A method and system for evaluating the multi-frequency insensitive blocking effect of electromagnetic radiation

Abstract

The present invention relates to an electromagnetic radiation multi-frequency insensitive blocking effect evaluation method and system, and relates to the field of electromagnetic effect. The method comprises constructing an effect index equation, performing a single-frequency electromagnetic radiation critical blocking effect test on a frequency device to be tested to obtain the relationship between the sensitive bandwidth and the single-frequency critical blocking interference field strength value and the radiation frequency deviation, performing an amplitude modulation wave electromagnetic radiation critical blocking effect test on the frequency device to be tested according to the sensitive bandwidth, obtaining a multi-frequency radiation field strength value set, obtaining a single-frequency critical blocking interference field strength value set according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation, obtaining a coefficient in the effect index equation according to a preset multi-frequency insensitive blocking effect index threshold and two sets, substituting the coefficient into the effect index equation to obtain a multi-frequency insensitive blocking effect evaluation model, and this model is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect on the frequency device to be tested. The present invention can evaluate the blocking effect of the multi-frequency insensitive phenomenon.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic environment effect test evaluation, and in particular to an electromagnetic radiation multi-frequency insensitive blocking effect evaluation method and system. Background Art

[0002] Frequency-using equipment such as unmanned equipment, communication radios, radars, and navigation receivers play an increasingly important role in various application scenarios. Frequency-using equipment will inevitably generate harmonics and noise radiation during operation. The simultaneous use of various high-power frequency-using equipment makes the surrounding electromagnetic environment extremely complex, which has a great impact on the normal operation of frequency-using equipment and may even cause it to lose its working efficiency. In order to better understand the anti-electromagnetic interference performance of frequency-using equipment, it is necessary to conduct effective electromagnetic environment effect testing and evaluation on it, which can provide support for the application of later equipment and electromagnetic protection reinforcement.

[0003] In recent years, the evaluation of electromagnetic environmental effects has been mainly based on quantitative research. In terms of environmental electromagnetic complexity evaluation, DS theory, fuzzy method, feature clustering and Hough transform, image entropy, grey theory and hierarchical analysis method are usually used. Signal features are generally selected from frequency domain, time domain and energy domain signals as evaluation indicators, and environmental electromagnetic complexity is divided into levels, such as simple, mild, moderate and severe. However, the above research only quantifies the electromagnetic complexity in a specific environment and does not focus on the adaptability of equipment in the electromagnetic environment.

[0004] In the evaluation of electromagnetic environmental effects on equipment, statistical analysis methods are used to establish a survival probability model for electronic systems. A model for evaluating electromagnetic damage effects on ship electronic equipment is constructed by combining the analytic hierarchy process and the comprehensive fuzzy evaluation method. Indicators closely related to the ability of Beidou user terminals to complete tasks are selected, and a weighted evaluation method based on the degree of adaptability of a single indicator to a complex electromagnetic environment is used to evaluate the adaptability of Beidou receivers to complex electromagnetic environments. However, these methods usually require the performance indicators of the test equipment, which not only makes the calculation process complex and inaccurate, but also has certain limitations in use.

[0005] In order to solve the above problems, the prior art uses the third-order power series expansion of the transfer function or the vector analysis method to analyze the blocking interference mechanism of the equipment RF front end, and constructs two different effect evaluation models, namely, field strength effective value sensitivity and peak sensitivity, to evaluate the effect of the in-band interference of the communication radio station, and can accurately evaluate the effect of the in-band multi-frequency interference of the communication radio station. However, when the radar is tested and evaluated for the multi-frequency electromagnetic radiation effect using the effect evaluation model based on the third-order power series expansion, it is found that when the target echo peak level is compressed by 6dB or 12dB as the blocking sensitivity criterion, the dual-frequency critical interference effect evaluation error will be greater than 3dB; the navigation receiver multi-frequency electromagnetic radiation effect test evaluation found that with the increase of the useful signal strength, the evaluation error is even greater than 10dB, indicating that the use of the effect evaluation model based on the third-order power series expansion on radars and navigation receivers is more defective. It is analyzed that the fifth-order term of the nonlinear system transfer function enhances the useful signal gain, making the multi-frequency interference efficiency lower than the single-frequency interference efficiency, and this is defined as the multi-frequency insensitive effect (Multi-frequency Insensitive However, no effect evaluation method for the insensitivity phenomenon has been proposed, so there is an urgent need for a blocking effect evaluation method for the multi-frequency insensitivity phenomenon. Summary of the invention

[0006] The purpose of the present invention is to provide a method and system for evaluating the blocking effect of electromagnetic radiation multi-frequency insensitivity, which can accurately evaluate the blocking effect of a test device with multi-frequency electromagnetic radiation insensitivity phenomenon.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A method for evaluating the multi-frequency insensitive blocking effect of electromagnetic radiation, comprising:

[0009] Construct the effect index equation;

[0010] A single-frequency electromagnetic radiation critical blocking effect test is performed on the frequency device to be tested to obtain the relationship between the sensitive bandwidth of the frequency device to be tested and the single-frequency critical blocking interference field strength value of the frequency device to be tested and the radiation frequency deviation; the radiation frequency deviation is the difference between the electromagnetic radiation frequency in the working environment of the frequency device to be tested and the working frequency of the frequency device to be tested; the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points in the sensitive bandwidth is less than 1dB, and the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points outside the sensitive bandwidth is less than 3dB;

