A high-power microwave stress testing system and method

Abstract

The present invention relates to the field of stress testing technology, and discloses a stress testing system and method for high-power microwaves. The system includes a test control module, and a stress test module, a signal path module, and a parameter characterization module connected to the test control module. The signal path module is connected to the stress test module and the parameter characterization module, respectively. The stress test module is used to generate a pulse signal of a high-power microwave; the signal path module is used to conduct the corresponding signal channel; the parameter characterization module is used to generate an analog working signal and perform signal characterization on the device to be tested. The present invention meets the test requirements of narrow-spectrum high-power microwave pulse injection under different conditions by synchronously testing the stress test and parameter characterization of narrow-spectrum high-power microwave pulses. By introducing the de-embedding concept, the accuracy of the stress test results is improved, and data support is provided for the device design of reverse guidance products and the reinforcement and protection of key sensitive parts of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of stress testing, and in particular to a high-power microwave stress testing system and method. Background Art

[0002] High-power microwaves typically refer to strong electromagnetic pulses with frequencies between 300MHz and 300GHz, peak powers exceeding 100MW, and average powers exceeding 1MW. This form of high-energy radiation can be used to target sensitive components within communications and reconnaissance equipment. High-power microwaves with carrier frequencies, or narrow-spectrum high-power microwaves, are commonly used in air defense, anti-missile defense, and counter-reconnaissance. These pulses have pulse widths ranging from tens of nanoseconds to tens of microseconds, and a spectrum ranging from tens of megahertz to hundreds of megahertz. Compared to other strong electromagnetic pulses, they can release enormous amounts of energy in a very short period of time, with a more concentrated energy density.

[0003] The degradation of electronic devices subjected to narrow-spectrum, high-power pulses is increasingly becoming a research focus in the field of high-energy radiation. This process can provide indirect guidance for device design and the reinforcement and protection of key sensitive parts of the system, which is of great significance for improving product reliability. However, the current conventional stress testing method for high-power microwaves requires manual control of stress input throughout the entire process. The device effect, monitoring, and characterization experimental platforms are separated, and the position of the test sample needs to be constantly adjusted. This not only consumes a lot of time and labor costs, but also fails to meet the product test accuracy requirements. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a high-power microwave stress testing system and method, which can solve the problems of cumbersome operation and low testing accuracy in the existing technology, and achieve the technical effect of simplifying the testing process, improving testing efficiency and testing accuracy.

[0005] In a first aspect, the present invention provides a high-power microwave stress testing system, the system comprising:

[0006] A test control module, and a stress test module, a signal path module and a parameter characterization module connected to the test control module, wherein the signal path module is connected to the stress test module and the parameter characterization module respectively;

[0007] The stress test module is used to generate a high-power microwave pulse signal according to the first control instruction from the test control module, and input the pulse signal into the signal path module;

[0008] The signal path module is used to conduct the corresponding signal channel according to the second control instruction from the test control module to achieve time-division multiplexing of the signal channel, wherein the signal channel includes a stress test signal channel and an analog test signal channel;

[0009] The signal path module includes a first bidirectional coupler, a second bidirectional coupler, a third bidirectional coupler, a first radio frequency switch, a second radio frequency switch, and a single-chip microcomputer. The first bidirectional coupler is connected to the stress test module and the first radio frequency switch, respectively. The second bidirectional coupler is connected to the third bidirectional coupler. A device under test is connected between the first bidirectional coupler and the second bidirectional coupler. The first radio frequency switch and the second radio frequency switch are both connected to the parameter characterization module and the single-chip microcomputer. The single-chip microcomputer is connected to the test control module.

[0010] The stress test signal channel is composed of the first bidirectional coupler, the second bidirectional coupler, and the third bidirectional coupler; the analog test signal channel is composed of the first RF switch, the second RF switch, the first bidirectional coupler, and the second bidirectional coupler; and the conduction of the analog test signal channel is controlled by the selection signal generated by the single-chip microcomputer according to the second control instruction;

[0011] The parameter characterization module is configured to generate a simulated operating signal of the device under test according to a third control instruction from the test control module, input the simulated operating signal to the first radio frequency switch and the second radio frequency switch respectively, perform signal characterization on the device under test, and input the obtained characterization signal to the test control module;

[0012] The test control module is used to generate control instructions for the stress test module, the signal path module and the parameter characterization module, the control instructions including a first control instruction, a second control instruction and a third control instruction, and perform failure point determination on the received characterization signal to realize stress testing of high-power microwaves.

[0013] Furthermore, the stress test module includes a function generator, a signal source, a power amplifier and a circulator connected in sequence, the function generator and the signal source are both connected to the test control module, and the circulator is connected to the first bidirectional coupler.

[0014] Furthermore, the device under test is an active radio frequency front-end device;

[0015] The parameter characterization module includes a vector network analyzer and a DC power supply, the vector network analyzer is respectively connected to the first RF switch, the second RF switch, the DC power supply and the test control module, and the DC power supply is respectively connected to the first RF switch, the second RF switch, the device under test and the test control module;

[0016] The vector network analyzer is configured to generate an analog operating signal of the device under test according to the third control instruction, and input the analog operating signal to the first radio frequency switch and the second radio frequency switch respectively, and perform signal characterization on the device under test, and input the obtained characterization signal to the test control module;

[0017] The DC power supply is used to provide an operating voltage for the first radio frequency switch, the second radio frequency switch, and the device under test.

[0018] Furthermore, the signal path module further includes a first power divider and a second power divider, and the parameter characterization module further includes a power meter and an oscilloscope;

[0019] The first power splitter is connected to the first bidirectional coupler, the power meter and the oscilloscope respectively, and the second power splitter is connected to the third bidirectional coupler, the power meter and the oscilloscope respectively;

[0020] The first power divider is used to divide the pulse signal received from the first bidirectional coupler into two equal parts, and input the two equally divided signals into the power meter and the oscilloscope respectively;

[0021] The second power divider is used to divide the pulse signal received from the third bidirectional coupler into two equal parts, and input the two equally divided signals into the power meter and the oscilloscope respectively;

[0022] The power meter is used to monitor the power of one signal output by the first power splitter and one signal output by the second power splitter respectively;

[0023] The oscilloscope is used to perform time domain waveform monitoring on the other signal output by the first power divider and the other signal output by the second power divider respectively.

