A method and apparatus for processing a chirp signal, and a storage medium

Abstract

The application discloses a method and device for processing a linear frequency modulation signal and a storage medium. The method comprises the following steps: obtaining first amplitude data of a specific frequency band of a to-be-tested object; constructing a linear frequency modulation signal with the same center frequency and bandwidth as the specific frequency band, the linear frequency modulation signal being represented by second amplitude data; performing interpolation on the first amplitude data to obtain third amplitude data, the third amplitude data comprising the same amount of data as the second amplitude data; superimposing the third amplitude data on the second amplitude data to obtain target amplitude data; performing pulse compression on a frequency modulation signal corresponding to the target amplitude data, and obtaining at least one of a main lobe broadening ratio, a peak sidelobe ratio and an integrated sidelobe ratio based on a pulse compression result. Thus, the pulse compression result of the linear frequency modulation signal can be derived, and the performance of the to-be-tested object can be accurately judged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of synthetic aperture radar (SAR) test technology, and in particular to a linear frequency modulation signal processing method and device and storage medium. BACKGROUND

[0002] Generally, the SAR generates a linear frequency modulation signal pulse train with a certain bandwidth and a certain time width. For the linear frequency modulation signal, a very important indicator for measuring its performance is the in-band amplitude fluctuation or in-band amplitude flatness. In the integrated test of the SAR system, the judgment of the performance of the transmission channel and the receiving channel is the pulse compression of the linear frequency modulation signal in the channel, and the main indicators concerned are the compressed main lobe spread ratio, the peak side lobe ratio and the integrated side lobe ratio, which cannot be directly associated with the in-band amplitude fluctuation of the transmission channel and the receiving channel obtained by using the spectrum analyzer, especially in the debugging stage of the radio frequency microwave assembly before the integrated test of the SAR system. In the debugging stage, the in-band amplitude fluctuation measured by the spectrum analyzer can be obtained, and the pulse compression result corresponding to the in-band amplitude fluctuation cannot be obtained by pulse compression of the test data. SUMMARY

[0003] To solve the above technical problems, the present application provides a linear frequency modulation signal processing method, device and storage medium.

[0004] The technical scheme of the present application is implemented as follows:

[0005] In one aspect, the present application provides a linear frequency modulation signal processing method, which comprises:

[0006] obtaining first amplitude data of a specific frequency band of a to-be-tested component;

[0007] constructing a linear frequency modulation signal with the same center frequency and bandwidth as the specific frequency band, and the linear frequency modulation signal is represented by second amplitude data;

[0008] interpolating the first amplitude data to obtain third amplitude data, the data amount included in the third amplitude data being the same as the data amount included in the second amplitude data;

[0009] superimposing the third amplitude data on the second amplitude data to obtain target amplitude data;

[0010] pulse compressing a frequency modulation signal corresponding to the target amplitude data, and obtaining at least one of a main lobe spread ratio, a peak side lobe ratio and an integrated side lobe ratio based on the pulse compression result.

[0011] In the above scheme, the method further comprises:

[0012] determine whether at least one of the main lobe broadening ratio, the peak sidelobe ratio and the integrated sidelobe ratio meets a system integration test index;

[0013] If the system integration test index is not met, the measured piece is debugged, and the processing method of the linear frequency modulation signal is repeatedly executed.

[0014] In another aspect, the embodiments of the present application provide a processing device of a linear frequency modulation signal, and the processing device comprises:

[0015] An acquisition unit is configured to acquire first amplitude data of a measured piece in a specific frequency band;

[0016] A processing unit is configured to construct a linear frequency modulation signal with a center frequency and a bandwidth same as those of the specific frequency band, the linear frequency modulation signal being represented by second amplitude data; perform interpolation on the first amplitude data to obtain third amplitude data, the third amplitude data including a same amount of data as the second amplitude data; and superimpose the third amplitude data on the second amplitude data to obtain target amplitude data.