[0011] An amplitude modulated wave test is performed on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, so as to obtain a set of multi-frequency radiation field strength values; the set of multi-frequency radiation field strength values ​​includes multi-frequency radiation field strength values ​​of carrier frequency, up-conversion frequency and down-conversion frequency in the amplitude modulated wave test; the amplitude modulated wave test is an amplitude modulated wave electromagnetic radiation critical blocking effect test or a dual-frequency electromagnetic radiation critical blocking effect test;

[0012] According to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using equipment to be tested, a single-frequency critical blocking interference field strength value set is obtained; the single-frequency critical blocking interference field strength value set includes the single-frequency critical blocking interference field strength values ​​of the electromagnetic interference frequency in the amplitude modulation wave test as the carrier frequency, up-conversion and down-conversion;

[0013] Determine a correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set;

[0014] The correction factor, the preset multi-frequency insensitive blocking effect index threshold, the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set are input into the effect index equation to obtain a normalized constant in the effect index equation; the preset multi-frequency insensitive blocking effect index threshold is 1;

[0015] Substituting the correction factor and the normalization constant into the effect index equation to obtain a multi-frequency insensitive blocking effect evaluation model;

[0016] Obtain the single-frequency critical blocking interference field strength value and multi-frequency radiation field strength value of the frequency-using equipment to be tested at all electromagnetic interference frequencies in the working environment;

[0017] The single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency equipment to be tested at all electromagnetic interference frequencies in the working environment are input into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency equipment to be tested. The multi-frequency insensitive blocking effect index is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect of the frequency equipment to be tested.

[0018] Optionally, the effect index equation is specifically:

[0019] Among them, S5 is the multi-frequency insensitive blocking effect index, Δ is the correction factor, η is the normalization constant, and E i0 The frequency of the equipment to be tested is f i The single-frequency critical blocking interference field strength value at time, E i The electromagnetic interference frequency of the equipment to be tested in the working environment is f i The radiation field strength value at that time.

[0020] Optionally, obtaining a single-frequency critical blocking interference field strength value set according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested specifically includes:

[0021] An interpolation method is adopted to obtain a set of single-frequency critical blocking interference field strength values ​​according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested.

[0022] Optionally, the correction factor in the effect index equation is determined according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set, specifically:

[0023] According to the formula Calculate the correction factor, where E i0 The electromagnetic interference frequency is f i The single-frequency critical blocking interference field strength value, E i The electromagnetic interference frequency is f i The multi-frequency radiation field strength value, Δ is the correction factor.

[0024] An electromagnetic radiation multi-frequency insensitive blocking effect evaluation system, comprising:

[0025] Building blocks for constructing effect index equations;

[0026] A sensitive bandwidth and relationship determination module is used to perform a single-frequency electromagnetic radiation critical blocking effect test on the frequency device to be tested to obtain the relationship between the sensitive bandwidth of the frequency device to be tested and the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency device to be tested; the radiation frequency deviation is the difference between the electromagnetic radiation frequency in the working environment of the frequency device to be tested and the working frequency of the frequency device to be tested; the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points in the sensitive bandwidth is less than 1dB and the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points outside the sensitive bandwidth is less than 3dB;

[0027] An amplitude modulated wave test multi-frequency radiation field strength value set determination module is used to perform an amplitude modulated wave test on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, and obtain a multi-frequency radiation field strength value set; the multi-frequency radiation field strength value set includes multi-frequency radiation field strength values ​​when the electromagnetic interference frequency in the amplitude modulated wave test is the carrier frequency, up-conversion and down-conversion; the amplitude modulated wave test is an amplitude modulated wave electromagnetic radiation critical blocking effect test or a dual-frequency electromagnetic radiation critical blocking effect test;

[0028] A module for determining a set of single-frequency critical blocking interference field strength values ​​corresponding to an amplitude modulated wave test, which is used to obtain a set of single-frequency critical blocking interference field strength values ​​according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested; the set of single-frequency critical blocking interference field strength values ​​includes single-frequency critical blocking interference field strength values ​​when the electromagnetic interference frequency in the amplitude modulated wave test is the carrier frequency, up-conversion and down-conversion;

[0029] A correction factor determination module, used to determine the correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set;

[0030] A normalization constant determination module, used for inputting the correction factor, the preset multi-frequency insensitive blocking effect index threshold, the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set into the effect index equation to obtain the normalization constant in the effect index equation; the preset multi-frequency insensitive blocking effect index threshold is 1;

[0031] A multi-frequency insensitive blocking effect evaluation model determination module is used to bring the correction factor and the normalization constant into the effect index equation to obtain a multi-frequency insensitive blocking effect evaluation model;

[0032] An evaluation data acquisition module is used to obtain the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency-using equipment to be tested at all electromagnetic interference frequencies in the working environment;

[0033] An evaluation module is used to input the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency-using equipment to be tested in the working environment at all electromagnetic interference frequencies into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency-using equipment to be tested, and the multi-frequency insensitive blocking effect index is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect of the frequency-using equipment to be tested.

[0034] Optionally, the effect index equation is specifically:

[0035] Among them, S5 is the multi-frequency insensitive blocking effect index, Δ is the correction factor, η is the normalization constant, and E i0 The frequency of the equipment to be tested is f i The single-frequency critical blocking interference field strength value at the time, E i The electromagnetic interference frequency of the equipment to be tested in the working environment is f i The radiation field strength value at that time.

