Strong electromagnetic pulse radiation effect equivalent test method under transmitting port matching condition

Abstract

The invention provides a strong electromagnetic pulse radiation effect equivalent test method under a transmitting port matching condition, and the method comprises the steps: carrying out the irradiation through employing a high-power electromagnetic pulse source under a first preset field intensity, and recording a first response signal of a target cable; stopping irradiation, clamping a current injection probe on the target cable, and connecting the target cable with a signal source; performing Fourier transform on the first response signal to obtain a frequency domain signal, and determining a target pulse signal according to the frequency domain signal; adjusting the injection voltage of the current injection probe according to the target pulse signal, and monitoring a second response signal of the target cable; and performing a high-field-intensity extrapolation test according to the second response signal to complete the electromagnetic radiation effect test process. According to the invention, the equivalent difference mode response of each line to the terminal in the tested end under the irradiation and injection conditions is taken as an equivalent basis, and the equivalent pulse during injection is calculated by using the response of the irradiation test, so that the strong electromagnetic pulse radiation effect equivalent test based on the large current injection technology is completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic radiation effects, and particularly relates to an equivalent test method for strong electromagnetic pulse radiation effects under the condition of matching the emission port. Background Art

[0002] In the modern battlefield environment, electronic information systems and command and control systems are important supports for combat operations. Shielded multi-core cables are a type of interconnected cable widely used in the electronic systems of various platforms. This type of cable has the advantages of anti-interference, high efficiency, and safety. However, electromagnetic pulse attack weapons, with their unique operating principles and powerful destructive forces, have become one of the new concept weapons that change the rules of war. Such weapons generate powerful electromagnetic pulses, causing interference and damage to the enemy's electronic devices and systems, posing a serious threat to information-based warfare. Therefore, it is necessary to conduct strong electromagnetic pulse radiation effect tests on the cable coupling channels of weapons and equipment.

[0003] Currently, using the direct irradiation method to test weapons and equipment requires the use of high-power electromagnetic pulse radiation sources, which are costly. Moreover, the direct irradiation method has extremely high requirements for the test site and great coordination difficulties. Summary of the Invention

[0004] In view of this, the present invention provides an equivalent test method for strong electromagnetic pulse radiation effects under the condition of matching the emission port, aiming to solve the problems in the prior art that the direct irradiation method has extremely high requirements for the test site and great coordination difficulties.

[0005] The first aspect of the embodiment of the present invention provides an equivalent test method for strong electromagnetic pulse radiation effects under the condition of matching the emission port, including:

[0006] Irradiate a parallel two-wire line with a high-power electromagnetic pulse source at a first preset field strength, and record the first response signal of the target cable; the shielded multi-core cable includes multiple pairs of wires; the target cable is any one pair of wires in the shielded multi-core cable;

[0007] Stop irradiating with the high-power electromagnetic pulse source, clip a current injection probe onto the target cable, and connect the current injection probe to a signal source at the same time;

[0008] Perform a Fourier transform on the first response signal to obtain a frequency-domain signal, and determine the target pulse signal according to the frequency-domain signal;

[0009] Adjust the injection voltage of the current injection probe according to the target pulse signal, and monitor the second response signal of the target cable;

[0010] Conduct a high-field-strength extrapolation test according to the second response signal to complete the electromagnetic radiation effect test process.

[0011] In a possible implementation manner, determining a target pulse signal according to a frequency-domain signal includes:

[0012] Performing an inverse Fourier transform on the product of the frequency-domain signal and a preset transfer function to obtain the target pulse signal.

[0013] In a possible implementation manner, the preset transfer function is determined according to the following steps:

[0014] When the current injection probe is clipped onto the target cable, measure the forward transmission gain of the two ports of the vector network analyzer;

[0015] Determine the preset transfer function according to the forward transmission gain.

[0016] In a possible implementation manner, determining the preset transfer function according to the forward transmission gain:

[0017] Determine the preset transfer function according to the test signal of the current injection probe and the corresponding forward transmission gain.

[0018] In a possible implementation manner, performing a high-field extrapolation test according to the second response signal to complete the electromagnetic radiation effect test process, including:

[0019] Connect the device under test to the shielded multi-core cable, increase the injection voltage of the current injection probe until the device under test shows a response, and complete the electromagnetic radiation effect test process; wherein, the response of the device under test is determined according to the second response signal.