[0017] A pulse compression unit is configured to perform pulse compression on a frequency modulation signal corresponding to the target amplitude data, and obtain at least one of a main lobe broadening ratio, a peak sidelobe ratio and an integrated sidelobe ratio based on a pulse compression result.

[0018] In the above scheme, the processing device further comprises:

[0019] A determination unit is configured to determine whether at least one of the main lobe broadening ratio, the peak sidelobe ratio and the integrated sidelobe ratio meets a system integration test index.

[0020] A debugging unit is configured to debug the measured piece if the system integration test index is not met, and trigger the acquisition unit, the processing unit and the pulse compression unit to repeatedly execute their functions.

[0021] In another aspect, the embodiments of the present application further provide a storage medium, and the storage medium stores executable instructions, when the executable instructions are executed by at least one processor, the processing method of the linear frequency modulation signal is implemented.

[0022] The embodiment of the present application provides a linear frequency modulation signal processing method, device and storage medium, the method comprises the following steps: obtaining first amplitude data of a to-be-tested object in a specific frequency band; constructing a linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band, the linear frequency modulation signal is represented by second amplitude data; interpolating the first amplitude data to obtain third amplitude data, the data amount included in the third amplitude data is the same as the data amount included in the second amplitude data; superimposing the third amplitude data on the second amplitude data to obtain target amplitude data; performing pulse compression on a frequency modulation signal corresponding to the target amplitude data, and obtaining at least one of a main lobe broadening ratio, a peak sidelobe ratio and an integrated sidelobe ratio based on a pulse compression result. The in-band amplitude fluctuation of the radio frequency microwave assembly measured by using the spectrum analyzer is associated with the system integration test index, so that the performance of the to-be-tested object can be accurately judged, the debugging direction is clear, the number of debugging times is reduced, and rework is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A flowchart of a traditional SAR system integration test process for a to-be-tested object;

[0024] Figure 2 A flowchart of a traditional process for measuring the in-band amplitude fluctuation of a to-be-tested object by using a spectrum analyzer;

[0025] Figure 3 A flowchart of a linear frequency modulation signal processing method provided by the embodiment of the present application;

[0026] Figure 4 An in-band amplitude fluctuation diagram of a to-be-tested object obtained by using a spectrum analyzer provided by the embodiment of the present application;

[0027] Figure 5 An amplitude-frequency characteristic diagram of an ideal linear frequency modulation signal with the same center frequency point and bandwidth created in a data analysis tool provided by the embodiment of the present application;

[0028] Figure 6 An amplitude-frequency characteristic diagram of a linear frequency modulation signal after interpolating the amplitude data of a to-be-tested object in a data analysis tool provided by the embodiment of the present application;

[0029] Figure 7 A target amplitude-frequency characteristic diagram obtained by superimposing the interpolated linear frequency modulation signal on the ideal linear frequency modulation signal in a data analysis tool provided by the embodiment of the present application;

[0030] Figure 8 A comparison diagram of a pulse compression result of a frequency modulation signal corresponding to target amplitude data and a pulse compression result of an ideal linear frequency modulation signal in a data analysis tool provided by the embodiment of the present application;

[0031] Figure 9 A structure schematic diagram of a linear frequency modulation signal processing device provided by an embodiment of the present application is provided; DETAILED DESCRIPTION

[0032] Generally, the SAR generates a linear frequency modulation signal pulse train with a certain bandwidth and a certain time width, radiates to a designated region through an antenna, receives ground echo and collects to obtain radar raw data. The linear frequency modulation signal bandwidth transmitted and received by the high-resolution SAR often needs to reach at least 1 GHz, and in some cases, the bandwidth may need to be close to 4 GHz.