[0036] Optionally, the module for determining a set of single-frequency critical blocking interference field strength values ​​of the amplitude modulation wave test specifically includes:

[0037] The single-frequency critical blocking interference field strength value set determination unit for the amplitude modulation wave test is used to obtain a single-frequency critical blocking interference field strength value set based on the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested by using an interpolation method.

[0038] Optionally, the correction factor determination module specifically includes:

[0039] Correction factor determination unit for use according to the formula Calculate the correction factor, where E i0 The electromagnetic interference frequency is f i The single-frequency critical blocking interference field strength value, E i The electromagnetic interference frequency is f i The multi-frequency radiation field strength value, Δ is the correction factor.

[0040] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the present invention constructs a multi-frequency insensitive blocking effect evaluation model, which represents the relationship between the multi-frequency insensitive blocking effect index and the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value set; the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value set of the frequency equipment to be tested are input into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency equipment to be tested, and the multi-frequency insensitive blocking effect index is used to evaluate the multi-frequency insensitive blocking effect of electromagnetic radiation of the frequency equipment to be tested, and the multi-frequency insensitive blocking effect evaluation model can evaluate the blocking effect of the dual-frequency insensitivity phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 A flowchart of a method for evaluating the multi-frequency insensitive blocking effect of electromagnetic radiation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] The embodiment of the present invention provides a method for evaluating the multi-frequency insensitive blocking effect of electromagnetic radiation, such as Figure 1 As shown, including:

[0046] Step 1: Construct the effect index equation.

[0047] Step 2: Perform a single-frequency electromagnetic radiation critical blocking effect test on the frequency-using equipment to be tested to obtain the relationship between the sensitive bandwidth of the frequency-using equipment to be tested and the single-frequency critical blocking interference field strength value of the frequency-using equipment to be tested and the radiation frequency deviation; the radiation frequency deviation is the difference between the electromagnetic radiation frequency in the working environment of the frequency-using equipment to be tested and the working frequency of the frequency-using equipment to be tested; the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points in the sensitive bandwidth is less than 1dB, and the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points outside the sensitive bandwidth is less than 3dB; specifically, perform a single-frequency electromagnetic radiation critical blocking effect test on the frequency-using equipment to be tested, reasonably select the test frequency point, make the single-frequency critical blocking interference field strength value of adjacent test frequency points within the sensitive bandwidth differ by less than 1dB, and the single-frequency critical blocking interference field strength value of adjacent test frequency points outside the band differ by less than 3dB, determine the relationship between its single-frequency critical blocking interference field strength value and the radiation frequency deviation (the difference between the electromagnetic radiation frequency f and the working frequency f0 of the test equipment), and give the sensitive bandwidth of the test equipment.

[0048] Step 3: Perform an amplitude modulated wave test on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, and obtain a set of multi-frequency radiation field strength values. The set of multi-frequency radiation field strength values ​​includes multi-frequency radiation field strength values ​​when the electromagnetic interference frequency in the amplitude modulated wave test is the carrier frequency, up-conversion and down-conversion; the amplitude modulated wave test is an amplitude modulated wave electromagnetic radiation critical blocking effect test or a dual-frequency electromagnetic radiation critical blocking effect test.

[0049] Step 4: According to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested, a single-frequency critical blocking interference field strength value set is obtained. The single-frequency critical blocking interference field strength value set includes the single-frequency critical blocking interference field strength values ​​of the electromagnetic interference frequency in the amplitude modulation wave test as the carrier frequency, up-conversion and down-conversion.

[0050] Step 5: Determine the correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set.

[0051] Step 6: Input the correction factor, the preset multi-frequency insensitive blocking effect index threshold, the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set into the effect index equation to obtain the normalized constant in the effect index equation; the preset multi-frequency insensitive blocking effect index threshold is 1.

[0052] Step 7: Substitute the correction factor and the normalization constant into the effect index equation to obtain a multi-frequency insensitive blocking effect evaluation model. Specifically, substitute the correction factor Δ value and the normalization constant η value determined by the above test into formula (16) to give a multi-frequency insensitive blocking effect evaluation model for the device under test, analyze the working electromagnetic environment of the device under test, and test or simulate and analyze to determine the radiation field strength E corresponding to different electromagnetic interference frequencies. i (i=1,2,3,…,n), according to the above relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation, interpolate and determine the single-frequency critical blocking interference field strength value E corresponding to different frequency deviations i0 , substitute into the above determined multi-frequency insensitive blocking effect evaluation model to calculate the effect index S5. If S5≥1, the device under test is blocked; otherwise, the device under test works normally.

[0053] Step 8: Obtain the single-frequency critical blocking interference field strength value and multi-frequency radiation field strength value of the frequency-using equipment to be tested at all electromagnetic interference frequencies in the working environment.

[0054] Step 9: Input the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency-using equipment to be tested at all electromagnetic interference frequencies in the working environment into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency-using equipment to be tested. The multi-frequency insensitive blocking effect index is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect of the frequency-using equipment to be tested.

