive downstream electronic components. The matching circuit (designed based on parasitic parameters) avoids interference from transient devices on communication signals. Passive components such as capacitors and inductors are used to match the parasitic parameters of the GDT and TVS under normal conditions, ensuring high impedance in the communication frequency band without affecting insertion loss and return loss. A multi-level protection structure achieves "gradual energy absorption + gradual signal purification." The GDT discharges main energy, the filter isolates interference signals, and the TVS further limits residual voltage, forming a complementary protection system. It supports flexible deployment and expanded applications. The GDT, filter, and TVS are integrated on the PCB to form a standard module, facilitating connection to communication systems as plug-ins or expansion modules. Multiple levels can also be cascaded to improve the protection level. Standard connector interfaces (SMA, BNC, etc.) adapt to various communication devices, improving versatility. The standard interface design allows the protector to be plug-and-play, suitable for communication systems with different connector types, requiring no additional equipment modification, improving practicality and compatibility. The shielding box effectively prevents external interference from entering the protector while enhancing structural strength, making it suitable for complex electromagnetic environments and mobile applications. It offers scalable protection capabilities, adapting to electromagnetic pulses of varying intensities. Cascading multiple protectors further enhances overall suppression capabilities, making it suitable for high electromagnetic pulse intensity scenarios such as military, radar, and electronic warfare applications. Interchangeable filter types (LC / ceramic / dielectric filters) expand applicable frequency bands and control costs. In different application scenarios, the filter type can be changed according to frequency requirements. LC filters offer low cost, ceramic filters provide good stability, and dielectric filters offer superior high-frequency performance, improving product adaptability.

[0057] Although embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and all of these are within the scope of protection of the present invention.

Claims

1. A high-frequency bandpass electromagnetic pulse protector, characterized in that, It includes, Shielding box (4) Protector (1), which is fixed inside the shielding box (4), includes, The PCB board has a microstrip filter (5) for signal passband transmission in the high-frequency communication band. Transient voltage suppressor diode (6), which is soldered to the PCB board and located at the device end, limits the residual voltage and current entering the protected communication equipment. Gas discharge tube (7), which is soldered to the PCB board and located at the cable end, is used to discharge current when a strong electromagnetic pulse overvoltage occurs. The matching circuit is connected to the gas discharge tube (7) and the transient suppression diode (6) respectively, and is designed based on its parasitic parameters to ensure that the protector does not affect the insertion loss and return loss of the communication signal under normal conditions. A connector assembly is provided in the shielding box (4) and connected to the PCB board to connect the protector in series in the communication link.

2. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, Preferably, the gas discharge tube (7), the microstrip filter (5) and the transient suppression diode (6) are connected in series to form a multi-level protection structure against strong electromagnetic pulses to suppress transient overcurrents in the hundreds of amperes.

3. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The microstrip filter (5) is a hairpin or parallel-coupled microstrip line structure with a center frequency of 1MHz to 6GHz, an in-band insertion loss of <2dB and an out-of-band rejection capability of >30dB.

4. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The breakdown voltage of the gas discharge tube (7) is 100V~500V, the response time is less than 100ns, and it conducts discharge to the ground under the action of strong electromagnetic pulse.

5. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The clamping voltage of the transient suppression diode (6) is 5V~40V, and the maximum current carrying capacity is greater than 50A.

6. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The matching circuit includes capacitors and inductors to simulate the parasitic parameters of a gas discharge tube and a transient suppression diode under normal conditions.

7. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The protector (1) under an IEC standard electromagnetic pulse with an injection current peak of 48A, the peak current flowing into the protected equipment after protection is less than 0.6A, the insertion loss is less than 2dB, and the return loss is greater than 20dB.

8. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The gas discharge tube (7) is replaced with a varistor or a semiconductor discharge tube; the transient suppression diode (6) is replaced with a thyristor or a bidirectional transient suppression device.

9. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The microstrip filter (5) is replaced by an LC filter, a ceramic filter, or a dielectric filter.

10. The high-frequency bandpass electromagnetic pulse protector according to claim 1, characterized in that, The connector assembly includes an SMA and a BNC that connect the protector in series in the communication link.

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