Electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna

Abstract

The invention provides an electromagnetic compatibility test method for a spaceborne synthetic aperture radar antenna and a data transmission antenna, and provides a method for fixing a waveguide slot unit module on a scanning frame in order to solve the problems that time and labor are wasted and repetition exists when a complete synthetic aperture radar antenna state is constructed in a scheme stage. By moving the scanning frame and adjusting the relative position relation between the data transmission antenna and the scanning frame, the electromagnetic compatibility test of the spaceborne synthetic aperture radar antenna and the data transmission antenna is completed. According to the method, the electromagnetic compatibility condition of the synthetic aperture radar antenna and the data transmission antenna can be obtained without constructing a complete synthetic aperture radar antenna, so that the development cost in a scheme stage is reduced; the electromagnetic compatibility test between the spaceborne synthetic aperture radar antenna and the data transmission antenna can be quickly completed, the correctness of electromagnetic compatibility simulation analysis of the two antennas is verified, and data support is provided for optimizing product design.

Description

Technical Field

[0001] The invention belongs to the field of antenna electromagnetic compatibility testing, and in particular, relates to an electromagnetic compatibility testing method for a spaceborne synthetic aperture radar antenna and a data transmission antenna. Background Art

[0002] Under the informationization conditions, products are equipped with a large number of electronic equipment such as communication, navigation, meteorology, radar, radio guidance, etc. The electromagnetic environment is becoming more and more complex, and the electromagnetic compatibility problem is becoming more and more prominent. In serious cases, it will cause information transmission interruption, blocking, bit errors, and reduce system performance, or even make it unable to work normally. How to solve the system-level electromagnetic compatibility problem has become one of the focuses of attention.

[0003] At present, satellite-borne synthetic aperture radar antennas have been widely used, with the antenna array expanding day by day, and the working mode and performance gradually improving. When the radar antenna is folded, it should meet the structural size restrictions of the satellite fairing and avoid interference with other satellite-borne antennas. However, the radar antenna is usually adjacent to the data transmission antenna in the frequency band or even has a spectrum overlap. After the satellite is put into orbit, the radar antenna must avoid electromagnetic compatibility problems with the data transmission antenna. Therefore, in the design stage, it has become an important task to determine the layout, functional performance parameters of the satellite-borne radar antenna and the data transmission antenna.

[0004] Traditional methods usually use simulation software or actual measurements of the entire array antenna to achieve design verification of the antenna layout. However, current simulation software is difficult to fully simulate large and complex arrays. It can usually only perform accurate electromagnetic compatibility simulation analysis of a single radar antenna element and a digital transmission antenna, or use a simple model to analyze the electromagnetic compatibility characteristics of the radar's entire array antenna and the digital transmission antenna. For complex full-array radar antennas, simulation software is difficult to complete accurate simulation tasks.

[0005] To conduct actual testing of a complete antenna with a full array, it is necessary to develop and produce physical antenna products. The testing cycle is long, the testing is complex, and the cost is high, making it difficult to adapt to the design iteration requirements in the scheme stage.

[0006] After inquiry, there are the following patents and papers in this technical field:

[0007] 1. Patent application number CN201210533319.1 for "EMC test method for deep space vehicle complex"

[0008] This patent document provides an EMC testing method for a deep space vehicle complex, which is mainly aimed at the deep space vehicle complex, quickly identifies the source of electromagnetic interference, safely and reliably detects electromagnetic interference and faults, and improves the EMC testing efficiency of the deep space vehicle complex.

[0009] The electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna proposed in the present invention is mainly used to verify the rationality of satellite layout and determine radio frequency performance indicators during the satellite scheme design stage, which is different from the purpose of the patent document.

[0010] 2. Patent application number CN201811082067.9 for "Electromagnetic compatibility test system and method for rocket wireless system"

[0011] This patent document proposes an electromagnetic compatibility test system and method for a rocket wireless system, which is mainly used to assess and verify the electromagnetic compatibility of the rocket in different flight postures during flight.

[0012] The electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna proposed in the present invention is mainly used in the satellite scheme design stage, which is different from the application background of the patent document.

[0013] 3. Patent application number of "Electromagnetic compatibility test system and method" CN201710369504.4

[0014] The electromagnetic compatibility testing system and method provided in this patent document are mainly used to determine whether a static image is a stagnant image caused by electromagnetic interference on an image acquisition device.

[0015] The electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna proposed in the present invention is mainly used in the satellite scheme design stage, which is different from the purpose and application scenario of the patent document.

