Oscilloscope with Baud diagram analysis function and control method thereof

Abstract

The invention relates to the technical field of signal testing, and provides an oscilloscope with a Baud diagram analysis function and a control method thereof, and the oscilloscope comprises a sweep frequency signal generation unit, a sweep frequency control unit and a waveform processing unit. The sweep frequency signal generation unit comprises a sweep frequency analyzer, the sweep frequency analyzer is configured with a plurality of sweep frequency modes, and a sweep frequency signal is generated according to the selected sweep frequency mode and configured parameters; the sweep frequency control acquisition unit is used for controlling a sweep frequency process to obtain waveform data; and the waveform processing unit is used for automatically processing the waveform data, reading related numerical values of the waveform, calculating to obtain the frequency response characteristics of the tested piece, and realizing linkage backtracking of the data based on a set data backtracking device and a data recording table. The oscilloscope is provided with an intelligent measurement and analysis system composed of a double-sweep-frequency system and multiple measurement tools, the problem of sweep-frequency dead angles is effectively solved, and automatic analysis of complex frequency response characteristic curves can be achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field related to signal testing, and in particular to an oscilloscope with a Bode diagram analysis function and a control method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] In the field of signal measurement technology, oscilloscopes have been widely used, and the Bode plot analysis function has become an indispensable tool in troubleshooting and locating faulty circuits or performing circuit design.

[0004] The inventors found in their research that the oscilloscopes currently on the market have two main problems in the Bode plot analysis function, which affect the actual application effect of the oscilloscopes. The main problems are as follows:

[0005] First, due to the limitations of the oscilloscope's hardware design or software algorithms, signals within certain frequency ranges cannot be effectively captured and analyzed, resulting in frequency sweep dead zones. Nonlinear frequency response systems have different response characteristics at different frequencies, especially at specific frequencies, where the system may exhibit significant nonlinear behavior. The existence of frequency sweep dead zones makes it impossible to determine the nonlinear response of the system at certain frequencies, which in turn affects the evaluation of system performance and stability. When designing circuits or troubleshooting, a comprehensive analysis of the performance of the circuit system over a wide frequency range is required. The frequency blind spots caused by frequency sweep dead zones will prevent certain potential faults or nonlinear behaviors from being discovered in a timely manner, affecting the efficiency of troubleshooting and system optimization;

[0006] Second, when measuring complex systems, the frequency response characteristic curve may become quite complicated, making it difficult to draw clear conclusions directly from the graph. Summary of the invention

[0007] In order to solve the above problems, the present disclosure proposes an oscilloscope with Bode plot analysis function and a control method thereof, which has an intelligent measurement and analysis system composed of a dual sweep frequency system and multiple measurement tools, effectively solves the sweep frequency blind spot problem, and can realize automatic analysis of complex frequency response characteristic curves.

[0008] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0009] One or more embodiments provide an oscilloscope with a Bode plot analysis function, the oscilloscope comprising a sweep signal generating unit, a sweep control unit, and a waveform processing unit;

[0010] The sweep frequency signal generating unit includes a sweep frequency analyzer, which is configured with a plurality of sweep frequency modes and generates a sweep frequency signal according to the selected sweep frequency mode and the configured parameters;

[0011] A frequency sweep control acquisition unit, used to control the frequency sweep process to obtain waveform data;

[0012] The waveform processing unit is used to automatically process the waveform data, read the relevant values ​​of the waveform, calculate the frequency response characteristics of the device under test, and realize the linkage backtracking of the data based on the set data backtracker and data recording table.

[0013] One or more embodiments provide a method for controlling an oscilloscope with a Bode diagram analysis function, comprising the following steps:

[0014] For the test piece, obtain the frequency sweep configuration data;

[0015] Configure multiple sweep modes, select the sweep mode according to the configuration data, match different sweep modes with different sweep point setting mechanisms, determine the sweep signal parameters of the oscilloscope based on the configuration data, and control the oscilloscope's own signal source module to output the corresponding sweep signal;

[0016] Through the interrupt service mechanism, a multi-threaded data synchronization algorithm is used to collect the waveform data generated by the oscilloscope during the frequency sweep process;

[0017] The acquired waveform data is analyzed to obtain the frequency response characteristics of the device under test.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention adopts a variety of sweep mode selections to cover different frequency ranges and test conditions, avoiding the possible blind spots of sweep in a single mode; the waveform processing unit can automatically process the collected waveform data and read the relevant values ​​of the waveform. For complex waveforms, the automated processing unit can quickly analyze and process them, avoiding the errors and delays that may occur when manually processing complex waveforms, and improving the efficiency and accuracy of data processing.

[0020] The oscilloscope disclosed in this disclosure effectively solves the problems of frequency sweep blind spots and the inability to analyze complex waveforms. Multiple frequency sweep modes and precise control ensure comprehensive waveform data acquisition and minimize frequency sweep blind spots; automated processing and frequency response characteristic calculation ensure accurate analysis of complex waveforms, and the data linkage backtracking function further enhances data management and analysis capabilities.

[0021] The advantages of the present disclosure and the advantages of additional aspects will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and the description thereof are used to explain the present disclosure but do not constitute a limitation of the present disclosure.

[0023] Figure 1 is a functional structural block diagram of an oscilloscope with a Bode diagram analysis function according to Embodiment 1 of the present disclosure;

[0024] Figure 2 It is a flow chart of adjusting the display position of a waveform on a screen by a time base adjuster and a vertical adjuster of Embodiment 1 of the present disclosure;

[0025] Figure 3 is a waveform acquisition control flow chart of a waveform data collector according to Embodiment 1 of the present disclosure;

[0026] Figure 4 It is a schematic diagram of managing the acquisition thread and the Bode diagram operation thread through semaphore control in Embodiment 1 of the present disclosure;

[0027] Figure 5 This is a functional interface diagram of the automatic measurement analyzer of Example 1 of the present disclosure. DETAILED DESCRIPTION

[0028] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof. It should be noted that, in the absence of conflict, the various embodiments in the present disclosure and the features in the embodiments can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0031] Example 1

[0032] In the technical solutions disclosed in one or more embodiments, Figures 1 to 5 As shown, an oscilloscope with a Bode diagram analysis function, the oscilloscope includes a sweep signal generating unit, a sweep control unit and a waveform processing unit;

[0033] The sweep frequency signal generating unit includes a sweep frequency analyzer, which is configured with a plurality of sweep frequency modes and generates a sweep frequency signal according to the selected sweep frequency mode and the configured parameters;

[0034] A frequency sweep control acquisition unit, used to control the frequency sweep process to obtain waveform data;

[0035] The waveform processing unit is used to automatically process the waveform data, read the relevant values ​​of the waveform, calculate the frequency response characteristics of the device under test, and realize the linkage backtracking of the data based on the set data backtracker and data recording table.

