A method for amplitude and phase calibration of phased array antenna

Abstract

The present invention provides a phased array antenna amplitude and phase calibration method, which is implemented by test data from two test systems. Both test systems include a tested antenna, a phase-stabilizing cable, a vector network, a ground inspection and a PC. The first test system also includes a tested antenna, a transfer tool, a test tool, a test antenna and an antenna packaging box. The transfer tool is placed inside the antenna packaging box, and the tested antenna and the test tool are installed on the transfer tool. The test antenna is installed above the test tool. The present invention has the following beneficial effects: saving test costs, greatly shortening darkroom test time and frequency, and the overall test cost is expected to be reduced by 30%; shortening the test cycle, greatly shortening the darkroom test time and frequency, and the overall test cycle is expected to be reduced by 30%.

Description

Technical Field

[0001] The invention belongs to the field of phased array antenna amplitude and phase calibration, and in particular relates to a phased array antenna amplitude and phase calibration method. Background Art

[0002] Phased array antenna is an antenna system that can electronically control the beam direction. It is widely used in radar, communication and other fields. The advantages of phased array antenna are: fast beam scanning, high gain, high directivity, and high reliability. With the advancement of technology, its application prospects are very broad.

[0003] The main methods for testing the directional pattern of phased array antennas are:

[0004] Near-field testing measures the antenna radiation pattern through a near-field scanner. The near-field data can be converted into far-field data through Fourier transform. This method can be completed at a shorter distance and is suitable for large antenna arrays. However, the test needs to traverse the entire antenna array. When the antenna size is relatively large, the test cycle is very long, which puts higher requirements on test reliability and test efficiency.

[0005] Far-field testing is usually performed in an open field or darkroom. The size of the far-field test site is determined by the size of the antenna being tested. A known standard source is required to calibrate the system, and a high-precision turntable is used to change the antenna direction. However, it is difficult to perform amplitude and phase balancing operations on each channel remotely for large phased array antennas. And it is difficult to find a suitable far-field test environment when the antenna is relatively large.

[0006] For large-scale satellite phased array antennas, most of them are currently tested in large near-field darkrooms, which are rare and very expensive. In addition, large-scale satellite phased array antennas need to undergo a variety of tests, such as deployment test, thermal cycle test, EMC test, thermal vacuum test, mechanical test, hint test, and whole-satellite joint test. Each test may change the amplitude and phase characteristics of the phased array antenna. If the directional pattern test is repeated in the darkroom every time, the cost and cycle are unbearable. Summary of the invention

[0007] In view of this, the present invention aims to provide a phased array antenna amplitude and phase calibration method to solve at least one problem existing in the above-mentioned prior art.

[0008] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0009] A phased array antenna amplitude and phase calibration method is implemented by test data of two test systems, both of which include a tested antenna, a phase-stabilizing cable, a vector network, a ground detector and a PC. The first test system also includes a tested antenna, a transfer tool, a test tool, a test antenna and an antenna packaging box. The transfer tool is placed inside the antenna packaging box, the tested antenna and the test tool are installed on the transfer tool, and the test antenna is installed above the test tool.

[0010] The second test system is carried out in a near-field darkroom. It also includes a scanning frame, darkroom test fixture and waveguide probe. The scanning frame can support the installation of the waveguide probe. The scanning frame moves the waveguide probe with the waveguide probe to achieve amplitude and phase acquisition at each point. The antenna under test is installed on the darkroom test fixture. The darkroom test fixture has multiple degrees of freedom and precise adjustable functions to ensure that the antenna under test and the waveguide probe have a precise positional relationship.

[0011] Testing methods for two test systems:

[0012] After the antenna is transported to the darkroom, the first test system is used to perform amplitude and phase tests;

[0013] Through the test of the first test system, three tables can be obtained: phase tables of 200 transmitting channels at different wave positions, amplitude tables of 200 receiving channels at different wave positions, and phase tables of 200 receiving channels at different wave positions.

[0014] After the first test system is tested, the second test system is used to conduct darkroom testing;

[0015] Through the test of the second test system, three tables measured by the second test system can be obtained, namely, the phase table of 200 transmitting channels at different wave positions, the amplitude table of 200 receiving channels at different wave positions, and the phase table of 200 receiving channels at different wave positions;

[0016] After the darkroom test is completed, the first test system is used to perform another test before the antenna under test is delivered. After the test is completed, three tables can be obtained: phase tables at different wave positions of 200 transmitting channels, amplitude tables at different wave positions of 200 receiving channels, and phase tables at different wave positions of 200 receiving channels. The above nine tables can perform amplitude and phase calibration for each transmitting and receiving channel of the phased array.

[0017] If the transmit channel is calibrated, the transmit channel of the first system for the first test is phase matrix A 1 64,200 ; The transmission channel of the second system test is phase matrix A 2 64,200 ; The transmission channel of the second test of the first system is phase matrix A 364,200 ;

[0018] The amplitude and phase calibration methods are as follows:

[0019] S1, phase matrix A 3 64,200 Subtract the phase matrix A 1 64,200 Get the new phase matrix A new 64,200 ;

[0020] S2, new phase matrix A new 64,200 Add the phase matrix A 2 64,200 Get the new phase matrix A j 64,200 .

[0021] S3, based on the new phase matrix A j 64,200 The phase value of each channel can fit a true value curve between the phase shift amount and the angle for each channel;

[0022] S4, there are 400 wave positions corresponding to wave positions 128-527, and the matrix A of the different wave displacement phasors is known theoretically l 400,200 , the matrix A l 400,200 Each wave position in the code is matched according to the true value curve of each channel obtained in the previous step, and a shift-bit characteristic matrix can be obtained. The shift-bit characteristic matrix is ​​the wave position code matrix B after calibration. 400,200 .

