Phased-array antenna darkroom test method

Abstract

The invention provides a phased-array antenna darkroom testing method, which is realized by a testing system, and the testing system mainly comprises a tested antenna, a four-port vector network, a ground detector, a PC (Personal Computer), a scanning frame, a testing tool, a stable-phase cable and a waveguide probe. The method has the beneficial effects that the problems of long test period of the large-scale phased-array antenna and overhigh test cost of the large-scale phased-array antenna can be solved, so that the cost is greatly reduced, the total test cost can be reduced by 30%, the test period can be greatly shortened, and the test period can be shortened by 30%.

Description

Technical Field

[0001] The invention belongs to the technical field of phased array antenna darkroom testing, and in particular relates to a phased array antenna darkroom testing method. Background Art

[0002] Phased array antenna is an advanced antenna technology that forms and steers the direction of a beam by electronically controlling the phase of multiple antenna elements without physically moving the antenna itself. This technology is widely used in satellite communications, radar systems, wireless communications and other fields.

[0003] There are two main methods for testing phased array antennas: 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.

[0004] 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.

[0005] The above two testing methods have their own advantages and disadvantages. Both testing methods are very expensive. Therefore, large phased array antenna testing faces the problems of long testing cycle and high testing cost. Summary of the invention

[0006] In view of this, the present invention aims to propose a phased array antenna darkroom testing method to solve the problems of long testing cycle and high testing cost for large phased array antennas.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows: A phased array antenna darkroom test method, the test method is implemented by a test system, the test system includes a tested antenna, a four-port vector network, a ground detector, a PC, a scanning frame, a test fixture, a phase-stabilizing cable and a waveguide probe; the scanning frame can support the installation of the waveguide probe, and the scanning frame moves the waveguide probe to achieve amplitude and phase acquisition at each point; the tested antenna is installed on the test fixture, and the test fixture has a function of accurately adjusting multiple degrees of freedom to ensure that the tested antenna and the waveguide probe have a precise positional relationship, the signal channel between the four-port vector network and the waveguide probe is data stream A, the signal channel between the four-port vector network and the tested antenna is data stream B and data stream C, the signal channel between the ground detector and the tested antenna is data stream D, the signal channel between the four-port 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 four-port vector network and the PC is data stream G, and the signal channel between the ground detector and the PC is data stream H; The test method includes a test system working sequence, a darkroom transmission pattern test method and a darkroom reception pattern test method. The test system working sequence includes a single-channel test sequence and a full-channel test sequence. The single-channel test sequence is applicable to the phase matching of the transmission channel and the amplitude matching and phase matching operation of the reception channel, and amplitude and phase operation is performed on each channel. The full-channel test sequence is applicable to the transmission pattern test and the reception pattern test operation. Darkroom emission pattern test method, including: Step 1: The phased array antenna is installed on the test fixture. The test fixture is installed in front of the scanning frame. The scanning frame probe is equipped with a dial indicator. The scanning frame is roughly adjusted to ensure that the error between the three coordinate axes of the antenna under test and the three coordinate axes of the scanning frame is within 5mm. The position of the test fixture is locked to ensure that the fixture position will not move. Step 2: Fine-tune the phased array antenna by fine-tuning the adjustment mechanism on the test fixture until the error between the three coordinate axes X, Y, and Z of the antenna under test and the three coordinate axes X, Y, and Z of the scanning frame is within 0.5 mm. The fine-tune mechanism on the test fixture is locked to ensure that the position of the antenna does not move during the test. Step 3, complete the test system connection, wherein the transceiver port of the antenna under test is connected to port 1 of the four-port vector network, the waveguide probe is connected to port 2 of the four-port vector network, and the calibration port of the antenna under test is connected to port 3 of the four-port vector network; Step 4: Power on the test system, set up the transmitter 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; Four-port vector network configuration, including output power, frequency, and sampling point configuration; The configuration of the antenna under test, including the number of wave positions, wave position number, and transmission phase working mode configuration; Step 5: Execute the transmission phase matching instruction. The test system completes the amplitude and phase data collection and calibration data collection of three frequency points at different wave positions of all transmission channels under the timing control of the ground inspection; Step 6: Change a group of wave positions, repeat steps 4 and 5 until all 64 phase shift state measurements of the phase shifters of all transmitting channels are completed, and finally the phase shift truth table of the transmitting phase shifter of each channel is obtained. The phase shift truth table is a three-dimensional matrix, in which one dimension is the channel number, one dimension is the wave position number, and one dimension is the frequency point; Step 7, selecting the phase truth table of the center frequency as compensation data; Step 8: The user specifies the pointing table of the phased array antenna. The ground detection host can calculate the phase shift of each channel under each pointing direction. The phase shift of each channel under each pointing direction is a one-dimensional matrix, and the value is a theoretical value. It needs to be compensated by the truth table measured in step 6. Step nine, according to the method of step eight, a shift-to-phase characteristic table of each orientation can be obtained; the shift-to-phase characteristic table is uploaded to the antenna under test, and the antenna under test stores it; Step 10: Direction pattern setting. The ground inspection host computer is configured as follows: Scanning frame configuration, including scanning trajectory, scanning range, number of sampling points, and scanning speed configuration; Four-port 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 transmission pattern test mode configuration; Step eleven, execute the directional pattern test instruction. After the test is completed, the ground inspection host computer can process the amplitude and phase data actually collected and obtain the final directional pattern.

