Method for electromagnetic compatibility test of space-borne synthetic aperture radar antenna and data transmission antenna

Abstract

The application provides a kind of space-borne synthetic aperture radar antenna and data transmission antenna electromagnetic compatibility test method, for scheme phase constructs complete synthetic aperture radar antenna state time-consuming and laborious, there is repeated, proposed to fix waveguide crack unit module on scanning frame, by moving scanning frame, adjusting the relative position relationship between data transmission antenna and scanning frame, complete space-borne synthetic aperture radar antenna and data transmission antenna electromagnetic compatibility test.The application does not need to construct complete synthetic aperture radar antenna, can obtain the electromagnetic compatibility of synthetic aperture radar antenna and data transmission antenna, reduce the development cost in scheme phase;It can quickly complete the electromagnetic compatibility test between space-borne synthetic aperture radar antenna and data transmission antenna, verify the correctness of the electromagnetic compatibility simulation analysis of two antennas, provide data support for optimizing product design.

Description

Technical Field

[0001] This invention belongs to the field of antenna electromagnetic compatibility testing, specifically relating to electromagnetic compatibility testing methods for spaceborne synthetic aperture radar antennas and data transmission antennas. Background Technology

[0002] In the information age, products are equipped with a large number of electronic devices such as communication, navigation, meteorology, radar, and radio guidance systems. The electromagnetic environment is becoming increasingly complex, and electromagnetic compatibility (EMC) issues are becoming more prominent. In severe cases, these issues can lead to information transmission interruptions, blockages, bit errors, degraded system performance, or even complete malfunction. Therefore, solving system-level EMC problems has become a major focus of attention.

[0003] Currently, spaceborne synthetic aperture radar (SAR) antennas are widely used, with antenna arrays becoming increasingly larger and operating modes and performance gradually improving. When the radar antenna is folded down, it must meet the dimensional constraints of the satellite radome structure and avoid interference with other spaceborne antennas. Furthermore, radar antennas and data transmission antennas often operate in adjacent or even overlapping frequency bands. After the satellite enters orbit, the radar antenna must avoid electromagnetic compatibility issues with the data transmission antenna. Therefore, determining the layout and functional performance parameters of the spaceborne radar and data transmission antennas becomes a crucial task during the design phase.

[0004] Traditional methods typically employ simulation software or full-array antenna measurements to verify the design of the antenna layout. However, current simulation software struggles to fully simulate large and complex arrays. It usually only performs precise electromagnetic compatibility simulation analysis of individual radar antenna elements and data transmission antennas, or uses simple models to analyze the electromagnetic compatibility characteristics of full-array radar antennas and data transmission antennas. For complex full-array radar antennas, simulation software struggles to complete accurate simulation tasks.

[0005] The actual testing of a complete full-array antenna requires the development and production of a physical antenna product, which involves a long testing cycle, complex testing, and high costs, making it difficult to meet the design iteration requirements of the scheme stage.

[0006] According to the search, the following patents and papers exist in this technical field:

[0007] 1. Patent application CN201210533319.1, entitled "An EMC Testing Method for a Deep Space Vehicle Complex".

[0008] This patent document provides an EMC testing method for deep space vehicle complexes, which is mainly designed for deep space vehicle complexes. It can quickly identify the source of electromagnetic interference, safely and reliably detect electromagnetic interference and faults, and improve the EMC testing efficiency of deep space vehicle complexes.

[0009] The electromagnetic compatibility testing method for spaceborne synthetic aperture radar antennas and data transmission antennas proposed in this invention is mainly used in the satellite design phase to verify the rationality of satellite layout and determine radio frequency performance indicators, which is different from the purpose of this patent document.

[0010] 2. Patent application number CN201811082067.9, entitled "An Electromagnetic Compatibility Test System and Method for a 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 attitudes during flight.

[0012] The electromagnetic compatibility testing method for spaceborne synthetic aperture radar antennas and data transmission antennas proposed in this invention is mainly used in the satellite design phase, which is different from the application background of this patent document.

[0013] 3. Patent application number CN201710369504.4 for "Electromagnetic Compatibility Testing System and Method".

