Equivalent Test Method and System for Electromagnetic Radiation Effect under Emission Port Matching Conditions

Abstract

The present invention provides a method and system for equivalent testing of electromagnetic radiation effects under the matching conditions of the transmitting port. Irradiate the parallel two-wire line and record the first response value of the target cable; the shielded multi-core cable includes multiple pairs of wire pairs, and the target cable is any one of the pairs of wire pairs; stop the irradiation, clip a current injection probe on the target cable and connect it to the signal source at the same time; adjust the injection power to obtain the equivalent injection excitation source corresponding to the radiation field strength; subsequently, conduct a high-field-strength extrapolation test to complete the electromagnetic radiation effect test process. This application takes the equality of the differential-mode responses at the terminals of each pair of wire pairs under two conditions as the equivalent basis, and finds that under the condition of impedance matching at the transmitting port, the equivalent correspondence between the injection excitation source of each pair of wire pairs and the radiation field strength is linear and equal, and is independent of the terminal impedance connected to each pair of wire pairs inside the test end. Therefore, the method for equivalent testing of the two-wire interconnection system is applied to the multi-core shielded cable to complete the electromagnetic radiation effect test process.

Description

Technical Field

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

[0002] In weaponry and equipment, anti-interference and highly efficient and safe interconnection cables are required, and shielded multi-core cables are a commonly used type. In the future informationized battlefield, high-power radio frequency electromagnetic radiation fields have brought the most severe challenges to weaponry and equipment, integrated electronic information systems, etc. Information transmission and power delivery are often achieved through cable interconnection between various devices or subsystems, which likely leads to weak links in electromagnetic protection mostly occurring in cable coupling channels. Therefore, it is necessary to conduct strong-field electromagnetic radiation effect test assessments on weaponry and equipment.

[0003] For this reason, the equivalent test technology for strong-field irradiation effect has received increasing widespread attention from scientific research personnel, such as the method of current injection. Among various current injection methods, the large current injection technology is relatively more mature. However, this method linearly extrapolates based on the response signal, is not applicable to non-linear systems, and can only be applied in the interconnection system of shielded two-core cables, and further research is still needed for multi-core shielded cables. Summary of the Invention

[0004] In view of this, the present invention provides an equivalent test method and system for electromagnetic radiation effect under the condition of emission port matching, aiming to solve the problem that it is difficult to conduct equivalent injection tests on multi-core shielded cables by the current injection method in the prior art.

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

[0006] Under the first preset field strength, irradiate a parallel two-wire line with a radiation source, and record the first response value 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;

[0007] Stop irradiating with the radiation source, clip a current injection probe on the target cable, and at the same time connect the current injection probe to a signal source;

[0008] Adjust the injection power of the current injection probe to make the differential mode response value of the target cable the same as the first response value, and obtain the equivalent injection excitation source corresponding to the radiation field strength;

[0009] Based on the equivalent injection excitation source, conduct a high-field strength extrapolation test to complete the electromagnetic radiation effect test process.

[0010] A second aspect of the embodiments of the present invention provides an equivalent electromagnetic radiation effect test system, including: a coaxial load, a shielded multi-core cable, an antenna, a signal source, a current injection probe, a through-type load, a signal conversion module, and a receiver;

[0011] The coaxial load, the shielded multi-core cable, the antenna, the current injection probe, and the through-type load are all arranged in a microwave anechoic chamber;

[0012] The current injection probe is arranged on the shielded multi-core cable; 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 anechoic chamber and the receiver outside the microwave anechoic chamber.