[0008] Furthermore, the darkroom receiving pattern test method is based on the same principle as the darkroom transmitting pattern test method, with the following differences: 1. The connection methods of the four-port vector network and the antenna under test are different. Port 1 of the four-port vector network is connected to the waveguide probe, port 2 of the four-port vector network is connected to the transceiver port of the antenna under test, and port 3 of the four-port vector network is connected to the calibration port of the antenna under test. 2. In addition to phase, the receiving test also includes amplitude, so in addition to the phase truth table, the amplitude truth table must also be measured.

[0009] Furthermore, the antenna under test is a phased array antenna with an antenna size of 4 meters × 1 meter and 800 channels. The transmitting channels all include phase shifters, and the receiving channels include phase shifters and attenuators. The bit numbers of the phase shifters and attenuators are both 6 bits, i.e., 64 wave position states. The antenna under test has two external RF ports, one of which is the transceiver port and the other is the calibration port.

[0010] Furthermore, the four-port vector network is used to complete the amplitude and phase value measurement of the antenna and the amplitude and phase measurement of the calibration channel; The ground detection is an embedded board, which serves as a medium between the ground detection host computer and the four-port vector network, the antenna under test, and the scanning frame. It is used to complete the control of the antenna under test, the four-port vector network, and the scanning frame as well as the data feedback.

[0011] Furthermore, the PC communicates with the ground inspection through a 232 interface. In addition, the PC communicates with the four-port vector network through a 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, the four-port vector network, and the scanning frame 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, the status of the four-port vector network, and the scanning frame status in real time; The amplitude and phase data of each position returned by the four-port vector network and the amplitude and phase data of the calibration channel are read and saved, and the data is processed to generate an analysis report and an amplitude and phase truth table, which can be sent to the phased array antenna to complete the amplitude and phase compensation of the channel.

[0012] Furthermore, the phase-stable cable has high amplitude and phase stability performance, which can ensure that each test of the antenna under test will not introduce amplitude and phase errors of the test cable.

[0013] Further, the data stream A is a radio frequency signal, which is connected to port 1 of the four-port vector network when the antenna under test is undergoing a receiving test, and is connected to port 2 of the four-port vector network when the antenna under test is undergoing a transmitting test; Data stream B: is the RF signal. When the antenna under test is doing a receiving test, it is connected to port 2 of the four-port vector network. When the antenna under test is doing a transmitting test, it is connected to port 1 of the four-port vector network. Data stream C: is the RF signal, calibration signal, connected to port 3 of the four-port vector network; 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 four-port vector network, which controls the four-port 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 four-port vector network, which is returned to the PC for data processing; Data stream H: digital signal, remote control and telemetry data between ground inspection and PC.