[0024] In a second aspect, the present invention provides a high-power microwave stress testing method, which is applied to the system described above and comprises:

[0025] According to the failure threshold to be tested, select the corresponding stress test type and set the corresponding test parameters. The failure threshold includes the stress cumulative damage failure threshold and the thermal cumulative damage failure threshold. The stress test type includes single pulse stress test and multi-pulse stress test. The test parameters include the input parameter range and input parameter step size.

[0026] According to the stress test type, the input parameters of the pulse signal are set according to the corresponding input parameter range, and the pulse signal is input into the device under test to perform a pulse stress test to determine whether a failure point exists. If not, the input parameters of the pulse signal are updated according to the input parameter step size, and the pulse signal is input into the device under test to perform the next pulse stress test until an iteration stop condition is met, wherein the iteration stop condition includes the existence of a failure point or the input parameter exceeds the input parameter range;

[0027] In response to the existence of a failure point, a corresponding failure threshold is determined according to the failure point.

[0028] Furthermore, the step of inputting a pulse signal into the device under test to perform a pulse stress test and determining whether a failure point exists includes:

[0029] Input a pulse signal into the device under test through the stress test signal channel to perform a pulse stress test until the number of tests reaches a preset test threshold and the signal input is stopped;

[0030] Generate an analog working signal, and input the analog working signal into the device under test through an analog test signal channel to perform parameter characterization to obtain a first scattering parameter of the device under test;

[0031] It is determined whether a failure point exists based on the first scattering parameter. If not, the next pulse stress test and parameter characterization are performed until the failure point is found or the number of characterizations reaches a preset characterization threshold.

[0032] Furthermore, the step of determining whether a failure point exists according to the first scattering parameter includes:

[0033] De-embedding the first scattering parameter according to a preset second scattering parameter, where the second scattering parameter is obtained by replacing the device under test with a background microstrip line, generating a simulated working signal, and inputting the background microstrip line through a simulated test signal channel for parameter characterization;

[0034] A stability coefficient is calculated according to the de-embedded first scattering parameter, and whether a failure point exists is determined according to the stability coefficient.

[0035] Furthermore, the first scattering parameter of de-embedding is expressed by the following formula:

[0036] S ij (f) = S ij-DUT (f)-S ij-ML (f) i = 1, 2; j = 1, 2;

[0037] Where S ij (f) represents the first scattering parameter of de-embedding at frequency f, S ij-DUT(f) represents the first scattering parameter at frequency f, S ij-ML (f) represents the second scattering parameter at frequency f;

[0038] The stability coefficient is expressed by the following formula:

[0039]

[0040] Where K(f) represents the stability coefficient at frequency f.

[0041] Furthermore, the step of setting the input parameters of the pulse signal according to the corresponding input parameter range based on the stress test type, inputting the pulse signal into the device under test, performing the pulse stress test, determining whether a failure point exists, and if not, updating the input parameters of the pulse signal according to the input parameter step size, inputting the pulse signal into the device under test, and performing the next pulse stress test until the iteration stop condition is reached includes:

[0042] In response to the stress test type being a single pulse stress test, the input parameter range includes a start power and an end power, and the input parameter step size includes a power step size;

[0043] With the starting power as the input power of the device under test, a single pulse signal is input into the device under test to perform a pulse stress test to determine whether there is a failure point;

[0044] If it does not exist, the input power is updated with the power step as the increment, and according to the updated input power, a single pulse signal is input into the device under test for the next pulse stress test until the stress accumulation damage failure threshold is found, or the updated input power is greater than the termination power.

[0045] Furthermore, the step of setting the input parameters of the pulse signal according to the corresponding input parameter range according to the stress test type, inputting the pulse signal into the device under test, performing a pulse stress test, determining whether a failure point exists, and if not, updating the input parameters of the pulse signal according to the input parameter step size, and inputting the pulse signal into the device under test, performing the next pulse stress test, until the iteration stop condition is reached includes:

[0046] In response to the stress test type being a multi-pulse stress test, the input parameter range includes a start power, an end power, a start pulse number, and an end pulse number, and the input parameter step size includes a power step size and a pulse number step size;

[0047] Taking the starting power as the input power of the device under test and the number of starting pulses as the number of pulse inputs, a multi-pulse signal is input to the device under test to perform a pulse stress test to determine whether there is a failure point.

[0048] If it does not exist, the number of pulse inputs is updated with the pulse number step as the increment, and according to the updated number of pulse inputs, the multi-pulse signal is input to the device under test for the next pulse stress test until the thermal cumulative damage failure threshold is found, or the updated number of pulse inputs is greater than the number of termination pulses;

[0049] When the updated number of pulse inputs is greater than the number of ending pulses, the input power is updated with the power step length as the increment, and the number of pulse inputs is updated to the number of starting pulses;

[0050] According to the updated input power and the updated number of pulse inputs, the multi-pulse signal is input to the device under test for the next pulse stress test until the thermal accumulation damage failure threshold is obtained or the updated input power is greater than the termination power.

[0051] The present invention provides a high-power microwave stress testing system and method. By simultaneously testing stress and parameter characterization of narrow-spectrum high-power microwave pulses, the present invention can meet the testing requirements of narrow-spectrum high-power microwave pulse injection under different conditions. By introducing the concept of de-embedding, the accuracy of stress test results can be improved, providing data support for reverse guidance of product device design and reinforcement and protection of key sensitive parts of the system, further improving product reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 1 is a schematic structural diagram of a high-power microwave stress testing system according to an embodiment of the present invention;

[0053] Figure 2 is a schematic diagram of three basic high-power microwave stresses in an embodiment of the present invention;

[0054] Figure 3 1 is a schematic structural diagram of a conventional high-power microwave injection test system according to an embodiment of the present invention;

[0055] Figure 4 Another structural diagram of a high-power microwave stress testing system according to an embodiment of the present invention;

[0056] Figure 5 1 is a flow chart of a stress testing method for high-power microwaves according to an embodiment of the present invention;

[0057] Figure 6 Schematic diagram of the basic process of pulse stress testing in an embodiment of the present invention;

[0058] Figure 7 yes Figure 1 Schematic diagram of the process of single pulse stress test;

[0059] Figure 8 yes Figure 1Schematic diagram of the process of multi-pulse stress testing. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0061] See also Figure 1 A high-power microwave stress testing system proposed in the first embodiment of the present invention includes a test control module 10, and a stress test module 20, a signal path module 30 and a parameter characterization module 40 connected to the test control module 10. The signal path module 30 is connected to the stress test module 20 and the parameter characterization module 40 respectively.

