Multi-frequency sensitivity test evaluation method and system

Abstract

The invention relates to a multi-frequency sensitivity test evaluation method and system, the evaluation method is realized based on a multi-frequency sensitivity test device, and the device comprises a signal generator, an attenuator, a power amplifier, a directional coupler, a power meter, a frequency spectrograph and an interference applying module. According to the evaluation method, the sensitivity of the electronic product to single-frequency interference and multi-frequency interference in different frequency bands can be determined, modes such as frequency band sub-band division and reverse frequency spectrum monitoring are designed, the influence of multi-frequency-point signal intermodulation interference on a test result can be reduced, and the test accuracy is improved. The problem that the accuracy of a multi-frequency-point sensitivity test result is affected due to the fact that a traditional multi-frequency-point test method generates extra interference risks on the tested electronic product is solved. Meanwhile, under the condition that the multi-frequency sensitivity indication parameter provided by the invention meets a certain condition, a continuous wave sensitivity test method can be adopted to replace a multi-frequency point sensitivity test method, so that the test cost is reduced.

Description

Technical Field

[0001] This invention relates to a multi-frequency sensitivity test evaluation method and system, belonging to the field of spacecraft electromagnetic compatibility technology. Background Technology

[0002] Electromagnetic compatibility (EMC) testing is a mandatory procedure for electronic products and equipment before delivery to ensure their compatibility with the electromagnetic environment. Traditionally, the ability of electronic products to function properly in an electromagnetic environment is assessed primarily through various radiation and conducted susceptibility tests. In frequency domain testing, the signals used are mainly continuous wave signals, meaning only one frequency is applied at any given time. However, with the increasing complexity of electromagnetic environment effects on equipment, this approach is becoming increasingly questionable in evaluating the adaptability of electronic products to the electromagnetic environment of actual equipment. This is because real-world electromagnetic environments often contain multiple frequencies simultaneously, making this single-frequency EMC testing method inadequate for verifying the normal operation of electronic products in electromagnetic environments with simultaneous multi-frequency interference.

[0003] Applying multi-frequency susceptibility testing to all electronic products based on actual electromagnetic environments is not entirely appropriate. Firstly, multi-frequency susceptibility testing places high demands on the testing system and incurs significant costs. Furthermore, electronic products are not necessarily more sensitive to multi-frequency interference than to single-frequency interference. If it can be determined that an electronic product is more sensitive to single-frequency interference, traditional continuous wave signal susceptibility testing can be used to assess its electromagnetic susceptibility. Secondly, directly using multi-frequency susceptibility testing may introduce intermodulation interference between the applied interference signals, posing additional interference risks to the tested electronic product. The final test results may not accurately represent the actual electromagnetic susceptibility of the electronic product. Finally, during the design phase of electronic products, the electromagnetic environment is generally not fully determined. There is a lack of necessary guidance on whether to design based on a single frequency or multi-frequency interference during electromagnetic compatibility design. This increases the risk that problems may only be discovered during the final acceptance testing phase, making electromagnetic interference issues difficult to resolve. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method and system for evaluating multi-frequency sensitivity testing during the product design stage. This method can determine the sensitivity of electronic products to single-frequency interference and multi-frequency interference in different frequency bands, providing a basis for the electromagnetic compatibility design of the product and the final electromagnetic compatibility test scheme design.

[0005] The technical solution of this invention is:

[0006] On one hand, the present invention proposes a multi-frequency sensitivity testing device, comprising: a signal generator, an attenuator, a power amplifier, a directional coupler, a power meter, a spectrum analyzer, and an interference application module;

[0007] The signal generator is used to generate continuous wave signals or comb wave signals, and the signal is attenuated by the attenuator to prevent the signal power from being too high and damaging the subsequent power amplifier. The power amplifier is used to amplify the output signal power. The output signal of the power amplifier is controlled by the directional coupler. The output signal of the directional coupler is sent to the interference application module to apply interference. The output signal after interference is output to the electronic product under test.