[0014] The electromagnetic compatibility testing system and method provided in this patent document are mainly used to determine whether a static image is caused by electromagnetic interference affecting the image acquisition device, resulting in image stagnation.

[0015] The electromagnetic compatibility testing method for spaceborne synthetic aperture radar antennas and data transmission antennas proposed in this invention is mainly used in the satellite design phase, which is different from the purpose and application scenario of the patent document.

[0016] 4. "Discussion on Electromagnetic Compatibility Testing Technology for Wireless Receivers under Complex Electromagnetic Environments" was published in "Electronic Testing" Issue 201802.

[0017] This paper mainly analyzes the electromagnetic compatibility (EMC) capabilities and EMC testing techniques of electronic devices, represented by wireless receivers.

[0018] The electromagnetic compatibility testing method for spaceborne synthetic aperture radar antennas and data transmission antennas proposed in this invention is mainly used in the satellite design phase to verify the rationality of satellite layout and determine radio frequency performance indicators, which is different from the purpose and application scenario of this paper.

[0019] 5. "Design Method for Electromagnetic Compatibility Protection of Satellite Radio Frequency Receivers" was published in Space Electronics Technology, 2014, Issue 3.

[0020] This paper describes a typical EMC protection design method for satellite radio frequency receivers.

[0021] The electromagnetic compatibility testing method for spaceborne synthetic aperture radar antennas and data transmission antennas proposed in this invention is mainly used in the satellite design phase, which is different from the application scenario of this paper.

[0022] 6. Patent application number 201611084686.2: "Ground Test Method for RF Compatibility of Synthetic Aperture Radar Satellites".

[0023] Based on the results of radio frequency compatibility tests on the sky and the ground, this patent document optimizes the spatial layout design of the fixed antenna and clarifies the on-orbit usage range of the deployable antenna beam direction.

[0024] The electromagnetic compatibility testing method for spaceborne synthetic aperture radar antennas and data transmission antennas proposed in this invention is mainly used in the satellite design phase, which is different from the purpose and application scenario of the patent document.

[0025] Analysis revealed that existing patent documents and papers differ from the application scenarios and purposes of this invention. Summary of the Invention

[0026] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for testing the electromagnetic compatibility of spaceborne synthetic aperture radar antennas and data transmission antennas.

[0027] According to the present invention, an electromagnetic compatibility (EMC) test method for a spaceborne synthetic aperture radar (SAR) antenna and a data transmission antenna is provided. The waveguide slot unit module of the spaceborne SAR antenna is fixed on a scanning frame. By moving the scanning frame and adjusting the relative positional relationship between the data transmission antenna and the scanning frame, the EMC results between the two antennas are obtained through physical product testing. The correctness of the EMC simulation is verified, and the structural layout between the loads is adjusted in a timely manner to complete the EMC test of the spaceborne SAR antenna and the data transmission antenna.

[0028] Preferably, it includes:

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

[0030] Step 2: Based on the satellite mission and operating conditions under the whole satellite environment, and the layout confirmed by the electromagnetic compatibility simulation of the synthetic aperture radar antenna and the data transmission antenna, place the data transmission antenna at the corresponding azimuth A of the synthetic aperture radar antenna array in a planar near-field anechoic chamber.

[0031] Step 3: At each scanning point of the waveguide slot antenna module, turn on the data transmission system and the waveguide slot antenna module, and use a spectrum analyzer to test and record the crosstalk signal strength leaked by the data transmission antenna received by the waveguide slot antenna module at each scanning point.

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

[0033] Preferably, the scanning range of the scanning frame system is larger than the entire radar antenna array. By moving the scanning frame to simulate the entire radar antenna array, the remote-controlled spectrum analyzer measures the spectrum characteristics of the acquired signal and the level of crosstalk signal in real time, and marks the position of the point with the maximum crosstalk signal strength by combining 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 the same performance as the spaceborne products.

[0035] Preferably, the data transmission antenna and the corresponding high-frequency cable are in the same product condition 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.

