Nuclear electromagnetic pulse protector

Abstract

The utility model relates to a nuclear electromagnetic pulse protector, and relates to the technical field of electromagnetic pulse protection, the protector comprises a high-pass filter and a PIN diode, the input end of the high-pass filter is connected with an antenna, the output end of the high-pass filter is connected with the anode of the PIN diode, and the cathode of the PIN diode is grounded; and the high-pass filter is used for limiting the nuclear electromagnetic pulse spectrum in a stop band of the high-pass filter. The utility model has the effect of reducing the size of the protector.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic pulse protection, and in particular to a nuclear electromagnetic pulse protector. Background Art

[0002] In recent years, with the rapid development of the microelectronics industry, the degree of integration of electronic information systems has become increasingly higher. At the same time, due to the demand for miniaturization and high speed, the size of components has become smaller and smaller, which has caused electronic systems to become more sensitive to interference from complex strong electromagnetic pulses. Antennas, as radio transmitting and receiving devices, are important equipment that affects signal strength and quality, and are indispensable components in modern wireless communications.

[0003] Nuclear electromagnetic pulse is an electromagnetic pulse interference source with high peak electric field intensity, fast rise time, wide spectrum and high energy. It is a short pulse signal of nanosecond level in time domain waveform and has a particularly wide spectrum coverage in frequency domain waveform. Once this transient high-power pulse signal is coupled into the electronic equipment system, it will cause serious damage to electronic components, etc. It can be coupled to the receiver and electronic equipment at the rear end of the antenna through the antenna effect, generating transient overvoltage and a large amount of energy, causing great damage to the electronic equipment. Therefore, it is of great significance to protect the antenna effect of high-altitude electromagnetic pulse (HEMP).

[0004] There are generally two types of current feed-type RF protectors. One uses a single gas discharge tube (GDT) to protect the antenna. On the one hand, the antenna and GDT need to be coaxially connected, which makes the protector larger. On the other hand, the protection technology of GDT has disadvantages such as slow response speed, high residual voltage, and poor reliability. The other protector is mainly for lightning surge protection. The first-level protection device of lightning surge protection is a varistor or a gas discharge tube. Both of them have slow response speed when facing strong electromagnetic pulse protection and have the risk of leaking high voltage. At the same time, the gas discharge tube's follow-up problem and the failure and spontaneous combustion problem of the varistor make the protection device less safe. When using a varistor for antenna protection, the antenna and the varistor are also coaxially connected.

[0005] The protector in the above technical solution is relatively large in size and is not applicable in some scenarios that have high requirements on the size and weight of the protector, such as the protection of vehicle-mounted antennas and aircraft-mounted antennas. Utility Model Content

[0006] In order to reduce the volume of a nuclear electromagnetic pulse protector, the present application provides a nuclear electromagnetic pulse protector.

[0007] The nuclear electromagnetic pulse protector provided in this application adopts the following technical solution:

[0008] A nuclear electromagnetic pulse protector comprises a high-pass filter and a PIN diode. The input end of the high-pass filter is connected to an antenna, the output end of the high-pass filter is connected to an anode of the PIN diode, and the cathode of the PIN diode is grounded. The high-pass filter is used to limit the nuclear electromagnetic pulse spectrum to the stop band of the high-pass filter.

[0009] By adopting the above technical solution, the protector uses a high-pass filter for primary protection and a PIN diode for secondary protection. On the premise of achieving protection against nuclear electromagnetic pulses, the smaller PIN diode is used instead of the larger gas discharge tube to achieve the effect of reducing the size of the protector.

[0010] In a possible implementation, the high-pass filter includes a first capacitor, a first inductor, and a second inductor. The first inductor and the second inductor are connected in series and then connected in parallel with the first capacitor.

[0011] In a possible implementation manner, when there is one PIN diode, the anode of the PIN diode is connected to the common end of the inductor, and the common end of the inductor is a common connection end of the first inductor and the second inductor.

[0012] In a possible implementation, when there are two PIN diodes, the protector includes a third inductor, the first inductor, the third inductor and the second inductor are connected in series in sequence, the anode of one PIN diode is connected to the common end of the first inductor, the anode of the other PIN diode is connected to the common end of the second inductor, the common end of the first inductor is the common end of the first inductor and the third inductor, the common end of the second inductor is the common end of the second inductor and the third inductor, and the cathodes of the two PIN diodes are grounded.