[0036] In this embodiment, the frequency sweep analyzer is configured with a variety of frequency sweep modes, and the user can select different frequency sweep modes according to specific test requirements. This diverse selection of frequency sweep modes can cover different frequency ranges and test conditions, avoiding the frequency sweep blind spots that may exist in a single mode, and ensuring that signals in all frequency bands can be effectively tested. The waveform processing unit can automatically process the collected waveform data and read the relevant values ​​of the waveform. For complex waveforms, the automated processing unit can quickly analyze and process them, avoiding errors and delays that may occur when manually processing complex waveforms, and improving the efficiency and accuracy of data processing.

[0037] Based on the set data tracer and data record table, data linkage backtracking is realized. Users can easily view and compare test data at different time points for in-depth analysis and verification. For complex waveforms, linkage backtracking can help users better understand waveform changes and frequency response characteristics, ensuring the accuracy and reliability of analysis results.

[0038] In some embodiments, the sweep signal generation unit includes a configuration data acquisition module, a sweep analyzer, and a signal source controller connected in sequence;

[0039] 1) A configuration data acquisition module, configured to acquire the user's frequency scanning configuration data;

[0040] Optionally, the configuration data includes the start frequency, end frequency and amplitude value of the sweep signal, the sweep mode, the number of sweep points, and the impedance value of the oscilloscope input and output channels;

[0041] In one achievable implementation method, a method for determining frequency sweep configuration data comprises the following steps:

[0042] Step 1.1, according to the physical characteristics of the DUT, determine the minimum and maximum frequency ranges of the input DUT as the sweep start frequency and end frequency of the Bode plot analysis;

[0043] Step 1.2, determine the voltage value that the device under test can withstand, as the amplitude value of the swept frequency signal for Bode plot analysis;

[0044] Step 1.3, determine the signal input point and output point of the device under test as two reference points for Bode plot analysis, and determine the frequency sweep mode and the number of frequency sweep points;

[0045] Preferably, a logarithmic frequency sweep mode and a frequency sweep point number within the range of [10, 500] may be selected;

[0046] Step 1.4, determine the impedance values ​​of the input and output points of the device under test as the impedance values ​​of the oscilloscope input and output channels; now the user has completed all configurations for Bode plot analysis of the device under test.

[0047] 2) A sweep frequency analyzer, configured with two sweep frequency modes, the sweep frequency analyzer being configured to determine sweep frequency signal parameters of the oscilloscope according to the acquired configuration parameters;

[0048] Specifically, according to the parameter configuration data, the start and end frequencies of the frequency sweep and the amplitude of the frequency sweep signal are determined; according to the frequency sweep mode set by the user, the frequency sweep step algorithm is determined; through the frequency sweep start frequency, end frequency, number of frequency sweep points and the frequency sweep step algorithm, the frequency sweep signal step value is determined, thereby determining the frequency sweep signal parameters;

[0049] Multiple sweep modes are used in combination to achieve "no blind spot" in observing frequency response. In this embodiment, two sweep modes are provided: logarithmic sweep and linear sweep. Different sweep modes are matched with different sweep point setting mechanisms to solve the problem of blind spots in the frequency response of the device under test. Since linear sweep can better provide more uniform frequency intervals in the low frequency band, it is more suitable for analyzing areas with small frequency changes or for accurately examining the characteristics of specific low frequency bands. Logarithmic sweep can better reflect frequency changes in the high frequency band, because in many actual systems, the frequency response changes in the high frequency band are often more drastic, and logarithmic sweep can more effectively cover a wider high frequency range. Multi-band segmented sweep is used to divide the entire frequency range into multiple small segments, and linear sweep and logarithmic sweep are performed respectively, which can effectively avoid missing certain frequency bands due to excessive sweep range at one time, thereby achieving "no blind spot" in observing frequency response.

[0050] Furthermore, when using two sweep modes in combination, it is necessary to pay attention to the connection point between the switching of the two sweep modes, ensure the continuity and accuracy of the measurement, reasonably set the switching frequency point and transition method, and at the same time, flexibly adjust the proportion and range of the two sweep modes according to specific test requirements and characteristics of the device (system) under test to obtain the most valuable test results.

[0051] Specifically, the theoretical model of the logarithmic sweep mode can be expressed as:

[0052]

[0053] Among them, f currentis the instantaneous frequency of the current output, f start is the sweep start frequency, f stop is the sweep end frequency, p sum is the total number of sweep points, p current The current sweep frequency points range from 10 to p sum between;

[0054] It can be seen that when p current Value, f start Value, f stop When the values ​​are the same, p sum The larger the value, the current The smaller the value, that is, the smaller the sweep frequency step value, the stronger the ability to capture abnormal frequency response of the device under test in this sweep frequency range.

[0055] Specifically, the theoretical model of the linear sweep mode can be expressed as:

[0056]

[0057] Among them, f current is the instantaneous frequency of the current output, f start is the sweep start frequency, f stop is the sweep end frequency, p sum is the total number of sweep points, p current The current sweep frequency points range from 10 to p sum between.

[0058] It can be seen that when p current Value, f start Value, f stop When the values ​​are the same, p sum The larger the value, the current The smaller the value, that is, the smaller the sweep frequency step value, the stronger the ability to capture abnormal frequency response of the device under test in this sweep frequency range.

[0059] When performing frequency response tests on circuits or systems, you can flexibly select the sweep mode and sweep points according to different test requirements to efficiently identify the sensitive signal frequency values ​​or signal frequency stability ranges of the circuit or system, thereby greatly improving the efficiency of circuit or system troubleshooting.

[0060] 3) A signal source controller, used to control the signal source module of the digital oscilloscope to output a corresponding sweep signal according to the sweep signal parameters determined by the sweep analyzer;

[0061] One specific way to achieve this is to use different sweep modes with different sweep point setting mechanisms, specifically:

[0062] 3.1) Use a high-frequency signal to sweep and analyze the circuit or system. The logarithmic sweep mode of the oscilloscope Bode plot function can be used; the specific setting mechanism is as follows:

[0063] Set the "Sweep Number / Decade Number" parameter to 2. The value range of "Sweep Number / Decade Number" is 1 to 8. The smaller the value, the fewer the sweep points and the faster the sweep speed.