[0013] The electromagnetic radiation effect equivalent test method and system provided by the embodiments of the present invention irradiate a parallel two-wire line with a radiation source under a first preset field strength, and record the first response value 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; stop irradiating the radiation source, clamp a current injection probe on the target cable, and connect the current injection probe to the signal source at the same time; adjust the injection power of the current injection probe to make the differential mode response value of the target cable the same as the first response value, and obtain an equivalent injection excitation source corresponding to the radiation field strength; based on the equivalent injection excitation source, perform a high field strength extrapolation test to complete the electromagnetic radiation effect test process. This application takes the equality of the differential mode responses at the terminals of each pair of wires under two conditions as the equivalent basis, and finds that under the condition of impedance matching at the transmitting port, the equivalent corresponding relationship between the injection excitation source of each pair of wires and the irradiation field strength is linear and equal, and has nothing to do with the terminal impedance connected to each pair of wires inside the test end. Therefore, the method for equivalent testing of a two-wire interconnection system is applied to a multi-core shielded cable to complete the electromagnetic radiation effect test process. Description of the Drawings

[0014] In order 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 following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic structural diagram of the equivalent electromagnetic radiation effect test system provided by the embodiments of the present invention;

[0016] Figure 2 It is a schematic structural diagram of the cross-section of the shielded multi-core cable;

[0017] Figure 3 It is a schematic structural diagram of the shielded multi-core cable interconnection system;

[0018] Figure 4 is the equivalent circuit diagram of the shielding layer under injection conditions;

[0019] Figure 5 is the circuit diagram of the internal transmission line of the shielded cable;

[0020] Figure 6 is the schematic diagram of the impedance transformation of the nth pair of lines;

[0021] Figure 7 is the implementation flowchart of the equivalent electromagnetic radiation effect test method under the matching condition of the transmitting port provided by the embodiment of the present invention;

[0022] Figure 8 is the result of the low-field strength simulation test;

[0023] Figure 9 is the result of the high-field strength simulation test;

[0024] Figure 10 is the experimental error curve graph at different frequencies. Detailed implementation manners

[0025] In the following description, specific details such as specific system structures 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.

[0026] Figure 1 is the structural schematic diagram of the equivalent electromagnetic radiation effect test system provided by the embodiment of the present invention. As Figure 1 shown, in some embodiments, the equivalent electromagnetic radiation effect test system includes: a coaxial load 11, a shielded multi-core cable 12, an antenna 13, a signal source 14, a current injection probe 15, a through-load 16, a signal conversion module 17, and a receiver 18; the coaxial load 11, the shielded multi-core cable 12, the antenna 13, the current injection probe 15, and the through-load 16 are all arranged in a microwave anechoic chamber; the current injection probe 15 is arranged on the shielded multi-core cable; the coaxial load 11 is connected to the first end of the shielded multi-core cable; the through-load 16 is connected to the second end of the shielded multi-core cable 12; the signal conversion module 17 is used to connect the through-load 16 arranged in the microwave anechoic chamber and the receiver 18 outside the microwave anechoic chamber.

[0027] Among them, the signal conversion module 17 includes two optoelectronic conversion modules. The two optoelectronic conversion modules are respectively connected to the through-type load 16 and the receiver 18, and the two optoelectronic conversion modules are connected by an optical fiber. The receiver 18 can be a device under test, a spectrum analyzer, etc., which is not limited here.

[0028] The DC regulated power supply and the power amplification module can be used as the signal source 14, or the transmitting end of the Vector Network Analyzers (VNA) can be used as the signal source 14. Additionally, an additional input device can be added on this basis to form the signal source 14, or a dual-channel vector signal source can be used as the signal source 14, which is not limited here. During the test process, the antenna 13 and the current injection probe 15 can both be connected to the corresponding signal source. At the same time, the receiver 18 can also be a VNA, and the optoelectronic conversion module is connected to the receiving end of the VNA.

[0029] When irradiating the shielded multi-core cable, the signal source and the antenna in the anechoic chamber form a radiation source. At the same time, the signal source outputs according to the power corresponding to the first preset field strength to complete the irradiation process.

[0030] When injecting current into the shielded multi-core cable, the signal source is connected to the current injection probe in the anechoic chamber. At the same time, the signal source outputs according to the injection power corresponding to the equivalent injection excitation source to complete the current injection process.