[0033] For the linear frequency modulation signal, a very important indicator for measuring its performance is the in-band amplitude fluctuation or in-band amplitude flatness in the frequency domain. In theory, the ideal linear frequency modulation signal has a characteristic of 0 dB in-band amplitude fluctuation in the frequency domain, but due to the non-ideal nature of the actual radio frequency microwave devices, and the complex impedance matching between the devices, circuits and process measures, the transmission channel and the receiving channel of the SAR system will deteriorate the in-band amplitude fluctuation of the linear frequency modulation signal.

[0034] Figure 1 A flowchart of a process for the traditional SAR system to perform integrated testing on a measured object is provided. As shown in Figure 1 The transmission channel and the receiving channel of the SAR system are composed of a large number of radio frequency microwave devices, such as low-noise amplifiers, power amplifiers, mixers, filters, microwave switches, power dividers, isolators, etc., which are of various types and constitute circuits and components of different functions. When testing the in-band amplitude fluctuation of the radio frequency microwave devices, circuits and components, the instruments used are general instruments, mainly signal sources, spectrum analyzers, oscilloscopes and vector network analyzers. Among them, the domestic oscilloscope is limited by high-speed digital devices, and its collectable frequency is relatively low, generally cannot meet the testing requirements above 4 GHz, while the measurable frequency of the domestic signal source, spectrum analyzer and vector network analyzer can reach 40 GHz or even 110 GHz, which can meet most testing scenarios. The signal source outputs a sweep signal with a certain bandwidth, which is more convenient and flexible in combination with the spectrum analyzer to observe the in-band amplitude fluctuation of the measured object in the frequency domain, and is also easier to obtain than the vector network analyzer.

[0035] Figure 2 A flowchart of a process for the traditional SAR system to perform integrated testing on a measured object is provided. As shown in Figure 2As shown, before the SAR system integration test, the radio frequency microwave assembly debugging stage. During debugging, the in-band amplitude fluctuation measured by the spectrum analyzer cannot be obtained. The pulse compression result corresponding to the in-band amplitude fluctuation cannot be obtained by pulse compression on the test data. However, when the SAR system is integrated and tested, the performance of the transmit channel and the receive channel is judged by pulse compression on the linear frequency modulation signal in the channel. The main indicators concerned are the compressed main lobe spread ratio, the peak side lobe ratio and the integrated side lobe ratio, which cannot be directly associated with the in-band amplitude fluctuation of the transmit channel and the receive channel obtained by using the spectrum analyzer.

[0036] To solve the above technical problems, the embodiment of the present application provides a linear frequency modulation signal processing method, device and storage medium.

[0037] In order to be able to more detailedly understand the features and technical contents of the present application, the implementation of the present application is described in detail below in combination with the drawings, and the drawings are only used for reference and do not limit the present application.

[0038] Figure 3 A flowchart of a linear frequency modulation signal processing method provided by the embodiment of the present application is shown in Figure 3 The method comprises the following steps:

[0039] Step 301: obtaining the first amplitude data of the measured object in a specific frequency band.

[0040] Step 302: constructing a linear frequency modulation signal with the same center frequency and bandwidth as the specific frequency band, and the linear frequency modulation signal is represented by the second amplitude data.

[0041] Step 303: interpolating the first amplitude data to obtain the third amplitude data, and the data amount included in the third amplitude data is the same as the data amount included in the second amplitude data.

[0042] Step 304: superimposing the third amplitude data on the second amplitude data to obtain the target amplitude data.

[0043] Step 305: pulse compression on the frequency modulation signal corresponding to the target amplitude data, and obtaining at least one of the main lobe spread ratio, the peak side lobe ratio and the integrated side lobe ratio based on the pulse compression result.

[0044] Further, in some optional real-time manner, the method further comprises the following steps:

[0045] Step 306: judging whether at least one of the main lobe spread ratio, the peak side lobe ratio and the integrated side lobe ratio obtained satisfies the system integration test index. If yes, step 307 is executed; if no, step 301 is repeatedly executed.

[0046] Step 307: output the result of the pulse compression.