[0064] The "start frequency" and "end frequency" of the sweep signal are set to 1KHz and 50MHz respectively; the frequency range of the sweep signal source is [100Hz, 50MHz];

[0065] The signal amplitude is configured according to the maximum rated voltage of the DUT, the oscilloscope input / output channel impedance is matched with the DUT impedance, and the frequency response curve of the DUT is drawn;

[0066] 3.2) Use a low-frequency signal to sweep the circuit or system and analyze it. Use the linear sweep mode of the oscilloscope Bode plot function. The specific setting mechanism is as follows:

[0067] Set the "Sweep Points" parameter to 100. The value range of "Sweep Points" is 10 to 500. The smaller the value, the more sweep points, the slower the sweep speed, and the higher the test accuracy.

[0068] The "start frequency" and "end frequency" of the sweep signal are set to 100Hz and 1KHz respectively; the frequency range of the sweep signal source is [100Hz, 50MHz];

[0069] The signal amplitude is configured according to the maximum rated voltage of the DUT. The input / output channel impedance of the oscilloscope must match the impedance of the DUT, and the frequency response curve of the DUT is drawn.

[0070] Observing abnormal gain fluctuations or changes in the position and amplitude of gain peaks and valleys in the amplitude-frequency characteristic curve may suggest that the parameters of certain components in the circuit deviate from normal values. For example, a decrease in the gain of an amplifier may indicate that its internal components are aging or damaged.

[0071] Observing the phase shift anomaly in the phase-frequency characteristic curve can also reflect problems in the circuit. For example, if the phase change pattern does not match the expected pattern, it may be due to the failure of components such as capacitors and inductors, or problems in the feedback loop.

[0072] Furthermore, by comparing the Bode diagrams under normal working conditions and fault conditions, the differences can be more intuitively found, thereby quickly locating the frequency band or component where the fault is located.

[0073] In some embodiments, the frequency sweep control unit includes a time base adjuster, a vertical adjuster, and a waveform data collector;

[0074] 4) Time base adjuster and vertical adjuster, used to adjust the horizontal time base and vertical range so that the signal waveform can be displayed at the appropriate set position on the screen;

[0075] The time base adjuster is used to control the horizontal axis (time axis) display range of the waveform on the oscilloscope screen, that is, the length of time represented by each horizontal grid (div). By adjusting the time base, the display of the waveform on the horizontal axis can be stretched or compressed, so that multiple cycles of signal waveforms can be displayed on the screen;

[0076] In a specific embodiment, during the frequency sweep process, the time base setting is automatically adjusted according to the frequency of the input signal, and the specific adjustment steps of the time base adjuster are as follows:

[0077] Step 2.1, detecting the frequency of the input signal in real time;

[0078] Step 2.2, calculate the best time base setting according to the signal frequency, and calculate the time base value for displaying the signal waveform of the set number of cycles;

[0079] For example, if the signal frequency is 1kHz, then one cycle is 1ms. To display five cycles, the time base should be set to 5ms / div.

[0080] Step 2.3: Automatically adjust the time base setting so that the signal waveform can display a waveform with the set number of cycles on the horizontal axis.

[0081] The vertical adjuster is used to control the vertical axis (amplitude axis) display range of the waveform on the oscilloscope screen, that is, the voltage value represented by each vertical grid (div). By adjusting the vertical range, the display of the waveform on the vertical axis can be stretched or compressed, so that the waveform amplitude can be displayed more clearly on the screen.

[0082] In a specific embodiment, the vertical adjuster automatically adjusts the vertical range according to the amplitude of the input signal, and the adjustment method is as follows:

[0083] Step 3.1, automatically detecting the peak voltage of the input signal of the oscilloscope;

[0084] Step 3.2, calculate the best vertical range according to the signal amplitude, and calculate the appropriate vertical range value so that the signal waveform image is displayed within the set positive and negative grid numbers;

[0085] For example, if the number of divisions is set to plus or minus 3 divisions, and the peak voltage of the signal is 3V, the vertical scale should be set to 1V / div.

[0086] Step 3.3. Automatically adjust the vertical range setting so that the amplitude of the signal waveform can be displayed within the positive and negative set grid numbers on the vertical axis.

[0087] In the above scheme, during the frequency sweep process, the vertical range and horizontal time base gear of the corresponding channel are adjusted in real time according to the signal frequency and amplitude of the two channels of the digital oscilloscope input to ensure that the waveforms of the two channels can be displayed at the appropriate position of the digital oscilloscope screen, that is, the vertical display range is within plus or minus 3 grids, and the horizontal direction ensures that the screen can display three to five cycles of signal waveforms, which can help users more intuitively observe the waveform amplitude difference and frequency attenuation between the two measurement points of the device under test during the frequency sweep process;

[0088] In this embodiment, the time base adjuster and vertical adjuster described are key sub-modules of the Bode plot analysis function. They adjust the horizontal and vertical ranges of the input waveform in real time according to the amplitude and frequency of the input waveform. This not only allows the user to more intuitively observe the waveform amplitude difference and frequency attenuation between two measuring points of the device under test during the frequency sweep process, but also improves the accuracy of the drawn amplitude-frequency and phase-frequency curves.

[0089] 5) a waveform data collector configured to collect waveform data generated by the oscilloscope during the frequency sweep process in real time;

[0090] Furthermore, the waveform data collector is deployed at the fluorescent interrupt type service interface of the digital oscilloscope, and data collection is realized through the interrupt service mechanism. The switch of the waveform data collector is deployed in the Bode diagram sweep thread, and the collector enable switch will only be turned on when the sweep thread starts working.

[0091] A specific implementation scheme, the interrupt service mechanism is as follows: when the oscilloscope generates a fluorescence interrupt, the waveform data collector detects the interrupt signal, and after receiving a preset number of fluorescence interrupt signals, the waveform data collector starts working and performs waveform data collection;

[0092] Specifically, the preset number of waiting interrupts can be set to 3;

[0093] like Figure 3 As shown, the two threads include a frequency sweeping thread and a collection thread. The frequency sweeping thread is used to control the sending of the frequency sweeping signal. By detecting the fluorescence interruption, the collection condition is met so that the collector enable switch is turned on, thereby collecting waveform data for caching.

[0094] In the above scheme, data acquisition is started after a set number of interrupt signals, and the frequency sweep signal is waited to reach a stable state before starting to collect data, thereby ensuring that the collected data is more accurate and reliable. After reaching the preset number of interrupts, the waveform data collector starts to collect waveform data and stores the data in a specific buffer. This design ensures the stability of the frequency sweep signal and improves the accuracy and reliability of data collection.