[0008] The power meter is connected to the forward power monitoring port of the directional coupler to monitor the forward output power; the spectrum analyzer is connected to the return signal monitoring port of the directional coupler to monitor the return signal spectrum.

[0009] Furthermore, if conducted interference is to be applied to the electronic device under test, an injection probe is used to apply the interference to the electronic device under test; if radiated interference is to be applied to the electronic device under test, an antenna is used to apply the interference to the electronic device under test.

[0010] On the other hand, the present invention also proposes a multi-frequency sensitivity test evaluation method, comprising the following steps:

[0011] (1) Within the sensitivity test frequency band, a continuous wave signal is used for sensitivity testing; the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator.

[0012] (2) During the continuous wave signal sensitivity test phase, the sensitivity thresholds at different frequencies are monitored by a power meter to monitor the working status of the electronic product and determine the disturbance mode of the electronic product.

[0013] (3) Divide the test frequency band into multiple sub-bands. The division principle is: in each sub-band, the electronic product has only one interference mode, and each sub-band does not exceed one tenth harmonic.

[0014] (4) Generate a comb wave signal in each sub-band and use the comb wave signal for sensitivity testing; for the comb wave signal, use at least three signals with different frequency intervals for sensitivity testing.

[0015] (5) For each comb wave signal, the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator. The forward average power and peak power of the electronic product when it is just interfered with are monitored by a power meter.

[0016] (6) Calculate the multi-frequency sensitivity indication parameter I;

[0017] (7) Determine the sensitivity test requirements for each sub-band based on the multi-band sensitivity indication parameter I;

[0018] (8) After all subbands have been tested and evaluated, the electromagnetic compatibility test requirements for the electronic equipment in the required frequency band are obtained. The electronic equipment can carry out targeted electromagnetic compatibility design according to the requirements. After the product is developed, electromagnetic compatibility test verification can also be carried out according to the requirements.

[0019] Furthermore, the determination of the frequency interval of the comb wave signal should meet the following principles:

[0020] (a) Monitor the spectrum of the return signal using a spectrum analyzer to ensure that no intermodulation interference frequency components are generated;

[0021] (b) The frequency component of the comb wave signal does not exceed 20.

[0022] Furthermore, the multi-frequency sensitivity indication parameter I is calculated, and the calculation principle is as follows:

[0023] (a) In each subband, if the average power fluctuation monitored during the sensitivity test of comb wave signals at different frequency intervals does not exceed a certain required value δ, then:

[0024]

[0025] (b) In each sub-band, if the peak power fluctuation monitored during the sensitivity test of the comb wave signal at different frequency intervals does not exceed a certain required value δ, then:

[0026]

[0027] (c) In each sub-band, if the average power and peak power monitored during the sensitivity test of the comb wave signal at different frequency intervals both exceed a certain required value δ, then:

[0028] I = 0

[0029] Where P is the forward average power; S is the sensitivity threshold; and N is the number of comb wave signals in each subband.

[0030] Furthermore, the determination of the sensitivity test requirements for each sub-band based on the multi-band sensitivity indication parameter I specifically involves:

[0031] (a) If:

[0032] I = 1

[0033] In this sub-band, the continuous wave signal sensitivity test method is equivalent to the multi-frequency signal sensitivity test method, and the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method.

[0034] (b) If:

[0035] I>1

[0036] In this sub-band, electronic devices are more sensitive to continuous wave signals, so the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method.

[0037] (c) If:

[0038] I<1

[0039] In this sub-band, electronic devices are more sensitive to multi-frequency signals. In this case, the continuous wave signal sensitivity test method cannot be used to replace the multi-frequency signal sensitivity test method. It is necessary to conduct multi-frequency signal sensitivity tests according to the actual electromagnetic environment.