[0047] For the above step 301, the obtaining the first amplitude data of the measured object in the specific frequency band comprises: testing the measured object by a spectrum analyzer to obtain amplitude-frequency data of the measured object in the specific frequency band; wherein the amplitude-frequency data represents that the in-band amplitude fluctuation of the measured object in the specific frequency band is presented on the spectrum analyzer; and the amplitude data in the amplitude-frequency data is obtained as the first amplitude data.

[0048] In some embodiments, the measured object can be, but is not limited to, a radio frequency microwave component.

[0049] In some embodiments, the specific frequency band can be defined by a center frequency point and a bandwidth. For example, the center frequency point is f1, the bandwidth is B1, and the specific frequency band is the frequency spectrum range defined by {f1-B1 / 2, f1+B1 / 2}.

[0050] In an example, taking the measured object as a radio frequency microwave component, the center frequency point and the bandwidth of the specific frequency band are 1 GHz and 1.2 GHz respectively, and the radio frequency microwave component is tested by using the spectrum analyzer. The shape of the in-band amplitude fluctuation of the radio frequency microwave component in the above specific frequency band is shown in the following figure. Figure 4

[0051] After obtaining the amplitude-frequency data of the measured object in the specific frequency band by the above scheme, not only the in-band amplitude fluctuation shape corresponding to the amplitude-frequency data can be presented on the screen of the spectrum analyzer, but further, the amplitude data can be obtained from the amplitude-frequency data, and the amplitude data is the first amplitude data.

[0052] In some embodiments, the amplitude data can be obtained from the amplitude-frequency data by the following method: a user operates the spectrum analyzer to save the amplitude-frequency data corresponding to the in-band amplitude fluctuation presented in the display screen in the form of “track” to obtain an Excel table with a suffix of.csv, the table has a total of 2 columns of data, which are the frequency point and the amplitude with a corresponding relationship, and the amplitude data is obtained from the table as the first amplitude data, which needs to be imported into a data analysis tool in subsequent processing.

[0053] The “data analysis tool” described in the embodiments of the present application can be, but is not limited to, MATLAB.

[0054] For the above step 302, the constructing the linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band comprises: constructing the linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band by a data analysis tool.

[0055] ​In one example, the center frequency and bandwidth of the specific frequency band are 1 GHz and 1.2 GHz respectively, and an ideal LFM signal with the center frequency and bandwidth of 1 GHz and 1.2 GHz respectively is created in MATLAB, and the amplitude-frequency characteristic of the LFM signal is as shown in Figure 5 .

[0056] For the step 303, the interpolation of the first amplitude-frequency data to obtain the third amplitude data includes: importing the first amplitude-frequency data into the data analysis tool, and interpolating the first amplitude-frequency data by the data analysis tool to obtain the third amplitude data.

[0057] In one example, the MATLAB interpolates the imported first amplitude data, the interpolation algorithm is the interpft function in the MATLAB function library, and the third amplitude data (i.e. the amplitude data corresponding to the in-band amplitude fluctuation) obtained after interpolation includes the same amount of data as the second amplitude data (i.e. the amplitude data corresponding to the LFM signal), and the amplitude-frequency characteristic corresponding to the third amplitude data is as shown in Figure 6 .

[0058] For the step 304, the superposition of the third amplitude data on the second amplitude data includes: superimposing the third amplitude data on the second amplitude data by the data analysis tool.

[0059] In one example, since the third amplitude data (i.e. the amplitude data corresponding to the in-band amplitude fluctuation) includes the same amount of data as the second amplitude data (i.e. the amplitude data corresponding to the LFM signal), the superposition of the two can be realized. After the superposition of the two by the MATLAB, the amplitude-frequency characteristic corresponding to the obtained amplitude data is as shown in Figure 7 . Figure 7 The amplitude-frequency characteristic shown in Figure 5 can be understood as the superposition of the amplitude-frequency characteristic shown in Figure 6 , Figure 7 The result of the superposition of the in-band amplitude fluctuation on the LFM signal or the result of the LFM signal superimposed with the in-band amplitude fluctuation is presented.