[0014] Furthermore, in the antenna configuration under test in step four, 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°, and the code word needs to be obtained after the amplitude modulation and phase modulation calibration is completed; wave position 328-wave position 527, which is the code word for different scanning angles in range, starting from -8°, stepping 0.08°, and ending at 8°, and the code word needs to be obtained after the amplitude modulation and phase modulation calibration is completed.

[0015] Compared with the prior art, the phased array antenna darkroom testing method described in the present invention has the following advantages: The phased array antenna darkroom testing method described in the present invention can solve the problem of long testing cycle for large phased array antennas and the problem of high testing cost for large phased array antennas, thereby greatly reducing costs, reducing the total testing cost by 30%, and greatly shortening the testing cycle by 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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: Figure 1 A schematic diagram of a test system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a single-channel test timing sequence according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the timing of the full-channel test according to an embodiment of the present invention; Figure 4 A schematic diagram of the wave position number according to an embodiment of the present invention; Figure 5 A schematic diagram of the phase truth value according to an embodiment of the present invention; Figure 6 It is a schematic diagram of the true value fitting curve described in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] 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.

[0018] 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.

[0019] 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.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0021] like Figures 1 to 6 As shown, a phased array antenna darkroom test method is implemented by a test system, and the test system mainly includes: a tested antenna, a four-port vector network, a ground detector, a PC, a scanning frame, a test tooling, a phase-stabilizing cable, and a waveguide probe.

[0022] The antenna under test, i.e., phased array antenna, is generally large in size and has a large number of channels. For the sake of convenience, the antenna size is set to 4 meters by 1 meter, with 800 channels. The transmitting channel includes a phase shifter, and the receiving channel includes a phase shifter and an attenuator. The number of bits of the phase shifter and the attenuator are both 6 bits, i.e., 64 wave position states. The antenna under test has two external RF ports, one of which is the transceiver port and the other is the calibration port.

[0023] Four-port vector network, completes the antenna amplitude and phase value measurement and the amplitude and phase measurement of the calibration channel; The ground inspection is an embedded board that serves as a medium between the ground inspection host computer and the four-port vector network, the antenna under test, and the scanning frame. It is used to complete the control of the antenna under test, the four-port vector network, and the scanning frame as well as the data feedback. It is precisely because of the high real-time performance of the ground inspection that the accuracy and efficiency of the test are guaranteed, greatly shortening the test time.

[0024] PC computer, the PC computer communicates with the ground inspection through the 232 interface, and communicates with the four-port vector network through the network port. The PC computer contains the ground inspection host computer software, which is a visualization software with the following main functions: 1. The configuration of the antenna under test, the configuration of the ground detector, the configuration of the four-port vector network, and the scanning frame are all performed through this software; 2. The software can display the status of the antenna under test, the status of the ground detector, the status of the four-port vector network, and the status of the scanning frame in real time; 3. Read the amplitude and phase data of each position returned by the four-port vector network, as well as the amplitude and phase data of the calibration channel, 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 phased array antenna to complete the amplitude and phase compensation of the channel.

[0025] The scanning frame supports high-precision adjustment of four degrees of freedom. The waveguide probe is installed on the scanning frame. The scanning frame carries the probe to complete high-precision position movement to achieve amplitude and phase acquisition at each point.

[0026] Test fixture, the antenna under test is installed on the test fixture, and the test fixture has multiple degrees of freedom and precise adjustable functions to ensure the precise positional relationship between the antenna under test and the probe, thereby ensuring the reliability of the test.