[0016] 4. "Discussion on electromagnetic compatibility test technology of wireless receivers under complex electromagnetic environment" published in "Electronic Test" 201802

[0017] This paper mainly analyzes the electromagnetic compatibility capability and electromagnetic compatibility testing technology of electronic equipment represented by wireless receivers.

[0018] The electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna proposed in the present invention is mainly used to verify the rationality of satellite layout and determine the radio frequency performance indicators during the satellite scheme design stage, which is different from the purpose and application scenario of this paper.

[0019] 5. “Electromagnetic compatibility protection design method for satellite radio frequency receiver”, published in Space Electronics Technology, No. 3, 2014

[0020] This paper describes a typical EMC protection design approach for satellite RF receivers.

[0021] The electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna proposed in this invention is mainly used in the satellite scheme design stage, which is different from the application scenario of this paper.

[0022] 6. Patent application number 201611084686.2 for “Ground test method for radio frequency compatibility of synthetic aperture radar satellite”

[0023] This patent document optimizes the spatial layout design of the fixed antenna based on the test results of the radio frequency compatibility between the sky and the ground, and clarifies the on-orbit usage range of the deployable antenna beam.

[0024] The electromagnetic compatibility test method for satellite-borne synthetic aperture radar antenna and data transmission antenna proposed in the present invention is mainly used in the satellite scheme design stage, which is different from the purpose and application scenario of the patent document.

[0025] After analysis, it is found that the application scenarios and purposes of the existing patent documents and papers are different from those of the present invention. Summary of the invention

[0026] In view of the defects in the prior art, the object of the present invention is to provide an electromagnetic compatibility test method for a spaceborne synthetic aperture radar antenna and a data transmission antenna.

[0027] According to a method for electromagnetic compatibility testing of a space-borne synthetic aperture radar antenna and a data transmission antenna provided by the present invention, a waveguide crack unit module of the space-borne synthetic aperture radar antenna is fixed on a scanning frame, and the electromagnetic compatibility result between the space-borne synthetic aperture radar antenna and the data transmission antenna is obtained by moving the scanning frame and adjusting the relative position relationship between the data transmission antenna and the scanning frame through a physical product test, the correctness of the electromagnetic compatibility simulation is verified, the structural layout of the payload is adjusted in time, and the electromagnetic compatibility test of the space-borne synthetic aperture radar antenna and the data transmission antenna is completed.

[0028] Preferably, it includes:

[0029] Step 1: Install the waveguide slot antenna module of the synthetic aperture radar antenna participating in the test on a planar near-field darkroom scanning frame, and connect the output end to a spectrum analyzer;

[0030] Step 2: According to the satellite mission and working conditions in the whole satellite environment, the layout of the synthetic aperture radar antenna and the digital transmission antenna confirmed by the electromagnetic compatibility simulation, the digital transmission antenna is placed at the corresponding position A of the synthetic aperture radar antenna array in a planar near-field darkroom;

[0031] Step 3: At each scanning point of the waveguide crack antenna module, the data transmission system and the waveguide crack antenna module are turned on, and the spectrum analyzer tests and records the crosstalk signal strength of the data transmission antenna leakage received by the waveguide crack antenna module at each scanning point;

[0032] Adjust the corresponding azimuth A of the data transmission antenna, repeat step three at different positions and angles, and finally obtain the full-scenario electromagnetic compatibility test results of the synthetic aperture radar antenna array and the data transmission antenna.

[0033] Preferably, the scanning range of the scanning frame system is larger than the entire radar antenna array. The entire radar antenna array is simulated by moving the scanning frame, and the remote-controlled spectrum analyzer measures the spectrum characteristics of the collected received signal and the level strength of the crosstalk signal in real time. The position of the point with the maximum crosstalk signal strength is marked in combination with the motion characteristics of the scanning frame system.

[0034] Preferably, the synthetic aperture radar antenna is mainly composed of multiple waveguide slot antenna modules spliced ​​together, and the waveguide slot antenna modules participating in the test should have performance consistent with that of the satellite-borne products.

[0035] Preferably, the product status of the data transmission antenna and the corresponding high-frequency cable is consistent with the status of the satellite-borne product, the working mode is the actual working condition, the antenna rotation angle meets the actual usage requirements, and the output power is simulated according to the maximum working condition.

[0036] Preferably, in step three, the scanning frame is moved in order of scanning points to cover the synthetic aperture radar antenna array surface, and the intensity distribution of the digital transmission antenna crosstalk signal received by the radar antenna array surface is obtained.

[0037] Preferably, the pointing angle of the two-dimensional structure of the data transmission antenna is adjusted, and the adjustment angle range is between the extreme angle position of the data transmission antenna on the right side of the satellite in orbit and the extreme angle position of the data transmission antenna on the left side of the satellite in orbit.