[0055] In practical applications, the effect index equation is specifically:

[0056] Among them, S5 is the multi-frequency insensitive blocking effect index, Δ is the correction factor, η is the normalization constant, and the frequency equipment to be tested is at the electromagnetic interference frequency of f i The single-frequency critical blocking interference field strength value at the time, E i The electromagnetic interference frequency of the equipment to be tested in the working environment is f i In the amplitude modulated wave test to determine the model parameters η and Δ, when i is 1, f i The value is down-conversion. When i is 2, f i The value is the carrier frequency. When i is 3, f i The value is up-conversion. When testing, f i is the electromagnetic interference frequency in the working environment.

[0057] In practical applications, the amplitude modulation wave test is performed on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested to obtain a set of multi-frequency radiation field strength values, specifically including:

[0058] According to the sensitive bandwidth of the frequency-using device to be tested, the frequency-using device to be tested is subjected to an AM wave electromagnetic radiation critical blocking effect test with an AM depth of 100% to obtain a multi-frequency radiation field strength value set. Specifically, an in-band frequency point is selected to conduct an AM wave electromagnetic radiation critical blocking effect test with an AM depth of 100% on the device under test (the modulation frequency should be less than 10% of the sensitive bandwidth of the device under test), and the multi-frequency radiation field strength value set E corresponding to the carrier frequency and the upper and lower sidebands is measured. i According to the above relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation, the single-frequency critical blocking interference field strength value E corresponding to different frequency deviations is determined by interpolation i0 .

[0059] In practical applications, the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested is used to obtain a single-frequency critical blocking interference field strength value set, which specifically includes:

[0060] An interpolation method is adopted to obtain a set of single-frequency critical blocking interference field strength values ​​according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested.

[0061] The specific idea of ​​this embodiment is:

[0062] Starting from the study of the mechanism of multi-frequency insensitivity electromagnetic radiation effect of frequency-using equipment, the evaluation model is studied. First, based on the nonlinear fifth-order power series expansion of the transfer function, the analytical expression of the useful signal gain under the action of multi-frequency electromagnetic radiation is derived, the multi-frequency insensitivity effect of the equipment is analyzed, and a multi-frequency insensitivity effect evaluation model is established. Secondly, the sweeping radar and communication radio are used as test objects to verify the accuracy and versatility of the proposed model.

[0063] Based on the fifth-order nonlinear power series expansion, the transfer function of the equipment under test can be expressed as

[0064] u o (t) = a0 + a1u i (t)+a2u i 2 (t)+a3u i 3 (t)+a4u i 4 (t)+a5u i 5 (t) (1)

[0065] Among them, ai (i=0,1,...,5) is the nonlinear coefficient, u i (t) is the input signal of the receiver, and u0(t) is the output signal of the receiver.

[0066] When the equipment under test is interfered by multi-frequency electromagnetic radiation, its input signal can be expressed as:

[0067]

[0068] Among them, A s E s is the amplitude of the useful signal, A i E i is the amplitude of the i-th single-frequency interference signal, ω s and ω i are the angular frequencies of the useful signal and the interference signal respectively, and t represents time.

[0069] Substituting equation (2) into equation (1), the useful signal gain under single-frequency electromagnetic radiation is obtained as follows:

[0070]

[0071] Similarly, when the useful signal remains unchanged, the useful signal gain under the dual-frequency electromagnetic radiation can be expressed as:

[0072]

[0073] It can be deduced that when n-frequency interference signals act together, the useful signal gain is:

[0074]

[0075] Based on the analysis of the blocking interference mechanism, it can be seen that the critical effective interference level of any single-frequency electromagnetic radiation signal acting alone is equal, that is,

[0076]

[0077] If the single-frequency critical blocking interference field strength value when the i-th single-frequency electromagnetic radiation signal acts alone is E i0 , when multi-frequency electromagnetic radiation signals act together, each interference component is normalized, that is, Combining formula (6), we can get

[0078] From formula (3), it can be obtained that the signal gain when critical interference occurs under the action of single-frequency interference is:

[0079]

[0080] From formula (5), the useful signal gain under multi-frequency electromagnetic radiation is:

[0081]

[0082] When critical interference occurs, the useful signal gain under the combined effect of multi-frequency interference signals should be the same as the useful signal gain under single-frequency interference, that is, K 10 =K n , can be obtained

[0083]

[0084] Then the nonlinear coefficient a5 can be expressed as

[0085]

[0086] When a single-frequency interference signal causes blocking interference to the equipment, the interference signal level is much greater than the useful signal level, that is, therefore The term approaches 0, then:

[0087]

[0088] When only the third-order term is considered to affect the useful signal, the critical interference At this time, a5 tends to 0, and when considering the fifth-order term, When the equipment has a dull effect, The above formula proves that the nonlinear coefficients a3 and a5 have opposite signs. When the third-order term weakens the gain of the useful signal, the fifth-order term must enhance the gain of the useful signal. When the multi-frequency insensitivity effect occurs, the influence of the fifth-order term on the enhancement of the useful signal cannot be ignored.