[0031] According to the electromagnetic field theory, the field line coupling process is linear, and the response process inside the device under test is non-linear. If, in some way, the excitation at the external port of the device under test is the same under irradiation and injection conditions, the non-linear changes that occur in the internal components of the device under test will be the same, and thus the responses of the device under test under the two conditions will also be the same. Since the excitation source coupled to the cable under irradiation conditions is obtained through a linear field line coupling process, the injection voltage source for the equivalent test of the large current injection method can also be obtained by linear extrapolation. At the same time, it is relatively easy to perform extrapolation for the large current injection method for the injection excitation source. If a new corresponding relationship between the irradiation field strength and other parameters is established, such as the equivalent corresponding relationship between the irradiation field strength and the injection excitation source, it may be possible to make the large current injection method equivalent to the high-field irradiation test.

[0032] The shielded multi-core cable is mainly composed of a shielding layer and internal core wires. The process of external interference coupling through the shielded multi-core cable is as follows: First, the interference induces an induced current and an induced voltage on the outer shielding layer, and then a distributed source is formed on the internal core wires through the transfer impedance and transfer admittance, and finally, it affects the device connected to the cable terminal.

[0033] Figure 2 It is a schematic structural diagram of the cross-section of the shielded multi-core cable. As Figure 2As shown, 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.

[0034] Figure 3 is the structural schematic diagram of the shielded multi-core wire interconnection system. As Figure 3 shown, the height of the cable from the ground is h, and the wire length is L. The ground impedances of the equipment shells at both ends of the cable are Z(e)0 and Z(e)L respectively. The characteristic impedance of the shielding layer is Z(e)C, and the propagation constant is γ (e) . Among them, the superscripts (e) and (i) respectively represent the outer loop and the inner loop, and the superscripts (inj) and (rad) respectively represent the injection condition and the irradiation condition.

[0035] Figure 4 is the equivalent circuit diagram of the shielding layer under the injection condition. As Figure 4 shown. When the current probe is clamped on the shielded cable, a loading impedance Z P and a loading admittance Y P will be coupled on the cable shielding layer. Since the width L P of the current probe is much smaller than L, so L P is ignored. The current probe is kL away from the left end of the cable, k ∈ (0, 1), and the coupled voltage is V S .

[0036] According to circuit theory, the distributed current of the outer shielding layer under the injection condition is:

[0037]

[0038] To reflect the transmission characteristics of the outer shielding layer, k1 to k4 are set as the coefficients before V S .

[0039] The excitation of the transmission line in the shielded wire can be determined by the distributed voltage source V′ si = Z tnx I S and the distributed current source I′ si = -Y tnx V S Determined. The cylindrical conductor has a very good shielding effect on the electric field. Therefore, the influence of the transfer admittance can be ignored. For the braided mesh shielded wire, considering that except for very large braided holes or large termination impedances of the shield to the ground, the transfer admittance Y tnxThe influence is negligible. At low frequencies, the shielding effect of the braided mesh on the electrostatic field of the multi-core cable is much better than that on the magnetic field. However, as the frequency increases, both the electric field and the magnetic field can pass through the braided mesh holes, and at this time, the role of the transfer admittance cannot be ignored. However, since most of the shielded multi-core cables transmit low-frequency signals, the high-frequency interference signals will attenuate sharply during the transmission process after being coupled to the internal core wires. Therefore, the influence of the transfer admittance can be ignored in the study of shielded multi-core wires.