[0095] The waveform data collector described in this embodiment is a key submodule of the Bode plot analysis function, and adopts a multi-threaded data synchronization algorithm to make the collected data closer to the actual frequency response characteristics of the device under test, and solve the data inconsistency and error problems that may occur when multiple threads simultaneously access and operate shared data;

[0096] Optional, multi-threaded data synchronization algorithm, through the semaphore control management acquisition thread and Bode diagram operation thread to access specific resources and share at the same time, the specific algorithm principle diagram is as follows Figure 4 As shown, the definition of the semaphore semphores sem_t semphores and the initialization init_sem(&semphores,0,0) are completed in the main thread. When the oscilloscope is in operation, the acquisition thread is always in the RUN state, and the Bode plot thread will enter the RUN state only when the user clicks the "Start Measurement" button on the Bode plot configuration interface. When the amplitude-frequency and phase-frequency curves are drawn, the Bode plot thread enters the STOP state.

[0097] In some embodiments, the waveform processing unit includes a waveform data processor, a waveform data tracer, a data recorder, and an automatic measurement analyzer;

[0098] 6) a waveform data processor, configured to quantize and process the acquired waveform data, and convert the data into an amplitude-frequency-phase-frequency curve according to a frequency sweep mode (logarithmic or linear) determined by a user;

[0099] Data quantization: The waveform data processor first normalizes the acquired waveform data and quantizes it to the coordinate interval of [-1,1]. This step helps to unify the data format and facilitate subsequent processing.

[0100] Mode conversion: According to the frequency sweep mode selected by the user, the waveform data processor draws amplitude-frequency-phase-frequency curves for the quantized data to show the amplitude and phase response of the system at different frequencies, which can be displayed on the oscilloscope screen.

[0101] The waveform data processor displays the generated amplitude-frequency-phase-frequency curve on the digital oscilloscope screen, and the user can intuitively observe and analyze the frequency response characteristics of the waveform. This information provides an important reference for circuit design and troubleshooting.

[0102] The coordinated work of the waveform data collector and the waveform data processor enables a comprehensive analysis of the signal frequency response, greatly improving the practicality and efficiency of the oscilloscope in circuit design and troubleshooting.

[0103] 7) A waveform data tracer, used to store the waveform data of the input and output channels in each frequency sweep process collected by the waveform collector into a waveform data buffer;

[0104] When performing Bode plot analysis, users can select any frequency sweep data through the data record table, and the waveform data tracer will reproduce the input and output channel waveforms of the frequency sweep in the traceback window. In this way, users can observe and analyze the response waveform of the device under test at a specific frequency in detail, which greatly facilitates the research and diagnosis of frequency response characteristics.

[0105] Specifically, the waveform data tracer is configured to perform the following process:

[0106] Step 4.1, data storage: During each frequency sweep, the waveform data of the input and output channels collected by the waveform collector is obtained, and the data is stored in the waveform data buffer in real time.

[0107] Step 4.2, waveform backtracking: After the user selects a certain frequency sweep data in the data record table, the waveform data backtracker will reproduce the waveform of the frequency sweep in the backtracking window, showing the specific waveform conditions of the input and output channels.

[0108] 8) Data recording table, which is used to record the signal amplitude gain and phase difference of the input and output channels during each frequency sweep process.

[0109] Specifically, after each frequency sweep, the signal amplitude gain and phase difference of the input and output channels will be recorded in the data recording table.

[0110] The data record table records the key signal characteristic data of all frequency sweep processes, which is convenient for users to quickly find and locate specific frequency sweep results when analyzing the Bode diagram. Through the data record table, users can easily select any frequency sweep data and reproduce the waveform of the frequency sweep in combination with the waveform data tracer to further analyze the frequency response characteristics.

[0111] The linked backtracking based on the waveform data backtracker and the data record table includes the following steps:

[0112] Step 5.1, establish the association relationship between each data in the data record table and the waveform in the waveform data tracer;

[0113] Step 5.2, obtain the user's sweep frequency data to view the selected area, and select a sweep frequency data according to the selected area;

[0114] Step 5.3, Linked Backtracking: After selecting a certain frequency sweep data, call the corresponding frequency sweep waveform in the waveform data backtracker according to the established association relationship, and reproduce the frequency sweep waveform for detailed analysis.

[0115] 9) Automatic measurement analyzer, used to automatically calculate the frequency response characteristics of the device under test after the frequency sweep is completed;

[0116] Specifically, the DUT frequency response characteristics include the upper cutoff frequency, lower cutoff frequency, bandwidth, gain margin, and phase margin of the DUT. These parameters can help users quickly understand and evaluate the frequency response characteristics of the DUT, greatly improving the analysis efficiency and accuracy.

[0117] The waveform data tracer, data recorder and automatic measurement analyzer together constitute a complete frequency response characteristics analysis system. The waveform data tracer is responsible for storing and tracing waveform data, the data recorder records the signal characteristic data of each frequency sweep, and the automatic measurement analyzer automatically calculates and displays the key frequency response characteristic parameters of the device under test. Through the collaborative work of these three tools, users can efficiently and accurately analyze the frequency response characteristics of the device under test.

[0118] A specific technical solution is to automatically calculate the frequency response characteristics of the device under test, and automatically identify the upper cutoff frequency, lower cutoff frequency, and bandwidth of the device under test, as follows:

[0119] Step 6.1, read the sweep output amplitude gain according to the waveform diagram, sort the sweep output amplitude gain results by size, take the maximum amplitude gain value of the set number, and calculate the maximum average amplitude gain;

[0120] Specifically, the sweep output amplitude gain results can be sorted from small to large, and then the five largest amplitude gain values ​​are taken (to reduce errors) to calculate the maximum average amplitude gain DB. MAX ;

[0121] Step 6.2: Subtract 3DB from the maximum average amplitude gain, that is, DB MAX -3, as the middle gain value;

[0122] Step 6.3: According to the maximum average amplitude gain DB MAX , get the current physical characteristics of the device under test, as follows:

[0123] When the amplitude gain at the starting point of the sweep frequency data is equal to the maximum average amplitude gain DB MAX When the absolute value of the difference is less than 3, the device under test is judged to have low-pass filter characteristics;

[0124] When the amplitude gain at the end point of the sweep data is equal to the maximum amplitude gain DB MAX When the absolute value of the difference is less than 3, the device under test is judged to have high-pass filter characteristics;

[0125] When the amplitude gain at the starting point of the sweep frequency data is equal to the maximum amplitude gain DB MAXThe absolute value of the difference is greater than 3 and the amplitude gain at the end point of the sweep data is greater than the maximum amplitude gain DB MAX When the absolute value of the difference is greater than 3, the device under test is judged to have a bandpass filter characteristic.