[0040] Thirdly, the present invention also proposes a multi-frequency sensitivity test evaluation system, comprising:

[0041] Continuous wave signal test module: Sensitivity test is conducted using continuous wave signals within the sensitivity test frequency band; the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator; during the continuous wave signal sensitivity test phase, the sensitivity threshold at different frequencies is monitored by a power meter to monitor the working status of the electronic product and determine the disturbance mode of the electronic product.

[0042] Subband division module: Divides the test frequency band into multiple subbands. The division principle is: in each subband, the electronic product has only one interference mode, and each subband does not exceed one tenth harmonic.

[0043] Comb wave signal test module: Generates a comb wave signal in each sub-band and uses the comb wave signal for sensitivity testing; for the comb wave signal, at least three signals with different frequency intervals are used for sensitivity testing;

[0044] Parameter calculation module: For each comb wave signal, the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator; the forward average power and peak power of the electronic product when it is just subjected to interference are monitored by a power meter; the multi-frequency sensitivity indication parameter I is calculated.

[0045] Sensitivity test requirement determination module: Based on the multi-band sensitivity indication parameter I, the sensitivity test requirements for each sub-band are determined; after completing the tests and evaluations for all sub-bands, the electromagnetic compatibility test requirements for the electronic device within the required frequency band are obtained. The electronic device can carry out targeted electromagnetic compatibility design according to these requirements. After the product is developed, electromagnetic compatibility test verification can also be carried out according to these requirements.

[0046] The advantages of this invention compared to the prior art are:

[0047] 1) This invention designs a system and evaluation method for testing the multi-frequency sensitivity of electronic devices. It can test and evaluate electromagnetic interference sensitive modules during the product design stage in order to determine the electromagnetic compatibility design status of the equipment and avoid over-design or under-design.

[0048] 2) The method designed in this invention can improve the pertinence of electromagnetic compatibility testing for electronic products in complex electromagnetic environments, and avoid the inability of traditional frequency domain sensitivity testing methods to verify the electromagnetic compatibility of electronic devices when there is actual multi-frequency interference.

[0049] 3) The method of the present invention provides an analysis method for the equivalence of continuous wave sensitivity and multi-frequency sensitivity based on comb wave signals. Under certain conditions, the continuous wave sensitivity test method can be used instead of the multi-frequency sensitivity test method, which can reduce the test cost.

[0050] 4) This invention designs frequency band sub-band division and back-to-back spectrum monitoring, which can reduce the impact of multi-frequency signal intermodulation interference on test results and avoid the problem that traditional multi-frequency test methods will cause additional interference risks to the electronic products under test and affect the accuracy of multi-frequency sensitivity test results.

[0051] 5) This invention adopts a targeted method for calculating multi-frequency sensitivity indication parameters in response to changes in average power and peak power during multi-frequency sensitivity tests. This method provides a more comprehensive consideration of the magnitude of the impact of multi-frequency sensitivity tests and makes the calculation of multi-frequency sensitivity indication parameters more accurate. Attached Figure Description

[0052] Figure 1 This is a block diagram of the testing system of the present invention;

[0053] Figure 2 This is a flowchart of the testing and evaluation method of the present invention. Detailed Implementation

[0054] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0055] like Figure 1 As shown, the present invention proposes a multi-frequency sensitivity testing device, comprising: a signal generator, an attenuator, a power amplifier, a directional coupler, a power meter, a spectrum analyzer, and an interference application module;

[0056] The signal generator is used to generate continuous wave signals or comb wave signals, and the signal is attenuated by the attenuator to prevent the signal power from being too high and damaging the subsequent power amplifier. The power amplifier is used to amplify the output signal power. The output signal of the power amplifier is controlled by the directional coupler. The output signal of the directional coupler is sent to the interference application module to apply interference. The output signal after interference is output to the electronic product under test.

[0057] The power meter is connected to the forward power monitoring port of the directional coupler to monitor the forward output power; the spectrum analyzer is connected to the return signal monitoring port of the directional coupler to monitor the return signal spectrum.