[0089] If the correction factor is defined

[0090]

[0091] Then formula (11) can be expressed as

[0092]

[0093] Substituting equation (13) into equation (8), the useful signal gain K when multiple frequencies act together is n It can be expressed in a form represented only by a1 and a3, that is,

[0094]

[0095] When only the influence of the third-order term on the useful signal gain is considered, Δ=0, then the useful signal gain when multi-frequency interference signals act together can be expressed as:

[0096]

[0097] At this time, the multi-frequency blocking interference effect index When considering the influence of fifth-order nonlinearity on the gain of useful signals, by analogy with equation (14) and equation (15), we can obtain the multi-frequency blocking interference effect index:

[0098]

[0099] Among them, η is a normalization constant, and its role is to use a specific multi-frequency critical blocking interference field strength value set data to calibrate the effect index, and the value of S5 should be 1. Since formula (16) is a general expression of the blocking interference effect index when considering the fifth-order nonlinearity, it should be applicable to various interference situations. The undetermined constant in the formula can use the critical blocking interference field strength value set of the amplitude modulation wave with an amplitude modulation depth of 100% and the single-frequency signal corresponding to 3 frequencies or any dual-frequency critical blocking interference field strength value set and its corresponding frequency single-frequency critical blocking interference field strength value test data. First, calculate and determine the value of Δ according to formula (12), and then substitute it into formula (16) and let S5 = 1 to determine the normalization constant η. After determining the model parameters Δ and η, the blocking interference effect index of the test equipment under the action of any multi-frequency electromagnetic radiation can be calculated and determined to evaluate whether it will be affected by blocking interference. When there is no insensitivity effect, Δ should be 0 and η should be 1. With the appearance of insensitivity effect, Δ and η will also increase, and the effect index will be corrected. When S5=1, the equipment is subject to critical blocking interference; when S5>1, the equipment is subject to effective interference; when S5<1, the equipment can work normally.

[0100] In view of the above method, this embodiment also provides an electromagnetic radiation multi-frequency insensitive blocking effect evaluation system, including:

[0101] Building blocks for constructing effect index equations.

[0102] A sensitive bandwidth and relationship determination module is used to perform a single-frequency electromagnetic radiation critical blocking effect test on a frequency device to be tested to obtain the relationship between the sensitive bandwidth of the frequency device to be tested and the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency device to be tested; the radiation frequency deviation is the difference between the electromagnetic radiation frequency in the working environment of the frequency device to be tested and the working frequency of the frequency device to be tested; the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points in the sensitive bandwidth is less than 1dB and the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points outside the sensitive bandwidth is less than 3dB.

[0103] A module for determining a set of multi-frequency radiation field strength values ​​for an amplitude modulated wave test is used to perform an amplitude modulated wave test on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, and obtain a set of multi-frequency radiation field strength values; the set of multi-frequency radiation field strength values ​​includes multi-frequency radiation field strength values ​​when the electromagnetic interference frequency in the amplitude modulated wave test is the carrier frequency, up-conversion and down-conversion; the amplitude modulated wave test is an amplitude modulated wave electromagnetic radiation critical blocking effect test or a dual-frequency electromagnetic radiation critical blocking effect test.

[0104] A module for determining a set of single-frequency critical blocking interference field strength values ​​for an amplitude modulated wave test is used to obtain a set of single-frequency critical blocking interference field strength values ​​based on the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using equipment to be tested; the single-frequency critical blocking interference field strength value set includes the single-frequency critical blocking interference field strength values ​​of the electromagnetic interference frequency in the amplitude modulated wave test as the carrier frequency, up-conversion and down-conversion.

[0105] The correction factor determination module is used to determine the correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set.

[0106] A normalization constant determination module is used to input the correction factor, the preset multi-frequency insensitive blocking effect index threshold, the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set into the effect index equation to obtain the normalization constant in the effect index equation; the preset multi-frequency insensitive blocking effect index threshold is 1.

[0107] The multi-frequency insensitive blocking effect evaluation model determination module is used to bring the correction factor and the normalization constant into the effect index equation to obtain the multi-frequency insensitive blocking effect evaluation model.

[0108] The evaluation data acquisition module is used to obtain the single-frequency critical blocking interference field strength value and multi-frequency radiation field strength value of the frequency-using equipment to be tested in the working environment at all electromagnetic interference frequencies.

[0109] An evaluation module is used to input the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency-using equipment to be tested in the working environment at all electromagnetic interference frequencies into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency-using equipment to be tested, and the multi-frequency insensitive blocking effect index is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect of the frequency-using equipment to be tested.

[0110] As an optional implementation, the effect index equation is specifically:

[0111] Among them, S5 is the multi-frequency insensitive blocking effect index, Δ is the correction factor, η is the normalization constant, and E i0The frequency of the equipment to be tested is f i The single-frequency critical blocking interference field strength value at time, E i The electromagnetic interference frequency of the equipment to be tested in the working environment is f i In the amplitude modulated wave test to determine the model parameters η and Δ, when i is 1, f i The value is down-conversion. When i is 2, f i The value is the carrier frequency. When i is 3, f i The value is up-conversion. When testing, f i is the electromagnetic interference frequency in the working environment.

[0112] As an optional implementation manner, the module for determining a set of multi-frequency radiation field strength values ​​of an amplitude modulated wave test specifically includes:

[0113] The multi-frequency radiation field strength value set determination unit is used to perform an AM wave electromagnetic radiation critical blocking effect test with an AM depth of 100% on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, and obtain a multi-frequency radiation field strength value set.

[0114] As an optional implementation manner, the module for determining a set of single-frequency critical blocking interference field strength values ​​of the amplitude modulation wave test specifically includes:

[0115] The single-frequency critical blocking interference field strength value set determination unit for the amplitude modulation wave test is used to obtain a single-frequency critical blocking interference field strength value set based on the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested by using an interpolation method.