[0023] Furthermore, the antenna under test includes a radiation unit and an antenna mounting plate, and a transfer tool installation and positioning interface is reserved on the side of the antenna mounting plate, and the transfer tool installation and positioning interface is used to install and position the transfer tool.

[0024] Furthermore, the transfer tooling includes a main frame and connecting lugs, the main frame is provided with test tooling locating pins, the test tooling locating pins are used to position the test tooling, and the connecting lugs are provided with fixing and locating holes, the fixing and locating holes are used to position and fasten with the transfer tooling installation and positioning interface on the antenna under test.

[0025] Furthermore, the test tooling is provided with a test tooling positioning hole and a test antenna mounting hole. The test tooling positioning hole is used for positioning with a test tooling positioning pin on the transfer tooling, and the test antenna mounting hole is used for mounting a test antenna.

[0026] Furthermore, the phase-stabilizing cable is used to ensure that each test of the antenna under test does not introduce amplitude or phase errors into the test antenna;

[0027] The vector network is a dual-port vector network, which is used to complete the amplitude and phase measurement of the antenna under test at different frequencies;

[0028] The ground detection is an embedded board, which serves as a medium between the ground detection host computer and the vector network and the antenna under test, and is used to complete the control of the antenna under test and the vector network and data return;

[0029] The PC communicates with the ground inspection through the 232 interface and with the vector network through the network port. The PC includes the ground inspection host computer software. The functions of the ground inspection host computer software include:

[0030] The configuration of the antenna under test, the ground inspection, and the vector network are all performed through the ground inspection host computer software;

[0031] The ground inspection host computer software can display the status of the antenna under test, the ground inspection status and the vector network status in real time;

[0032] The ground inspection host computer software can read the amplitude and phase data of each channel and each frequency point returned by the vector network, save them to disk, and process the amplitude and phase data to generate analysis reports and amplitude and phase truth tables. The amplitude and phase truth tables can be sent to the antenna under test to complete the amplitude and phase compensation of the channel.

[0033] Furthermore, the signal channel between the vector network and the test antenna is data stream a, the signal channel between the vector network and the antenna under test is data stream b, the signal channel between the ground detector and the antenna under test is data stream c, the signal channel between the vector network and the PC is data stream d, the signal channel between the vector network and the ground detector is data stream e, and the signal channel between the ground detector and the PC is data stream f;

[0034] Data stream a: is the RF signal, which is the RF signal output from the vector network port 1 to the test antenna;

[0035] The data stream b is a radio frequency signal, which is output by the antenna under test and connected to the vector network port 2;

[0036] The data stream c is a digital signal, which includes the command and timing control signal output by the ground detector to the antenna under test, and the telemetry parameters returned by the antenna under test;

[0037] The data stream d is a digital signal, the amplitude and phase data returned by the vector network, which is returned to the PC for data processing;

[0038] The data stream e is a digital signal, which is a synchronization signal output by the ground detector to the vector network, controlling the vector network to perform data sampling according to the timing;

[0039] The data stream f is a digital signal, which is the remote control and telemetry data between the ground inspection and the PC.

[0040] Furthermore, the signal channel between the vector network and the waveguide probe is data stream A, the signal channel between the vector network and the antenna under test is data stream B, the signal channel between the ground detector and the antenna under test is data stream D, the signal channel between the vector network and the ground detector is data stream E, the signal channel between the ground detector and the scanning frame is data stream F, the signal channel between the vector network and the PC is data stream G, and the signal channel between the ground detector and the PC is data stream C;

[0041] The data stream A is a radio frequency signal. When the antenna under test is performing a receiving test, it is connected to the vector network port 1. When the antenna under test is performing a transmitting test, it is connected to the vector network port 2.

[0042] Data stream B: is the RF signal. When the antenna under test is doing a receiving test, it is connected to the vector network port 2. When the antenna under test is doing a transmitting test, it is connected to the vector network port 1.

[0043] Data stream C: digital signal, remote control and telemetry data between ground inspection and PC;

[0044] Data stream D: It is a digital signal, which includes the command and timing control signal output by the ground detector to the antenna under test, and the telemetry parameters returned by the antenna under test;

[0045] Data stream E: It is a digital signal. The synchronous signal output by the ground detector is sent to the vector network to control the vector network to perform data sampling according to the timing.

[0046] Data stream F: digital signal, servo control signal of the scanning frame and position signal of the scanning frame;

[0047] Data stream G: It is a digital signal, the amplitude and phase data returned by the vector network, which is returned to the PC for data processing.

[0048] Furthermore, after the antenna is transported to the darkroom, the first test system performs amplitude and phase tests. The test steps are as follows:

[0049] Step 1: Connect the antenna under test to the transfer tooling, fasten them with screws, and place them in the antenna packaging box with the radiation surface facing upwards.

[0050] Step 2: Connect the test fixture to the transfer fixture and fasten them with screws;

[0051] Step 3: Connect the test antenna to the test fixture and fasten them with screws. Place absorbing materials inside the antenna packaging box.

[0052] Step 4: Connect the two ports of the vector network to the phase-stabilized cables, complete the frequency point and output power setting of the vector network, and use the standard calibration parts to complete the calibration of the vector network;

[0053] Step 5: Complete the wiring of the first test system, where VAN port 1 is connected to the test antenna, and VAN port 2 is connected to the transceiver port of the antenna under test;

[0054] Step 6: Set the number of channels, number of wave positions, wave position number, and frequency point parameters on the ground inspection host computer;

[0055] Step 7: The first test system is powered on, and the test start command is executed on the ground inspection host computer;

[0056] Step 8: Under the control of the ground inspection, the vector network completes the acquisition of different wave positions and different frequency points of all channels, and transmits the acquired data to the ground inspection host computer. The ground inspection host computer completes data analysis and generates a test report. The report will show the amplitude and phase difference between this measurement and the test value before the transfer, and a two-dimensional matrix can be obtained, one dimension is the channel number, and the other dimension is the wave position number;

[0057] Step 9: Repeat the above steps to complete the amplitude and phase acquisition of each receiving channel of 64 wave positions;

[0058] Step 10: Adjust the VNA cable, connect VNA port 1 to the antenna under test, and connect VNA port 2 to the test antenna; re-change the host computer settings, change the antenna to the transmit mode, and execute the above steps to complete the amplitude and phase acquisition of each transmit channel of the 64 wave positions.