[0020] In a possible implementation manner, the electric field strength corresponding to the injection voltage when the device under test shows a response is equal to the product of the electric field strength corresponding to the second response signal and a first coefficient, and the first coefficient is the increasing ratio of the injection voltage.

[0021] The second aspect of the embodiments of the present invention provides an equivalent electromagnetic radiation effect test system. The strong electromagnetic pulse radiation effect equivalent test method under the emission port matching condition in the first aspect above is applied to this system. The system includes: a transmitter, a shielded multi-core cable, a signal conversion module, an oscilloscope, a pulse attenuator, a high-power electromagnetic pulse source, a current injection probe, a power amplifier, an adjustable attenuator, and an arbitrary waveform generator;

[0022] The transmitter is connected to the first end of the shielded multi-core cable, and the second end of the shielded multi-core cable is connected to the oscilloscope through the signal conversion module;

[0023] The pulse attenuator is connected to the high-power electromagnetic pulse source;

[0024] The current injection probe is arranged on the shielded multi-core cable; the current injection probe is sequentially connected to the arbitrary waveform generator through the power amplifier and the adjustable attenuator.

[0025] In a possible implementation, when irradiating the shielded multi-core cable, the high-power electromagnetic pulse source outputs according to the power corresponding to the first preset field strength to complete the irradiation process.

[0026] In a possible implementation, when injecting current into the shielded multi-core cable, the system controls the arbitrary waveform generator to adjust the injection voltage of the current injection probe according to the target pulse signal through the adjustable attenuator to complete the current injection process.

[0027] The third aspect of the embodiments of the present invention provides a transfer function test device, including a coaxial load, a shielded multi-core cable, a through-type load, a signal conversion module, a current injection probe, a power amplifier, and a vector network analyzer;

[0028] The coaxial load, the shielded multi-core cable, the current injection probe, and the through-type load are all arranged in the anechoic chamber;

[0029] The current injection probe is arranged on the shielded multi-core cable; the current injection probe is connected to the output end of the vector network analyzer through the power amplifier; the coaxial load is connected to the first end of the shielded multi-core cable; the through-type load is connected to the second end of the shielded multi-core cable; the signal conversion module is used to connect the through-type load arranged in the anechoic chamber to the input end of the vector network analyzer outside the anechoic chamber.

[0030] The equivalent test method for the strong electromagnetic pulse radiation effect under the matching condition of the emission port provided by the embodiments of the present invention irradiates the parallel twin-wire with a high-power electromagnetic pulse source at the first preset field strength, and records the first response signal of the target cable; stops the irradiation of the high-power electromagnetic pulse source, clips a current injection probe on the target cable, and at the same time connects the current injection probe to the signal source; performs Fourier transform on the first response signal to obtain the frequency-domain signal, and determines the target pulse signal according to the frequency-domain signal; adjusts the injection voltage of the current injection probe according to the target pulse signal, and monitors the second response signal of the target cable; performs a high-field-strength extrapolation test according to the second response signal to complete the electromagnetic radiation effect test process. The present invention takes the equality of the differential-mode responses of each wire pair at the terminal of the test end under irradiation and injection conditions as the equivalent basis, and at the same time uses the response of the irradiation test to calculate the equivalent pulse during injection for the test, so as to complete the equivalent test of the strong electromagnetic pulse radiation effect based on the large current injection technology. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 is a schematic structural diagram of an equivalent electromagnetic radiation effect test system provided by an embodiment of the present invention;

[0033] Figure 2 is a schematic structural diagram of the cross-section of a shielded multi-core cable;

[0034] Figure 3 is a schematic structural diagram of a shielded multi-core cable interconnection system;

[0035] Figure 4 is a flowchart of the implementation of an equivalent test method for strong electromagnetic pulse radiation effect under the matching conditions of the transmitting port provided by an embodiment of the present invention;

[0036] Figure 5 is a schematic diagram of an irradiation response waveform;

[0037] Figure 6 is a schematic structural diagram of a transfer function test configuration;

[0038] Figure 7 is a graph of the change in the forward transmission gain before and after the cable is inserted into the probe;

[0039] Figure 8 is an equivalent injection waveform diagram obtained with line pairs I, II, and III as reference line pairs;

[0040] Figure 9 is a result graph of the low-field strength pre-test of line pair 1;