[0116] As an optional implementation manner, the correction factor determination module specifically includes:

[0117] Correction factor determination unit for use according to the formula Calculate the correction factor, where E i0 The electromagnetic interference frequency is f i The single-frequency critical blocking interference field strength value, E i The electromagnetic interference frequency is f i The multi-frequency radiation field strength value, Δ is the correction factor. When calculating the correction factor, when i is 1, f i The value is down-conversion. When i is 2, f i The value is the carrier frequency. When i is 3, f i The value is up-conversion.

[0118] The present invention also provides an embodiment of using the above method to process radar and radio station:

[0119] A radar dual-frequency electromagnetic radiation effect test platform was used. Two microwave signal generators (Agilent E8257D) were used to generate dual-frequency continuous waves, which were sent to a broadband microwave power amplifier (Amplifier Research Model 200T8G18A) through a combiner for amplification. The directional coupler (coupling degree 50dB) fed the radiating antenna (Schwarzbeck BBHA 9120D). The interference end radiating antenna also served as the radar detection target. A certain type of Ku-band frequency stepped continuous wave radar was selected as the test object at the test end. Considering the stability and repeatability of the test results, the static target ranging function was selected for research. The polarization direction and electromagnetic wave radiation direction of the electromagnetic radiation antenna of the effect test system were adjusted to make the tested radar most sensitive to electromagnetic radiation. During the test, the position of the equipment should be kept unchanged.

[0120] The target echo peak level compression of 1.5dB, 6dB and 12dB is used as the radar sensitivity criterion. When the interference frequency offset sets are -30MHz and 30MHz, 0Hz and 90MHz respectively, the dual-frequency critical blocking interference field strength value set and the single-frequency critical blocking interference field strength value of each frequency offset are measured. The normalized components of the dual-frequency interference field strength set are expressed as E1 / E 10 and E2 / E 20 . Since the correction factor Δ and the normalization constant η are closely related to the sensitivity criterion, in the radar test, it is necessary to select a set of test data under each different sensitivity criterion, and calculate the effect index correction factor Δ and the normalization constant η under the specific sensitivity criterion according to equations (12) and (16), and use them in the multi-frequency insensitivity effect evaluation model. In the test, the frequency offset sets 0Hz and 90MHz were selected under different sensitivity criteria, and the first test data were used to determine the model parameters Δ and η. The test data and model parameters are shown in Table 1. In the test, S3 (effect evaluation index based on third-order terms) and S5 were used for effect evaluation, and the evaluation results are shown in Tables 2 to 4.

[0121] Table 1 Model parameters under different sensitivity criteria

[0122]

[0123] Table 2 Peak level compression 1.5dB test results

[0124]

[0125] Table 3 Peak level compression 6dB test results

[0126]

[0127] Table 4 Peak level compression 12dB test results

[0128]

[0129] As shown in Table 1, when the target echo peak level is compressed by 1.5dB, the equipment itself has no obvious insensitivity effect, Δ takes a value less than 0.1, can be approximated to 0, and the normalized constant η is close to 1; when the echo peak level is compressed by 6dB and 12dB, an insensitivity effect occurs at this time, Δ increases to about 0.2, and η also increases accordingly, which is consistent with the theoretical analysis results. As shown in Table 2, when the equipment itself has no obvious insensitivity phenomenon, the relative error of S5 is less than S3, and the error can be controlled at 0.5dB, indicating that the fifth-order effect evaluation model proposed in this embodiment can accurately evaluate the interference effect. As shown in Tables 3 and 4, when the peak level is compressed by 6dB and 12dB respectively, an insensitivity effect occurs at this time, and the calculation result of the third-order effect evaluation index S3 is much greater than 1, indicating that the third-order effect evaluation model cannot be used well for insensitivity effect evaluation. When the proposed fifth-order effect evaluation model is used for effect evaluation, the calculation error of S5 can be controlled at ±1dB. This theoretical calculation result not only verifies the effectiveness of the proposed multi-frequency insensitivity effect model, but also shows that the fifth-order term does increase the useful signal gain and cannot be ignored in the multi-frequency insensitivity effect evaluation.

[0130] In the dual-frequency electromagnetic radiation effect test of communication radio stations, in order to avoid the influence of the external electromagnetic environment, the radio transmitting antenna, interference antenna, receiving antenna and receiving radio station are placed in the shielded room, and other equipment is placed outside the shielded room. The spatial layout of the receiving antenna and the transmitting antenna is adjusted to make the tested system in the most sensitive state. In order to ensure the stability of the test data, the posture of each antenna and the relative position of the radio station must be kept unchanged.

[0131] When the radio station operating frequency f0 was 60MHz and 80MHz respectively, multiple groups of effect tests were conducted under different interference frequencies and different interference intensity sets. Since the communication radio station always uses only one sensitivity criterion 28 in the test, it is only necessary to select any set of test data. In the test, the operating frequency was selected as 60MHz, and the frequency deviation set was -20kHz and 10kHz. The effect test data was used. and The effect index correction factor Δ=0.09 and the normalization constant η=1.10 were calculated, and the effect indexes S3 and S5 were used for effect evaluation. The critical interference effect evaluation results are shown in Tables 5 and 6, respectively.