[0038] Preferably, the scanning in step three includes two steps: rough scanning and fine scanning;

[0039] The coarse scan obtains the distribution of digital signal levels received by the entire array through large step interval scanning;

[0040] Fine scanning reduces the step size and scans again for areas where the level exceeds the set threshold to further analyze the level distribution.

[0041] Preferably, the coarse scanning step is no greater than 1 / 2 of the product size of the waveguide crack module, and the fine scanning step is no greater than 1 / 10 of the product size.

[0042] According to an electromagnetic compatibility testing method between antennas provided by the present invention, the transmitting unit module of the first antenna is fixed on a scanning frame, and the electromagnetic compatibility result between the first antenna and the second antenna is obtained through physical product testing by moving the scanning frame and adjusting the relative position relationship between the second antenna and the scanning frame, and the correctness of the electromagnetic compatibility simulation is verified. The structural layout of the load room is adjusted in time to complete the electromagnetic compatibility test of the first antenna and the second antenna.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The present invention does not need to construct a complete synthetic aperture radar antenna, but can obtain the electromagnetic compatibility of the synthetic aperture radar antenna and the data transmission antenna, thereby reducing the development cost at the scheme stage;

[0045] 2. The present invention can quickly complete the electromagnetic compatibility test between the satellite-borne synthetic aperture radar antenna and the data transmission antenna, verify the correctness of the electromagnetic compatibility simulation analysis of the two antennas, and provide data support for optimizing product design;

[0046] 3. The test method of the present invention has unified standards, a wide range of applications, and requires few test equipment. It can be applied to different types of synthetic aperture radar antenna products and accurately determine the receiving system parameters of each antenna receiving unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0048] Figure 1 It is a test scheme diagram of the electromagnetic compatibility test method of the spaceborne synthetic aperture radar antenna and the data transmission antenna proposed by the present invention.

[0049] Figure 2 This is a schematic diagram of the relative positions of the synthetic aperture radar array antenna and the data transmission antenna.

[0050] Figure 3 It is a schematic diagram of the scanning method of the waveguide crack antenna module. DETAILED DESCRIPTION

[0051] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0052] The present invention discloses an electromagnetic compatibility test method for a satellite-borne synthetic aperture radar antenna and a data transmission antenna. Synthetic aperture radar satellites need to complete detection and ground data transmission tasks under the condition that all systems are electromagnetically compatible. In order to ensure that the detection task and the ground data transmission task can be completed independently at the same time, it is necessary to analyze the electromagnetic compatibility of the synthetic aperture radar antenna and the data transmission antenna in the scheme design stage to determine the filter design and relative position relationship of the two antennas. In order to ensure the effectiveness of the simulation analysis, if necessary, the electromagnetic compatibility of the two antennas is tested and verified, and the design of the two antennas is optimized and the layout position is adjusted.

[0053] In view of the fact that it is time-consuming and laborious to construct a complete synthetic aperture radar antenna state in the scheme stage, and there are repeated situations, the present invention proposes to fix the waveguide crack unit module on the scanning frame, and complete the electromagnetic compatibility test of the spaceborne synthetic aperture radar antenna and the data transmission antenna by moving the scanning frame and adjusting the relative position relationship between the data transmission antenna and the scanning frame. Specifically, the electromagnetic compatibility result between the two antennas is obtained through the physical product test, the correctness of the electromagnetic compatibility simulation is verified, and the structural layout of the load room is adjusted in time.

[0054] A method for testing electromagnetic compatibility of a spaceborne synthetic aperture radar antenna and a data transmission antenna provided by the present invention comprises the following steps:

[0055] Step 1, such as Figure 1 As shown in the figure, the test plan involves the following products and equipment: waveguide crack antenna module, digital transmission antenna and bracket, antenna module scanning frame, spectrum analyzer, data server, digital transmission signal source and ground detection, power amplifier and ground detection, high-frequency cable, etc. The waveguide crack antenna module of the synthetic aperture radar antenna participating in the test is installed on the planar near-field darkroom scanning frame, and the output end is connected to the spectrum analyzer.

[0056] Among them, the scanning range of the scanning frame system should be larger than the entire radar antenna array. The entire radar antenna array is simulated by moving the scanning frame, and the remote-controlled spectrum analyzer measures the spectrum characteristics of the collected received signal and the level strength of the crosstalk signal in real time. Combined with the motion characteristics of the scanning frame system, the position of the maximum crosstalk signal intensity point is marked.

[0057] The synthetic aperture radar antenna is mainly composed of multiple waveguide slot antenna modules. The waveguide slot antenna modules participating in the test should be consistent with the performance of the satellite-borne products, such as operating frequency, standing wave ratio, etc.