[0027] The phase-stable cable (i.e., the cable carrier for data stream A, data stream B, and data stream C) has high amplitude and phase stability, which ensures that the amplitude and phase errors of the test cable will not be introduced into the antenna under test each time, thus ensuring the test accuracy.

[0028] The data flow is described as follows: Data stream A: RF signal. When the antenna under test is receiving, it is connected to port 1 of the four-port vector network. When the antenna under test is transmitting, it is connected to port 2 of the four-port vector network. Data stream B: RF signal. When the antenna under test is receiving, it is connected to port 2 of the four-port vector network. When the antenna under test is transmitting, it is connected to port 1 of the four-port vector network. Data stream C: RF signal, calibration signal, connected to port 3 of the four-port vector network; Data stream D: digital signal, command and timing control signal output by the ground detector to the antenna under test, and telemetry parameters returned by the antenna under test; Data stream E: digital signal, the synchronization signal output by the ground detector to the four-port vector network, controlling the four-port 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: digital signal, amplitude and phase data returned by the four-port vector network, returned to the PC for data processing; Data stream H: digital signal, remote control and telemetry data between ground inspection and PC.

[0029] Test system working sequence: In order to pursue high test efficiency, the present invention adopts an automated multi-task test method. In one test task, the amplitude and phase measurement of different wave positions and different frequency points 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 four-port vector network, the scanning frame, and the ground detection host computer to work according to the established timing. There are two main test timings here: Single channel test timing, this is mainly applicable to the phase matching of the transmitting channel and the amplitude matching and phase matching operation of the receiving channel. The amplitude and phase operation is performed on each channel. The test timing is as follows Figure 2 shown.

[0030] Full channel test timing, this is mainly applicable to the transmission pattern test and the reception pattern test operation. The test timing is as follows Figure 3 shown.

[0031] Darkroom emission pattern test process and method: Step 1: The phased array antenna is installed on the test fixture. The test fixture is installed in front of the scanning frame. The scanning frame probe is equipped with a dial indicator. The scanning frame is roughly adjusted to ensure that the error between the three coordinate axes of the antenna under test and the three coordinate axes of the scanning frame is within 5mm. The position of the test fixture is locked to ensure that the fixture position will not move. Step 2: Fine-tune the phased array antenna. Fine-tune it through the adjustment mechanism on the test fixture. The whole process requires repeated adjustment of the 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. Then lock the fine-tune mechanism to ensure that the position of the antenna does not move during the test. Step 3: Follow Figure 1 Complete the system connection, where the antenna transceiver port under test is connected to port one of the four-port vector network, the waveguide probe is connected to port two of the four-port vector network, and the calibration port of the antenna under test is connected to port three of the four-port vector network; Step 4: Power on the system, set up the transmitter phase, and complete the following configuration on the ground inspection host computer: Scanning frame configuration, including scanning frame coordinate file import, scanning speed setting, etc. Four-port vector network configuration, including output power, frequency, sampling point number configuration, etc.; The configuration of the antenna under test includes the number of wave positions, wave position number, and the configuration of the transmitting phase matching working mode. The wave position number is defined as wave position 0 to wave position 63, which is the phase shift test wave position; wave position 64 to wave position 127, which is the receiving amplitude modulation test wave position; wave position 128 to wave position 327, which is the code word for different scanning angles in azimuth, starting from -2°, stepping 0.02°, and ending at 2°. The code word needs to be obtained after the amplitude modulation and phase modulation calibration is completed; wave position 328 to wave position 527, which is the code word for different scanning angles in distance, starting from -8°, stepping 0.08°, and ending at 8°. The code word needs to be obtained after the amplitude modulation and phase modulation calibration is completed. Figure 4 shown.

[0032] Step 5: Execute the transmission phase matching instruction. The system completes the amplitude and phase data collection and calibration data collection of three frequency points at different wave positions of all transmission channels 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 states of all transmit channel phase shifters are measured. Finally, the phase shift truth table of each channel’s transmit phase shifter is obtained, which is actually a three-dimensional matrix. One dimension is the channel number, one dimension is the wave position number, and one dimension is the frequency point. Figure 5 shown.