[0036] Preferably, in step three, the scanning frame is moved in sequence according to the scanning points to cover the synthetic aperture radar antenna array, thereby obtaining the intensity distribution of the crosstalk signal received by the data transmission antenna of the radar antenna array.

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

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

[0039] Coarse scanning obtains the data transmission signal level distribution received across the entire array by scanning with large step intervals;

[0040] For areas where the level exceeds the set threshold, the fine scan reduces the step size and scans again to further analyze the level distribution.

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

[0042] According to the electromagnetic compatibility (EMC) testing method between antennas provided by the present invention, the transmitting unit module of the first antenna is fixed on the scanning frame. By moving the scanning frame and adjusting the relative positional relationship between the second antenna and the scanning frame, the EMC results between the first antenna and the second antenna are obtained through physical product testing, the correctness of the EMC simulation is verified, and the structural layout between the loads is adjusted in a timely manner to complete the EMC test between the first antenna and the second antenna.

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

[0044] 1. This invention does not require the construction of a complete synthetic aperture radar antenna, but can obtain a preliminary understanding of the electromagnetic compatibility between the synthetic aperture radar antenna and the data transmission antenna, thereby reducing the development cost in the design phase.

[0045] 2. This invention can quickly complete the electromagnetic compatibility test between the spaceborne 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 testing method of this invention has a unified standard, a wide range of applications, requires few testing equipment, can be applied to different types of synthetic aperture radar antenna products, and can accurately determine the receiving system parameters of each antenna receiving unit. Attached Figure Description

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

[0048] Figure 1 This is a test scheme diagram for the electromagnetic compatibility test method of spaceborne synthetic aperture radar antenna and data transmission antenna proposed in this invention.

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

[0050] Figure 3 This is a schematic diagram of the scanning method of the waveguide slot antenna module. Detailed Implementation

[0051] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0052] This invention discloses an electromagnetic compatibility (EMC) testing method for a spaceborne synthetic aperture radar (SAR) antenna and a data transmission antenna. SAR satellites need to complete detection and Earth data transmission tasks under EMC conditions across all systems. To ensure that detection and Earth data transmission tasks can be completed simultaneously and independently, the EMC of the SAR antenna and the data transmission antenna needs to be analyzed during the design phase to determine the filtering design and relative positional relationship of the two antennas. To ensure the effectiveness of the simulation analysis, it is necessary to conduct experimental verification of the EMC of the two antennas, and optimize the design and adjust the layout of the two antennas as needed.

[0053] This invention addresses the time-consuming and labor-intensive nature of constructing a complete synthetic aperture radar (SAR) antenna configuration during the design phase, which often involves repetitive iterations. It proposes fixing waveguide slot unit modules onto a scanning frame and performing electromagnetic compatibility (EMC) testing on the spaceborne SAR antenna and data transmission antenna by moving the scanning frame and adjusting their relative positions. Specifically, EMC results between the two antennas are obtained through testing with physical products, verifying the accuracy of the EMC simulation and allowing for timely adjustments to the structural layout between the loads.

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

[0055] Step 1, as follows Figure 1 As shown, the test plan involves the following products and equipment: waveguide slot antenna module, data transmission antenna and support, antenna module scanning frame, spectrum analyzer, data server, data transmission signal source and ground detector, power amplifier and ground detector, high-frequency cable, etc. The waveguide slot antenna module of the synthetic aperture radar antenna participating in the test is mounted on the planar near-field anechoic chamber scanning frame, and the output is connected to the spectrum analyzer.

[0056] 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. The remote-controlled spectrum analyzer measures and collects the spectrum characteristics of the received signal and the level of crosstalk signal in real time. The location of the point with the maximum crosstalk signal intensity is marked by combining the motion characteristics of the scanning frame system.

[0057] Synthetic aperture radar antennas are mainly composed of multiple waveguide slot antenna modules. The waveguide slot antenna modules used in the test should have the same performance as the spaceborne products, such as operating frequency and VSWR.