[0058] The product status of the digital transmission antenna and the corresponding high-frequency cable is consistent with that of the satellite-borne product, and the working mode should be the actual working condition, that is, the antenna rotation angle should meet the actual usage requirements, and the output power should be simulated according to the maximum working condition.

[0059] Step 2: According to the satellite mission and working conditions in the whole satellite environment, the layout of the synthetic aperture radar antenna and the digital transmission antenna is confirmed by the electromagnetic compatibility simulation, and the digital transmission antenna is placed at the corresponding position A of the synthetic aperture radar antenna array in a planar near-field darkroom.

[0060] The corresponding azimuth A, i.e., the distance L, B, H between the normal line of the synthetic aperture radar array and the center of the digital antenna beam, and the normal angle а are jointly determined. L, B, and H determine the installation position of the digital antenna on the satellite, and the two-dimensional structural pointing angle of the digital antenna determines the normal angle а. The digital antenna bracket can simulate the antenna structure and drive to meet the test angle change requirements. Among them, L, B, and H represent the geodetic longitude, geodetic latitude, and geodetic height of the geodetic coordinate system, respectively.

[0061] Step 3: At each scanning point of the waveguide crack antenna module, turn on the digital transmission system and the waveguide crack antenna module, and use a spectrum analyzer to test and record the crosstalk signal strength of the digital transmission antenna leakage received by the waveguide crack antenna module at each scanning point. Move the scanning frame to cover the synthetic aperture radar antenna array in the order of scanning points to obtain the digital transmission antenna crosstalk signal strength distribution received by the radar antenna array.

[0062] like Figure 2 , Figure 3 As shown, the size of the waveguide slot antenna module is length L m ×Width B m , the full size of the synthetic aperture radar antenna array is length L s ×Width B s , where L s =L m ×N c , B s =B m ×N c , N c 、N r They are the number of waveguide slot antenna modules in the X and Y directions of the full-array radar antenna respectively.

[0063] Turn on the digital transmission system to ensure that the output power of the digital transmission antenna meets the actual index requirements, and record the crosstalk signal strength E1 received by the spectrum analyzer at this time.

[0064] The scanning frame moves, and the waveguide crack antenna module moves accordingly, wherein the stepping interval in the X direction is Δx, and the stepping interval in the Y direction is Δy, and the scanning is performed in a "Z" shape, that is, from Figure 3 The scanning point "1" is the initial position, and the Y axis moves Δy in the negative direction to the scanning point "2". The signal strength E2 received by the spectrum analyzer is recorded. After the Y axis scans one column, move Δx to the second column. Repeat the above steps until the scan covers the entire radar antenna array and the crosstalk signal strength of all scanning points S is recorded.

[0065] Adjust the corresponding azimuth A of the data transmission antenna, repeat step three at different positions and angles, and finally obtain the full-scenario electromagnetic compatibility test results of the synthetic aperture radar antenna array and the data transmission antenna.

[0066] Among them, the two-dimensional structure pointing angle of the data transmission antenna is adjusted, that is, the normal angle а is taken in the test (35°, 55°, 60°, 65°, 75°, 85°), where 35° corresponds to the extreme angle position of the data transmission antenna on the right side of the satellite in orbit, and 65° corresponds to the extreme angle position of the data transmission antenna on the left side of the satellite in orbit. Repeat step 3 at different angle values ​​and record the crosstalk signal strength of all scanning points.

[0067] The full-scenario electromagnetic compatibility test results of the synthetic aperture radar antenna array and data transmission antenna are obtained as shown in the following table.

[0068] Table 1 Electromagnetic compatibility full-scenario test results

[0069]

[0070]

[0071] Xm and Yn represent the horizontal and vertical coordinates of the scanning point at the mth row and nth column respectively;

[0072] Emn represents the signal strength received by the spectrum analyzer corresponding to the scanning point in the mth row and nth column;

[0073] Step three: scanning is divided into two steps. The coarse scan obtains the digital signal level distribution received by the entire array surface by scanning with large step intervals. The fine scan reduces the step size of the stronger area and scans again to further analyze the level distribution. The coarse scan step should not be larger than 1 / 2 of the waveguide crack module product size, and the fine scan step should not be larger than 1 / 10 of the product size.