[0058] If conducted interference is to be applied to the electronic device under test, an injection probe is used to apply the interference to the electronic device under test; if radiated interference is to be applied to the electronic device under test, an antenna is used to apply the interference to the electronic device under test.

[0059] like Figure 2 As shown, based on the above-mentioned test apparatus, the present invention also proposes a multi-frequency sensitivity test evaluation method, comprising the following steps:

[0060] (1) Within the sensitivity test frequency band, a continuous wave signal is used for sensitivity testing; the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator.

[0061] (2) During the continuous wave signal sensitivity test phase, the sensitivity thresholds at different frequencies are monitored by a power meter to monitor the working status of the electronic product and determine the disturbance mode of the electronic product.

[0062] (3) Divide the test frequency band into multiple sub-bands. The division principle is: in each sub-band, the electronic product has only one interference mode, and each sub-band does not exceed one tenth harmonic.

[0063] (4) Generate a comb wave signal in each sub-band and use the comb wave signal for sensitivity testing; for the comb wave signal, use at least three signals with different frequency intervals for sensitivity testing.

[0064] The following principles should be met when determining the frequency interval of a comb wave signal:

[0065] (a) Monitor the spectrum of the return signal using a spectrum analyzer to ensure that no intermodulation interference frequency components are generated;

[0066] (b) The frequency component of the comb wave signal does not exceed 20.

[0067] (5) For each comb wave signal, the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator. The forward average power and peak power of the electronic product when it is just interfered with are monitored by a power meter.

[0068] (6) Calculate the multi-frequency sensitivity indication parameter I. The calculation principle is as follows:

[0069] (a) In each subband, if the average power fluctuation monitored during the sensitivity test of comb wave signals at different frequency intervals does not exceed a certain required value δ, then:

[0070]

[0071] (b) In each sub-band, if the peak power fluctuation monitored during the sensitivity test of the comb wave signal at different frequency intervals does not exceed a certain required value δ, then:

[0072]

[0073] (c) In each sub-band, if the average power and peak power monitored during the sensitivity test of the comb wave signal at different frequency intervals both exceed a certain required value δ, then:

[0074] I = 0

[0075] Where P is the forward average power; S is the sensitivity threshold; and N is the number of comb wave signals in each subband.

[0076] (7) Determine the sensitivity test requirements for each sub-band based on the multi-band sensitivity indication parameter I, specifically as follows:

[0077] (a) If:

[0078] I = 1

[0079] In this sub-band, the continuous wave signal sensitivity test method is equivalent to the multi-frequency signal sensitivity test method, and the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method.

[0080] (b) If:

[0081] I>1

[0082] In this sub-band, electronic devices are more sensitive to continuous wave signals, so the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method.

[0083] (c) If:

[0084] I<1

[0085] In this sub-band, electronic devices are more sensitive to multi-frequency signals. In this case, the continuous wave signal sensitivity test method cannot be used to replace the multi-frequency signal sensitivity test method. It is necessary to conduct multi-frequency signal sensitivity tests according to the actual electromagnetic environment.

[0086] (8) After all subbands have been tested and evaluated, the electromagnetic compatibility test requirements for the electronic equipment in the required frequency band are obtained. The electronic equipment can carry out targeted electromagnetic compatibility design according to the requirements. After the product is developed, electromagnetic compatibility test verification can also be carried out according to the requirements.

[0087] On the other hand, the present invention also proposes a multi-frequency sensitivity test evaluation system, comprising:

[0088] Continuous wave signal test module: Sensitivity test is conducted using continuous wave signals within the sensitivity test frequency band; the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator; during the continuous wave signal sensitivity test phase, the sensitivity threshold at different frequencies is monitored by a power meter to monitor the working status of the electronic product and determine the disturbance mode of the electronic product.

[0089] Subband division module: Divides the test frequency band into multiple subbands. The division principle is: in each subband, the electronic product has only one interference mode, and each subband does not exceed one tenth harmonic.