[0013] In a possible implementation, when there is one PIN diode, the protector includes a third inductor and a transient voltage suppressor diode, the first inductor, the third inductor and the second inductor are connected in series in sequence, the anode of the PIN diode is connected to the common end of the first inductor, the anode of the transient voltage suppressor diode is connected to the common end of the second inductor, the common end of the first inductor is the common end of the first inductor and the third inductor, the common end of the second inductor is the common end of the second inductor and the third inductor, and the cathodes of the PIN diode and the transient voltage suppressor diode are grounded.

[0014] In a possible implementation manner, the protector includes a circuit board and a protective shell, and the protective shell cover is disposed on the circuit board.

[0015] In one possible implementation, the high-pass filter and the PIN diode are installed on the side of the circuit board facing the protective shell. The high-pass filter and the PIN diode are inside the protective shell. A semicircular opening is opened on the edge of the circuit board. The high-pass filter and the PIN diode are connected to the antenna or load device through the semicircular opening.

[0016] By adopting the above technical solution, a semicircular opening is provided to reserve a connection position with an antenna or a load device, thereby avoiding the use of a coaxial connector, which would cause the protector to occupy too large a volume.

[0017] In a possible implementation manner, an insulating layer is coated on the high pass filter and the PIN diode.

[0018] By adopting the above technical solution, the discharge problem caused by insufficient spacing between various components in the high-pass filter and the PIN diode is avoided, thereby ensuring the safe use of the protector.

[0019] In a possible implementation manner, a conductive metal layer is provided on a side of the circuit board facing away from the protective housing.

[0020] In a possible implementation, a plurality of small holes and a plurality of large holes are provided on the circuit board, wherein the diameter of the small holes is smaller than the diameter of the large holes, the large holes are used to release stress, and the small holes are used to improve the filtering performance of the high-pass filter.

[0021] In summary, the present application includes the following beneficial technical effects:

[0022] The protector uses a high-pass filter for primary protection and a PIN diode for secondary protection. On the premise of achieving protection against nuclear electromagnetic pulses, the smaller PIN diode is used instead of the larger gas discharge tube to achieve the effect of reducing the size of the protector. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of an implementation scheme of a nuclear electromagnetic pulse protector provided in an embodiment of the present application.

[0024] Figure 2 It is a structural schematic diagram of an implementation scheme of a nuclear electromagnetic pulse protector provided in an embodiment of the present application.

[0025] Figure 3 It is a structural schematic diagram of an implementation scheme of a nuclear electromagnetic pulse protector provided in an embodiment of the present application.

[0026] Figure 4 It is a structural schematic diagram of the relationship between the circuit board and the protective shell in the nuclear electromagnetic pulse protector provided in the embodiment of the present application.

[0027] Figure 5It is a bottom view of the circuit board in the nuclear electromagnetic pulse protector provided in the embodiment of the present application.

[0028] Explanation of the accompanying drawings: 1. high-pass filter; 11. first capacitor; 12. first inductor; 13. second inductor; 2. PIN diode; 3. third inductor; 4. transient voltage suppression diode; 5. circuit board; 51. semicircular opening; 52. small hole; 53. large hole; 54. conductive metal layer; 6. protective shell. DETAILED DESCRIPTION

[0029] The following is combined with Figure 1-5 This application is described in further detail.

[0030] The coaxial cables of some antenna systems transmit power feed and RF signals at the same time. The protection of such antenna equipment needs to protect the back-end circuit under the premise of ensuring the normal transmission of RF and DC feed. At this time, conventional LC filtering, 1 / 4 wavelength and other protection solutions will hinder the DC feed function of the equipment and cannot be used. In order to ensure the normal transmission of RF and DC feed, surge protection devices must be combined for protection, such as gas discharge tubes, transient voltage suppressor diodes 4 (transient voltage suppressor, TVS), etc., but conventional protection devices will have higher leakage and safety issues when facing the ns-level rising edge of HEMP.

[0031] There are two main types of current feed-type RF protectors: one is a single gas discharge tube, and the other is a varistor. Gas discharge tubes and varistor react slowly when facing strong electromagnetic pulse protection, and there is a risk of leaking high voltage. The above two types of protection use coaxial connections, which are not suitable for some occasions with high requirements on the size and weight of the protector.