[0132] Table 5 Results of dual-frequency critical interference test in the communication radio band at 60MHz operating frequency

[0133]

[0134] Table 6 Test results of dual-frequency critical interference in-band of communication radio station at 80MHz operating frequency

[0135]

[0136]

[0137] From the calculation results of the effect index of the test data of non-insensitivity effect communication radio stations in Tables 5 and 6, in the electromagnetic radiation effect evaluation of equipment without insensitivity effect, when the insensitivity effect index S5 is used for evaluation, the value of Δ is also less than 0.1, which is consistent with the theoretical analysis results of the proposed fifth-order effect evaluation model, and the calculation error of the effect index can also be controlled within ±1dB, which once again shows that the electromagnetic radiation insensitivity effect evaluation model based on the fifth-order term is also applicable to non-insensitivity equipment, and the effect index calculated by S5 is less than the result obtained by S3, which also confirms the theoretical analysis results of the fifth-order term enhancing the useful signal gain.

[0138] This embodiment is based on the analysis of the blocking interference mechanism. By combining theoretical deduction with experimental verification, the multi-frequency insensitive blocking effect mechanism is revealed and a multi-frequency insensitive electromagnetic radiation blocking effect model is established. The conclusions are as follows:

[0139] (1) Based on the analysis of the blocking interference mechanism, the analytical expression of the useful signal gain under the action of multi-frequency electromagnetic radiation is derived using the fifth-order power series expansion. It is explained that the fifth-order nonlinearity is the fundamental reason why the frequency-using equipment is insensitive to the blocking of multi-frequency electromagnetic radiation. On this basis, the effect evaluation index is defined and a multi-frequency insensitive electromagnetic radiation blocking effect model is established.

[0140] (2) A certain type of Ku-band radar and ultra-short wave communication radio were used as the test equipment to test and verify the applicability and accuracy of the multi-frequency insensitive electromagnetic radiation blocking effect model. The test results of the dual-frequency electromagnetic radiation critical blocking effect showed that the error calculation results of the effect evaluation index based on the fifth-order term were smaller than the effect index evaluation error based on the third-order term, regardless of whether the equipment had multi-frequency electromagnetic radiation blocking insensitivity or not, and the evaluation error could be controlled within ±1dB. This not only confirmed the theoretical analysis results of the insensitivity effect mechanism, but also verified the universality and accuracy of the multi-frequency insensitive electromagnetic radiation blocking effect model.

[0141] (3) Limited by the test conditions, this embodiment only carried out a dual-frequency electromagnetic radiation effect test on the proposed insensitivity effect evaluation model. However, from the theoretical derivation, the model is also applicable to the evaluation of three-frequency and more-frequency electromagnetic radiation effects.

[0142] The present invention has the following technical effects:

[0143] The present invention can accurately evaluate the dual-frequency and multi-frequency insensitivity phenomena and the blocking effect without the dual-frequency and multi-frequency insensitivity phenomena, solves the problem of poor universality of the electromagnetic radiation effect evaluation model, and has high evaluation accuracy.

[0144] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0145] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for evaluating the multi-frequency insensitive blocking effect of electromagnetic radiation, characterized in that: include: Construct an effect index equation; the effect index equation is specifically: Among them, S5 is the multi-frequency insensitive blocking effect index, Δ is the correction factor, η is the normalization constant, and E i0 The frequency of the equipment to be tested is at the electromagnetic interference frequency f i The single-frequency critical blocking interference field strength value at the time, E i The electromagnetic interference frequency of the equipment to be tested in the working environment is f i The radiation field strength value at ; A single-frequency electromagnetic radiation critical blocking effect test is performed on the frequency device to be tested to obtain the relationship between the sensitive bandwidth of the frequency device to be tested and the single-frequency critical blocking interference field strength value of the frequency device to be tested and the radiation frequency deviation; the radiation frequency deviation is the difference between the electromagnetic radiation frequency in the working environment of the frequency device to be tested and the working frequency of the frequency device to be tested; the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points in the sensitive bandwidth is less than 1dB, and the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points outside the sensitive bandwidth is less than 3dB; Performing an amplitude modulated wave test on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested to obtain a set of multi-frequency radiation field strength values; the set of multi-frequency radiation field strength values ​​includes multi-frequency radiation field strength values ​​when the electromagnetic interference frequency in the amplitude modulated wave test is the carrier frequency, the upper side frequency and the lower side frequency; the amplitude modulated wave test is an amplitude modulated wave electromagnetic radiation critical blocking effect test or a dual-frequency electromagnetic radiation critical blocking effect test; performing an amplitude modulated wave test on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested to obtain a set of multi-frequency radiation field strength values ​​specifically includes: performing an amplitude modulated wave electromagnetic radiation critical blocking effect test with an amplitude modulation depth of 100% on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested to obtain a set of multi-frequency radiation field strength values; According to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using equipment to be tested, a set of single-frequency critical blocking interference field strength values ​​is obtained; the set of single-frequency critical blocking interference field strength values ​​includes single-frequency critical blocking interference field strength values ​​of the electromagnetic interference frequency in the amplitude modulation wave test as the carrier frequency, the upper sideband and the lower sideband; according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using equipment to be tested, the set of single-frequency critical blocking interference field strength values ​​is obtained, specifically including: using an interpolation method to obtain a set of single-frequency critical blocking interference field strength values ​​according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using equipment to be tested; Determine the correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set; Determine the correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set, specifically: According to the formula Calculate the correction factor, where E i0 The electromagnetic interference frequency is f i The single-frequency critical blocking interference field strength value, E i The electromagnetic interference frequency is f i The multi-frequency radiation field strength value, Δ is the correction factor; The correction factor, the preset multi-frequency insensitive blocking effect index threshold, the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set are input into the effect index equation to obtain a normalized constant in the effect index equation; the preset multi-frequency insensitive blocking effect index threshold is 1; Substituting the correction factor and the normalization constant into the effect index equation to obtain a multi-frequency insensitive blocking effect evaluation model; Obtain the single-frequency critical blocking interference field strength value and multi-frequency radiation field strength value of the frequency-using equipment to be tested at all electromagnetic interference frequencies in the working environment; The single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency equipment to be tested at all electromagnetic interference frequencies in the working environment are input into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency equipment to be tested. The multi-frequency insensitive blocking effect index is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect of the frequency equipment to be tested.