[0040] Therefore, the source S of the transmission line in the cable 1nx , S 2nx is:

[0041]

[0042]

[0043] After integration, we can get:

[0044]

[0045]

[0046]

[0047]

[0048] Figure 5 is the circuit diagram of the transmission line inside the shielded cable. As Figure 5 shown, the circuit of each pair of wires is a simplified weakly unbalanced circuit. Z nx,y (x = a, b, e y = 0, L) is the terminal impedance of the nth pair of wires. The lengths of the internal core wires are all L. Assuming that the media inside the shield layer are the same, the propagation constant of the pair of wires is γ (i) , and Z(i)Cnx is the characteristic impedance of the core wire x (x = a, b) of the nth pair of wires. V na , V nb and I na , I nb are the voltage and current of the core wires a and b of the nth pair of wires respectively.

[0049] According to the BLT equation, the voltages between the right ends of the core wires a and b of the nth pair of wires and the shield layer are respectively:

[0050]

[0051]

[0052] Among them, the reflection coefficient is:

[0053]

[0054] It can be seen from that the differential-mode response of the nth pair of wires at the right end of the cable is:

[0055]

[0056] Due to the linear relationship of field-wire coupling, the transmission line source S 1nx in the cable under irradiation conditions can be obtained. S 2nx are respectively where a1 and a2 are related to the incident angle, polarization direction, propagation constant γ (e) of the radiation field, as well as the ground impedances Z(e)0 and Z(e)L of the equipment enclosures at both ends of the cable.

[0057] Similar to the injection condition, it can be known that the voltages between the cores a and b of the nth pair of wires at the right end and the shielding layer are respectively:

[0058]

[0059]

[0060] Then the differential-mode response of the nth pair of wires at the right end of the cable under irradiation conditions is:

[0061]

[0062] To make the differential-mode responses of each pair of wires of the device under test equal under injection and irradiation conditions, it is necessary to satisfy In this way, the excitations at the external ports of the device under test under irradiation and injection conditions are consistent, and the non-linear changes in the impedance of the device under test under the two conditions are also consistent.

[0063] When Equation (11) is equal to Equation (14), there will be an equivalent correspondence relationship between V S and the irradiation field strength E0(ω) for each pair of wires. Each equivalent correspondence relationship is related to the impedance of the equipment at both ends of the cable. Since the impedance of the device under test is prone to non-linear changes under high field strength conditions, the equivalent correspondence relationship should not contain relevant parameters regarding the impedance of the device under test. To make each pair of wires equivalent simultaneously with one injection, it is necessary to ensure that the equivalent correspondence relationships of each pair of wires are the same. If the equivalent correspondence relationships of each pair of wires are to be the same, it is necessary to satisfy that the left-end reflection coefficients of each pair of wires are equal.

[0064] That is:

[0065] ρ ia,0 = ρ jb,0 (i,j = 1~n) (15)

[0066] Next, the possibility of Equation (15) in engineering practice will be discussed.

[0067] Figure 6 It is a schematic diagram of impedance transformation for the nth group of wire pairs. As Figure 6 shown, when processing shielded multi-core cables used in interconnected systems, multiple identical wires are often bundled together and then wrapped with a shielding layer of aluminum foil or braided mesh on the outside. Therefore, the characteristic impedance of each core wire is approximately the same. According to the Y-Δ theory of impedance transformation:

[0068]

[0069]

[0070]

[0071] Among them, Z n1 is the impedance connected to the terminal of the nth group of wire pairs, and the expressions of Z n2 and Z n3 usually take the form of capacitors.

[0072] Analyzing the cross-section of such cables, it can be found that the relative positions between each wire and the shielding layer are approximately the same. Therefore, the capacitance between each wire pair and the shielding layer is approximately equal. That is:

[0073] Z i2 = Z j3 (19)

[0074] Therefore, there is:

[0075] Z ia,0 = Z jb,0 (20)

[0076] When weapon equipment is in the design and finalization stage, in order to improve the signal utilization efficiency, the output impedance of the transmitting end is often designed to match the characteristic impedance of the cable. That is:

[0077]

[0078] When the impedance of the device connected to each group of wire pairs satisfies the above characteristics, formula (15) holds.