[0041] Figure 10 is a result graph of the low-field strength pre-test of line pair 2;

[0042] Figure 11 is a result graph of the low-field strength pre-test of line pair 3;

[0043] Figure 12 is a result graph of the high-field strength extrapolation test of line pair 1;

[0044] Figure 13 is a result graph of the high-field strength extrapolation test of line pair 1;

[0045] Figure 14 is a result graph of the high-field strength extrapolation test of line pair 1. Detailed implementation manners

[0046] In the following description, specific details such as specific system architectures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0047] Currently, the method of using direct irradiation to test and assess weapons and equipment requires the use of high-power electromagnetic pulse radiation sources, which are costly. Moreover, the method of direct irradiation has extremely high requirements for the test site and great coordination difficulties. Therefore, seeking an equivalent alternative test method for strong electromagnetic pulse radiation effects has become a research hotspot.

[0048] In this context, the method of bulk current injection (BCI) equivalent to strong electromagnetic pulse radiation effects provides an idea for solving this problem. Currently, this technology is mainly applied to the research of conducted susceptibility, but the research on the electromagnetic radiation effects of the device under test needs to be further expanded. The bulk current injection method is a test technology that injects electromagnetic interference in the form of radio frequency noise current into the device under test through a toroidal probe clamped on the wire harness. Currently, for the equivalent test of strong field irradiation effects, the equivalent test method using bulk current injection is to establish an equivalent correspondence relationship between the irradiation field strength and a certain parameter under low field strength conditions, and then linearly extrapolate this parameter to conduct the equivalent test of strong field irradiation effects. However, this method can only be applied in the interconnected system of shielded two-core wires. Whether this method can be applied in the interconnected system of shielded multi-core cables remains to be further studied.

[0049] The pulse current injection method (PCI) is similar to BCI, but the injected current is a pulse signal, which is generally used to confirm the transient suppression and attenuation functions of circuit protection devices. The experimental objects include various wires and cables such as power lines, data lines, and signal lines in the radiation field, as well as the line shielding of radio frequency antennas. Due to the frequency selection characteristics of cable coupling, there are significant differences in the response waveforms of different cables to the electromagnetic pulse field. Currently, there is still a lack of specific and effective implementation methods for using the PCI technology in equivalent electromagnetic pulse radiation effect tests.

[0050] For the research of multi-core cables, most current researchers adopt the method of equivalent testing by referring to the two-wire interconnection system. However, when this method is applied to multi-core cables, each pair of wires needs to be studied separately. Once the number of wire pairs is large, the operation process is very cumbersome and the testing efficiency is low. The ideal method is that under the injection condition, the current probe clamps all wire pairs, and the response of each wire pair is equal to the response under the irradiation condition at the same time. To explore the feasibility of this idea, the following conducts research on the equivalent testing method for the radiation effect of the shielded multi-core cable coupled with high-intensity electromagnetic pulses.

[0051] Figure 1 It is a schematic structural diagram of the equivalent electromagnetic radiation effect test system provided by an embodiment of the present invention. As Figure 1 shown, in some embodiments, the equivalent electromagnetic radiation effect test system includes: a transmitter 10, a shielded multi-core cable 11, a signal conversion module 12, an oscilloscope 13, a pulse attenuator 14, a high-power electromagnetic pulse source 15, a current injection probe 16, a power amplifier 17, an adjustable attenuator 18, and an arbitrary waveform generator 19;

[0052] The transmitter 10 is connected to the first end of the shielded multi-core cable 11, and the second end of the shielded multi-core cable 11 is connected to the oscilloscope 13 through the signal conversion module 12;

[0053] The pulse attenuator 15 is connected to the high-power electromagnetic pulse source 15;

[0054] The current injection probe 16 is arranged on the shielded multi-core cable 11; the current injection probe 16 is sequentially connected to the arbitrary waveform generator 19 through the power amplifier 17 and the adjustable attenuator 18.