2. An electromagnetic radiation multi-frequency insensitive blocking effect evaluation system, characterized in that: include: A construction module is used to construct an effect index equation; the effect index equation is specifically: Among them, S5 is the multi-frequency insensitive blocking effect index, Δ is the correction factor, η is the normalization constant, and E i0 The frequency of the equipment to be tested is at the electromagnetic interference frequency f i The single-frequency critical blocking interference field strength value at the time, E i The electromagnetic interference frequency of the equipment to be tested in the working environment is f i The radiation field strength value at ; A sensitive bandwidth and relationship determination module is used to perform a single-frequency electromagnetic radiation critical blocking effect test on the frequency device to be tested to obtain the relationship between the sensitive bandwidth of the frequency device to be tested and the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency device to be tested; the radiation frequency deviation is the difference between the electromagnetic radiation frequency in the working environment of the frequency device to be tested and the working frequency of the frequency device to be tested; the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points in the sensitive bandwidth is less than 1dB and the difference in single-frequency critical blocking interference field strength values ​​of adjacent test frequency points outside the sensitive bandwidth is less than 3dB; A module for determining a set of multi-frequency radiation field strength values ​​in an amplitude modulated wave test is used to perform an amplitude modulated wave test on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, and obtain a set of multi-frequency radiation field strength values; the set of multi-frequency radiation field strength values ​​includes multi-frequency radiation field strength values ​​when the electromagnetic interference frequency in the amplitude modulated wave test is the carrier frequency, the upper sideband and the lower sideband; the amplitude modulated wave test is an amplitude modulated wave electromagnetic radiation critical blocking effect test or a dual-frequency electromagnetic radiation critical blocking effect test; the module for determining a set of multi-frequency radiation field strength values ​​in an amplitude modulated wave test specifically includes: a multi-frequency radiation field strength value set determining unit, used to perform an amplitude modulated wave electromagnetic radiation critical blocking effect test with an amplitude modulation depth of 100% on the frequency-using device to be tested according to the sensitive bandwidth of the frequency-using device to be tested, and obtain a set of multi-frequency radiation field strength values; A module for determining a set of single-frequency critical blocking interference field strength values ​​in an amplitude modulated wave test is used to obtain a set of single-frequency critical blocking interference field strength values ​​according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested; the single-frequency critical blocking interference field strength value set includes single-frequency critical blocking interference field strength values ​​of the electromagnetic interference frequency in the amplitude modulated wave test as the carrier frequency, the upper sideband and the lower sideband; the module for determining a set of single-frequency critical blocking interference field strength values ​​in an amplitude modulated wave test specifically includes: an amplitude modulated wave test single-frequency critical blocking interference field strength value set determining unit, used to obtain a set of single-frequency critical blocking interference field strength values ​​according to the relationship between the single-frequency critical blocking interference field strength value and the radiation frequency deviation of the frequency-using device to be tested by adopting an interpolation method; A correction factor determination module is used to determine the correction factor in the effect index equation according to the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set; the correction factor determination module specifically includes: a correction factor determination unit, which is used to determine the correction factor in the effect index equation according to the formula Calculate the correction factor, where E i0 The electromagnetic interference frequency is f i The single-frequency critical blocking interference field strength value, E i The electromagnetic interference frequency is f i The multi-frequency radiation field strength value, Δ is the correction factor; A normalization constant determination module, used for inputting the correction factor, the preset multi-frequency insensitive blocking effect index threshold, the multi-frequency radiation field strength value set and the single-frequency critical blocking interference field strength value set into the effect index equation to obtain the normalization constant in the effect index equation; the preset multi-frequency insensitive blocking effect index threshold is 1; A multi-frequency insensitive blocking effect evaluation model determination module, used for substituting the correction factor and the normalization constant into the effect index equation to obtain a multi-frequency insensitive blocking effect evaluation model; An evaluation data acquisition module is used to obtain the single-frequency critical blocking interference field strength value and multi-frequency radiation field strength value of the frequency-using equipment to be tested at all electromagnetic interference frequencies in the working environment; An evaluation module is used to input the single-frequency critical blocking interference field strength value and the multi-frequency radiation field strength value of the frequency-using equipment to be tested in the working environment at all electromagnetic interference frequencies into the multi-frequency insensitive blocking effect evaluation model to obtain the multi-frequency insensitive blocking effect index of the frequency-using equipment to be tested, and the multi-frequency insensitive blocking effect index is used to evaluate the electromagnetic radiation multi-frequency insensitive blocking effect of the frequency-using equipment to be tested.

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