[0079] When formula (15) is satisfied, the equivalent correspondence relationship of each group of wire pairs is the same, that is, the following equivalent correspondence relationship can be obtained. In some embodiments, the equivalent correspondence relationship is:

[0080]

[0081] Among them, V S is the coupling voltage of the current injection probe, a1 and a2 are related to the incident angle, polarization direction, propagation constant of the radiation field, and the impedance of the device housing at both ends of the cable to the ground, ρ n,0Γ0 is the reflection coefficient at the leftmost end of the nth group of wire pairs, and E0(ω) is the irradiance field strength.

[0082] Analyzing Equation (22), it can be seen that the equivalent correspondence is related to the following factors: the impedance to ground of the outer shells of the two-terminal devices (Z(e)0 and Z(e)L), the characteristic impedance of the shielding layer (Z(e)C), the propagation constant (γ (e) and γ (i) ), the position of the current probe, the loading impedance and admittance coupled by the current probe to the cable shielding layer (Z P and Y P ), the characteristic impedance of the internal core wire (Z(i)Cnx), and the impedance of the device under test at the left end of the cable (Z nx,0 ). One end of the cable interconnection system is usually used as the transmitting end (corresponding to the left end of the cable in the model), and its impedance is often relatively stable. Through the above analysis, it can be seen that the equivalent correspondence between the injection excitation source corresponding to each group of wire pairs and the irradiance field strength is linear and equal. This indicates that when the equivalent correspondence of one group of wire pairs is established, the equivalent relationships of other wire pairs are also established. In engineering, it is possible to only complete the response equivalence of one group of wire pairs to achieve the simultaneous equivalence of all wire pairs.

[0083] It should be noted that the equivalent correspondence is independent of the impedance of the device under test at the right end. This shows that even if the impedance of the device under test undergoes a non-linear change, it will not affect the equivalent correspondence in Equation (22).

[0084] Based on the above theory, the electromagnetic radiation equivalent injection test of shielded multi-core cables can be realized according to the current injection method. Figure 7 is the implementation flowchart of the equivalent test method for electromagnetic radiation effects under the matching condition of the transmitting port provided by the embodiment of the present invention. As Figure 7 shown, in some embodiments, the equivalent test method for electromagnetic radiation effects under the matching condition of the transmitting port includes:

[0085] S210, irradiate the parallel twin wires with a radiation source at a first preset field strength, and record the first response value of the target cable; 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;

[0086] S220, stop irradiating the radiation source, clip a current injection probe on the target cable, and at the same time connect the current injection probe to the signal source;

[0087] S230, adjust the injection power of the current injection probe to make the differential mode response value of the target cable the same as the first response value, and obtain the equivalent injection excitation source corresponding to the radiation field strength;

[0088] S240, based on the equivalent injection excitation source, conduct a high-field strength extrapolation test to complete the electromagnetic radiation effect test process.

[0089] In the embodiments of the present invention, before conducting an experiment, test preparation should be carried out first. Disconnect the device under test, and use the radio frequency transmission system to monitor the response of a certain pair of wires in the shielded multi-core cable. The first preset field strength can be any field strength value that the antenna can radiate, and can be specifically set according to expert experience, which is not limited herein.

[0090] Under irradiation conditions, the signal source is connected to the antenna, the antenna height is 0.9 m, and the distance from the cable is 1 m. Under injection conditions, the signal source is connected to the current probe (ZN23102A), and the position of the current probe is 10 cm away from the housing of the device under test.

[0091] In some embodiments, S240 includes: connecting the device under test to the shielded multi-core cable, increasing the output power of the current injection probe until the device under test shows a response, and determining the electromagnetic radiation sensitivity threshold according to the equivalent correspondence between the radiation field strength and the injection excitation source, thus completing the electromagnetic radiation effect test process.