[0058] The data transmission antenna and its corresponding high-frequency cable should be in the same condition as the satellite-borne product. The operating 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: Based on the satellite mission and operating conditions under the overall satellite environment, and the layout confirmed by the electromagnetic compatibility simulation of the synthetic aperture radar antenna and the data transmission antenna, place the data transmission antenna at the corresponding azimuth A of the synthetic aperture radar antenna array in a planar near-field anechoic chamber.

[0060] The corresponding azimuth A, i.e., the distances L, B, and H between the normal of the synthetic aperture radar array and the center of the data transmission antenna beam, as well as the included angle α of the normals, are jointly determined. L, B, and H determine the installation position of the data transmission antenna on the satellite, and the pointing angle of the two-dimensional mechanism of the data transmission antenna determines the included angle α of the normals. The data transmission antenna bracket can simulate the antenna mechanism and drive, meeting the requirements for testing angle changes. Here, L, B, and H represent the geodetic longitude, geodetic latitude, and geodetic height in the geodetic coordinate system, respectively.

[0061] Step 3: At each scanning point of the waveguide slot antenna module, activate the data transmission system and the waveguide slot antenna module. Use a spectrum analyzer to test and record the crosstalk signal strength leaked by the data transmission antenna received by the waveguide slot antenna module at each scanning point. Move the scanning frame sequentially to cover the synthetic aperture radar antenna array to obtain the crosstalk signal strength distribution of the data transmission antenna received by the radar antenna array.

[0062] like Figure 2 , Figure 3 As shown, the waveguide slot antenna module has a length L. m ×widthB m The total size of the synthetic aperture radar antenna array is length L. s ×widthB s L s =L m ×N c B s =B m ×N c N c N r These represent the number of waveguide slot antenna modules in the X and Y directions of the full-array radar antenna, respectively.

[0063] The data transmission system is powered on and the output power of the data transmission antenna is ensured to meet the actual specifications. The crosstalk signal strength E1 received by the spectrum analyzer at this time is recorded.

[0064] The waveguide slot antenna module moves with the moving scanning frame, with a step distance of Δx in the X direction and Δy in the Y direction, scanning in a "Z" shaped pattern. Figure 3 The initial position is the scanning point "1". Move Δy in the negative Y-axis direction to the scanning point "2" and record the signal strength E2 received by the spectrum analyzer at this time. After completing one column of Y-axis scanning, move Δx to the second column and repeat the above steps until the scanning covers the entire radar antenna array. Record the crosstalk signal strength of all scanning points S.

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

[0066] In this experiment, the pointing angle of the two-dimensional mechanism of the data transmission antenna was adjusted, i.e., the included angle α of the normal was set to (35°, 55°, 60°, 65°, 75°, 85°). 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. Step three was repeated at different angle values, and the crosstalk signal strength at all scanning points was recorded.

[0067] The electromagnetic compatibility (EMC) test results for the synthetic aperture radar antenna array and data transmission antenna in the following table are obtained across all scenarios.

[0068] Table 1. Electromagnetic compatibility test results across all scenarios

[0069]

[0070]

[0071] Xm and Yn represent the horizontal and vertical coordinates of the scan point in the m-th row and n-th column, respectively;

[0072] Emn represents the signal strength received by the spectrum analyzer corresponding to the scan point in the m-th row and n-th column;

[0073] Step 3 scanning is divided into two steps. The coarse scan obtains the data transmission signal level distribution of the entire array by scanning with a large step interval. The fine scan reduces the step interval for stronger areas and scans again to further analyze the level distribution. The step interval for the coarse scan should not be greater than 1 / 2 of the waveguide slot module product size, and the step interval for the fine scan should not be greater than 1 / 10 of the product size.

[0074] In summary, this invention is applicable to the design phase of satellite development. It proposes an electromagnetic compatibility (EMC) testing system and method for spaceborne synthetic aperture radar (SAR) antennas and data transmission antennas. Using a radar antenna waveguide slot antenna module and a data transmission antenna, the EMC test between the SAR antenna and the data transmission antenna can be completed quickly and efficiently in a microwave anechoic chamber via a moving scanning frame. This provides data support and simulation verification for determining the layout positions of the two antennas, system transmit and receive parameters, and other indicators. At the same time, the testing method has strong applicability and is also suitable for EMC testing between large array antennas and other antennas.