[0126] Step 6.4: According to the current physical characteristics of the device under test, the maximum average amplitude gain and the intermediate gain value, the upper cutoff frequency, lower cutoff frequency or bandwidth of the device under test is obtained. The specific method is as follows:

[0127] Step 641: For the low-pass filter characteristic DUT, only the upper cutoff frequency needs to be calculated. The calculation method is to traverse the frequency sweep database once and calculate the amplitude gain DB and DB of all frequency sweep points. MAX -3 distance difference ΔDb i , and for ΔDb i Sorting, the smallest distance difference ΔDb min This is the upper cutoff frequency f of the device under test. up .

[0128] Step 642: For the high-pass filter characteristic DUT, only the lower cutoff frequency needs to be calculated. The calculation method is to traverse the frequency sweep database once and calculate the amplitude gain DB and DB of all frequency sweep points. MAX -3 distance difference ΔDb i , and for ΔDb i Sorting, the smallest distance difference ΔDb min This is the lower cutoff frequency f of the device under test. down .

[0129] Step 643: For the tested device with bandpass filter characteristics, it is necessary to calculate the upper and lower cutoff frequencies and bandwidth. The frequency sweep database needs to be divided into two sub-databases. Then, the upper cutoff frequency f can be calculated by using the above method for calculating low-pass and high-pass characteristics. up With the lower cut-off frequency f up , bandwidth BW = f up -f down .

[0130] Furthermore, the method for calculating the gain margin in automatic measurement is as follows:

[0131] First, the gain margin is defined as: in the amplitude-frequency-phase-frequency curve, when the phase difference of the phase-frequency curve is equal to 0, the amplitude gain DB value of the amplitude-frequency curve corresponding to the frequency value is the gain margin.

[0132] The specific calculation method is: traverse the phase-frequency curve sweep frequency database, and determine the frequency value f corresponding to the phase difference value of 0 on the amplitude-frequency phase-frequency curve ph＝0 , then according to f ph＝0 Determine the corresponding This is the gain margin value.

[0133] Furthermore, the method for calculating the phase margin in automatic measurement is as follows:

[0134] The definition of phase margin is: in the amplitude-frequency phase-frequency curve, the phase difference value of the phase-frequency curve corresponding to the frequency value when the amplitude gain value of the amplitude-frequency curve is equal to 0 is the phase margin.

[0135] The specific calculation method is: traverse the amplitude-frequency curve sweep frequency database, and determine the frequency value f corresponding to the amplitude gain value of 0 on the amplitude-frequency phase-frequency curve db＝0 , then according to f db＝0 Determine the corresponding phase in the phase-frequency curve This is the phase margin value.

[0136] Furthermore, the automatic measurement analyzer is also configured to perform cursor measurement, and the cursor measurement method includes the following steps:

[0137] Step 7.1, obtain the cursor measurement configuration of the configuration interface of the oscilloscope Bode diagram, and when the cursor measurement enabling data is obtained, execute step 7.2;

[0138] When the user needs to start the Bode plot cursor measurement function, find the cursor measurement option in the configuration interface of the oscilloscope Bode plot and enable it.

[0139] Step 7.2, obtaining the selected cursor type, maintaining the corresponding cursor at a set distance according to the cursor type for cursor linkage, and setting the cursor at a specified position according to the cursor position selection data;

[0140] Specifically, the cursor types include horizontal cursors and vertical cursors; horizontal cursors X1 and X2 are used to measure signal frequency, and vertical cursors Y1 and Y2 are used to measure amplitude gain and phase difference. When [Cursor Linkage] is selected, X1 and X2 will maintain a fixed distance and slide left and right with each other, and Y1 and Y2 will maintain a fixed distance and slide up and down with each other;

[0141] The cursor can be placed according to the cursor position. The cursor position data selection can be achieved through operation: through the multi-function knob on the oscilloscope panel or the up, down, left, and right buttons on the configuration interface or by clicking a row of data in the Bode diagram data record table to confirm, the cursor can be placed at the position to be measured.

[0142] Step 7.3, output the measured value and position value between the cursors;

[0143] Specifically, this step realizes the reading of the measurement results, and the output data can be displayed on the oscilloscope interface, including the measurement value between the cursors and the current position value;

[0144] Optionally, the measurement values ​​between the cursors include frequency difference, amplitude gain difference and phase difference; the current position value includes frequency value, amplitude gain value and phase difference value.

[0145] The Bode diagram analysis function of the digital oscilloscope in this embodiment integrates powerful auxiliary analysis and measurement tools. The function interface is shown in the figure below. Figure 5 As shown in the figure, it includes: cursor measurement, automatic measurement of key indicators, frequency sweep data record table and waveform tracing display. Engineers can call these four measurement tools after completing the Bode plot frequency sweep process according to test requirements, which can greatly improve the work efficiency of engineers. In particular, the Bode plot analysis function on the market today does not currently have the function of reviewing the waveform of the input and output channels during the measurement process. The waveform tracing device mentioned in this embodiment solves the problem of engineers wanting to review the waveform.

[0146] Example 2

[0147] Based on Example 1, this embodiment provides a control method for an oscilloscope with a Bode diagram analysis function described in Example 1, including the following steps:

[0148] Step S1: acquiring frequency sweep configuration data for the test piece;

[0149] Step S2, configuring multiple frequency sweep modes, selecting a frequency sweep mode according to the configuration data, matching different frequency sweep modes with different frequency sweep point setting mechanisms, determining the frequency sweep signal parameters of the oscilloscope based on the configuration data, and controlling the signal source module of the oscilloscope itself to output the corresponding frequency sweep signal;

[0150] Step S3, using an interrupt service mechanism and a multi-threaded data synchronization algorithm to collect waveform data generated by the oscilloscope during the frequency sweep process;

[0151] Step S4: Analyze the acquired waveform data to obtain the frequency response characteristics of the device under test.

[0152] A further technical solution, a method for determining configuration data, comprises the following steps:

[0153] Step 1.1, according to the physical characteristics of the DUT, determine the minimum and maximum frequency ranges of the input DUT as the sweep start frequency and end frequency of the Bode plot analysis;

[0154] Step 1.2, determine the voltage value that the device under test can withstand, as the amplitude value of the swept frequency signal for Bode plot analysis;

[0155] Step 1.3, determine the signal input point and output point of the device under test as two reference points for Bode plot analysis, and determine the frequency sweep mode and the number of frequency sweep points;

[0156] Preferably, a logarithmic frequency sweep mode and a frequency sweep point number within the range of [10, 500] may be selected;

[0157] Step 1.4, determine the impedance values ​​of the input and output points of the device under test as the impedance values ​​of the oscilloscope input and output channels; now the user has completed all configurations for Bode plot analysis of the device under test.