[0033] Step 7: Here, the phase truth table of the center frequency is selected as the compensation data. Figure 5 Frequency 3 in .

[0034] Step eight, the user specifies the pointing table of the phased array antenna, and 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, which needs to be compensated by the truth table measured in step six. 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°}, and the measured truth table is used to find the measured value of each channel with a phase shift ratio of 0 {100.68°, 105.82°, 114.76°, ..., 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°}. This is the phase shift that needs to be adjusted for each channel. Since each channel already has a phase shift truth table, such as Figure 5 As shown, each channel can be fitted with a curve, such as Figure 6As shown, the dotted line is the ideal curve, and the solid line is the measured value fitting curve. 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, ..., A800} that needs to be adjusted for each channel can be found. The phase shift characteristic is the calibrated normal wave position code.

[0035] Step 9: According to the method of step 8, 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.

[0036] Step 10: Direction pattern setting. The ground inspection host computer is configured as follows: Scanning frame configuration, including scanning trajectory, scanning range, number of sampling points, scanning speed settings, etc.; Four-port vector network configuration, including output power, frequency, sampling point number configuration, etc.; Configuration of the antenna under test, including the number of wave positions, wave position number, transmission pattern test mode configuration, etc.

[0037] Step 11, execute the directional pattern test instruction. After the test is completed, the ground inspection software can process the amplitude and phase data actually collected and obtain the final directional pattern.

[0038] Darkroom reception pattern test process and method: The receiving pattern test method is basically the same as the previous transmitting pattern test process and method, with the following differences: 1. The connection methods of the four-port vector network and the antenna under test are different. Here, port 1 of the four-port vector network is connected to the waveguide probe, port 2 of the four-port vector network is connected to the transceiver port of the antenna under test, and port 3 of the four-port vector network is connected to the calibration port of the antenna under test. 2. In addition to phase, the receiving test also includes amplitude. Therefore, in addition to measuring the phase truth table, the amplitude truth table also needs to be measured.

[0039] Advantages of the present invention: The present invention can significantly reduce the cost, and the total test cost can be reduced by 30%; the present invention can significantly shorten the cycle, and the test cycle can be shortened by 30%.