[0074] In summary, the present invention is applicable to the scheme design stage of satellite development, and proposes a satellite-borne synthetic aperture radar antenna and data transmission antenna electromagnetic compatibility test system and method. By using a radar antenna waveguide crack antenna module and a data transmission antenna, the electromagnetic compatibility test between the synthetic aperture radar antenna and the data transmission antenna can be completed quickly and efficiently in a microwave darkroom through a mobile scanning frame, providing data support and simulation verification for determining the layout positions of the two antennas, system transceiver parameters and other indicators. At the same time, the test method has strong applicability and is also suitable for electromagnetic compatibility tests between large array antennas and other antennas.

[0075] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for testing electromagnetic compatibility of a spaceborne synthetic aperture radar antenna and a data transmission antenna, characterized in that: The waveguide crack unit module of the spaceborne synthetic aperture radar antenna is fixed on the scanning frame. By moving the scanning frame and adjusting the relative position relationship between the digital transmission antenna and the scanning frame, the electromagnetic compatibility results between the spaceborne synthetic aperture radar antenna and the digital transmission antenna are obtained through physical product testing. The correctness of the electromagnetic compatibility simulation is verified, and the structural layout of the payload is adjusted in time to complete the electromagnetic compatibility test of the spaceborne synthetic aperture radar antenna and the digital transmission antenna.

2. The electromagnetic compatibility test method of spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: include: Step 1: Install the waveguide slot antenna module of the synthetic aperture radar antenna participating in the test on a planar near-field darkroom scanning frame, and connect the output end to a spectrum analyzer; Step 2: According to the satellite mission and working conditions in the whole satellite environment, the layout of the synthetic aperture radar antenna and the digital transmission antenna confirmed by the electromagnetic compatibility simulation, the digital transmission antenna is placed at the corresponding position A of the synthetic aperture radar antenna array in a planar near-field darkroom; Step 3: At each scanning point of the waveguide crack antenna module, the data transmission system and the waveguide crack antenna module are turned on, and the spectrum analyzer tests and records the crosstalk signal strength of the data transmission antenna leakage received by the waveguide crack antenna module at each scanning point; Adjust the corresponding azimuth A of the data transmission antenna, repeat step three at different positions and angles, and finally obtain the full-scenario electromagnetic compatibility test results of the synthetic aperture radar antenna array and the data transmission antenna.

3. The electromagnetic compatibility test method of spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: The scanning range of the scanning frame system is larger than the entire radar antenna array. The entire radar antenna array is simulated by moving the scanning frame. The remote-controlled spectrum analyzer measures the spectrum characteristics of the collected received signal and the level strength of the crosstalk signal in real time. Combined with the motion characteristics of the scanning frame system, the position of the maximum crosstalk signal strength point is marked.

4. The electromagnetic compatibility test method for spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: The synthetic aperture radar antenna is mainly composed of multiple waveguide slot antenna modules. The waveguide slot antenna modules participating in the test should have performance consistent with that of the satellite-borne products.

5. The electromagnetic compatibility test method for spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: The digital transmission antenna and the corresponding high-frequency cable have the same product status as the satellite-borne product, the working mode is the actual working condition, the antenna rotation angle meets the actual usage requirements, and the output power is simulated according to the maximum working condition.

6. The electromagnetic compatibility test method for spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: In the step three, the scanning frame is moved to cover the synthetic aperture radar antenna array in the order of scanning points, and the intensity distribution of the data transmission antenna crosstalk signal received by the radar antenna array is obtained.

7. The electromagnetic compatibility test method for spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: Adjust the pointing angle of the two-dimensional structure of the data transmission antenna, and the adjustment angle range is between the extreme angle position of the data transmission antenna on the right side of the satellite in orbit and the extreme angle position of the data transmission antenna on the left side of the satellite in orbit.

8. The electromagnetic compatibility test method for spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 1 is characterized in that: The scanning in step 3 includes two steps: rough scanning and fine scanning; The coarse scan obtains the distribution of digital signal levels received by the entire array through large step interval scanning; Fine scanning reduces the step size and scans again for areas where the level exceeds the set threshold to further analyze the level distribution.

9. The electromagnetic compatibility test method for spaceborne synthetic aperture radar antenna and data transmission antenna according to claim 8, characterized in that: The coarse scanning step is no greater than 1 / 2 of the waveguide crack module product size, and the fine scanning step is no greater than 1 / 10 of the product size.

10. A method for testing electromagnetic compatibility between antennas, characterized in that: The transmitting unit module of the first antenna is fixed on the scanning frame. By moving the scanning frame and adjusting the relative position relationship between the second antenna and the scanning frame, the electromagnetic compatibility results between the first antenna and the second antenna are obtained through physical product testing, the correctness of the electromagnetic compatibility simulation is verified, and the structural layout of the payload is adjusted in time to complete the electromagnetic compatibility test of the first antenna and the second antenna.

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