[0032] PIN diode 2 is widely used due to the self-modulation effect of its conductivity, for example, as a limiter or attenuator. The limiter and attenuator have different working principles under different bias states, and the impedance values ​​presented are also different, which has the function of controlling a larger microwave signal with a smaller bias signal. PIN diode 2 can be regarded as a short circuit or an open circuit in the forward or reverse bias state, similar to a variable resistor. In terms of electromagnetic pulse protection, PIN diode 2 has the characteristics of rapid response, short recovery time, and large power capacity, and does not have the safety issues of conventional high-power protection devices. At the same time, the size of PIN diode 2 is smaller than that of GDT, which is conducive to reducing the size of the protector and is suitable for more usage scenarios.

[0033] The present application embodiment discloses a nuclear electromagnetic pulse protector. Figure 1The nuclear electromagnetic pulse protector includes a high-pass filter 1 and a PIN diode 2. The input end of the high-pass filter 1 is connected to the antenna, the output end of the high-pass filter 1 is connected to the anode of the PIN diode 2, and the cathode of the PIN diode 2 is grounded. The high-pass filter 1 includes a first capacitor 11, a first inductor 12, and a second inductor 13. The first inductor 12 and the second inductor 13 are connected in series and then connected in parallel with the first capacitor 11. The high-pass filter 1 is used to limit the nuclear electromagnetic pulse spectrum to the stop band of the high-pass filter 1. When there is only one PIN diode 2, the anode of the PIN diode 2 is connected to the common end of the inductor, and the common end of the inductor is the common end of the first inductor 12 and the second inductor 13.

[0034] The above-mentioned solution of using a single PIN diode 2 to achieve nuclear electromagnetic pulse protection is for equipment with lower protection requirements. The above-mentioned protection requirements refer to the size of the residual pressure. The larger the residual pressure, the lower the protection requirement. Conversely, the smaller the residual pressure, the higher the protection requirement. However, the specific range of the protection requirements needs to be determined according to the device parameters of the PIN diode 2 and the high-pass filter 1, and is not limited here.

[0035] Reference Figure 2 When there is one PIN diode 2, the protector includes a third inductor 3 and a transient voltage suppressor diode 4. The first inductor 12, the third inductor 3 and the second inductor 13 are connected in series in sequence. The anode of the PIN diode 2 is connected to the common end of the first inductor, the anode of the transient voltage suppressor diode 4 is connected to the common end of the second inductor, the common end of the first inductor is the common end of the first inductor 12 and the third inductor 3, the common end of the second inductor is the common end of the second inductor 13 and the third inductor 3, and the cathodes of the PIN diode 2 and the transient voltage suppressor diode 4 are grounded.

[0036] Due to the different frequencies of DC, nuclear electromagnetic pulse and radio frequency, the impedance presented by each component in the protector at each frequency is also different. The working process of the protector is explained based on the relative size of the impedance of each component in the protector at the above three frequencies.

[0037] In the frequency range corresponding to the radio frequency, the protector needs to minimize the impact on the radio frequency microwave transmission. The radio frequency signal is input from the input end and output from the output end. The first capacitor C1, the first inductor L1 and the second inductor L2 form a microstrip line high-pass filter 1. The high-pass filter 1 places the nuclear electromagnetic pulse spectrum in the stop band, showing extremely high attenuation, and shows extremely low attenuation for the radio frequency signal, ensuring that the signal transmission is not affected.

[0038] In the frequency range corresponding to the nuclear electromagnetic pulse, the high voltage of the nuclear electromagnetic pulse enters the protector through the input end. Because the spectrum of the nuclear electromagnetic pulse is within the stop band of the high-pass filter 1, the LC filter is designed specifically for the nuclear electromagnetic pulse spectrum, and a part of the nuclear electromagnetic pulse energy is short-circuited and reflected. The remaining part of the electromagnetic pulse energy passes through the first inductor 12L1 to short-circuit the pulse so that it directly reaches the PIN diode 2. The PIN diode 2 is turned on under the action of high voltage and discharges the energy through the ground wire. Compared with the gas discharge tube commonly used for lightning protection, the PIN diode 2 has a fast reaction speed and low residual voltage. The rising edge speed of the nuclear electromagnetic pulse is n seconds, and the voltage ranges from several thousand V to tens of thousands of V. The PIN diode 2 needs to select a suitable reverse breakdown voltage and a suitable thickness of the I zone depletion layer according to the DC feed voltage and the nuclear electromagnetic pulse voltage to ensure that the withstand power is sufficient and the residual voltage is greater than the starting voltage of the TVS, so that the TVS works and further releases the pulse energy.