[0092] In some embodiments, the electromagnetic radiation sensitivity threshold is:

[0093]

[0094] wherein, E0 is the first preset field strength, P0 is the output power of the current injection probe corresponding to the first preset field strength, P0 is the output power of the current injection probe when the device under test shows a response, and E1 is the field strength corresponding to P0.

[0095] In the embodiments of the present invention, an equivalent injection excitation source is searched for. Under irradiation conditions, a small power (corresponding to the field strength of E0) is used to irradiate the cable, and the response P0 of this pair of wires is recorded at this time. Then, under injection conditions, the injection power is adjusted so that the response of this pair of wires at this time is consistent with that under irradiation conditions (P0). Subsequently, the device under test is reconnected to the cable. Gradually increase the injection power until the device under test shows an effect, that is, the injection power corresponding to the strong electric field strength is E1. Through calculation, the electromagnetic radiation sensitivity threshold of this device under test

[0096] In some embodiments, the reflection coefficient of the antenna at the leftmost end of the shielded multi-core cable is equal to the reflection coefficient of the current injection probe antenna at the leftmost end of the shielded multi-core cable.

[0097] Figure 8 is the result of the low-field strength simulation test. Figure 9 is the result of the high-field strength simulation test. As Figure 8 and 9As shown below, simulation experiments are carried out according to the above method to verify the effectiveness of the present invention. The specific steps are as follows:

[0098] First, a low-field pre-test is carried out. Under irradiation conditions, the output power of the signal source is 10 dBm. The output end of the optoelectronic module is successively connected to the spectrum analyzer, and the responses of wire pairs I, II, and III in the test end are respectively recorded. Then, a current probe is clamped on the overall multi-core cable and switched to the injection condition. Taking wire pair III as the reference wire pair, the output power of the signal source is adjusted so that the response of wire pair III under the injection condition is the same as that under the irradiation condition. Record the responses of wire pairs I and II under the condition of this output power.

[0099] Subsequently, a high-field extrapolation test is carried out. The impedance values of the through-type loads of each wire pair in the test end are changed to simulate the non-linear change of the impedance of the test equipment under strong-field radiation conditions. The load change situation is shown in Table 1. The output powers of the signal sources for irradiation and injection at this frequency point are respectively amplified by 10 dB, and the responses of wire pairs I, II, and III under the two conditions are respectively recorded.

[0100] Table 1 Resistance values of the through-type loads at the test end

[0101]

[0102] From the above experimental results, it can be obtained that P 注入 The corresponding data represents the output power of the signal source under the injection condition at this frequency point. When the responses of each wire pair under the irradiation and injection conditions are the same, the power required for injection is much smaller than the power required for irradiation (10 dBm), indicating that the efficiency of the large current injection method is higher than that of the irradiation method.

[0103] When wire pair III is used as the equivalent wire pair, the response curves of wire pairs I and II are almost coincident. This shows that the equivalent correspondence relationship between the injection excitation source of each wire pair obtained under low field strength and the irradiation field strength is consistent, and the obtained equivalent injection source is effective. This shows that under the condition of impedance matching at the transmitting end, when using the large current injection method to carry out the strong-field irradiation effect test of the shielding multi-core cable coupling channel, when one group of wire pairs is equivalent, the other wire pairs have also achieved equivalence.

[0104] Although the impedance of each pair of wires in the DUT has changed, the response curves of each pair of wires under irradiation and injection conditions basically coincide. In the high-field strength extrapolation test, the error of each pair of wires is within the range of 3 dB. This shows that the equivalent injection source obtained under low-field strength is effective. After extrapolating by the same multiple of the irradiation power, the equivalent injection source is still effective. It is proved that the equivalent correspondence between the injection excitation source and the irradiation field strength of each pair of wires in formula (22) 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 DUT in formula (22) will not affect the equivalent correspondence between the injection excitation source and the irradiation field strength. This shows that even if the impedance of the DUT changes non-linearly under strong-field conditions, due to the consistent external port excitation under irradiation and injection conditions, the non-linear changes of the internal impedance of the DUT under the two conditions are the same, and the non-linear responses generated are also the same.