[0090] Comb wave signal test module: Generates a comb wave signal in each sub-band and uses the comb wave signal for sensitivity testing; for the comb wave signal, at least three signals with different frequency intervals are used for sensitivity testing;

[0091] Parameter calculation module: For each comb wave signal, the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator; the forward average power and peak power of the electronic product when it is just subjected to interference are monitored by a power meter; the multi-frequency sensitivity indication parameter I is calculated.

[0092] Sensitivity test requirement determination module: Based on the multi-band sensitivity indication parameter I, the sensitivity test requirements for each sub-band are determined; after completing the tests and evaluations for all sub-bands, the electromagnetic compatibility test requirements for the electronic device within the required frequency band are obtained. The electronic device can carry out targeted electromagnetic compatibility design according to these requirements. After the product is developed, electromagnetic compatibility test verification can also be carried out according to these requirements.

[0093] Example:

[0094] Based on the electromagnetic compatibility (EMC) test results of an inherited equipment system, an electronic device exhibits multi-frequency interference on its power lines within the 1–30 MHz frequency range. This electronic device needs to determine the EMC design of its power supply module and whether to use a continuous wave signal sensitivity test or a multi-frequency signal sensitivity test for the common-mode conducted susceptibility of the power lines. Therefore, during the design phase, a multi-frequency sensitivity test evaluation of the power supply module is conducted.

[0095] like Figure 1As shown, the testing system of the present invention comprises seven parts:

[0096] The first part is a signal generator, which includes a radio frequency signal source that can generate continuous wave signals and an arbitrary waveform generator that can generate comb wave signals.

[0097] The second part is a signal attenuator with an adjustable attenuation value of 0-100dB. This signal attenuator is used to protect the test system from damage to the subsequent power amplifier due to excessive signal power. It is also used to adjust the output power of the test system.

[0098] The third part is a power amplifier used to amplify the output signal power.

[0099] The fourth part is a directional coupler with one input port and three output ports, used to control the direction of the output signal.

[0100] The fifth part is a power meter used to monitor the forward output power.

[0101] The sixth part is a spectrum analyzer used to monitor the spectrum of the returning signal.

[0102] The seventh part is the interference application module, used to apply interference to the electronic product under test. For conducted interference, an injection probe is used; for radiated interference, an antenna is used. In this embodiment, a conducted sensitivity test is being performed, so this module is an injection probe.

[0103] The connections between the seven parts are as follows:

[0104] The signal generator output is connected to the attenuator input. The attenuator output is connected to the power amplifier input. The power amplifier output is connected to the directional coupler input. The directional coupler's main power output is injected into the probe; of the other two output ports, the forward power monitoring port is connected to a power meter, and the backward signal monitoring port is connected to a spectrum analyzer.

[0105] like Figure 2 As shown, the steps of the testing and evaluation methods are as follows:

[0106] 1. The signal generator uses an RF signal source capable of generating continuous wave signals. Sensitivity testing is conducted using continuous wave signals within the sensitivity test frequency band of 1–30 MHz. The test level is adjusted by modifying the signal generator's output power and the attenuation level of the attenuator.

[0107] 2. During the continuous wave signal sensitivity testing phase, a power meter is used to monitor the sensitivity thresholds at different frequencies to determine the disturbance mode of the electronic product. In this embodiment, the power module under test exhibits a fault mode where the output voltage fluctuation exceeds the required value in the 1–30 MHz range. Power meter monitoring shows that the sensitivity threshold of the power module is 16 dBm in the 1–7 MHz range and 7 dBm in the 7–30 MHz range.

[0108] 3. Divide the test frequency band into multiple sub-bands, based on the following principles:

[0109] (a) In each subband, the electronic product has only one harassment mode.

[0110] (b) Each subband shall not exceed one tenth harmonic.

[0111] In this embodiment, since there is only one disturbance mode, and each sub-band is guaranteed to be no more than one tenth harmonic, and considering the change in sensitivity threshold, the test frequency band 1-30MHz is divided into two sub-bands: 1-7MHz and 7-30MHz.