[0060] For the step 305, the pulse compression of the frequency modulation signal corresponding to the target amplitude data includes: pulse compression of the frequency modulation signal corresponding to the target amplitude data by the data analysis tool.

[0061] In one example, the MATLAB pulse compresses the frequency modulation signal corresponding to the target amplitude data (the result of the LFM signal superimposed with the in-band amplitude fluctuation), and at least one of the main lobe broadening ratio, the peak sidelobe ratio and the integrated sidelobe ratio can be obtained. As shown inFigure 8 The pulse compression results of the ideal linear frequency modulation signal and the linear frequency modulation signal superimposed with the in-band amplitude fluctuation are given, according to Figure 8 The pulse compression results shown in the figure can be analyzed to obtain the corresponding main lobe spread ratio, peak sidelobe ratio and integrated sidelobe ratio.

[0062] In some embodiments, the results obtained by pulse compression of the target amplitude data corresponding to the frequency modulation signal and the results obtained by pulse compression of the ideal linear frequency modulation signal are compared, including three main indicators: main lobe spread ratio, peak sidelobe ratio and integrated sidelobe ratio. As shown in the following table, the target pulse compression refers to pulse compression of the target amplitude data corresponding to the frequency modulation signal; the ideal pulse compression refers to pulse compression of the ideal linear frequency modulation signal.

[0063] Indicator Main lobe broadening ratio Peak side lobe ratio Integrated side lobe ratio Ideal pulse compression 1 -13.37 dB -13.37 dB Target pulse compression 0.9991 -13.37 dB -13.37 dB

[0064] Specifically, the present application can derive the pulse compression results of the linear frequency modulation signal corresponding to the in-band amplitude fluctuation of the measured object, i.e. the main lobe spread ratio, the peak sidelobe ratio and the integrated sidelobe ratio, by measuring the in-band amplitude fluctuation of the measured object with a spectrum analyzer, so that the performance of the measured object can be accurately judged during the debugging stage; in the case of determined RF microwave device and circuit design, the debugging results of each stage can be compared with the SAR system integrated test indicators, avoiding the invalid debugging process and reducing the number of debugging.

[0065] Figure 9 A structure diagram of a linear frequency modulation signal processing device provided by an embodiment of the present application is shown in FIG. 1. Figure 9 As shown in the figure, the processing device comprises:

[0066] The processing unit 901 is configured to acquire first amplitude data of a measured object in a specific frequency band.

[0067] The processing unit 902 is configured to construct a linear frequency modulation signal with the same center frequency and bandwidth as the specific frequency band, the linear frequency modulation signal being represented by second amplitude data; interpolate the first amplitude data to obtain third amplitude data, the third amplitude data including the same amount of data as the second amplitude data; and superimpose the third amplitude data on the second amplitude data to obtain target amplitude data.

[0068] The pulse compression unit 903 is configured to pulse compress a frequency modulation signal corresponding to the target amplitude data, and obtain at least one of a main lobe spread ratio, a peak sidelobe ratio and an integrated sidelobe ratio based on the pulse compression result.

[0069] The judging unit 904 is configured to judge whether at least one of the obtained main lobe broadening ratio, peak side lobe ratio and integrated side lobe ratio meets the system integration test index.

[0070] The debugging unit 905 is configured to debug the DUT if the system integration test index is not met, and trigger the obtaining unit, the processing unit and the pulse compression unit to repeatedly perform their functions.

[0071] In some embodiments, the obtaining unit 901 is configured to test the DUT by a spectrum analyzer to obtain amplitude-frequency data of the DUT in a specific frequency range; wherein the amplitude-frequency data is used to present the in-band amplitude fluctuation of the DUT in the specific frequency range on the spectrum analyzer; and amplitude data in the amplitude-frequency data is obtained as the first amplitude data.