[0105] Figure 10 is the experimental error curve graph at different frequencies. As Figure 10 shown, by analyzing the possible causes of the error, the transfer admittance exists in the actual test and has an impact on the results of the equivalent irradiation effect. As the frequency increases, the influence of the transfer admittance will also increase. However, since the shielded wire transmits low-frequency signals, as the frequency increases, the signal loss during transmission will increase. Therefore, within the applicable frequency range of the shielded wire, the influence of the transfer admittance can be ignored. The maximum error of each pair of wires in the equivalent strong-field irradiation effect test is less than 3 dB, which can meet the requirements of engineering practice. The test results can prove that the proposed equivalent test method for the coupling continuous-wave strong-field electromagnetic radiation effect of shielded multi-core wires under the matching condition of the equipment emission port is effective.

[0106] The beneficial effects of the present invention are as follows:

[0107] 1) Based on the equality of the differential-mode responses of the terminals of each pair of wires in the DUT under irradiation and injection conditions as the equivalent basis, an equivalent correspondence 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 correspondence 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 DUT.

[0108] 2) An equivalent test method for the electromagnetic radiation effect of shielded multi-core coupled continuous wave strong field 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 line pairs by simply monitoring the response of any group of line pairs. 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 line pairs for testing, and there is no need to perform an equivalent test on the response of each line pair. That is: when one group of line pairs is equivalent, the remaining line 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 line pairs under the injection condition proposed at the beginning of this article and the response of each line pair is equal to the response under the irradiation condition at the same time is achieved.

[0109] 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 nonlinearly under strong field conditions, the error of each line pair is within 3dB, which verifies the effectiveness of the proposed test method.

[0110] 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.

[0111] 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. An equivalent test method for electromagnetic radiation effects under the matching conditions of the emission port, characterized in that Including: Under the first preset field strength, irradiate the parallel twin lines with a radiation source and record the first response value of the target cable; The shielded multi-core cable includes multiple groups of wire pairs; the target cable is any one of the wire pairs in the shielded multi-core cable; Stop irradiating with the radiation source, clip a current injection probe onto the target cable, and at the same time connect the current injection probe to a signal source; Adjust the injection power of the current injection probe to make the differential mode response value of the target cable the same as the first response value, and obtain the equivalent injection excitation source corresponding to the radiation field strength; Based on the equivalent injection excitation source, conduct a high-field strength extrapolation test to complete the electromagnetic radiation effect test process; The differential mode response under injection conditions is: Among them, is the differential-mode response of the nth pair under the injection condition, is the voltage between the right end of cable a and the shielding layer in the nth pair under the injection condition, is the voltage between the right end of cable b and the shielding layer in the nth pair under the injection condition, ρ na,L is the reflection coefficient when the current injection probe is at the rightmost end of cable a, is the first distributed source of cable a in the nth pair under the injection condition, is the second distributed source of cable a in the nth pair under the injection condition, ρ na,0 is the reflection coefficient when the current injection probe is at the leftmost end of cable a, ρ nb,L is the reflection coefficient when the current injection probe is at the rightmost end of cable b, is the first distributed source of cable b in the nth pair under the injection condition, is the second distributed source of cable b in the nth pair under the injection condition, ρ nb,0 is the reflection coefficient when the current injection probe is at the leftmost end of cable b, γ(i) is the propagation constant, and L is the length of the shielded multi-core cable.