[0062] Before describing the stress testing system for high-power microwaves provided by the present invention, the existing stress testing methods are briefly described. The damage effects of narrow-spectrum high-power microwave pulses on devices are mainly divided into three main types, including long pulse effect, single pulse effect and continuous pulse effect. The schematic diagrams of these three stresses are shown in FIG. Figure 2 As shown, Figure 2 (a) is a schematic diagram of a long pulse. Figure 2 (b) is a schematic diagram of a single pulse. Figure 2 (c) is a schematic diagram of multiple pulses. Specifically, a long pulse refers to a pulse with a pulse length on the order of s, typically ranging from several seconds to tens of seconds, with a duty cycle η≈1. A single pulse refers to a pulse with a pulse length on the order of tens of nanoseconds, with a duty cycle η<<1. Multiple pulses are a series of pulse signals with a certain duty cycle, typically with a pulse width on the order of tens of nanoseconds. Regarding the three effects described above, long pulses and single pulses can be categorized as the first category, while multiple pulse input effects can be classified as the second.

[0063] The input test of existing high power microwave two-port devices is as follows: Figure 3As shown in (a) (typical frequency is 300MHz-18GHz). For traditional high-power microwave testing, the high-power microwave pulse source signal is amplified by a solid-state power amplifier and input into the device under test; after a certain attenuation at the incident end of the coupler, the waveform and power of the high-power microwave stress are monitored using an oscilloscope, and after adding an attenuator to the output end of the coupler, the spectrum information of the output signal is observed using a spectrum analyzer. By analyzing the spectrum distribution, the status information of the device under test is obtained. After the above high-power microwave stress test process, the electrical parameter characterization of the device after stress requires the device to be removed and placed at both ends of the network parameter analyzer, such as Figure 3 As shown in Figure (b), only by using a DC power supply can the changes in the scattering parameters (S parameters) of the two-port device be characterized. Therefore, traditional testing methods require manual control of stress input throughout the entire process. The device effect, monitoring, and characterization experimental platforms are separated, and the position of the sample under test must be constantly adjusted, consuming a large amount of time and labor costs. Based on this, the present invention provides a new test system and test method that can achieve faster and more efficient high-power microwave stress testing and device parameter characterization.

[0064] like Figure 1 As shown, the stress testing system provided by the present invention is divided into four modules, wherein the stress test module 20 is used to generate a high-power microwave pulse signal according to the first control instruction from the test control module 10 and input it into the signal path module 30; the signal path module 30 is used to conduct the corresponding signal channel according to the second control instruction from the test control module 10 to achieve time-division multiplexing of the signal channel; the parameter characterization module 40 is used to generate an analog working signal of the device under test according to the third control instruction from the test control module 10 and perform signal characterization on the device under test; the test control module 10 is used to generate control instructions for each module and perform failure point determination on the characterization signal from the parameter characterization module 40 to achieve stress testing of high-power microwaves. The structure and function of each module are described below.

[0065] Please refer to 4. In this embodiment, the stress test module 20 includes a function generator, a signal source, a power amplifier and a circulator connected in sequence, wherein the function generator and the signal source are both connected to the test control module 10 and controlled by it. Specifically, the function generator is used to generate a pulse signal with a certain repetition frequency, adjustable rising and falling edge time and duty cycle, and the number of pulses can be controlled according to actual needs; the signal source can generate a high-frequency continuous sine wave signal with an extremely narrow spectrum distribution range, which is modulated with the repetition frequency signal of the function generator to output the narrow-spectrum high-power microwave pulse signal required for the test; the power amplifier is used to proportionally amplify the narrow-spectrum high-power microwave pulse generated by the modulation; the circulator has the characteristics of low insertion loss and high reverse isolation, which is used to prevent the reflected power from reversely coupling into the output end of the power amplifier and causing irreversible damage to it. In addition, an absorption load is also provided on the circulator, which is used to absorb the reflected power and convert it into heat energy dissipation.

[0066] The signal path module 30 includes a first bidirectional coupler, a second bidirectional coupler, a third bidirectional coupler, a first RF switch, a second RF switch, and a single-chip microcomputer. The first bidirectional coupler has an input connected to the output of the circulator, a coupling connected to the input of the first RF switch, and an output connected to the input of the device under test. The second bidirectional coupler has an input connected to the output of the device under test, a coupling connected to the second RF switch, an isolation connected to a 50Ω matched load, and an output connected to the input of the third bidirectional coupler. The isolation and output of the third bidirectional coupler are each connected to a 50Ω matched load. The first channels of the first RF switch and the second RF switch are both connected to the parameter characterization module 40, and their second channels are both connected to a 50Ω matching load. Specifically, the first channels are both connected to the vector network analyzer in the parameter characterization module 40, and the channels of the two RF switches are controlled by a single-chip microcomputer; the single-chip microcomputer can generate low-level and high-level signals sufficient to turn off or on the RF switch, and control the on and off of the RF switch. When the RF switch pin receives a high-level signal higher than 3.3V, the first channel of the RF switch is turned on; when receiving a low-level signal lower than 3.3V, the second channel of the RF switch is turned on.

[0067] According to the above connection relationship, the signal path module 30 in this embodiment actually includes two signal channels, namely a stress test signal channel and an analog test signal channel, wherein the stress test signal channel is composed of a first bidirectional coupler, a second bidirectional coupler, and a third bidirectional coupler, and is used to input the pulse signal generated by the stress test module 20 into the device under test to realize pulse stress testing, and the analog test signal channel is composed of the first RF switch, the second RF switch, the first bidirectional coupler and the second bidirectional coupler, and is used to input the analog working signal generated by the parameter characterization module 40 into the device under test to realize S parameter characterization.

[0068] Since active devices are more vulnerable to the directed energy attacks of high-power microwaves than passive devices, the study of active devices is more representative. Therefore, in this embodiment, the device to be tested is a two-port active RF front-end device, typical devices of which are a low-noise amplifier and a power amplifier. At the same time, in order to avoid crossing and entanglement between wires to the greatest extent, thereby reducing the signal interference and noise signals introduced by mutual inductance and crosstalk of wires at high frequencies, the signal path module 30 is integrated in the test box, and there are connection interfaces and identifications of other modules on the outside of the test box to ensure the correctness of the line connection.