[0055] Specifically, the verification test is carried out in a microwave anechoic chamber. The shielded multi-core cable 11 can be a shielded six-core cable. The shielded six-core cable interconnection system can be divided into three parts: a transmitting end, a shielded six-core cable, and a receiving end. This system is placed on a rotating table in the microwave anechoic chamber, and the system is rotated to an angle where the interconnected shielded six-core cable is parallel to the electric field direction. The length of the shielded six-core cable is 1.5 m. The shielding layers of the cable are respectively connected to the aluminum shielding shells at the transmitting end and the receiving end. Inside the transmitting end, three pairs of wires are respectively connected to 50 Ω coaxial loads to simulate the impedance matching situation at the transmitting end of the system. In order to monitor the response at the cable terminal, inside the receiving end, the cable terminals are respectively connected to through-type loads with different impedance values. Then each through-type load is respectively terminated with a radio frequency optical fiber transmission system, and then the oscilloscope is used to monitor the response of each wire pair.

[0056] Figure 2 It is a schematic structural diagram of the cross-section of the shielded multi-core cable. As Figure 2As shown in the figure, the shielded multi-core cable from outside to inside is successively an insulating layer, a shielding layer, and a filling medium. The internal core wires are grouped in pairs, and the line pair numbers are successively 1 to n. The core wire numbers of each line pair in each group are a and b. Let Z tnx and Y tnx be the transfer impedance and transfer admittance of the core wire x (x = a, b) in line pair n respectively.

[0057] Due to the symmetry of the positions of each core wire relative to the shielding layer, there are:

[0058] Z tix = Z tjx Y tix = Y tjx (i, j = I to n x = a, b) (1)

[0059] Figure 3 is the structural schematic diagram of the shielded multi-core wire interconnection system. As Figure 3 shown, both ends of the cable shielding layer are connected to the shielding housing. From left to right are successively the transmitting end, the shielded multi-core wire, and the tested end. The ground impedances of the shielding layers at both ends are Z(e)L and Z(e)R respectively. Inside the transmitting end, the terminal impedance of each internal core wire is Z L Pair n . Inside the tested end, the terminal impedance of each internal core wire is Z R Pair n . The process of external interference coupling through the shielded multi-core cable channel is as follows: First, the interference excites an induced current and an induced voltage on the outer shielding layer, then forms a distributed source on the internal core wires through the transfer impedance and transfer admittance, and finally affects the equipment connected to the cable terminals, which can be regarded as a first-order small quantity. If the mutual influence between the core wires is considered, this influence can be regarded as a second-order small quantity of radiation emission. Therefore, the mutual coupling between the core wires can be ignored.

[0060] For both the irradiation and injection conditions, the input ends of the radiation field and the current injection probe and each line pair of the tested end can form multiple two-port networks. The system can be regarded as a multi-port network during the test process.

[0061] According to the two-port network theorem, there is

[0062]

[0063] where a represents the input and b represents the output. Therefore, a corresponds to the irradiation field strength or the injection voltage, and b corresponds to the response at the line pair terminal.

[0064] Therefore, if at this time, there is

[0065]

[0066] In Equation (4), m and n are certain definite values. When the boundary conditions at the transmitting end are determined, i.e., the impedance at the left end is relatively stable, S 21pair n is a certain fixed value.

[0067] If

[0068]

[0069] In this way, the equivalent correspondence between the irradiation field strength and the injection voltage is linear and independent of the terminal impedance.

[0070] The following discusses the feasibility.

[0071] If the influence of the current injection probe on the parameters of S 22 is very small after it is connected to the system, the above conditions are satisfied. Theoretically analyzed, due to the existence of the shielding layer, the mutual coupling between the shielding layer and the core wire is weak, and the shielding effectiveness can reach 20 dB. Therefore, the influence of the loading impedance and loading admittance coupled by the current probe to the shielding layer can be ignored. In addition, analyzing the specific circuit, the loading impedance and loading admittance coupled by the circuit probe in the common-mode loop can be ignored. In this model, the shielding layer and the ground can form a common-mode loop.

[0072] In addition, when , the excitation of the external ports of the DUT under irradiation and injection conditions is the same, and the changes in the impedance of the DUT under the two conditions are also the same, that is, the DUT will exhibit the same non-linear response under the two conditions.

[0073] Therefore, it can hold.

[0074] At this time, Equation (5) represents the equivalent correspondence between the irradiation field strength and the injection voltage mapped to each pair of wires. If it is desired to simultaneously equalize the injection into each pair of wires, it is necessary to satisfy

[0075] S 21pair i = S 21pair j (i,j = I~n) (6)

[0076] In practice, when the impedance of the equipment's transmitting port is matched, Equation (6) holds. During the equipment design process, in order to ensure that signals can be transmitted and received maximally and achieve the best output efficiency, the transmitting port often undergoes impedance matching design.