[0112] 4. Replace the signal generator with an arbitrary waveform generator capable of producing comb wave signals. Generate comb waves in each sub-band and use these comb wave signals for sensitivity testing. For the comb wave signals, use at least three signals with different frequency intervals for sensitivity testing. The determination of the frequency intervals for the comb wave signals should meet the following principles:

[0113] (a) Monitor the spectrum of the return signal using a spectrum analyzer to ensure that no intermodulation interference frequency components are generated.

[0114] (b) The frequency component of the comb wave signal does not exceed 20.

[0115] In this embodiment, sub-band 1 generates three comb wave signals at frequency intervals of 0.5MHz, 0.6MHz, and 1MHz, respectively; sub-band 2 generates three comb wave signals at frequency intervals of 2.3MHz, 2.875MHz, and 4.6MHz, respectively.

[0116] 5. For each comb wave, adjust the test magnitude by adjusting the output power of the signal generator and the attenuation level of the attenuator. Use a power meter to monitor the forward average power and peak power of the electronic product when it is just subjected to interference.

[0117] 6. Calculate the multi-frequency sensitivity indication parameter I. The calculation principle is as follows:

[0118] (a) In each subband, if the average power fluctuation monitored during the sensitivity test of comb wave signals at different frequency intervals does not exceed a certain required value δ, then:

[0119]

[0120] (b) In each sub-band, if the peak power fluctuation monitored during the sensitivity test of the comb wave signal at different frequency intervals does not exceed a certain required value δ, then:

[0121]

[0122] (c) In each sub-band, if the average power and peak power monitored during the sensitivity test of the comb wave signal at different frequency intervals both exceed a certain required value δ, then:

[0123] I = 0

[0124] Where P is the forward average power; S is the sensitivity threshold; and N is the number of comb signals in each subband.

[0125] In this embodiment, the monitoring signal power is shown in the table below.

[0126]

[0127]

[0128] The power fluctuation limit δ = 1 dB is set. For sub-band 1, the average power fluctuation value does not exceed 1 dB, and the calculated multi-frequency sensitivity indication parameters I for the three comb waves are 5.25, 4.20, and 2.37, respectively. For sub-band 2, the peak power fluctuation value does not exceed 1 dB, and the calculated multi-frequency sensitivity indication parameters I for the three comb waves are 0.99, 0.95, and 0.64, respectively.

[0129] 7. Determine the sensitivity test requirements for each sub-band based on the multi-band sensitivity indication parameters, specifically as follows:

[0130] (a) If:

[0131] I = 1

[0132] In this sub-band, the continuous wave signal sensitivity test method is equivalent to the multi-frequency signal sensitivity test method, and the continuous wave signal sensitivity test method can replace the multi-frequency signal sensitivity test method.

[0133] (b) If:

[0134] I>1

[0135] In this sub-band, electronic devices are more sensitive to continuous wave signals, and the continuous wave signal sensitivity test method can be used instead of the multi-frequency signal sensitivity test method. Note that the electromagnetic compatibility test conditions for electronic devices in this case are more severe than the actual electromagnetic environment.

[0136] (c) If:

[0137] I<1

[0138] In this sub-band, electronic devices are more sensitive to multi-frequency signals. In this case, the continuous wave signal sensitivity test method cannot be used to replace the multi-frequency signal sensitivity test method. It is necessary to conduct multi-frequency signal sensitivity tests according to the actual electromagnetic environment.

[0139] In this embodiment, since I > 1 for sub-band 1, the continuous wave signal sensitivity test method can be used instead of the multi-frequency signal sensitivity test method. Since I < 1 for sub-band 2, the continuous wave signal sensitivity test method cannot be used instead of the multi-frequency signal sensitivity test method, and a multi-frequency signal sensitivity test needs to be performed based on the actual electromagnetic environment.