[0069] In this embodiment, the parameter characterization module 40 includes a vector network analyzer and a DC power supply. The vector network analyzer is connected to the first RF switch, the second RF switch, the DC power supply, and the test control module, respectively. The DC power supply is connected to the first RF switch, the second RF switch, the device under test, and the test control module, respectively. The vector network analyzer is used to generate analog operating signals to characterize the S parameters of the device under test, thereby understanding changes in device performance indicators before and after testing. The DC power supply is used to provide operating voltage to the first RF switch, the second RF switch, and the device under test, and can also monitor the operating current in real time.

[0070] The test control module 10 can be understood as a computer control system, which is used to control the instruments in each module. The test control module 10 establishes communication with the function generator, signal source, DC power supply and vector network analyzer through the network port, and exchanges information with the microcontroller through the UART serial port; the test control module 10 can also store and process the data collected by each instrument to realize high-power microwave stress testing. The specific processing process will be described in detail in the subsequent methods.

[0071] In a preferred embodiment, the signal path module 30 also includes a first power divider and a second power divider, and the parameter characterization module 40 also includes a power meter and an oscilloscope, wherein the first power divider is respectively connected to the first bidirectional coupler, the power meter and the oscilloscope, and the second power divider is respectively connected to the third bidirectional coupler, the power meter and the oscilloscope. Specifically, the first power divider is connected to the isolation end of the first bidirectional coupler, and the second power divider is connected to the coupling end of the third bidirectional coupler. The first power divider and the second power divider respectively divide the received signal into two signal channels, one of which is observed by the oscilloscope for time domain waveform, and the other is tested by the power meter for power size. By monitoring the waveform and power, it is determined whether the settings of the stress test system are correct, thereby ensuring the accurate execution of the stress test.

[0072] See also Figure 5 Based on the above stress testing system, the present invention provides a high-power microwave stress testing method, including steps S10 to S30:

[0073] Step S10: Select a corresponding stress test type based on the failure threshold to be tested, and set corresponding test parameters. The failure threshold includes a stress cumulative damage failure threshold and a thermal cumulative damage failure threshold. The stress test types include a single-pulse stress test and a multi-pulse stress test. The test parameters include an input parameter range and an input parameter step size.

[0074] Step S20: setting the input parameters of the pulse signal according to the corresponding input parameter range based on the stress test type, inputting the pulse signal into the device under test, performing a pulse stress test, and determining whether a failure point exists. If not, updating the input parameters of the pulse signal based on the input parameter step size, and inputting the pulse signal into the device under test for the next pulse stress test until an iteration stop condition is met, wherein the iteration stop condition includes the existence of a failure point or the input parameter exceeds the input parameter range.

[0075] Step S30: In response to the existence of a failure point, determining a corresponding failure threshold according to the failure point.

[0076] In this embodiment, according to the above description, high-power microwave pulses are divided into three main types, and long pulses and single pulses can be classified into one category, and multi-pulses can be classified into another category. Based on the two different pulse types, in this embodiment, the stress test type is divided into single-pulse stress test and multi-pulse stress test. The single-pulse stress test can capture the failure threshold of the device caused by stress accumulation damage caused by a single pulse stress, and the multi-pulse stress test can capture the failure threshold of the device caused by thermal accumulation damage caused by multiple pulses.

[0077] The difference between the two tests lies in the different input parameters of the pulse signal input to the device under test and the steps of iterative testing based on the input parameters. However, the similarity between the two lies in the same steps of inputting the pulse signal to the device under test, performing the pulse stress test, and determining whether a failure point exists during the test process. That is, both use the basic process of pulse stress testing. In a preferred embodiment, the specific steps of the basic process of pulse stress testing include:

[0078] Input a pulse signal into the device under test through the stress test signal channel to perform a pulse stress test until the number of tests reaches a preset test threshold and the signal input is stopped;

[0079] Generate an analog working signal, and input the analog working signal into the device under test through an analog test signal channel to perform parameter characterization to obtain a first scattering parameter of the device under test;

[0080] It is determined whether a failure point exists based on the first scattering parameter. If not, the next pulse stress test and parameter characterization are performed until the failure point is found or the number of characterizations reaches a preset characterization threshold.

[0081] In this embodiment, based on the above system, it can be seen that two modes of testing can be implemented through the test system, namely stress test mode and characterization test mode, such as Figure 6 As shown, stress test mode involves turning on the second channels of the first and second RF switches, conducting the stress test signal channel, and generating a pulse signal from the function generator, which modulates the sine wave generated by the signal source. The modulated, narrow-spectrum, high-power pulse signal is amplified by the power amplifier and then passes through the first bidirectional coupler's input port. After interacting with the device under test, the signal enters the second and third bidirectional couplers, respectively.

[0082] In addition, preferably, the system can be judged to be normal by whether the oscilloscope and power meter are triggered. If the oscilloscope and power meter do not capture the relevant information of the current pulse, it means that the trigger threshold of the oscilloscope or power meter is set incorrectly, the experiment cannot continue, the program is terminated, and the correct parameters need to be reset. If the oscilloscope and power meter are both triggered, the experiment proceeds normally, and the DC power supply current value and the oscilloscope and power meter trigger data are stored for subsequent data analysis.

[0083] The characterization test mode refers to turning on the first channels of the first and second RF switches and conducting the analog test signal channels. At this time, the high-power microwave stress test ends, and the narrow-spectrum high-power microwave pulse signal is no longer generated by the signal source. The analog working signal emitted by the vector network analyzer is coupled to the device port through the first channels of the first and second RF switches and the reflection ports of the first and second bidirectional couplers to characterize the S parameters of the device under test after the high-power microwave pulse input, thereby realizing time-sharing multiplexing of different signal channels. For the S parameters obtained by characterization, a preset algorithm is used for data processing and failure point determination.