[0077] Therefore, when the impedance of the equipment transmitting port is matched, the equivalent correspondence between the injection excitation source and the irradiation field strength for each pair of wires is linear and equal. In the frequency domain, it can be written as

[0078] V S (jω) = F(jω)E(jω) (7)

[0079] Using the relationship between Fourier transform and inverse transform, we can obtain

[0080]

[0081] From the previous derivation, it can be known that in the frequency domain, the equivalent correspondence between the irradiation field strength and the injection excitation source is linear and independent of the impedance of the device under test at the right end. Therefore, the characteristics of this equivalent correspondence can be mapped to the time domain.

[0082] In summary, when the impedance of the equipment transmitting port is matched, for the test of the strong electromagnetic pulse radiation effect coupled by shielded multi-core cables, a low-field pre-test can be used to obtain the equivalent injection waveform, and then a high-field linear extrapolation method can be adopted. In this way, the cable bundle can be clamped by a current probe, and only an equivalent test for one pair of wires needs to be carried out, while the other pairs of wires are equivalent at the same time, without the need for multiple repeated tests.

[0083] Figure 4 is the implementation flowchart of the equivalent test method for the strong electromagnetic pulse radiation effect under the condition of transmitting port matching provided by the embodiment of the present invention. As Figure 4 shown, the equivalent test method for the strong electromagnetic pulse radiation effect under the condition of transmitting port matching includes:[[]]

[0084] S410, irradiate the parallel two-wire line with a high-power electromagnetic pulse source at the first preset field strength, and record the first response signal of the target cable; the shielded multi-core cable includes multiple pairs of wires; the target cable is any pair of wires in the shielded multi-core cable;

[0085] S420, stop irradiating with the high-power electromagnetic pulse source, clamp a current injection probe on the target cable, and connect the current injection probe to the signal source at the same time;

[0086] S430, perform Fourier transform on the first response signal to obtain the frequency-domain signal, and determine the target pulse signal according to the frequency-domain signal;

[0087] S440, adjust the injection voltage of the current injection probe according to the target pulse signal, and monitor the second response signal of the target cable;

[0088] S450, perform a high-field extrapolation test according to the second response signal to complete the electromagnetic radiation effect test process.

[0089] In an embodiment of the present invention, first, the device under test needs to be removed, and any one line pair is arbitrarily selected for monitoring the response; then, under the irradiation condition, the response waveform V(rad)pair n(t) is obtained, and then it is converted into a frequency-domain signal V(rad)pair n(jω); then, under the injection condition, a current injection probe is clamped onto the cable to obtain S 21 parameter, and the transfer function F(jω) is obtained; then, the inverse Fourier transform is performed on F(jω)V(rad)pair n(jω) to obtain the injection waveform V(inj)S(t); the calculated waveform is injected, and the terminal response V(inj)pair n(t) of the corresponding line pair is monitored; finally, an extrapolation test is performed, and the device under test is reconnected to the cable. The injection voltage V(inj)S(t) is gradually increased until an effect occurs in the device under test, that is, the strong electric field intensity corresponding to the injection voltage waveform kV(inj)S(t) is E high . It can be calculated that the electromagnetic radiation sensitivity threshold E high of the device under test is kE low . Where k is the first coefficient.

[0090] In some embodiments, determining a target pulse signal according to the frequency-domain signal includes: performing an inverse Fourier transform on the product of the frequency-domain signal and a preset transfer function to obtain the target pulse signal.

[0091] In some embodiments, the preset transfer function is determined according to the following steps: when the current injection probe is clamped onto the target cable, the forward transmission gain is measured; according to the forward transmission gain, the preset transfer function is determined.

[0092] In an embodiment of the present invention,

[0093] In some embodiments, determining the preset transfer function according to the forward transmission gain:

[0094] The preset transfer function is determined according to the test signal of the current injection probe and the forward transmission gain corresponding to the test signal.

[0095] In an embodiment of the present invention,

[0096] In some embodiments, performing a high-field-strength extrapolation test according to the second response signal to complete the electromagnetic radiation effect test process includes: connecting the device under test to a shielded multi-core cable, increasing the injection voltage of the current injection probe until a response occurs in the device under test, and completing the electromagnetic radiation effect test process; wherein, the response of the device under test is determined according to the second response signal.