[0059] Further, after the first test system is tested, the second test system is used to perform a darkroom test, and the steps are as follows:

[0060] Step 1: The antenna to be tested is installed on the test fixture. The test fixture is installed in front of the scanning frame. A dial indicator is installed on the scanning frame. The scanning frame is roughly adjusted to ensure that the error between the X, Y, and Z axes of the antenna to be tested and the X, Y, and Z axes of the scanning frame is within 5 mm. The position of the test fixture is locked to ensure that the fixture position will not move.

[0061] Step 2: Fine-tune the antenna under test by using the test fixture. The whole process requires repeated adjustments in three axes until the error between the X, Y, and Z coordinate axes of the antenna under test and the X, Y, and Z coordinate axes of the scanning frame is within 0.5 mm. The test fixture is locked to ensure that the position of the antenna does not move during the test.

[0062] Step 3, complete the connection of the second test system, where the transceiver port of the antenna under test is connected to the vector network port 1, and the waveguide probe is connected to the vector network port 2;

[0063] Step 4: Power on the second test system, set up the transmission phase, and complete the following configuration on the ground inspection host computer:

[0064] Scanning frame configuration, including scanning frame coordinate file import and scanning speed setting;

[0065] Vector network configuration, including output power, frequency, and sampling point configuration;

[0066] Configuration of the antenna under test, including the number of wave positions, wave position number, and working mode configuration;

[0067] Step 5: execute the transmission phase matching instruction, and the second test system completes the amplitude and phase data collection and calibration data collection at the center frequency points of all transmission channels at different wave positions under the timing control of the ground detection;

[0068] Step 6: Change a group of wave positions and repeat steps 4 and 5 until all 64 phase shift state measurements of the phase shifters of all transmission channels are completed, and finally the phase shift truth table of the transmission phase shifter of each channel is obtained;

[0069] Step 7: The user formulates the pointing table of the phased array antenna. The host will calculate the phase shift of each channel under each pointing direction. The phase shift is a one-dimensional matrix with a theoretical value. It needs to be compensated by the phase shift truth table measured in step 6 to obtain the phase shift phase characteristic table that needs to be adjusted for each channel.

[0070] Step 8: According to the method of step 7, a shift-to-phase characteristic table of each orientation can be obtained, and the shift-to-phase characteristic table is uploaded to the antenna under test, and the antenna under test stores the table;

[0071] Step 9: To set the direction diagram, configure the ground inspection host computer as follows:

[0072] Scanning frame configuration, including scanning trajectory, scanning range, number of sampling points, and scanning speed settings;

[0073] Vector network configuration, including output power, frequency, and sampling point configuration;

[0074] Configuration of the antenna under test, including the number of wave positions, wave position number, and working mode configuration;

[0075] Step ten, execute the directional pattern test command. After the test is completed, the ground inspection software processes the actually collected amplitude and phase data and obtains the final directional pattern.

[0076] Compared with the prior art, the phased array antenna amplitude and phase calibration method described in the present invention has the following advantages:

[0077] The phased array antenna amplitude and phase calibration method described in the present invention saves test costs, greatly shortens darkroom test time and frequency, and the overall test cost is expected to be reduced by 30%; shortens the test cycle, greatly shortens the darkroom test time and frequency, and the overall test cycle is expected to be reduced by 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0079] Figure 1 A schematic diagram of a test system according to an embodiment of the present invention;

[0080] Figure 2 A schematic diagram of an antenna under test according to an embodiment of the present invention;

[0081] Figure 3 This is a schematic diagram of a transfer tooling according to an embodiment of the present invention;

[0082] Figure 4 A schematic diagram of a test tool according to an embodiment of the present invention;

[0083] Figure 5 This is a schematic diagram of placing the absorbing material according to an embodiment of the present invention;

[0084] Figure 6 This is a schematic diagram of the principle of a first test system according to an embodiment of the present invention;

[0085] Figure 7 A test timing diagram according to an embodiment of the present invention;

[0086] Figure 8 This is a schematic diagram of the principle of a second test system according to an embodiment of the present invention;

[0087] Fig. 9 This is a schematic diagram of a single-channel test timing sequence according to an embodiment of the present invention;

[0088] Fig.10 This is a schematic diagram of the timing of the full-channel test according to an embodiment of the present invention;

[0089] Fig.11 A schematic diagram of the wave position number according to an embodiment of the present invention;

[0090] Fig.12 This is a schematic diagram of a true value fitting curve according to an embodiment of the present invention;

[0091] Fig.13 The phase matrix A described in the embodiment of the present invention is 1 64,200 Schematic diagram;

[0092] Fig.14 The phase matrix A described in the embodiment of the present invention is 2 64,200 Schematic diagram;

[0093] Fig.15 The phase matrix A described in the embodiment of the present invention is3 64,200 Schematic diagram;

[0094] Fig.16 Schematic diagram of the wave control code matrix according to an embodiment of the present invention.