[0084] In this embodiment, the basic flow of the pulse stress test is derived from a combination of the two modes described above. Assuming the stress test mode performs G tests and the characterization test mode performs C characterizations, the basic flow of the pulse stress test can be described as follows: After each C stress test, a parameter characterization is performed. After each parameter characterization, the test control module processes the S parameters obtained by characterization to determine whether the device under test has failed after G stress tests. If no failure point is found, the stress test and characterization test are repeated after the characterization process to continue searching for the failure point. If a failure point is found, the pulse stress test is terminated. Otherwise, the iterative process continues until the stress test is performed G×C times. At this point, the device parameter characterization results after C, 2C, 3C, and so on, G×C stress tests are obtained, thus completing the basic pulse stress test flow.

[0085] In this embodiment, the failure point of the device under test is determined based on the stability coefficient. That is, the S parameters of the device under test are obtained through parameter characterization, and the stability coefficient K(f) at the scanning frequency set by the vector network analyzer is calculated. If K(f)>1, it indicates that at this frequency point f, the high-power microwave pulse stress on the device under test has no obvious impact on the stability of the device under test; if K(f)<1, it indicates that the high-power microwave pulse stress has caused an irreversible impact on the device, causing the device to be in an unstable working state at the frequency point f, that is, the device is considered to have failed. The failure point refers to the number of pulses of the input pulse signal that causes the device to fail. Based on the monitoring data of instruments such as the vector network analyzer, the number of pulses that causes the device to fail under the condition of the input power value at the frequency point f can be obtained, and the power value and number of pulses of the input pulse signal that cause the device to fail are used as the failure threshold.

[0086] During actual testing, due to the influence of noise and other factors, the characterized S parameters contain noise information and thus have errors. To eliminate the errors introduced by the signal loop and obtain the true frequency domain parameters of the device, in a preferred embodiment, the present invention first de-embeds the scattering parameters before calculating the stability coefficient to obtain more accurate scattering parameters, thereby improving the accuracy of the calculated stability coefficient. The specific steps include:

[0087] De-embedding the first scattering parameter according to a preset second scattering parameter, where the second scattering parameter is obtained by replacing the device under test with a background microstrip line, generating a simulated working signal, and inputting the background microstrip line through a simulated test signal channel for parameter characterization;

[0088] A stability coefficient is calculated according to the de-embedded first scattering parameter, and whether a failure point exists is determined according to the stability coefficient.

[0089] In this embodiment, the de-embedding operation is performed based on the second scattering parameter. The second scattering parameter is an S parameter obtained by replacing the device under test with a background microstrip line and inputting an analog working signal for parameter characterization before the test starts. Specifically, before the test starts, the first and second RF switches are placed in the first channel, the background microstrip line of the active two-port device under test is placed at the position of the device under test, and the S parameters of the background microstrip line are characterized by a vector network analyzer. The obtained S parameters are recorded as S ML (f) After the stress test, the S parameters of the device under test are characterized and the obtained S parameters are recorded as S DUT (f) Since the analog working signal path before and after the test is consistent, the error introduced into the test is also consistent, and the microstrip line is the background of the device under test, the error introduced by the signal loop can be eliminated through the de-embedding operation to obtain the true frequency domain parameters of the device. The de-embedding formula is expressed as:

[0090] S(f)=S DUT (f)-S ML (f)

[0091] Since the S parameters obtained by characterization include S 11 、S 12 、S 21 、S 22 , so the de-embedding formula can be expanded as:

[0092] S ij (f) = S ij-DUT (f)-S ij-ML (f) i = 1, 2; j = 1, 2;

[0093] That is:

[0094] S 11 (f) = S 11-DUT (f)-S 11-ML (f)

[0095] S 12 (f) = S 12-DUT (f)-S 12-ML (f)

[0096] S 21 (f) = S 21-DUT (f)-S 21-ML (f)

[0097] S 22 (f) = S 22-DUT (f)-S 22-ML (f)

[0098] Then, the stability coefficient is calculated based on the de-embedded S parameters. The specific calculation formula is:

[0099]

[0100] The stability coefficient is calculated according to the above formula, and the frequency point causing device failure is found by comparing the stability coefficient with the coefficient threshold. Then, the failure threshold causing device failure can be accurately captured, that is, the power value and number of pulses of the input pulse signal.

[0101] Based on the basic pulse test process and the differences in narrow-spectrum high-power microwave pulse stress, the test steps for single-pulse stress testing and multi-pulse stress testing in this embodiment are also different. Specifically, for single-pulse stress testing, the specific test steps include:

[0102] In response to the stress test type being a single pulse stress test, the input parameter range includes a start power and an end power, and the input parameter step size includes a power step size;

[0103] With the starting power as the input power of the device under test, a single pulse signal is input into the device under test to perform a pulse stress test to determine whether there is a failure point;

[0104] If it does not exist, the input power is updated with the power step as the increment, and according to the updated input power, a single pulse signal is input into the device under test for the next pulse stress test until the stress accumulation damage failure threshold is found, or the updated input power is greater than the termination power.

[0105] In this embodiment, since the input is a single pulse signal, it is only necessary to set the starting power, ending power and power step of the device under test. Figure 7 , the starting power is expressed as P B1 , the termination power is expressed as P E1 , the power step is represented by P S1 , the input power of the device under test is expressed as P, then the process of single pulse stress test can be expressed as (P = P B1 ; P≤P E1 ; P=P+P S1 ) is the iterative loop condition, and the basic process of the pulse stress test is iterated until the failure point is found or the iterative loop condition is false.

[0106] If a failure point is found, it means that a certain number of pulses under the conditions of this power value will cause the device to fail. At this time, the device needs to be replaced, and the single-pulse stress test should be repeated with the sum of the current power value and the power step length as the new starting power to find the failure point under other power conditions. If a failure point is not found within the starting and ending power range, the next round of testing should be repeated with the sum of the current ending power and the power step length as the new starting power until the power value and number of pulses that can cause device failure are found. It should be noted that the processing steps for finding a failure point in the multi-pulse stress test or not finding a failure point under the current input parameters are the same as those for the single-pulse stress test and will not be repeated later.

[0107] The following example illustrates the steps for a single-pulse stress test. The device under test (DUT) is a BGA2869 microwave monolithic integrated circuit (MMIC) low-noise amplifier. This device operates in the DC-2.2 GHz frequency range, has a maximum input power rating of 10 dBm, and operates at a voltage between 9 and 12 V. For the study of in-band damage effects on this device, the signal source frequency is set to f0 = 500 MHz, the function generator repetition rate f1 = 125 Hz, and the duty cycle DC = 50%. Before the test begins, a background microstrip line with consistent thickness and impedance, similar to the device's transmission path, is placed at the DUT's location. The frequency sweep range is set from DC to 2.2 GHz, and its S-parameters are measured and saved.