[0072] The embodiments of the present application provide a storage medium, and the storage medium stores executable instructions. When the executable instructions are executed by at least one processor, the processing method of the linear frequency modulation signal is implemented.

[0073] The technical solutions disclosed in the embodiments of the present application can be combined arbitrarily without conflict.

[0074] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application.

Claims

1. A method of processing a chirp signal, characterized by, The method comprises: obtaining first amplitude data of a measured object in a specific frequency band; constructing a linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band, the linear frequency modulation signal being represented by second amplitude data; interpolating the first amplitude data to obtain third amplitude data, the third amplitude data including the same amount of data as the second amplitude data; superimposing the third amplitude data on the second amplitude data to obtain target amplitude data; performing pulse compression on a frequency modulation signal corresponding to the target amplitude data, and obtaining at least one of a main lobe broadening ratio, a peak sidelobe ratio, and an integrated sidelobe ratio based on a pulse compression result; wherein the obtaining of the first amplitude data of the measured object in the specific frequency band comprises: testing the measured object by a spectrum analyzer to obtain amplitude-frequency data of the measured object in the specific frequency band; wherein the amplitude-frequency data is used to present in-band amplitude fluctuation of the measured object in the specific frequency band on the spectrum analyzer; and obtaining amplitude data in the amplitude-frequency data as the first amplitude data; the constructing of the linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band comprises: constructing the linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band by a data analysis tool; the interpolating of the first amplitude data to obtain the third amplitude data comprises: importing the first amplitude data into the data analysis tool, and interpolating the first amplitude data by the data analysis tool to obtain the third amplitude data; the superimposing of the third amplitude data on the second amplitude data comprises: superimposing the third amplitude data on the second amplitude data by the data analysis tool; the pulse compression on the frequency modulation signal corresponding to the target amplitude data comprises: pulse compression on the frequency modulation signal corresponding to the target amplitude data by the data analysis tool.

2. The treatment method according to claim 1, characterized in that, The method further comprises: judging whether the obtained at least one of the main lobe broadening ratio, the peak sidelobe ratio, and the integrated sidelobe ratio meets a system integration test index; if the system integration test index is not met, debugging the measured object, and repeatedly executing the linear frequency modulation signal processing method.

3. A processing device for a chirp signal, characterized in that The processing device comprises: an obtaining unit configured to obtain first amplitude data of a measured object in a specific frequency band; a processing unit configured to construct a linear frequency modulation signal with the same center frequency point and bandwidth as the specific frequency band, the linear frequency modulation signal being represented by second amplitude data; interpolate the first amplitude data to obtain third amplitude data, the third amplitude data including the same amount of data as the second amplitude data; and superimpose the third amplitude data on the second amplitude data to obtain target amplitude data; a pulse compression unit configured to perform pulse compression on a frequency modulation signal corresponding to the target amplitude data, and obtain at least one of a main lobe broadening ratio, a peak sidelobe ratio, and an integrated sidelobe ratio based on a pulse compression result. The acquisition unit is further configured to test the measured object by a spectrum analyzer to obtain amplitude-frequency data of the measured object in a specific frequency band; the amplitude-frequency data is used to present in-band amplitude fluctuation of the measured object in the specific frequency band on the spectrum analyzer; and amplitude data in the amplitude-frequency data is obtained as the first amplitude data. The processing device further includes a judging unit configured to judge whether at least one of the obtained main lobe broadening ratio, peak side lobe ratio and integrated side lobe ratio meets a system integration test index; and a debugging unit configured to debug the measured object if the system integration test index is not met, and trigger the acquisition unit, the processing unit and the pulse compression unit to repeatedly perform their functions.

4. A storage medium, characterized by The storage medium stores executable instructions, and when the executable instructions are executed by at least one processor, the method in any one of claims 1 to 2 is implemented.

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