[0158] In step 2, the start and end frequencies of the frequency sweep and the amplitude of the frequency sweep signal are determined according to the parameter configuration data; the frequency sweep step algorithm is determined according to the frequency sweep mode set by the user; the frequency sweep signal step value is determined by the frequency sweep start frequency, end frequency, number of frequency sweep points and the frequency sweep step algorithm, thereby determining the frequency sweep signal parameters;

[0159] When performing frequency response tests on circuits or systems, you can flexibly select the sweep mode and sweep points according to different test requirements to efficiently identify the sensitive signal frequency values ​​or signal frequency stability ranges of the circuit or system, thereby greatly improving the efficiency of circuit or system troubleshooting.

[0160] One specific way to achieve this is to use different sweep modes with different sweep point setting mechanisms, specifically:

[0161] 3.1) Use a high-frequency signal to sweep and analyze the circuit or system. The logarithmic sweep mode of the oscilloscope Bode plot function can be used; the specific setting mechanism is as follows:

[0162] Set the "Sweep Number / Decade Number" parameter to 2. The value range of "Sweep Number / Decade Number" is 1 to 8. The smaller the value, the fewer the sweep points and the faster the sweep speed.

[0163] The "start frequency" and "end frequency" of the sweep signal are set to 1KHz and 50MHz respectively; the frequency range of the sweep signal source is [100Hz, 50MHz];

[0164] The signal amplitude is configured according to the maximum rated voltage of the DUT, the oscilloscope input / output channel impedance is matched with the DUT impedance, and the frequency response curve of the DUT is drawn;

[0165] 3.2) Use a low-frequency signal to sweep the circuit or system and analyze it. Use the linear sweep mode of the oscilloscope Bode plot function. The specific setting mechanism is as follows:

[0166] Set the "Sweep Points" parameter to 100. The value range of "Sweep Points" is 10 to 500. The smaller the value, the more sweep points, the slower the sweep speed, and the higher the test accuracy.

[0167] The "start frequency" and "end frequency" of the sweep signal are set to 100Hz and 1KHz respectively; the frequency range of the sweep signal source is [100Hz, 50MHz];

[0168] The signal amplitude is configured according to the maximum rated voltage of the DUT. The input / output channel impedance of the oscilloscope must match the impedance of the DUT, and the frequency response curve of the DUT is drawn.

[0169] Observing abnormal gain fluctuations or changes in the position and amplitude of gain peaks and valleys in the amplitude-frequency characteristic curve may suggest that the parameters of certain components in the circuit deviate from normal values. For example, a decrease in the gain of an amplifier may indicate that its internal components are aging or damaged.

[0170] Observing the phase shift anomaly in the phase-frequency characteristic curve can also reflect problems in the circuit. For example, if the phase change pattern does not match the expected pattern, it may be due to the failure of components such as capacitors and inductors, or problems in the feedback loop.

[0171] In a specific implementation scheme, in step S3, the interrupt service mechanism is as follows: when the oscilloscope generates a fluorescence interrupt, the waveform data collector detects the interrupt signal, and after receiving a preset number of fluorescence interrupt signals, the waveform data collector starts working and performs waveform data collection;

[0172] Specifically, the preset number of waiting interrupts can be set to 3;

[0173] In the above scheme, data acquisition is started after a set number of interrupt signals, and the sweep signal is waited to reach a stable state before starting to collect data, thereby ensuring that the collected data is more accurate and reliable. After reaching the preset number of interrupts, the waveform data collector starts to collect waveform data and stores the data in a specific buffer. This design ensures the stability of the sweep signal and improves the accuracy and reliability of data acquisition.

[0174] In this embodiment, a multi-threaded data synchronization algorithm is used to make the collected data closer to the actual frequency response characteristics of the device under test;

[0175] Optional, multi-threaded data synchronization algorithm, through the semaphore control management acquisition thread and Bode diagram operation thread to access specific resources and share at the same time, the specific algorithm principle diagram is as follows Figure 4 As shown, the definition of the semaphore semphores sem_t semphores and the initialization init_sem(&semphores,0,0) are completed in the main thread. When the oscilloscope is in operation, the acquisition thread is always in the RUN state, and the Bode plot thread will enter the RUN state only when the user clicks the "Start Measurement" button on the Bode plot configuration interface. When the amplitude-frequency and phase-frequency curves are drawn, the Bode plot thread enters the STOP state.

[0176] Furthermore, in step S4, analysis is performed based on the acquired waveform data to implement joint backtracking, including the following process:

[0177] Step S41, quantizing and processing the collected waveform data, and converting the data into an amplitude-frequency-phase-frequency curve according to a frequency sweep mode (logarithmic or linear) determined by the user;

[0178] Data quantization: First, the collected waveform data is standardized and quantized to the coordinate interval of [-1,1]. This step helps to unify the data format and facilitate subsequent processing.

[0179] Mode conversion: According to the sweep mode, the waveform data processor draws amplitude-frequency-phase-frequency curves for the quantized data to show the amplitude and phase response of the system at different frequencies, which can be displayed on the oscilloscope screen.

[0180] Step S42, storing the waveform data of the input and output channels in each frequency sweep process collected by the waveform collector into the waveform data buffer;

[0181] Step S43, constructing a data recording table to record the signal amplitude gain and phase difference of the input and output channels during each frequency sweep process;

[0182] Step S44, establishing an association relationship between each piece of data in the data record table and the waveform in the waveform data buffer;

[0183] Step S45, obtaining a selected area in the data record table, and determining frequency sweep data according to the selected area;

[0184] Step S46: After a certain frequency sweep data is selected, the corresponding frequency sweep waveform in the waveform data tracer is called according to the established association relationship to reproduce the frequency sweep waveform.

[0185] Specifically, the DUT frequency response characteristics include the upper cutoff frequency, lower cutoff frequency, bandwidth, gain margin, and phase margin of the DUT. These parameters can help users quickly understand and evaluate the frequency response characteristics of the DUT, greatly improving the analysis efficiency and accuracy.