[0095] Description of reference numerals:

[0096] 1. Antenna under test; 2. Transfer tooling; 3. Test tooling; 4. Test antenna; 5. Antenna packaging box;

[0097] 101. Radiating unit; 102. Antenna mounting plate; 1021. Transfer tooling installation and positioning interface;

[0098] 201, main frame; 2011, test fixture positioning pin; 202, connecting lug; 2021, fixing and positioning hole;

[0099] 301, test tool positioning hole; 302, test antenna installation hole. DETAILED DESCRIPTION

[0100] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0101] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0102] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0103] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0104] like Figures 1 to 16 As shown, a phased array antenna amplitude and phase calibration method is performed based on test data from two test systems. Both systems include the following modules: antenna under test 1, phase-stabilizing cable, vector network, ground detection, and PC, which are referred to as common modules.

[0105] The first system introduction:

[0106] like Figure 1 , Figure 6 As shown, the first test system includes a tested antenna 1, a transfer tool 2, a test tool 3, a test antenna 4 and an antenna packaging box 5.

[0107] like Figure 2 As shown, the antenna 1 under test, i.e., a phased array antenna, is generally large in size and has a large number of channels. Here, an example of 1 meter × 1 meter in size and 200 channels is used for illustration. The antenna 1 under test has two external RF ports, one of which is a transceiver port and the other is a calibration port. The antenna 1 under test includes a radiation unit 101 and an antenna mounting plate 102. The side of the antenna mounting plate 102 has a transfer tool installation and positioning interface 1021, i.e., two threaded holes plus two pin holes.

[0108] The antenna packaging box 5, inside which the antenna is placed during transportation, has a shock-absorbing function.

[0109] like Figure 3 As shown, the transfer tooling 2 is connected to the antenna 1 under test with high precision and reliability through pins and fastening screws. The transfer tooling 2 is in direct contact with the antenna packaging box 5 to ensure that the front and back sides of the antenna 1 under test are not subjected to force. The transfer tooling 2 includes a main frame 201 and a connecting lug 202. A test tooling locating pin 2011 is provided on the main frame 201. The test tooling locating pin 2011 is used to locate the test tooling 3. A fixing and positioning hole 2021 is also reserved on the connecting lug 202. The fixing and positioning hole 2021 includes two fixing holes and two positioning holes, which are used to locate and fasten with the transfer tooling installation and positioning interface 1021 on the antenna 1 under test. Since the antenna 1 under test and the transfer tooling 2 are not disassembled as a whole, there is only a connection error between the two. The center straightness of the two positioning holes is 0.01 (IT6 grade), the positioning pin shaft fit belongs to the basic shaft system (G7h6) clearance fit, and the error between holes is within 0.02. The connection error between the two is controlled within 0.03mm, and the flatness is guaranteed to be within 0.1mm through processing.

[0110] like Figure 4As shown, the test fixture 3 and the test antenna 4, the test fixture 3 is provided with a test fixture positioning hole 301 and a test antenna installation hole 302, and two test fixture positioning holes 301 are left at the bottom of the test fixture 3 for positioning with the test fixture positioning pin 2011 on the transfer fixture 2, the center straightness of the two test fixture positioning holes 301 is 0.015 (IT6 grade), the positioning pin shaft fit belongs to the basic shaft system (G7h6) clearance fit, the hole error is within 0.02, the connection error between the two is controlled within 0.035mm, and the flatness is guaranteed to be within 0.1mm through processing. Once the test antenna 4 and the test fixture 3 are fastened by bolts, they will not be disassembled again, and there is no problem of repeated positioning accuracy. Therefore, the whole set of tests only has the above two positioning errors, which are generally within 0.065mm and the flatness is within 0.2mm.

[0111] The high amplitude and phase stability of the phase-stable cable ensures that each test of the antenna 1 under test will not introduce amplitude and phase errors into the test antenna 4, thereby ensuring the test accuracy.

[0112] Vector network, dual-port vector network, completes the amplitude and phase measurement of different frequency points of the antenna 1 under test.

[0113] The ground detection is an embedded board, which serves as a medium between the ground detection host computer and the vector network and the antenna 1 under test. It is used to complete the control of the antenna 1 under test and the vector network and the data feedback. It is precisely because of the high real-time performance of the ground detection that the accuracy and efficiency of the test are guaranteed, greatly shortening the test time.

[0114] PC computer, PC computer communicates with ground inspection through 232 interface, and communicates with vector network through network port. PC computer contains ground inspection host computer software, which is a visualization software, and its main functions are:

[0115] 1. The configuration of the antenna 1 under test, the configuration of the ground detector, and the configuration of the vector network are all performed through this software;

[0116] 2. The software can display the status of the antenna 1 under test, the status of the ground detector, and the status of the vector network in real time;

[0117] 3. Read the amplitude and phase data of each channel and each frequency point returned by the vector network, save them to disk, and process the data to generate an analysis report and an amplitude and phase truth table. The truth table can be sent to the antenna 1 under test to complete the amplitude and phase compensation of the channel.

[0118] The data flow is described as follows:

[0119] Data stream a: RF signal, the RF signal output from vector network port 1 to test antenna 4;

[0120] Data stream b: RF signal, the RF signal output by the antenna 1 under test is connected to the vector network port 2;

[0121] Data stream c: digital signal, command and timing control signal output by the ground detector to the antenna 1 under test, and telemetry parameters returned by the antenna 1 under test;

[0122] Data stream d: digital signal, amplitude and phase data returned by the vector network, is returned to the PC for data processing;

[0123] Data stream e: digital signal, the synchronization signal output by the ground detector to the vector network, controlling the vector network to perform data sampling according to the timing;

[0124] Data stream f: digital signal, remote control and telemetry data between ground inspection and PC.

[0125] The second system introduction:

[0126] like Figure 8 As shown, the second test system is carried out in a near-field darkroom. In addition to the above-mentioned common modules, it also includes a scanning frame, a darkroom test fixture, and a waveguide probe.

[0127] The scanning frame supports the installation of a waveguide probe with four degrees of freedom and high precision adjustment on the scanning frame. The scanning frame carries the waveguide probe to complete high-precision position movement and realizes amplitude and phase acquisition at each point.