2. The electromagnetic radiation effect equivalent test method under the emission port matching condition according to claim 1, characterized in that The first response value under irradiation conditions is: Wherein, is the first response value of the nth pair under irradiation conditions, is the voltage between the right end of cable a and the shielding layer in the nth pair under irradiation conditions, is the voltage between the right end of cable b and the shielding layer in the nth pair under irradiation conditions, ρ na,L is the reflection coefficient when the antenna is at the rightmost end of cable a, is the first distributed source of cable a in the nth pair under irradiation conditions, is the second distributed source of cable a in the nth pair under irradiation conditions, ρ na,0 is the reflection coefficient when the antenna is at the leftmost end of cable a, ρ nb,L is the reflection coefficient when the antenna is at the rightmost end of cable b, is the first distributed source of cable b in the nth pair under injection conditions, is the second distributed source of cable b in the nth pair under injection conditions, ρ nb,0 is the reflection coefficient when the antenna is at the leftmost end of cable b, γ(i) is the propagation constant, and L is the length of the shielded multi-core cable.

3. The electromagnetic radiation effect equivalent test method under the emission port matching condition according to claim 2, wherein Based on the equivalent injection excitation source, conduct a high-field strength extrapolation test to complete the electromagnetic radiation effect test process, including: Connect the device under test to the shielded multi-core cable, increase the output power of the current injection probe until the device under test shows a response, and determine the electromagnetic radiation sensitivity threshold according to the equivalent correspondence between the radiation field strength and the injection excitation source to complete the electromagnetic radiation effect test process.

4. The electromagnetic radiation effect equivalent test method under the emission port matching condition according to claim 3, characterized in that The electromagnetic radiation sensitivity threshold is: where E0 is the first preset field strength, and P1 (inj) is the output power of the current injection probe corresponding to the first preset field strength, is the output power of the current injection probe when the device under test shows a response, and E1 is the corresponding field strength.

5. The electromagnetic radiation effect equivalent test method under the emission port matching conditions according to claim 4, characterized in that The reflection coefficient of the antenna at the leftmost end of the shielded multi-core cable is equal to the reflection coefficient of the current injection probe antenna at the leftmost end of the shielded multi-core cable.

6. The electromagnetic radiation effect equivalent test method under the emission port matching condition according to claim 5, wherein The equivalent correspondence is: Among them, V S is the coupling voltage of the current injection probe. a1 and a2 are related to the incident angle, polarization direction, propagation constant of the radiation field, and the impedance of the equipment housing at both ends of the cable to the ground. ρ n,0 is the reflection coefficient at the leftmost end of the nth pair of wires, and E0(ω) is the irradiation field strength. The height of the cable from the ground is h, the length of the wire is L, and the characteristic impedance of the shielding layer is Z (e) C, γ is the propagation constant. Among them, the superscripts (e) and (i) represent the outer loop and the inner loop respectively, and the superscripts (inj) and (rad) represent the injection condition and the irradiation condition respectively. Z tnx is the transfer impedance of the core wires x = a, b in the nth wire pair. The current probe is kL away from the left end of the cable, k ∈ (0, 1), and k1 to k4 are all coefficients used to reflect the transmission characteristics of the outer shielding layer.

7. An equivalent electromagnetic radiation effect test system, characterized in that The electromagnetic radiation effect equivalent test method under the emission port matching condition as described in any one of claims 1-6 above is applied to this system, and the system includes: a coaxial load, a shielded multi-core cable, an antenna, a signal source, a current injection probe, a through-type load, a signal conversion module, and a receiver; The coaxial load, the shielded multi-core cable, the antenna, the current injection probe, and the through-type load are all arranged in a microwave anechoic chamber; The current injection probe is arranged on the shielded multi-core cable; 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 anechoic chamber to the receiver outside the microwave anechoic chamber.

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 signal source and the antenna in the microwave anechoic chamber form a radiation source, and at the same time the signal source outputs according to the power corresponding to the first preset field strength to complete the irradiation process.

9. The equivalent electromagnetic radiation effect test system according to claim 8, wherein, When the system injects current into the shielded multi-core cable, the signal source is connected to the current injection probe in the microwave anechoic chamber, and at the same time the signal source outputs according to the injection power corresponding to the equivalent injection excitation source to complete the current injection process.

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