[0108] For the single pulse stress test of the device under test, the number of pulses to be tested and the irreversible permanent damage to the device under test after the single pulse are determined, that is, the stress cumulative damage failure threshold. In the single pulse stress test, the default output pulse number N = 1 after the function generator is triggered, and the starting power P of the signal source input is set. B1 =-4.5dBm, the corresponding power amplifier output power is 36.97dBm, the signal source input termination power P E1 =-3.5dBm, the corresponding amplifier output power is 37.71dBm, the power step size P S1 =0.1dBm, the number of stress tests in the basic process of pulse test G=1, and the number of characterization tests C=5000.

[0109] It should be noted that the input power value condition that causes device failure is actually the power value output by the signal source after the power amplifier. For the sake of convenience, in this embodiment and the subsequent multi-pulse stress test, the power value output by the signal source after the power amplifier is used as the starting power P B1 and termination power P E1 , the single pulse stress test step is to reduce the input power of the device under test from P B1 Start with PS1 The step size is gradually increased to P E1 Approximation, after each input, the basic process of pulse stress test is executed until the failure point is found or the input power of the device under test is greater than P E1 , reaching the test termination condition, and by analyzing the S parameters, finding the injection power and number of pulses that cause device failure, we can accurately capture the pulse threshold of single-pulse stress-induced cumulative damage to the device. Taking the aforementioned device under test as an example, through single-pulse stress testing, it can be found that at a power value of 37.07dBm, it fails after 2947 single pulses; at a power value of 37.21dBm, it fails after 50 single pulses; and at a power value of 37.43dBm, it fails after 1 single pulse.

[0110] In this embodiment, for the multi-pulse stress test, the specific test steps include:

[0111] In response to the stress test type being a multi-pulse stress test, the input parameter range includes a start power, an end power, a start pulse number, and an end pulse number, and the input parameter step size includes a power step size and a pulse number step size;

[0112] Taking the starting power as the input power of the device under test and the number of starting pulses as the number of pulse inputs, a multi-pulse signal is input to the device under test to perform a pulse stress test to determine whether there is a failure point.

[0113] If it does not exist, the number of pulse inputs is updated with the pulse number step as the increment, and according to the updated number of pulse inputs, the multi-pulse signal is input to the device under test for the next pulse stress test until the thermal cumulative damage failure threshold is found, or the updated number of pulse inputs is greater than the number of termination pulses;

[0114] When the updated number of pulse inputs is greater than the number of ending pulses, the input power is updated with the power step length as the increment, and the number of pulse inputs is updated to the number of starting pulses;

[0115] According to the updated input power and the updated number of pulse inputs, the multi-pulse signal is input to the device under test for the next pulse stress test until the thermal accumulation damage failure threshold is obtained or the updated input power is greater than the termination power.

[0116] In this embodiment, for the multi-pulse stress test, what needs to be found is at which pulse and at what power the device has an irreparable impact, resulting in a change in electrical parameters. Since the input is a multi-pulse signal, compared with the single-pulse stress test, in addition to setting the starting power, ending power and power step, the multi-pulse stress test also needs to set the starting pulse number, ending pulse number and pulse number step. Due to the additional input condition of the number of pulses, the iterative step of the multi-pulse stress test will have an additional cyclic condition of the number of pulses compared to the iterative step of the single-pulse stress test.

[0117] In this embodiment, the cycle condition of the number of pulses is used as the inner cycle condition, and the cycle condition of the power is used as the outer cycle condition to perform the iterative operation of the basic process of the pulse stress test. Figure 8 , the starting power is expressed as P B2 , the termination power is expressed as P E2 , the power step is represented by P S2 , the number of starting pulses is expressed as N B , the number of termination pulses is expressed as N E , the pulse number step is expressed as Step, the input power of the device under test is expressed as P, and the number of input pulses of the device under test is expressed as N. The process of multi-pulse stress test can be expressed as (N=N B ; N≤N E ; N=N+Step) is the inner iteration loop condition, with (P=P B2 ; P≤P E2 ; P=P+P S2 ) is the outer iteration loop condition, and the basic process of the pulse stress test is iterated until the failure point is found or the iteration loop condition is false.

[0118] Taking the device under test in the single pulse stress test as an example, for the multi-pulse stress test of the device, set the stress test number G=1 and the characterization test number C=1 in the basic process of the pulse test; set the starting power P of the signal source input B2 =-8dBm, the corresponding power amplifier output power is 34.37dBm, the termination power of the signal source input is P E2 =-7dBm, the corresponding amplifier output power is 35.24dBm, the power step size is P S2 =0.1dBm, number of starting pulses N B =5, the number of termination pulses N E =1000, pulse number step Step=5.

[0119] The multi-pulse stress test is performed with an input power of P B2 Under the condition, N is injected into the device under test. BPulses, N S The number of pulses is increased by steps. After each injection of multi-pulse signal, the basic process of pulse stress test is executed until the failure point is found or the number of pulses is greater than N E , when no failure point is found under this power value, P S2 As the step size, update the input power and update the number of input pulses to the initial starting pulse number N B , continue to execute the next loop operation until the failure point is found or the test termination condition is reached.

[0120] By analyzing S parameters and identifying the injection power and number of consecutive pulses that cause device failure, we can accurately capture the threshold point for device failure caused by thermal cumulative damage from multi-pulse stress. Taking the aforementioned device under test as an example, multi-pulse stress testing revealed that at a power level of 34.44dBm, the device failed after 560 consecutive pulses; at a power level of 34.67dBm, it failed after 220 consecutive pulses; and at a power level of 34.86dBm, it failed after 125 consecutive pulses.

[0121] It should be noted that in order to eliminate the influence of the cumulative effect of the device in repeated high-power microwave tests and further detect the accurate threshold point of device failure, it is possible to repeatedly replace the same device with a new one near the failure threshold point analyzed by the instrument monitoring data to ensure that the accurate failure threshold of this type of device is obtained.