[0128] Darkroom test fixture, the antenna 1 under test is installed on the darkroom test fixture, and the darkroom test fixture has multiple degrees of freedom and precise adjustable functions, which ensures that there is a precise positional relationship between the antenna 1 under test and the waveguide probe, thereby ensuring the reliability of the test.

[0129] The data flow is described as follows:

[0130] Data stream A: RF signal. When the antenna 1 under test is doing a receiving test, it is connected to the vector network port 1. When the antenna 1 under test is doing a transmitting test, it is connected to the vector network port 2.

[0131] Data stream B: RF signal. When the antenna 1 under test is doing a receiving test, it is connected to the vector network port 2. When the antenna 1 under test is doing a transmitting test, it is connected to the vector network port 1.

[0132] Data stream C: digital signal, remote control and telemetry data between ground inspection and PC;

[0133] Data stream D: digital signal, command and timing control signal output by the ground detector to the antenna 1 under test, and telemetry parameters returned by the antenna 1 under test;

[0134] Data stream E: digital signal, the synchronization signal output by the ground detector to the vector network, controls the vector network to perform data sampling according to the timing;

[0135] Data stream F: digital signal, servo control signal of the scanning frame and position signal of the scanning frame;

[0136] Data stream G: digital signal, amplitude and phase data returned by the vector network, is returned to the PC for data processing.

[0137] like Figure 7 The test system working sequence is shown:

[0138] In order to pursue high test efficiency, the present invention adopts an automated multi-task test mode. In one test task, the amplitude and phase measurement of different wave positions and different frequencies in the whole channel or any specified channel and the amplitude and phase measurement of the calibration channel can be realized. The test workload is very large, and how to quickly complete all test tasks is particularly important. Here, the ground detection plays a vital role, which controls the antenna under test, the vector network, the scanning frame, and the ground detection host computer to work according to the established timing.

[0139] The testing process and method of the present invention:

[0140] After the antenna is transported to the darkroom, the first test system is used to perform amplitude and phase tests. The test steps are as follows:

[0141] Step 1: The antenna 1 to be tested is connected to the transfer tooling 2 with high precision and fastened with screws, and the whole is placed in the antenna packaging box 5 with the radiation surface facing upwards;

[0142] Step 2: The test fixture 3 and the transfer fixture 2 are connected with high precision and fastened with screws;

[0143] Step 3: The test antenna 4 is connected to the test fixture 3 with high precision and fastened with screws. The antenna packaging box 5 is filled with absorbing materials, such as Figure 5 As shown;

[0144] Step 4: Connect the two ports of the vector network to the phase-stabilized cable, complete the settings of the frequency point, output power, etc., and use the standard calibration parts to complete the calibration of the vector network;

[0145] Step 5: Follow Figure 6 Complete the system wiring, where VN port 1 is connected to the test antenna 4, and VN port 2 is connected to the transceiver port of the antenna 1 under test;

[0146] Step 6: The ground inspection host computer sets the number of channels (here set to 200), the number of wave positions (here set to 16), the wave position number (from 1 to 16), the frequency point (here set to 1 frequency point, i.e. the center frequency point) and other parameter settings;

[0147] Step 7: Power on the system and execute the test start command on the ground inspection host computer;

[0148] Step 8: Under the control of the ground inspection, the vector network completes the acquisition of different wave positions and different frequency points of all channels. The test sequence is as follows: Figure 7As shown. The collected data is transmitted to the ground inspection host computer, which completes the data analysis and generates a test report. The report will show the amplitude and phase difference between this measurement and the test value before the transfer, so that designers can judge whether the radiation performance of the antenna is affected. A two-dimensional matrix will be obtained, with one dimension being the channel number and the other dimension being the wave position number;

[0149] Step 9: Repeat the above steps to complete the amplitude and phase acquisition of each receiving channel of 64 wave positions;

[0150] Step 10: Adjust the VNA cable, connect VNA port 1 to the antenna 1 under test, and VNA port 2 to the test antenna 4. Re-change the host computer settings, change the antenna to the transmit mode, and execute the above steps to complete the amplitude and phase acquisition of each transmit channel of the 64 wave positions.

[0151] In summary, through the above steps, we can obtain three tables measured by the first test system, namely, the phase table of 200 transmitting channels at different wave positions, the amplitude table of 200 receiving channels at different wave positions, and the phase table of 200 receiving channels at different wave positions.

[0152] After the first system test is completed, the second system is used for darkroom testing. The steps are as follows:

[0153] Step 1: The antenna 1 under test is installed on the test fixture 3, and the test fixture 3 is placed in front of the scanning frame. A dial indicator is installed on the scanning frame, and the scanning frame is roughly adjusted to ensure that the errors of the X, Y, and Z coordinate axes of the antenna 1 under test and the X, Y, and Z coordinate axes of the scanning frame are within 5 mm. The position of the test fixture 3 is locked to ensure that the fixture position will not move;

[0154] Step 2: Fine-tune the antenna 1 under test by using the test fixture 3. The whole process requires repeated adjustment of the three axes until the error between the X, Y, and Z coordinate axes of the antenna 1 under test and the X, Y, and Z coordinate axes of the scanning frame is within 0.5 mm. The test fixture 3 is locked to ensure that the position of the antenna does not move during the test.

[0155] Step 3: Follow Figure 8 Complete the system connection, where the transceiver port of the antenna 1 under test is connected to the vector network port 1, and the waveguide probe is connected to the vector network port 2;

[0156] Step 4: Power on the system, set up the transmitter phase, and complete the following configuration on the ground inspection host computer:

[0157] Scanning frame configuration, including scanning frame coordinate file import, scanning speed setting, etc.