[0186] A specific technical solution is to automatically calculate the frequency response characteristics of the device under test, and automatically identify the upper cutoff frequency, lower cutoff frequency, and bandwidth of the device under test, as follows:

[0187] Step 6.1, read the sweep output amplitude gain according to the waveform diagram, sort the sweep output amplitude gain results by size, take the maximum amplitude gain value of the set number, and calculate the maximum average amplitude gain;

[0188] Specifically, the sweep output amplitude gain results can be sorted from small to large, and then the five largest amplitude gain values ​​are taken (to reduce errors) to calculate the maximum average amplitude gain DB. MAX ;

[0189] Step 6.2, subtract the set value from the maximum average amplitude gain to obtain the intermediate gain value;

[0190] The set value can be set as needed, such as 3DB, that is, DB MAX -3,

[0191] Step 6.3: According to the maximum average amplitude gain DB AAX , get the current physical characteristics of the device under test, as follows:

[0192] When the amplitude gain at the starting point of the sweep frequency data is equal to the maximum average amplitude gain DB MAX When the absolute value of the difference is less than 3, the device under test is judged to have low-pass filter characteristics;

[0193] When the amplitude gain at the end point of the sweep data is equal to the maximum amplitude gain DB MAX When the absolute value of the difference is less than 3, the device under test is judged to have high-pass filter characteristics;

[0194] When the amplitude gain at the starting point of the sweep frequency data is equal to the maximum amplitude gain DB MAX The absolute value of the difference is greater than 3 and the amplitude gain at the end point of the sweep data is greater than the maximum amplitude gain DB mAX When the absolute value of the difference is greater than 3, the device under test is judged to have a bandpass filter characteristic.

[0195] Step 6.4: According to the current physical characteristics of the device under test, the maximum average amplitude gain and the intermediate gain value, the upper cutoff frequency, lower cutoff frequency or bandwidth of the device under test is obtained. The specific method is as follows:

[0196] Step 641: For the low-pass filter characteristic DUT, only the upper cutoff frequency needs to be calculated. The calculation method is to traverse the frequency sweep database once and calculate the amplitude gain DB and DB of all frequency sweep points. MAx -3 distance difference ΔDb i , and for ΔDb i Sort by the smallest distance interpolation ΔDb min This is the upper cutoff frequency f of the device under test. up .

[0197] Step 642: For the high-pass filter characteristic DUT, only the lower cutoff frequency needs to be calculated. The calculation method is to traverse the frequency sweep database once and calculate the amplitude gain DB and DB of all frequency sweep points. MAx -3 distance difference ΔDb i , and for ΔDbi Sort by the smallest distance interpolation ΔDb min This is the lower cutoff frequency f of the device under test. down .

[0198] Step 643: For the tested device with bandpass filter characteristics, it is necessary to calculate the upper and lower cutoff frequencies and bandwidth. The frequency sweep database needs to be divided into two sub-databases. Then, the upper cutoff frequency f can be calculated by using the above method for calculating low-pass and high-pass characteristics. up With the lower cut-off frequency f up , bandwidth BW = f up -f down .

[0199] Furthermore, the method for calculating the gain margin in automatic measurement is as follows:

[0200] First, the gain margin is defined as: in the amplitude-frequency-phase-frequency curve, when the phase difference of the phase-frequency curve is equal to 0, the amplitude gain DB value of the amplitude-frequency curve corresponding to the frequency value is the gain margin.

[0201] The specific calculation method is: traverse the phase-frequency curve sweep frequency database, and determine the frequency value f corresponding to the phase difference value of 0 on the amplitude-frequency phase-frequency curve ph＝0 , then according to f ph＝0 , determine the corresponding This is the gain margin value.

[0202] Furthermore, the method for calculating the phase margin in automatic measurement is as follows:

[0203] The definition of phase margin is: in the amplitude-frequency phase-frequency curve, the phase difference value of the phase-frequency curve corresponding to the frequency value when the amplitude gain value of the amplitude-frequency curve is equal to 0 is the phase margin.

[0204] The specific calculation method is: traverse the amplitude-frequency curve sweep frequency database, and determine the frequency value f corresponding to the amplitude gain value of 0 on the amplitude-frequency phase-frequency curve db＝0 , then according to f db＝0 Determine the corresponding phase in the phase-frequency curve This is the phase margin value.

[0205] The cursor measurement method includes the following steps:

[0206] Step 7.1 obtains the cursor measurement configuration of the configuration interface of the oscilloscope Bode plot. When the cursor measurement enabling data is obtained, execute step 7.2;

[0207] When the user needs to start the Bode plot cursor measurement function, find the cursor measurement option in the configuration interface of the oscilloscope Bode plot and enable it.

[0208] Step 7.2 obtains the selected cursor type, maintains the corresponding cursor at a set distance according to the cursor type to perform cursor linkage, and sets the cursor at a specified position according to the cursor position selection data;

[0209] Specifically, the cursor types include horizontal cursors and vertical cursors; horizontal cursors X1 and X2 are used to measure signal frequency, and vertical cursors Y1 and Y2 are used to measure amplitude gain and phase difference. When "Cursor linkage" is selected, X1 and X2 will maintain a fixed distance and slide left and right with each other, and Y1 and Y2 will maintain a fixed distance and slide up and down with each other;

[0210] The cursor can be placed according to the cursor position. The cursor position data selection can be achieved through operation: through the multi-function knob on the oscilloscope panel or the up, down, left, and right buttons on the configuration interface or by clicking a row of data in the Bode diagram data record table to confirm, the cursor can be placed at the position to be measured.

[0211] Step 7.3 Output the measured value and position value between the cursors;

[0212] Specifically, this step realizes the reading of the measurement results, and the output data can be displayed on the oscilloscope interface, including the measurement value between the cursors and the current position value;

[0213] Optionally, the measurement values ​​between the cursors include frequency difference, amplitude gain difference and phase difference; the current position value includes frequency value, amplitude gain value and phase difference value.

[0214] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

[0215] Although the above describes the specific implementation methods of the present disclosure in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present disclosure. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims

1. An oscilloscope with Bode diagram analysis function, characterized in that: The oscilloscope comprises a sweep signal generating unit, a sweep control unit and a waveform processing unit; The sweep frequency signal generating unit includes a sweep frequency analyzer, which is configured with a plurality of sweep frequency modes and generates a sweep frequency signal according to the selected sweep frequency mode and the configured parameters; A frequency sweep control acquisition unit, used to control the frequency sweep process to obtain waveform data; The waveform processing unit is used to automatically process the waveform data, read the relevant values ​​of the waveform, calculate the frequency response characteristics of the device under test, and realize the linkage backtracking of the data based on the set data backtracker and data recording table.

2. An oscilloscope with Bode plot analysis function as claimed in claim 1, characterized in that: The sweep signal generating unit comprises a configuration data acquisition module, a sweep analyzer and a signal source controller connected in sequence; A configuration data acquisition module is configured to acquire the user's frequency scanning configuration data; A swept frequency analyzer, configured with two swept frequency modes, the swept frequency analyzer being configured to determine swept frequency signal parameters of the oscilloscope according to the acquired configuration parameters; The signal source controller is used to control the signal source module of the digital oscilloscope to output the corresponding sweep signal according to the sweep signal parameters determined by the sweep analyzer.