[0122] In addition, in a preferred embodiment, the determination of the failure point, i.e., the calculation of the stability coefficient of the S parameter, can be set after all iterative cycles are completed. That is, in the basic process of the pulse stress test, the determination of the failure point is removed. After the iterative steps of the single-pulse stress test or the multi-pulse stress test are completed, all parameter characterization results are stored, and the failure threshold of the device is found through data backtracking. Alternatively, the step of determining the failure point after several parameter characterizations is also included in the stress testing method of this embodiment. That is, the order of the steps described in this embodiment is only preferred and not specifically limited. The test steps of the stress test provided in this embodiment can be adaptively adjusted according to actual conditions. Adjusting the order of the steps does not affect the results of the stress test.

[0123] This embodiment provides a high-power microwave stress testing method. By simultaneously testing stress and parameter characterization of narrow-spectrum high-power microwave pulses, it meets the testing requirements of narrow-spectrum high-power microwave pulse injection under different conditions. By introducing the concept of de-embedding, the accuracy of test parameters is improved, and quantitative analysis of the state of the device under test is achieved, thereby improving the accuracy of stress test results. This provides data support for reverse guidance of product device design and reinforcement protection of key sensitive parts of the system, further improving product reliability.

[0124] In summary, an embodiment of the present invention proposes a stress testing system and method for high-power microwaves, the system comprising a test control module, and a stress test module, a signal path module and a parameter characterization module connected to the test control module, the signal path module being connected to the stress test module and the parameter characterization module respectively; the stress test module being used to generate a high-power microwave pulse signal according to a first control instruction from the test control module and input the signal path module; the signal path module being used to turn on the corresponding signal channel according to a second control instruction from the test control module to achieve time-division multiplexing of the signal channel, the signal channel comprising a stress test signal channel and an analog test signal channel; wherein the signal path module comprises a first bidirectional coupler, a second bidirectional coupler, a third bidirectional coupler, a first RF switch, a second RF switch and a single-chip microcomputer, the first bidirectional coupler being connected to the stress test module and the first RF switch respectively, the second bidirectional coupler being connected to the third bidirectional coupler, a device to be tested being connected between the first bidirectional coupler and the second bidirectional coupler, the first RF switch The switch and the second RF switch are both connected to the parameter characterization module and the single-chip microcomputer, and the single-chip microcomputer is connected to the test control module; the stress test signal channel is composed of the first bidirectional coupler, the second bidirectional coupler, and the third bidirectional coupler, and the analog test signal channel is composed of the first RF switch, the second RF switch, the first bidirectional coupler, and the second bidirectional coupler. The conduction of the analog test signal channel is controlled by the selection signal generated by the single-chip microcomputer according to the second control instruction; the parameter characterization module is used to generate an analog working signal of the device under test according to the third control instruction from the test control module, and input the first RF switch and the second RF switch respectively, and perform signal characterization on the device under test, and input the obtained characterization signal into the test control module; the test control module is used to generate control instructions for the stress test module, the signal path module, and the parameter characterization module, the control instructions including the first control instruction, the second control instruction, and the third control instruction, and perform failure point judgment on the received characterization signal to achieve stress testing of high-power microwaves. The present invention meets the test requirements of narrow-spectrum high-power microwave pulse injection under different conditions by conducting simultaneous tests on stress testing and parameter characterization of narrow-spectrum high-power microwave pulses. By introducing the de-embedding concept, the accuracy of test parameters is improved, and quantitative analysis of the state of the device under test is achieved, thereby improving the accuracy of stress test results. This provides data support for reverse guidance of product device design and reinforcement protection of key sensitive parts of the system, further improving product reliability.

[0125] Each embodiment in this specification is described in a progressive manner, and the same or similar parts of each embodiment can be directly referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. It should be noted that the various technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above-described embodiments merely represent several preferred implementations of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art could make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be based on the scope of protection of the claims.

Claims

1. A high-power microwave stress testing system, characterized in that: include: A test control module, and a stress test module, a signal path module and a parameter characterization module connected to the test control module, wherein the signal path module is connected to the stress test module and the parameter characterization module respectively; The stress test module is used to generate a high-power microwave pulse signal according to the first control instruction from the test control module, and input the pulse signal into the signal path module; The signal path module is used to conduct the corresponding signal channel according to the second control instruction from the test control module to achieve time-division multiplexing of the signal channel, wherein the signal channel includes a stress test signal channel and an analog test signal channel; The signal path module includes a first bidirectional coupler, a second bidirectional coupler, a third bidirectional coupler, a first radio frequency switch, a second radio frequency switch, and a single-chip microcomputer. The first bidirectional coupler is connected to the stress test module and the first radio frequency switch, respectively. The second bidirectional coupler is connected to the third bidirectional coupler. A device under test is connected between the first bidirectional coupler and the second bidirectional coupler. The first radio frequency switch and the second radio frequency switch are both connected to the parameter characterization module and the single-chip microcomputer. The single-chip microcomputer is connected to the test control module. The stress test signal channel is composed of the first bidirectional coupler, the second bidirectional coupler, and the third bidirectional coupler; the analog test signal channel is composed of the first RF switch, the second RF switch, the first bidirectional coupler, and the second bidirectional coupler; and the conduction of the analog test signal channel is controlled by the selection signal generated by the single-chip microcomputer according to the second control instruction; The parameter characterization module is configured to generate a simulated operating signal of the device under test according to a third control instruction from the test control module, input the simulated operating signal to the first radio frequency switch and the second radio frequency switch respectively, perform signal characterization on the device under test, and input the obtained characterization signal to the test control module; The test control module is used to generate control instructions for the stress test module, the signal path module and the parameter characterization module, the control instructions including a first control instruction, a second control instruction and a third control instruction, and perform failure point determination on the received characterization signal to realize stress testing of high-power microwaves.

2. The high-power microwave stress testing system according to claim 1, characterized in that: The stress test module includes a function generator, a signal source, a power amplifier and a circulator connected in sequence. The function generator and the signal source are both connected to the test control module, and the circulator is connected to the first bidirectional coupler.