[0158] Vector network configuration, including output power, frequency (1 center frequency), sampling point configuration, etc.;

[0159] The configuration of antenna 1 under test includes the number of wave positions (16), wave position number, working mode (transmitting phase matching mode) configuration, etc. The wave position number is defined as wave position 0-wave position 63, which is the phase shift test wave position; wave position 64-wave position 127, which is the receiving amplitude modulation test wave position; wave position 128-wave position 327, which is the code word for different scanning angles in azimuth, starting from -2°, stepping 0.02°, and ending at 2°. This code word needs to be obtained after completing the amplitude modulation and phase modulation calibration; wave position 328-wave position 527, which is the code word for different scanning angles in distance, starting from -8°, stepping 0.08°, and ending at 8°. This code word needs to be obtained after completing the amplitude modulation and phase modulation calibration. Fig.11 shown.

[0160] Step 5: Execute the transmission phase matching instruction. The system completes the amplitude and phase data collection and calibration data collection at the center frequency points of all transmission channels at different wave positions under the timing control of the ground detection. The test timing is as follows: Fig. 9 As shown;

[0161] Step 6: Change a group of wave positions and repeat steps 4 and 5 until all 64 phase shift state measurements of the phase shifters of all transmission channels are completed, and finally the phase shift truth table of the transmission phase shifter of each channel is obtained, which is actually a two-dimensional matrix. One dimension is the channel number and the other dimension is the wave position number.

[0162] Step 7: The user formulates the pointing table of the phased array antenna. The host will calculate the phase shift of each channel under each pointing direction. The phase shift is a one-dimensional matrix with theoretical values. It needs to be compensated by the truth table measured in step 6. Here, the compensation method is explained by taking the normal direction as an example. If it is the normal direction, the theoretical value of each channel is {0°, 0°, ..., 0°}. The measured values ​​of each channel with phase shift characteristic 0 {100.68°, 105.82°, 114.76°, ..., 0°} are found in the measured truth table. ....., 126.85°}, the measured value minus the theoretical value is {100.68°, 105.82°, 114.76°, ..., 126.85°}, and the smallest value is used as the reference for normalization to obtain {0°, 5.14°, 14.08°, ..., 26.17°}, which is the phase shift that needs to be adjusted for each channel. Since each channel already has a phase shift truth table, a curve can be fitted for each channel, such as Fig.12 As shown, the dotted line is the ideal curve, and the solid line is the fitting curve of the measured value. By substituting the phase shift amount that needs to be adjusted for each channel into the fitting curve of each channel, the phase shift characteristic table {A1, A2, A3, ..., A200} that needs to be adjusted for each channel can be found. The phase shift characteristic is the calibrated normal wave position code.

[0163] Step 8: According to the method in step 7, a shift-to-signal table of each orientation can be obtained. The shift-to-signal table is uploaded to the antenna under test, and the antenna under test stores it.

[0164] Step 9: Direction pattern setting. The ground inspection host computer is configured as follows:

[0165] Scanning frame configuration, including scanning trajectory, scanning range, number of sampling points, scanning speed settings, etc.;

[0166] Vector network configuration, including output power, frequency (3 frequencies), sampling point configuration, etc.;

[0167] Configuration of antenna 1 under test, including the number of beam positions (16 beam positions), beam position number, working mode (transmission pattern test mode) configuration, etc.

[0168] Step 10: Execute the directional pattern test command. The test sequence is as follows: Fig.10 After the test is completed, the ground inspection software can process the actual collected amplitude and phase data and obtain the final directional diagram.

[0169] In summary, through the above steps, we can obtain three tables measured by the second test system, namely, the phase table of 200 transmitting channels at different wave positions, the amplitude table of 200 receiving channels at different wave positions, and the phase table of 200 receiving channels at different wave positions.

[0170] After the darkroom test is completed, the phased array antenna (test antenna 1) is tested again with the first test system before delivery. After the test is completed, three tables can be obtained: phase tables at different wave positions of 200 transmitting channels, amplitude tables at different wave positions of 200 receiving channels, and phase tables at different wave positions of 200 receiving channels. The above 9 tables can be used to calibrate the amplitude and phase of each transmitting and receiving channel of the phased array.

[0171] Here we take the transmission channel calibration as an example to illustrate.

[0172] The first set of system tests before the transmission channel phase matrix A 1 64,200 like Fig.13 shown.

[0173] The transmit channel phase matrix A of the second system test 2 64,200 like Fig.14 shown.

[0174] The latest transmission channel phase matrix A tested using the first system 3 64,200 like Fig.15 shown.

[0175] The calibration method is as follows:

[0176] Step 1: Phase matrix A 3 64,200 Subtract the phase matrix A 1 64,200 Get the new phase matrix A new 64,200 .

[0177] Step 2: New phase matrix A new 64,200 Add the phase matrix A 2 64,200 Get the new phase matrix A j 64,200 .

[0178] Step 3: Based on matrix A j 64,200 The phase value of each channel can be fitted with a true value curve between the phase shift amount and the angle for each channel;

[0179] Step 4: In this example, there are 400 wave positions corresponding to wave positions 128 to 527. The theoretical matrix A of the displacement phasors of different wave positions is known. l 400,200 , correspond each wave position in the matrix according to the true value curve of each channel obtained in the previous step, and a shift-bit characteristic matrix will be obtained. The shift-bit characteristic matrix is ​​the wave position code matrix B after calibration 400,200 .like Fig.16 shown.

[0180] The present invention can solve the cost problem. Through the method proposed by the present invention, the darkroom test time and frequency are greatly shortened, resulting in reduced test costs; the present invention can solve the cycle problem. Through the method proposed by the present invention, the darkroom test time and frequency are greatly shortened, resulting in reduced test cycles.

[0181] Advantages of the present invention:

[0182] Save testing costs, the darkroom testing time and frequency are greatly shortened, and the overall testing cost is expected to be reduced by 30%; shorten the testing cycle, the darkroom testing time and frequency are greatly shortened, and the overall testing cycle is expected to be reduced by 30%.