[0075] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for electromagnetic compatibility test of a space-borne synthetic aperture radar antenna and a data transmission antenna, characterized in that, The waveguide slit unit module of the space-borne synthetic aperture radar antenna is fixed on a scanning frame, the relative position relationship between the data transmission antenna and the scanning frame is adjusted by moving the scanning frame, the electromagnetic compatibility result between the space-borne synthetic aperture radar antenna and the data transmission antenna is obtained through physical product testing, the correctness of the electromagnetic compatibility simulation is verified, the structure layout between the loads is timely adjusted, and the electromagnetic compatibility testing of the space-borne synthetic aperture radar antenna and the data transmission antenna is completed; Comprise: Step one, install the waveguide slit antenna module of the synthetic aperture radar antenna participating in the test on the scanning frame of the plane near-field darkroom, and connect the output end to the spectrum analyzer; Step two, according to the layout situation of the electromagnetic compatibility simulation confirmation of the synthetic aperture radar antenna and the data transmission antenna under the satellite environment and working condition, place the data transmission antenna in the corresponding azimuth A of the synthetic aperture radar antenna array in the plane near-field darkroom; Step three, turn on the data transmission transmitting system and the waveguide slit antenna module at each scanning point of the waveguide slit antenna module, and test and record the crosstalk signal strength of the data transmission antenna leakage received by the waveguide slit antenna module at each scanning point; Adjust the corresponding azimuth A of the data transmission antenna, repeat step three under different positions and angles, and finally obtain the electromagnetic compatibility full-scene testing result of the synthetic aperture radar antenna array and the data transmission antenna; The scanning range of the scanning frame system is greater than the entire radar antenna array, the entire radar antenna array is simulated by moving the scanning frame, the spectrum analyzer is remotely controlled to measure and collect the received signal spectrum characteristics and crosstalk signal level strength in real time, and the position of the maximum crosstalk signal strength point is marked in combination with the motion characteristics of the scanning frame system; The synthetic aperture radar antenna is mainly composed of multiple waveguide slit antenna modules, and the waveguide slit antenna modules participating in the test should be consistent with the performance of the space-borne product; In the step three, the scanning frame is moved according to the scanning point sequence to cover the synthetic aperture radar antenna array, and the crosstalk signal strength distribution of the data transmission antenna received by the radar antenna array is obtained.

2. The method of claim 1, wherein, The data transmission antenna and the corresponding high-frequency cable are consistent with the state of the space-borne product, the working mode is the actual working condition, the antenna rotation angle meets the actual use demand, and the output power is simulated according to the maximum working condition.

3. The method of claim 1, wherein the method further comprises: The pointing angle of the two-dimensional mechanism of the data transmission antenna is adjusted, and the angle range is between the limit angle position of the right side of the satellite in orbit and the limit angle position of the left side of the satellite in orbit.

4. The method of claim 1, wherein the method further comprises: The scanning of the step three comprises two steps of coarse scanning and fine scanning; The coarse scanning obtains the data transmission signal level distribution received by the entire array through large-step interval scanning; The fine scanning further analyzes the level distribution by reducing the step and scanning again in the region where the level exceeds the set threshold.

5. The method of claim 4, wherein the method further comprises: The coarse scanning step is not greater than 1 / 2 of the product size of the waveguide slit module, and the fine scanning step is not greater than 1 / 10 of the product size.

6. A method of electromagnetic compatibility testing between antennas, characterized by, The electromagnetic compatibility test method of the satellite-borne synthetic aperture radar antenna and the data transmission antenna according to any one of claims 1 to 5 fixes the transmitting unit module of the first antenna on a scanning frame, adjusts the relative position relationship between the second antenna and the scanning frame by moving the scanning frame, obtains the electromagnetic compatibility result between the first antenna and the second antenna through physical product test, verifies the correctness of the electromagnetic compatibility simulation, adjusts the structural layout between the loads in time, and completes the electromagnetic compatibility test of the first antenna and the second antenna.

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