3. The high-power microwave stress testing system according to claim 1, characterized in that: The device under test is an active radio frequency front-end device; The parameter characterization module includes a vector network analyzer and a DC power supply, the vector network analyzer is respectively connected to the first RF switch, the second RF switch, the DC power supply and the test control module, and the DC power supply is respectively connected to the first RF switch, the second RF switch, the device under test and the test control module; The vector network analyzer is configured to generate an analog operating signal of the device under test according to the third control instruction, and input the analog operating signal to the first radio frequency switch and the second radio frequency switch respectively, and perform signal characterization on the device under test, and input the obtained characterization signal to the test control module; The DC power supply is used to provide an operating voltage for the first radio frequency switch, the second radio frequency switch, and the device under test.

4. The high-power microwave stress testing system according to claim 3, characterized in that: The signal path module further includes a first power divider and a second power divider, and the parameter characterization module further includes a power meter and an oscilloscope; The first power splitter is connected to the first bidirectional coupler, the power meter and the oscilloscope respectively, and the second power splitter is connected to the third bidirectional coupler, the power meter and the oscilloscope respectively; The first power divider is used to divide the pulse signal received from the first bidirectional coupler into two equal parts, and input the two equally divided signals into the power meter and the oscilloscope respectively; The second power divider is used to divide the pulse signal received from the third bidirectional coupler into two equal parts, and input the two equally divided signals into the power meter and the oscilloscope respectively; The power meter is used to monitor the power of one signal output by the first power splitter and one signal output by the second power splitter respectively; The oscilloscope is used to perform time domain waveform monitoring on the other signal output by the first power divider and the other signal output by the second power divider respectively.

5. A high power microwave stress testing method, characterized in that: The method is applied to the system according to any one of claims 1 to 4, and the method includes: According to the failure threshold to be tested, select the corresponding stress test type and set the corresponding test parameters. The failure threshold includes the stress cumulative damage failure threshold and the thermal cumulative damage failure threshold. The stress test type includes single pulse stress test and multi-pulse stress test. The test parameters include the input parameter range and input parameter step size. According to the stress test type, the input parameters of the pulse signal are set according to the corresponding input parameter range, and the pulse signal is input into the device under test to perform a pulse stress test to determine whether a failure point exists. If not, the input parameters of the pulse signal are updated according to the input parameter step size, and the pulse signal is input into the device under test to perform the next pulse stress test until an iteration stop condition is met, wherein the iteration stop condition includes the existence of a failure point or the input parameter exceeds the input parameter range; In response to the existence of a failure point, a corresponding failure threshold is determined according to the failure point.

6. The high-power microwave stress testing method according to claim 5, characterized in that: The step of inputting a pulse signal into the device under test to perform a pulse stress test and determining whether a failure point exists includes: Input a pulse signal into the device under test through the stress test signal channel to perform a pulse stress test until the number of tests reaches a preset test threshold and the signal input is stopped; Generate an analog working signal, and input the analog working signal into the device under test through an analog test signal channel to perform parameter characterization to obtain a first scattering parameter of the device under test; It is determined whether a failure point exists based on the first scattering parameter. If not, the next pulse stress test and parameter characterization are performed until the failure point is found or the number of characterizations reaches a preset characterization threshold.

7. The high-power microwave stress testing method according to claim 6, characterized in that: The step of determining whether a failure point exists according to the first scattering parameter includes: De-embedding the first scattering parameter according to a preset second scattering parameter, where the second scattering parameter is obtained by replacing the device under test with a background microstrip line, generating a simulated working signal, and inputting the background microstrip line through a simulated test signal channel for parameter characterization; A stability coefficient is calculated according to the de-embedded first scattering parameter, and whether a failure point exists is determined according to the stability coefficient.

8. The high-power microwave stress testing method according to claim 7, characterized in that: The first scattering parameter of de-embedding is expressed as follows: S ij (f)=S ij-DUT (f)-S ij-ML (f)i=1,2;j=1,2; Where S ij (f) represents the first scattering parameter of de-embedding at frequency f, S ij-DUT (f) represents the first scattering parameter at frequency f, S ij-ML (f) represents the second scattering parameter at frequency f; The stability coefficient is expressed by the following formula: Where K(f) represents the stability coefficient at frequency f.

9. The high-power microwave stress testing method according to claim 6, characterized in that: The steps of setting the input parameters of the pulse signal according to the corresponding input parameter range according to the stress test type, inputting the pulse signal into the device under test, performing the pulse stress test, determining whether a failure point exists, and if not, updating the input parameters of the pulse signal according to the input parameter step size, inputting the pulse signal into the device under test, and performing the next pulse stress test until the iteration stop condition is reached include: In response to the stress test type being a single pulse stress test, the input parameter range includes a start power and an end power, and the input parameter step size includes a power step size; With the starting power as the input power of the device under test, a single pulse signal is input into the device under test to perform a pulse stress test to determine whether there is a failure point; If it does not exist, the input power is updated with the power step as the increment, and according to the updated input power, a single pulse signal is input into the device under test for the next pulse stress test until the stress accumulation damage failure threshold is found, or the updated input power is greater than the termination power.

10. The high power microwave stress testing method according to claim 6, characterized in that: The steps of setting the input parameters of the pulse signal according to the corresponding input parameter range according to the stress test type, inputting the pulse signal into the device under test, performing the pulse stress test, judging whether there is a failure point, and if not, updating the input parameters of the pulse signal according to the input parameter step size, inputting the pulse signal into the device under test, and performing the next pulse stress test until the iteration stop condition is reached include: In response to the stress test type being a multi-pulse stress test, the input parameter range includes a start power, an end power, a start pulse number, and an end pulse number, and the input parameter step size includes a power step size and a pulse number step size; Taking the starting power as the input power of the device under test and the number of starting pulses as the number of pulse inputs, a multi-pulse signal is input to the device under test to perform a pulse stress test to determine whether there is a failure point. If it does not exist, the number of pulse inputs is updated with the pulse number step as the increment, and according to the updated number of pulse inputs, the multi-pulse signal is input to the device under test for the next pulse stress test until the thermal cumulative damage failure threshold is found, or the updated number of pulse inputs is greater than the number of termination pulses; When the updated number of pulse inputs is greater than the number of ending pulses, the input power is updated with the power step length as the increment, and the number of pulse inputs is updated to the number of starting pulses; According to the updated input power and the updated number of pulse inputs, the multi-pulse signal is input to the device under test for the next pulse stress test until the thermal accumulation damage failure threshold is obtained or the updated input power is greater than the termination power.

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