[0097] In some embodiments, the electric field intensity corresponding to the injection voltage when the device under test has a response is equal to the product of the electric field intensity corresponding to the second response signal and the first coefficient, and the first coefficient is the increasing ratio of the injection voltage.

[0098] Based on the system shown Figure 1 above, the test process of the present invention is specifically as follows:

[0099] (1) Obtain the irradiation response waveform

[0100] Turn on the pulse source, and use an oscilloscope to monitor the response waveforms of the terminals of the three wire pairs respectively. Figure 5 is a schematic diagram of the irradiation response waveform. The responses of wire pairs I, II, and III are as Figure 5 shown. Among them, the horizontal axis is time, with the unit of s, and the vertical axis is the response value, with the unit of V.

[0101] (2) Obtain the injection transfer function

[0102] Clamp the current injection probe onto the cable under test, select different reference wire pairs respectively, and obtain the transfer function from the injection end of the equivalent current probe to the cable terminal. Figure 6 is a schematic diagram of the structure of the transfer function test configuration. Before obtaining the transfer function, it is necessary to verify the influence of the current probe clamped into the cable on the system S22. The test configuration is the same as Figure 6 .

[0103] (3) Calculate the equivalent injection waveform

[0104] Use MATLAB to calculate the equivalent injection waveform, Figure 7 is the graph of the forward transmission gain change when the cable is clamped into the probe successively. The horizontal axis is frequency, with the unit of Hz, and the vertical axis is S22, with the unit of dB. Figure 8 is the equivalent injection waveform diagram obtained with wire pairs I, II, and III as reference wire pairs. It can be seen from Figure 8 that after the current probe is clamped into the cable, there is almost no influence on the forward transmission gain parameter, verifying the previous theoretical analysis.

[0105] To prevent damage to the power amplifier, the input end of an adjustable attenuator is terminated at port 1 of the vector network analyzer, the output end of the attenuator is connected to the input end of the power amplifier, then the output end of the amplifier is connected to the current injection probe, and the terminal of wire pair I is connected to port 2 of the vector network analyzer to measure the forward transmission gain (in complex form).

[0106] It should be noted that since there is always a DC component after the waveform of the irradiation response undergoes Fourier transform, and the starting working frequency of the vector network analyzer is 100 kHz, it is necessary to interpolate the DC component for the obtained forward transmission gain data. The Lagrange interpolation method is used in this test.

[0107] (4) Inject using an arbitrary waveform generator

[0108] Inject the calculated equivalent waveform into the cable under test through a current probe using an arbitrary waveform generator, and then monitor the response of the oscilloscope at this time. Compare the response waveforms of the three wire pairs with the waveforms under irradiation conditions.

[0109] (5) Conduct a high-field strength extrapolation test.

[0110] Change the impedance value of the through-type load to simulate the nonlinearity that occurs in the device under test under strong field conditions. The impedance value settings of the through-type loads connected to the terminals of each wire pair are shown in Table 1. Extrapolate the irradiation and injected excitations by 10 dB respectively. Compare the response waveforms of the three opposite pairs again under irradiation and injection conditions.

[0111] Table 1 Impedance values of through-type loads at wire pair terminals

[0112]

[0113] Figure 9 is the result diagram of the low-field strength pre-test of wire pair 1; Figure 10 is the result diagram of the low-field strength pre-test of wire pair 2; Figure 11 is the result diagram of the low-field strength pre-test of wire pair 3. As Figures 9 - 11 shown, the terminals of each wire pair of the shielded six-core cable generate typical damped oscillation waveforms. Organize these experimental results to obtain Table 2 below.

[0114] Table 2 Low-field strength pre-test results

[0115]

[0116] From Figures 9 - 11 it can be seen that when using a certain group of wire pairs as equivalent wire pairs, the response curves of the other two groups of wire pairs are almost coincident. This shows that the three calculated equivalent injection waveforms are correct and have been successfully injected into the device under test. At the same time, it also shows that under the condition of impedance matching at the transmitting port, when using the large current injection method for the equivalent substitution test of the strong electromagnetic pulse radiation effect of the coupling channel of the shielded multi-core cable, when one group of wire pairs is equivalent,