[0039] In the frequency range corresponding to DC, DC current enters from the input end, and the reverse breakdown voltage of PIN diode 2 and the working voltage of TVS are both higher than the DC feed voltage. Therefore, for DC, PIN diode 2 and TVS are equivalent to open circuits, and DC is transmitted to the output end through L1, L2, and L3.

[0040] In the embodiment provided in the present application, since the reflection effect of the high-pass filter 1 reflects part of the nuclear electromagnetic pulse energy, a smaller PIN diode 2 can be used to protect the device. Since the residual voltage of the PIN diode 2 is low, the TVS can use a TVS in an SMA (400W) package, which can reduce the overall size of the protector while ensuring the protection performance of the protector. In other implementations, other types of PIN diodes 2 and TVS can be selected according to actual protection requirements, which are not limited here.

[0041] Reference Figure 3 When there are two PIN diodes 2, the protector includes a third inductor 3, the first inductor 12, the third inductor 3 and the second inductor 13 are connected in series in sequence, the anode of one PIN diode 2 is connected to the common end of the first inductor, the anode of the other PIN diode 2 is connected to the common end of the second inductor, the common end of the first inductor is the common end of the first inductor 12 and the third inductor 3, the common end of the second inductor is the common end of the second inductor 13 and the third inductor 3, and the cathodes of the two PIN diodes 2 are grounded. The protector with two PIN diodes 2 is used for equipment with higher requirements.

[0042] Reference Figure 4-5The protector comprises a circuit board 5 and a protective shell 6, and the protective shell 6 is covered on the circuit board 5. The high-pass filter 1 and the PIN diode 2 are installed on the side of the circuit board 5 facing the protective shell 6, and the high-pass filter 1 and the PIN diode 2 are inside the protective shell 6. A semicircular opening 51 is opened on the edge of the circuit board 5, and the high-pass filter 1 and the PIN diode 2 are connected to the antenna or the load device through the semicircular opening 51. A conductive metal layer 54 is provided on the side of the circuit board 5 away from the protective shell 6.

[0043] By making the protector on-board, it can be directly applied to the protected equipment, which can effectively solve the problem of tight space and difficulty in installing coaxial protectors on some protected equipment. The front side of the circuit board 5 of the protector uses a microstrip semicircular port 51 as input and output, which is convenient for welding. At the same time, due to the reduction of input and output connectors, the RF passband performance is improved. A large area of ​​copper is used on the back side to ensure good grounding of the protector and rapid release of transient energy. The front side of the circuit board 5 refers to the side of the circuit board 5 facing the protective shell 6, and the back side refers to the side of the circuit board 5 away from the protective shell 6. In other embodiments, other conductive metals can also be laid on the back side to achieve good grounding of the protector and rapid release of transient energy.

[0044] The high-pass filter 1 and the PIN diode 2 are coated with an insulating layer. Since nuclear electromagnetic pulses will generate transient high voltage, while reducing the overall volume of the protector, the safety spacing between the various components in the protector and between the components and the protective shell 6 may be insufficient, so the tip discharge of the device may occur, which may cause damage to the device. Therefore, applying suitable silicone rubber to the various components of the protector to increase the insulation performance can effectively increase safety and prevent possible discharge problems. In other embodiments, other insulating materials can also be used to coat the various components in the protector to achieve the effect of increasing the insulation performance of the components.

[0045] The circuit board 5 is provided with a plurality of small holes 52 and a plurality of large holes 53, wherein the diameter of the small holes 52 is smaller than the diameter of the large holes 53, the large holes 53 are used to release stress, and the small holes 52 are used to improve the filtering performance of the high-pass filter 1. It is understood that the relative positions of the large holes 53 and the small holes 52 are determined according to the relative positions of the various components in the protector, and are specifically set by those skilled in the art according to actual conditions, and are not limited here.

[0046] The present application separates the RF signal from the feed, ensures good transmission of the RF signal and the feed while protecting against strong electromagnetic pulses, and uses a PIN diode 2 for protection, thereby achieving the effect of reducing the size of the protector and reducing the residual pressure while ensuring the protection effect. By installing the protector on the circuit board 5 to form a board-mounted form, the protector is small in size and light in weight, and can be installed on the circuit board 5 of the protected device, solving the problem of space shortage.