3. An oscilloscope with Bode plot analysis function as claimed in claim 2, characterized in that: The method for determining the frequency sweep configuration data comprises the following steps: According to the physical characteristics of the DUT, determine the minimum and maximum frequency ranges of the input DUT as the start and end frequencies of the frequency sweep for Bode plot analysis; Determine the voltage value that the device under test can withstand, which is used as the amplitude value of the swept frequency signal for Bode plot analysis; Determine the signal input point and output point of the device under test as two reference points for Bode plot analysis, and determine the frequency sweep mode and the number of sweep points; Determine the impedance values ​​of the input and output points of the device under test as the impedance values ​​of the oscilloscope input and output channels; Alternatively, two sweep modes include logarithmic sweep and linear sweep; The theoretical model of the logarithmic sweep mode is expressed as: Among them, f current is the instantaneous frequency of the current output, f start is the sweep start frequency, f stop is the sweep end frequency, p sum is the total number of sweep points, p current is the current frequency sweep point number; The theoretical model of the linear frequency sweep mode is expressed as: Among them, f current is the instantaneous frequency of the current output, f start is the sweep start frequency, f stop is the sweep end frequency, p sum is the total number of sweep points, p current The current frequency sweep points.

4. An oscilloscope with Bode plot analysis function as claimed in claim 1, characterized in that: The frequency sweep control unit includes a time base adjuster, a vertical adjuster and a waveform data collector; The time base adjuster and vertical adjuster are used to adjust the horizontal time base and vertical range so that the signal waveform can be displayed at the set position on the screen; The waveform data collector is configured to collect waveform data generated by the oscilloscope during the frequency sweep process in real time.

5. An oscilloscope with Bode plot analysis function as claimed in claim 2, characterized in that: The waveform data collector is deployed at the fluorescent interrupt type service interface of the digital oscilloscope, and data collection is realized through the interrupt service mechanism; the switch of the waveform data collector is deployed in the Bode diagram sweep thread. When the sweep thread starts working, the collector enable switch is turned on according to the interrupt mechanism; The interrupt service mechanism is specific as follows: when the oscilloscope generates a fluorescence interrupt, the waveform data collector detects the interrupt signal, and after receiving a preset number of fluorescence interrupt signals, the waveform data collector starts working and performs waveform data collection.

6. An oscilloscope with Bode plot analysis function as claimed in claim 1, characterized in that: The waveform processing unit includes a waveform data processor, a waveform data tracer, a data recorder, and an automatic measurement analyzer; A waveform data processor is configured to quantize and process the collected waveform data and convert the data into an amplitude-frequency-phase-frequency curve according to a frequency sweep mode; The waveform data tracer is used to store the waveform data of the input and output channels in each frequency sweep process collected by the waveform collector into the waveform data buffer; Data recording table, used to record the signal amplitude gain and phase difference of input and output channels during each frequency sweep process; Automatic measurement analyzer, used to automatically calculate the frequency response characteristics of the device under test after the frequency sweep is completed.

7. An oscilloscope with Bode plot analysis function as claimed in claim 6, characterized in that: The linked backtracking based on the waveform data backtracker and the data record table includes the following steps: Establish the association relationship between each data in the data record table and the waveform in the waveform data tracer; Get the user's frequency sweep data to view the selected area, and select a frequency sweep data according to the selected area; After selecting a certain frequency sweep data, the corresponding frequency sweep waveform in the waveform data tracer is called according to the established association relationship to reproduce the frequency sweep waveform; Alternatively, the frequency response characteristics of the device under test can be automatically calculated, and the upper cutoff frequency, lower cutoff frequency, and bandwidth of the device under test can be automatically identified as follows: According to the waveform diagram, read the sweep output amplitude gain, sort the sweep output amplitude gain results by size, take the maximum amplitude gain values ​​of the set number, and calculate the maximum average amplitude gain; Subtract the set value from the maximum average amplitude gain to obtain the intermediate gain value. According to the maximum average amplitude gain, the physical characteristics of the current device under test are obtained; According to the current physical characteristics of the device under test, the maximum average amplitude gain and the intermediate gain value, the upper cutoff frequency, the lower cutoff frequency or the bandwidth of the device under test is obtained.

8. The control method of an oscilloscope with Bode diagram analysis function according to any one of claims 1 to 7, characterized in that: The steps include: For the test piece, obtain the frequency sweep configuration data; Configure multiple sweep modes, select the sweep mode according to the configuration data, match different sweep modes with different sweep point setting mechanisms, determine the sweep signal parameters of the oscilloscope based on the configuration data, and control the oscilloscope's own signal source module to output the corresponding sweep signal; Through the interrupt service mechanism, a multi-threaded data synchronization algorithm is used to collect the waveform data generated by the oscilloscope during the frequency sweep process; The acquired waveform data is analyzed to obtain the frequency response characteristics of the device under test.

9. The control method according to claim 8, characterized in that: Analyze the acquired waveform data to achieve joint backtracking, including the following process: Quantify and process the acquired waveform data, and convert the data into amplitude-frequency-phase-frequency curves according to the frequency sweep mode determined by the user; The waveform data of the input and output channels collected by the waveform collector in each frequency sweep process are stored in the waveform data buffer; Construct a data record table to record the signal amplitude gain and phase difference of the input and output channels during each frequency sweep; Establishing the association relationship between each data in the data record table and the waveform in the waveform data buffer; Obtain the selected area in the data record table, and determine the frequency sweep data according to the selected area; After a certain frequency sweep data is selected, the corresponding frequency sweep waveform in the waveform data tracer is called according to the established association relationship to reproduce the frequency sweep waveform.

10. The control method according to claim 8, characterized in that: Automatically calculate the frequency response characteristics of the device under test, and automatically identify the upper cutoff frequency, lower cutoff frequency, and bandwidth of the device under test. The details are as follows: According to the waveform, read the sweep output amplitude gain, sort the sweep output amplitude gain results by size, take the maximum amplitude gain values ​​of the set number, and calculate the maximum average amplitude gain; Subtract the set value from the maximum average amplitude gain to obtain the intermediate gain value. According to the maximum average amplitude gain, the physical characteristics of the current device under test are obtained; According to the current physical characteristics of the device under test, the maximum average amplitude gain and the intermediate gain value, the upper cutoff frequency, the lower cutoff frequency or the bandwidth of the device under test is obtained.

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