[0117] Figure 12 is the result diagram of the high-field strength extrapolation test of wire pair 1; Figure 13 is the result diagram of the high-field strength extrapolation test of wire pair 1; Figure 14 is the result diagram of the high-field strength extrapolation test of wire pair 1. The results of the high-field strength extrapolation test are as Figures 12 - 14As shown, although the impedance of each pair of wires in the test end has changed, the response curves of each pair of wires under irradiation and injection conditions are basically coincident. It can be seen that in the high-field strength extrapolation test, the errors of the key parameters (correlation coefficient, peak-to-peak value, rise time) of the response waveforms of each pair of wires under irradiation and injection conditions are very small. This shows that the equivalent injection waveform obtained under low-field strength is effective, and after extrapolating by the same multiple of the irradiation power, the equivalent injection waveform is still effective. It proves that the equivalent corresponding relationship between the injection excitation source and the irradiation field strength of each pair of wires in formula (4) is linear. At the same time, the test results also prove that the change of the terminal impedance connected to each pair of wires in the test end in formula (4) will not affect the equivalent corresponding relationship between the injection excitation source and the irradiation field strength. This indicates that even if the impedance of the test equipment changes nonlinearly under strong-field conditions, due to the consistent external port excitation under irradiation and injection conditions, the nonlinearly changed internal impedance of the test equipment is the same under the two conditions, and the generated nonlinearly responses are also the same. The equivalent of the remaining pairs of wires has also been achieved. By sorting out these experimental results, Table 3 below can be obtained.

[0118] Table 3 Results of High-Field Strength Extrapolation Test

[0119]

[0120] The equivalent injection waveforms obtained by taking three pairs of wires as reference pairs of wires respectively are not completely the same. This is due to the process reasons during the factory processing, resulting in the lengths of the six core wires inside the shielded six-core wire not being strictly equal. However, from the perspective of the equivalent test results, the error is within an acceptable range. In addition, the transfer admittance exists in the actual test and has an impact on the results of the equivalent irradiation effect. However, due to broadband electromagnetic pulses (HEMP, LEMP), their energy spectra are mainly concentrated in the low frequency. Therefore, the influence of the transfer admittance can be ignored. The response waveforms of each pair of wires in the test of the equivalent strong-field irradiation effect are basically coincident, which can meet the requirements of engineering practice. The test results can prove that the proposed equivalent test method for the coupling effect of strong electromagnetic pulses on shielded multi-core wires under the matching conditions of the equipment emission port is effective.

[0121] In summary, the beneficial effects of the present invention are as follows:

[0122] 1) Based on the equality of the differential-mode responses of the terminals of each pair of wires in the test end under irradiation and injection conditions as the equivalent basis, an equivalent corresponding relationship between the injection excitation source and the irradiation field strength is established. Through theoretical derivation, it can be known that under the condition of impedance matching at the emission port, the equivalent corresponding relationship between the injection excitation source and the irradiation field strength of each pair of wires is linear and equal, and is independent of the impedance parameters of the test end.

[0123] 2) An equivalent test method for the radiation effect of shielded multi-core wire coupling strong electromagnetic pulse under equipment port matching conditions is proposed. This method can establish the equivalent correspondence between the injection excitation source and the irradiation field strength of all wire pairs by simply monitoring the response of any group of wire pairs. Then the equivalent injection waveform is calculated using Fourier and inverse Fourier transform. This method expands the application scope of large current injection technology. It is extended from the equipment strong field radiation effect test applied to the two-wire coupling channel to the shielded multi-core coupling channel. During the test, the operator only needs to select any group of wire pairs for testing, without the need to perform an equivalent test on the response of each wire pair. That is, when one group of wire pairs is equivalent, the remaining wire pairs have also achieved equivalence. The test process and steps are simplified and the test efficiency is improved. The purpose of the current probe clamping all wire pairs under the injection condition proposed at the beginning of this article and the response of each wire pair is equal to the response under the irradiation condition at the same time is achieved.

[0124] 3) A typical shielded six-core cable was selected and a through-type load test was conducted. The test results show that even if the terminal impedance of each line pair connected to the test end changes under strong field conditions, the response waveforms of each line pair are basically the same, verifying the effectiveness of the proposed test method.