[0140] 8. Based on the combined test and evaluation results of each subband, it is concluded that during the design and testing phases of the power module of this electronic device, electromagnetic compatibility design should be performed according to continuous wave interference for the 1–7MHz range, and according to multi-frequency interference for the 7–30MHz range. After the electronic device is completed, during the power cable conducted sensitivity test, sensitivity testing should be performed according to continuous wave interference for the 1–7MHz range, and according to multi-frequency interference for the 7–30MHz range.

[0141] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A multi-frequency sensitivity testing device, characterized in that, include: Signal generator, attenuator, power amplifier, directional coupler, power meter, spectrum analyzer, and interference application module; The signal generator is used to generate continuous wave signals or comb wave signals, and the signal is attenuated by the attenuator to prevent the signal power from being too high and damaging the subsequent power amplifier. The power amplifier is used to amplify the output signal power. The output signal of the power amplifier is controlled by the directional coupler. The output signal of the directional coupler is sent to the interference application module to apply interference. The output signal after interference is output to the electronic product under test. The power meter is connected to the forward power monitoring port of the directional coupler to monitor the forward output power; the spectrum analyzer is connected to the return signal monitoring port of the directional coupler to monitor the return signal spectrum.

2. The multi-frequency sensitivity testing device according to claim 1, characterized in that: If conducted interference is to be applied to the electronic device under test, an injection probe is used to apply the interference to the electronic device under test; if radiated interference is to be applied to the electronic device under test, an antenna is used to apply the interference to the electronic device under test.

3. A method for evaluating multi-frequency sensitivity tests implemented by the multi-frequency sensitivity test evaluation system according to claim 1, characterized in that, include: (1) Within the sensitivity test frequency band, a continuous wave signal is used for sensitivity testing; the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator. (2) During the continuous wave signal sensitivity test, the sensitivity thresholds at different frequencies are monitored by a power meter to monitor the working status of the electronic product and determine the disturbance mode of the electronic product. (3) Divide the test frequency band into multiple sub-bands. The division principle is: in each sub-band, the electronic product has only one interference mode, and each sub-band does not exceed one tenth harmonic. (4) Generate a comb wave signal in each sub-band and use the comb wave signal for sensitivity testing; for the comb wave signal, use at least three signals with different frequency intervals for sensitivity testing. (5) For each comb wave signal, the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator. The forward average power and peak power of the electronic product when it is just interfered with are monitored by a power meter. (6) Calculate the multi-frequency sensitivity indication parameter I; (7) Determine the sensitivity test requirements for each sub-band based on the multi-band sensitivity indication parameter I; (8) After all subbands have been tested and evaluated, the electromagnetic compatibility test requirements for the electronic equipment in the required frequency band are obtained. The electronic equipment can carry out targeted electromagnetic compatibility design according to the requirements. After the product is developed, electromagnetic compatibility test verification can also be carried out according to the requirements.

4. The multi-frequency sensitivity test evaluation method according to claim 3, characterized in that: The following principles should be met when determining the frequency interval of a comb wave signal: (a) Monitor the spectrum of the return signal using a spectrum analyzer to ensure that no intermodulation interference frequency components are generated; (b) The frequency component of the comb wave signal does not exceed 20.

5. The multi-frequency sensitivity test evaluation method according to claim 3, characterized in that: The calculation principle for the multi-frequency sensitivity indication parameter I is as follows: (a) In each subband, if the average power fluctuation monitored during the sensitivity test of comb wave signals at different frequency intervals does not exceed a certain required value δ, then: (b) In each sub-band, if the peak power fluctuation monitored during the sensitivity test of the comb wave signal at different frequency intervals does not exceed a certain required value δ, then: (c) In each sub-band, if the average power and peak power monitored during the sensitivity test of the comb wave signal at different frequency intervals both exceed a certain required value δ, then: I＝0 Where P is the forward average power; S is the sensitivity threshold; and N is the number of comb signals in each subband.