[0047] The implementation principle of a nuclear electromagnetic pulse protector in the embodiment of the present application is: the protector uses a high-pass filter 1 as the primary protection and a PIN diode 2 as the secondary protection. Under the premise of achieving nuclear electromagnetic pulse protection and ensuring feed transmission, the smaller PIN diode 2 is used to replace the larger gas discharge tube to achieve the effect of reducing the size of the protector. It is suitable for scenarios such as vehicle-mounted antennas and airborne antennas that have high requirements on the size of the protector. The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A nuclear electromagnetic pulse protector, characterized in that: The invention comprises a high-pass filter (1) and a PIN diode (2), wherein the input end of the high-pass filter (1) is connected to an antenna, the output end of the high-pass filter (1) is connected to an anode of the PIN diode (2), and the cathode of the PIN diode (2) is grounded; the high-pass filter (1) is used to limit the nuclear electromagnetic pulse spectrum to the stop band of the high-pass filter (1).

2. The nuclear electromagnetic pulse protector according to claim 1, characterized in that: The high-pass filter (1) comprises a first capacitor (11), a first inductor (12) and a second inductor (13); the first inductor (12) and the second inductor (13) are connected in series and then connected in parallel with the first capacitor (11).

3. The nuclear electromagnetic pulse protector according to claim 2, characterized in that: When there is one PIN diode (2), the anode of the PIN diode (2) is connected to the common end of the inductor, and the common end of the inductor is the common connection end of the first inductor (12) and the second inductor (13).

4. The nuclear electromagnetic pulse protector according to claim 2, characterized in that: When there are two PIN diodes (2), the protector comprises a third inductor (3), the first inductor (12), the third inductor (3) and the second inductor (13) are connected in series in sequence, the anode of one of the PIN diodes (2) is connected to the common end of the first inductor, the anode of the other PIN diode (2) is connected to the common end of the second inductor, the common end of the first inductor is the common end for connecting the first inductor (12) and the third inductor (3), the common end of the second inductor is the common end for connecting the second inductor (13) and the third inductor (3), and the cathodes of the two PIN diodes (2) are grounded.

5. The nuclear electromagnetic pulse protector according to claim 2, characterized in that: When there is only one PIN diode (2), the protector comprises a third inductor (3) and a transient voltage suppressor diode (4); the first inductor (12), the third inductor (3) and the second inductor (13) are connected in series in sequence; the anode of the PIN diode (2) is connected to the common end of the first inductor; the anode of the transient voltage suppressor diode (4) is connected to the common end of the second inductor; the common end of the first inductor is the common end for connecting the first inductor (12) and the third inductor (3); the common end of the second inductor is the common end for connecting the second inductor (13) and the third inductor (3); and the cathodes of the PIN diode (2) and the transient voltage suppressor diode (4) are connected to the ground.

6. The nuclear electromagnetic pulse protector according to claim 1, characterized in that: The protector comprises a circuit board (5) and a protective shell (6), wherein the protective shell (6) is covered on the circuit board (5).

7. The nuclear electromagnetic pulse protector according to claim 6, characterized in that: The high-pass filter (1) and the PIN diode (2) are mounted on a side of the circuit board (5) facing the protective housing (6); the high-pass filter (1) and the PIN diode (2) are inside the protective housing (6); a semicircular opening (51) is provided on the edge of the circuit board (5); and the high-pass filter (1) and the PIN diode (2) are connected to an antenna or a load device via the semicircular opening (51).

8. The nuclear electromagnetic pulse protector according to claim 7, characterized in that: The high-pass filter (1) and the PIN diode (2) are coated with an insulating layer.

9. The nuclear electromagnetic pulse protector according to claim 6, characterized in that: A conductive metal layer (54) is provided on the side of the circuit board (5) facing away from the protective shell (6).

10. The nuclear electromagnetic pulse protector according to claim 6, characterized in that: The circuit board (5) is provided with a plurality of small holes (52) and a plurality of large holes (53); the diameter of the small holes (52) is smaller than the diameter of the large holes (53); the large holes (53) are used to release stress, and the small holes (52) are used to improve the filtering performance of the high-pass filter (1).

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