[0125] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0126] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for equivalent testing of strong electromagnetic pulse radiation effects under transmission port matching conditions, characterized in that: include: Under a first preset field strength, a high-power electromagnetic pulse source is used to irradiate the parallel double wires, and a first response signal of the target cable is recorded; The shielded multi-core cable includes multiple groups of wire pairs; the target cable is any group of wire pairs in the shielded multi-core cable; Stop irradiation with the high-power electromagnetic pulse source, insert a current injection probe into the target cable, and connect the current injection probe to the signal source; Performing Fourier transform on the first response signal to obtain a frequency domain signal, and determining a target pulse signal according to the frequency domain signal; adjusting the injection voltage of the current injection probe according to the target pulse signal, and monitoring a second response signal of the target cable; A high field strength extrapolation test is performed according to the second response signal to complete the electromagnetic radiation effect test process.

2. The method for equivalent testing of strong electromagnetic pulse radiation effect under transmission port matching conditions according to claim 1 is characterized in that: Determining a target pulse signal according to the frequency domain signal includes: The product of the frequency domain signal and the preset transfer function is subjected to inverse Fourier transform to obtain the target pulse signal.

3. The method for equivalent testing of strong electromagnetic pulse radiation effect under transmission port matching conditions according to claim 2 is characterized in that: The preset transfer function is determined according to the following steps: When the current injection probe is stuck on the target cable, the forward transmission gain of the two ports of the vector network analyzer is measured; The preset transfer function is determined according to the forward transmission gain.

4. The method for equivalent testing of strong electromagnetic pulse radiation effect under transmission port matching conditions according to claim 2 is characterized in that: According to the forward transmission gain, the preset transfer function is determined: The preset transfer function is determined according to the test signal of the current injection probe and the forward transmission gain corresponding to the test signal.

5. The method for equivalent testing of strong electromagnetic pulse radiation effect under transmission port matching conditions according to claim 1 is characterized in that: According to the second response signal, a high field strength extrapolation test is performed to complete the electromagnetic radiation effect test process, including: Connect the device under test to the shielded multi-core cable, increase the injection voltage of the current injection probe, and complete the electromagnetic radiation effect test process until the device under test responds; wherein the response of the device under test is determined according to the second response signal.

6. The method for equivalent testing of strong electromagnetic pulse radiation effect under transmission port matching conditions according to claim 5 is characterized in that: The electric field strength corresponding to the injected voltage when the device under test responds is equal to the product of the electric field strength corresponding to the second response signal and the first coefficient, and the first coefficient is the increase ratio of the injected voltage.

7. An equivalent electromagnetic radiation effect test system, characterized in that: The equivalent test method for the radiation effect of a strong electromagnetic pulse under the condition of matching the transmitting port as claimed in any one of claims 1 to 7 is applied to the system, the system comprising: a transmitter, a shielded multi-core cable, a signal conversion module, an oscilloscope, a pulse attenuator, a high-power electromagnetic pulse source, a current injection probe, a power amplifier, an adjustable attenuator, and an arbitrary waveform generator; The transmitter is connected to a first end of the shielded multi-core cable, and a second end of the shielded multi-core cable is connected to the oscilloscope through the signal conversion module; The pulse attenuator is connected to the high-power electromagnetic pulse source; The current injection probe is arranged on the shielded multi-core cable; the current injection probe is connected to the arbitrary waveform generator through the power amplifier and the adjustable attenuator in sequence.

8. The equivalent electromagnetic radiation effect test system according to claim 7, characterized in that: When the system irradiates the shielded multi-core cable, the high-power electromagnetic pulse source outputs power corresponding to the first preset field intensity to complete the irradiation process.

9. The equivalent electromagnetic radiation effect test system according to claim 8, characterized in that: When the system performs current injection into a shielded multi-core cable, the system controls the arbitrary waveform generator through the adjustable attenuator to adjust the injection voltage of the current injection probe according to the target pulse signal to complete the current injection process.

10. A transfer function test device, characterized in that: Includes coaxial loads, shielded multicore cables, through-type loads, signal conversion modules, current injection probes, power amplifiers, and vector network analyzers; The coaxial load, shielded multi-core cable, current injection probe and through-type load are all arranged in a microwave darkroom; The current injection probe is arranged on the shielded multi-core cable; the current injection probe is connected to the output end of the vector network analyzer through the power amplifier; the coaxial load is connected to the first end of the shielded multi-core cable; the through-type load is connected to the second end of the shielded multi-core cable; the signal conversion module is used to connect the through-type load arranged in the microwave darkroom with the input end of the vector network analyzer outside the microwave darkroom.

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