6. The multi-frequency sensitivity test evaluation method according to claim 3, characterized in that: The sensitivity test requirements for each sub-band are determined based on the multi-band sensitivity indication parameter I, specifically as follows: (a) If: I＝1 In this sub-band, the continuous wave signal sensitivity test method is equivalent to the multi-frequency signal sensitivity test method, and the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method. (b) If: I＞1 In this sub-band, electronic devices are more sensitive to continuous wave signals, so the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method. (c) If: I＜1 In this sub-band, electronic devices are more sensitive to multi-frequency signals. In this case, the continuous wave signal sensitivity test method cannot be used to replace the multi-frequency signal sensitivity test method. It is necessary to conduct multi-frequency signal sensitivity tests according to the actual electromagnetic environment.

7. A multi-frequency sensitivity test evaluation system, characterized in that, include: Continuous wave signal test module: Sensitivity test is conducted using continuous wave signals within the sensitivity test frequency band; the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator; during the continuous wave signal sensitivity test phase, the sensitivity threshold at different frequencies is monitored by a power meter to monitor the working status of the electronic product and determine the disturbance mode of the electronic product. Subband division module: Divides the test frequency band into multiple subbands. The division principle is: in each subband, the electronic product has only one interference mode, and each subband does not exceed one tenth harmonic. Comb wave signal test module: Generates a comb wave signal in each sub-band and uses the comb wave signal for sensitivity testing; for the comb wave signal, at least three signals with different frequency intervals are used for sensitivity testing; Parameter calculation module: For each comb wave signal, the test level is adjusted by adjusting the output power of the signal generator and the attenuation level of the attenuator; the forward average power and peak power of the electronic product when it is just subjected to interference are monitored by a power meter; the multi-frequency sensitivity indication parameter I is calculated. Sensitivity test requirement determination module: Based on the multi-band sensitivity indication parameter I, the sensitivity test requirements for each sub-band are determined; after completing the tests and evaluations for all sub-bands, the electromagnetic compatibility test requirements for the electronic device within the required frequency band are obtained. The electronic device can carry out targeted electromagnetic compatibility design according to these requirements. After the product is developed, electromagnetic compatibility test verification can also be carried out according to these requirements.

8. The system according to claim 7, characterized in that: The following principles should be met when determining the frequency interval of a comb wave signal: (a) Monitor the spectrum of the return signal using a spectrum analyzer to ensure that no intermodulation interference frequency components are generated; (b) The frequency component of the comb wave signal does not exceed 20.

9. The system according to claim 7, characterized in that: The calculation principle for the multi-frequency sensitivity indication parameter I is as follows: (a) In each subband, if the average power fluctuation monitored during the sensitivity test of comb wave signals at different frequency intervals does not exceed a certain required value δ, then: (b) In each sub-band, if the peak power fluctuation monitored during the sensitivity test of the comb wave signal at different frequency intervals does not exceed a certain required value δ, then: (c) In each sub-band, if the average power and peak power monitored during the sensitivity test of the comb wave signal at different frequency intervals both exceed a certain required value δ, then: I＝0 Where P is the forward average power; S is the sensitivity threshold; and N is the number of comb signals in each subband.

10. The system according to claim 7, characterized in that: The sensitivity test requirements for each sub-band are determined based on the multi-band sensitivity indication parameter I, specifically as follows: (a) If: I＝1 In this sub-band, the continuous wave signal sensitivity test method is equivalent to the multi-frequency signal sensitivity test method, and the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method. (b) If: I＞1 In this sub-band, electronic devices are more sensitive to continuous wave signals, so the continuous wave signal sensitivity test method is used instead of the multi-frequency signal sensitivity test method. (c) If: I＜1 In this sub-band, electronic devices are more sensitive to multi-frequency signals. In this case, the continuous wave signal sensitivity test method cannot be used to replace the multi-frequency signal sensitivity test method. It is necessary to conduct multi-frequency signal sensitivity tests according to the actual electromagnetic environment.

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