[0183] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A phased array antenna amplitude and phase calibration method, characterized by: It is realized by the test data of two test systems. Both test systems include the antenna under test, phase-stabilizing cable, vector network, ground inspection and PC. The first test system also includes the antenna under test, transfer tooling, test tooling, test antenna and antenna packaging box. The transfer tooling is placed inside the antenna packaging box, the antenna under test and the test tooling are installed on the transfer tooling, and the test antenna is installed above the test tooling. The second test system is carried out in a near-field darkroom. It also includes a scanning frame, darkroom test fixture and waveguide probe. The scanning frame can support the installation of the waveguide probe. The scanning frame moves the waveguide probe with the waveguide probe to achieve amplitude and phase acquisition at each point. The antenna under test is installed on the darkroom test fixture. The darkroom test fixture has multiple degrees of freedom and precise adjustable functions to ensure that the antenna under test and the waveguide probe have a precise positional relationship. Testing methods for two test systems: After the antenna is transported to the darkroom, the first test system is used to perform amplitude and phase tests; Through the test of the first test system, three tables can be obtained: phase tables of 200 transmitting channels at different wave positions, amplitude tables of 200 receiving channels at different wave positions, and phase tables of 200 receiving channels at different wave positions. After the first test system is tested, the second test system is used to conduct darkroom testing; Through the test of the second test system, three tables measured by the second test system can be obtained, namely, the phase table of 200 transmitting channels at different wave positions, the amplitude table of 200 receiving channels at different wave positions, and the phase table of 200 receiving channels at different wave positions; After the darkroom test is completed, the first test system is used to perform another test before the antenna under test is delivered. After the test is completed, three tables can be obtained: phase tables at different wave positions of 200 transmitting channels, amplitude tables at different wave positions of 200 receiving channels, and phase tables at different wave positions of 200 receiving channels. The above nine tables can perform amplitude and phase calibration for each transmitting and receiving channel of the phased array. If the transmit channel is calibrated, the transmit channel of the first system for the first test is phase matrix A 1 64,200 ; The transmission channel of the second system test is phase matrix A 2 64,200 ; The transmission channel of the second test of the first system is phase matrix A 3 64,200 ; The amplitude and phase calibration methods are as follows: S1, phase matrix A 3 64,200 Subtract the phase matrix A 1 64,200 Get the new phase matrix A new 64,200 ; S2, new phase matrix A new 64,200 Add the phase matrix A 2 64,200 Get the new phase matrix A j 64,200 ; S3, based on the new phase matrix A j 64,200 The phase value of each channel can fit a true value curve between the phase shift amount and the angle for each channel; S4, there are 400 wave positions corresponding to wave positions 128-527, and the matrix A of the different wave displacement phasors is known theoretically l 400,200 , the matrix A l 400,200 Each wave position in the code is matched according to the true value curve of each channel obtained in the previous step, and a shift-bit characteristic matrix can be obtained. The shift-bit characteristic matrix is ​​the wave position code matrix B after calibration. 400,200 .

2. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: The antenna under test includes a radiation unit and an antenna mounting plate. A transfer tool installation and positioning interface is reserved on the side of the antenna mounting plate. The transfer tool installation and positioning interface is used to install and position the transfer tool.

3. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: The transfer tooling includes a main frame and connecting lugs. The main frame is provided with a test tooling locating pin, which is used to position the test tooling. The connecting lugs are provided with fixing and locating holes, which are used to position and fasten with the transfer tooling installation and positioning interface on the antenna under test.

4. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: The test fixture is provided with a test fixture positioning hole and a test antenna installation hole. The test fixture positioning hole is used for positioning with the test fixture positioning pin on the transfer fixture, and the test antenna installation hole is used for installing the test antenna.

5. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: The phase-stable cable is used to ensure that each test of the antenna under test does not introduce amplitude or phase errors into the test antenna; The vector network is a dual-port vector network, which is used to complete the amplitude and phase measurement of the antenna under test at different frequencies; The ground detection is an embedded board, which serves as a medium between the ground detection host computer and the vector network and the antenna under test, and is used to complete the control of the antenna under test and the vector network and data return; The PC communicates with the ground inspection through the 232 interface and with the vector network through the network port. The PC includes the ground inspection host computer software. The functions of the ground inspection host computer software include: The configuration of the antenna under test, the ground inspection, and the vector network are all performed through the ground inspection host computer software; The ground inspection host computer software can display the status of the antenna under test, the ground inspection status and the vector network status in real time; The ground inspection host computer software can read the amplitude and phase data of each channel and each frequency point returned by the vector network, save them to disk, and process the amplitude and phase data to generate analysis reports and amplitude and phase truth tables. The amplitude and phase truth tables can be sent to the antenna under test to complete the amplitude and phase compensation of the channel.

6. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: The signal channel between the vector network and the test antenna is data stream a, the signal channel between the vector network and the antenna under test is data stream b, the signal channel between the ground detector and the antenna under test is data stream c, the signal channel between the vector network and the PC is data stream d, the signal channel between the vector network and the ground detector is data stream e, and the signal channel between the ground detector and the PC is data stream f; Data stream a: is the RF signal, which is the RF signal output from the vector network port 1 to the test antenna; The data stream b is a radio frequency signal, which is output by the antenna under test and connected to the vector network port 2; The data stream c is a digital signal, which includes the command and timing control signal output by the ground detector to the antenna under test, and the telemetry parameters returned by the antenna under test; The data stream d is a digital signal, the amplitude and phase data returned by the vector network, which is returned to the PC for data processing; The data stream e is a digital signal, which is a synchronization signal output by the ground detector to the vector network, controlling the vector network to perform data sampling according to the timing; The data stream f is a digital signal, which is the remote control and telemetry data between the ground inspection and the PC.

7. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: The signal channel between the vector network and the waveguide probe is data stream A, the signal channel between the vector network and the antenna under test is data stream B, the signal channel between the ground detector and the antenna under test is data stream D, the signal channel between the vector network and the ground detector is data stream E, the signal channel between the ground detector and the scanning frame is data stream F, the signal channel between the vector network and the PC is data stream G, and the signal channel between the ground detector and the PC is data stream C; The data stream A is a radio frequency signal. When the antenna under test is performing a receiving test, it is connected to the vector network port 1. When the antenna under test is performing a transmitting test, it is connected to the vector network port 2. Data stream B: is the RF signal. When the antenna under test is doing a receiving test, it is connected to the vector network port 2. When the antenna under test is doing a transmitting test, it is connected to the vector network port 1. Data stream C: digital signal, remote control and telemetry data between ground inspection and PC; Data stream D: It is a digital signal, which includes the command and timing control signal output by the ground detector to the antenna under test, and the telemetry parameters returned by the antenna under test; Data stream E: It is a digital signal. The synchronous signal output by the ground detector is sent to the vector network to control the vector network to perform data sampling according to the timing. Data stream F: digital signal, servo control signal of the scanning frame and position signal of the scanning frame; Data stream G: It is a digital signal, the amplitude and phase data returned by the vector network, which is returned to the PC for data processing.

8. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: After the antenna is transported to the darkroom, the first test system performs amplitude and phase tests. The test steps are as follows: Step 1: Connect the antenna under test to the transfer tooling, fasten them with screws, and place them in the antenna packaging box with the radiation surface facing upwards. Step 2: Connect the test fixture to the transfer fixture and fasten them with screws; Step 3: Connect the test antenna to the test fixture and fasten them with screws. Place absorbing materials inside the antenna packaging box. Step 4: Connect the two ports of the vector network to the phase-stabilized cables, complete the frequency point and output power setting of the vector network, and use the standard calibration parts to complete the calibration of the vector network; Step 5: Complete the wiring of the first test system, where VAN port 1 is connected to the test antenna, and VAN port 2 is connected to the transceiver port of the antenna under test; Step 6: Set the number of channels, number of wave positions, wave position number, and frequency point parameters on the ground inspection host computer; Step 7: The first test system is powered on, and the test start command is executed on the ground inspection host computer; Step 8: Under the control of the ground inspection, the vector network completes the acquisition of different wave positions and different frequency points of all channels, and transmits the acquired data to the ground inspection host computer. The ground inspection host computer completes data analysis and generates a test report. The report will show the amplitude and phase difference between this measurement and the test value before the transfer, and a two-dimensional matrix can be obtained, one dimension is the channel number, and the other dimension is the wave position number; Step 9: Repeat the above steps to complete the amplitude and phase acquisition of each receiving channel of 64 wave positions; Step 10: Adjust the VNA cable, connect VNA port 1 to the antenna under test, and connect VNA port 2 to the test antenna; re-change the host computer settings, change the antenna to the transmit mode, and execute the above steps to complete the amplitude and phase acquisition of each transmit channel of the 64 wave positions.

9. The phased array antenna amplitude and phase calibration method according to claim 1, characterized in that: After the first test system is tested, the second test system is used for darkroom testing. The steps are as follows: Step 1: The antenna to be tested is installed on the test fixture. The test fixture is installed in front of the scanning frame. A dial indicator is installed on the scanning frame. The scanning frame is roughly adjusted to ensure that the error between the X, Y, and Z axes of the antenna to be tested and the X, Y, and Z axes of the scanning frame is within 5 mm. The position of the test fixture is locked to ensure that the fixture position will not move. Step 2: Fine-tune the antenna under test by using the test fixture. The whole process requires repeated adjustments in three axes until the error between the X, Y, and Z coordinate axes of the antenna under test and the X, Y, and Z coordinate axes of the scanning frame is within 0.5 mm. The test fixture is locked to ensure that the position of the antenna does not move during the test. Step 3, complete the connection of the second test system, where the transceiver port of the antenna under test is connected to the vector network port 1, and the waveguide probe is connected to the vector network port 2; Step 4: Power on the second test system, set up the transmission phase, and complete the following configuration on the ground inspection host computer: Scanning frame configuration, including scanning frame coordinate file import and scanning speed setting; Vector network configuration, including output power, frequency, and sampling point configuration; Configuration of the antenna under test, including the number of wave positions, wave position number, and working mode configuration; Step 5: execute the transmission phase matching instruction, and the second test system completes the amplitude and phase data collection and calibration data collection at the center frequency points of all transmission channels at different wave positions under the timing control of the ground detection; Step 6: Change a group of wave positions and repeat steps 4 and 5 until all 64 phase shift state measurements of the phase shifters of all transmission channels are completed, and finally the phase shift truth table of the transmission phase shifter of each channel is obtained; Step 7: The user formulates the pointing table of the phased array antenna. The host will calculate the phase shift of each channel under each pointing direction. The phase shift is a one-dimensional matrix with a theoretical value. It needs to be compensated by the phase shift truth table measured in step 6 to obtain the phase shift phase characteristic table that needs to be adjusted for each channel. Step 8: According to the method of step 7, a shift-to-signal table of each orientation can be obtained, and the shift-to-signal table is uploaded to the antenna under test, and the antenna under test stores the table; Step 9: To set the direction diagram, configure the ground inspection host computer as follows: Scanning frame configuration, including scanning trajectory, scanning range, number of sampling points, and scanning speed settings; Vector network configuration, including output power, frequency, and sampling point configuration; Configuration of the antenna under test, including the number of wave positions, wave position number, and working mode configuration; Step ten, execute the directional pattern test command. After the test is completed, the ground inspection software processes the amplitude and phase data actually collected and obtains the final directional pattern.

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