[0040] 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 principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A phased array antenna darkroom testing method, characterized by: The test method is implemented by a test system, which includes an antenna under test, a four-port vector network, a ground detector, a PC, a scanning frame, a test fixture, a phase-stabilizing cable and a waveguide probe; the scanning frame can support the installation of the waveguide probe, and the scanning frame moves the waveguide probe to achieve amplitude and phase acquisition at each point; the antenna under test is installed on the test fixture, and the 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, the signal channel between the four-port vector network and the waveguide probe is data stream A, the signal channel between the four-port vector network and the antenna under test is data stream B and data stream C, the signal channel between the ground detector and the antenna under test is data stream D, the signal channel between the four-port 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 four-port vector network and the PC is data stream G, and the signal channel between the ground detector and the PC is data stream H; The test method includes the test system working sequence, the darkroom transmission pattern test method and the darkroom reception pattern test method. The test system working sequence includes the single-channel test sequence and the full-channel test sequence. The single-channel test sequence is applicable to the phase matching of the transmission channel and the amplitude matching and phase matching operation of the reception channel, and the amplitude and phase operation is performed on each channel. The full channel test sequence is applicable to the transmission pattern test and the reception pattern test operation; Darkroom emission pattern test method, including: Step 1: The phased array antenna is installed on the test fixture. The test fixture is installed in front of the scanning frame. The scanning frame probe is equipped with a dial indicator. The scanning frame is roughly adjusted to ensure that the error between the three coordinate axes of the antenna under test and the three coordinate axes of the scanning frame is within 5mm. The position of the test fixture is locked to ensure that the fixture position will not move. Step 2: Fine-tune the phased array antenna by fine-tuning the adjustment mechanism on the test fixture until the error between the three coordinate axes X, Y, and Z of the antenna under test and the three coordinate axes X, Y, and Z of the scanning frame is within 0.5 mm. The fine-tune mechanism on the test fixture is locked to ensure that the position of the antenna does not move during the test. Step 3, complete the test system connection, wherein the transceiver port of the antenna under test is connected to port 1 of the four-port vector network, the waveguide probe is connected to port 2 of the four-port vector network, and the calibration port of the antenna under test is connected to port 3 of the four-port vector network; Step 4: Power on the test system, set up the transmitter 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; Four-port vector network configuration, including output power, frequency, and sampling point configuration; The configuration of the antenna under test, including the number of wave positions, wave position number, and transmission phase working mode configuration; Step 5: Execute the transmission phase matching instruction. The test system completes the amplitude and phase data collection and calibration data collection of three frequency points at different wave positions of all transmission channels under the timing control of the ground inspection; Step 6: Change a group of wave positions, repeat steps 4 and 5 until all 64 phase shift state measurements of the phase shifters of all transmitting channels are completed, and finally the phase shift truth table of the transmitting phase shifter of each channel is obtained. The phase shift truth table is a three-dimensional matrix, in which one dimension is the channel number, one dimension is the wave position number, and one dimension is the frequency point; Step 7, selecting the phase truth table of the center frequency as compensation data; Step 8: The user specifies the pointing table of the phased array antenna. The ground detection host can calculate the phase shift of each channel under each pointing direction. The phase shift of each channel under each pointing direction is a one-dimensional matrix, and the value is a theoretical value. It needs to be compensated by the truth table measured in step 6. Step nine, according to the method of step eight, a shift-to-phase characteristic table of each orientation can be obtained; the shift-to-phase characteristic table is uploaded to the antenna under test, and the antenna under test stores it; Step 10: Direction pattern setting. The ground inspection host computer is configured as follows: Scanning frame configuration, including scanning trajectory, scanning range, number of sampling points, and scanning speed configuration; Four-port 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 transmission pattern test mode configuration; Step eleven, execute the directional pattern test instruction. After the test is completed, the ground inspection host computer can process the amplitude and phase data actually collected and obtain the final directional pattern.

2. The phased array antenna darkroom testing method according to claim 1, characterized in that: The darkroom receiving pattern test method is based on the same principle as the darkroom transmitting pattern test method, with the following differences:

1. The connection methods of the four-port vector network and the antenna under test are different. Port 1 of the four-port vector network is connected to the waveguide probe, port 2 of the four-port vector network is connected to the transceiver port of the antenna under test, and port 3 of the four-port vector network is connected to the calibration port of the antenna under test.

2. In addition to phase, the receiving test also includes amplitude, so in addition to the phase truth table, the amplitude truth table must also be measured.

3. The phased array antenna darkroom testing method according to claim 1, characterized in that: The antenna under test is a phased array antenna with a size of 4 meters × 1 meter and 800 channels. The transmitting channels all include phase shifters, and the receiving channels include phase shifters and attenuators. The bit numbers of the phase shifters and attenuators are both 6 bits, that is, 64 wave position states. The antenna under test has two external RF ports, one of which is the transceiver port and the other is the calibration port.

4. The phased array antenna darkroom testing method according to claim 1, characterized in that: The four-port vector network is used to complete the antenna amplitude and phase value measurement and the amplitude and phase measurement of the calibration channel; The ground detection is an embedded board, which serves as a medium between the ground detection host computer and the four-port vector network, the antenna under test, and the scanning frame. It is used to complete the control of the antenna under test, the four-port vector network, and the scanning frame as well as the data feedback.

5. The phased array antenna darkroom testing method according to claim 1, characterized in that: The PC communicates with the ground inspection through the 232 interface. In addition, the PC communicates with the four-port 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, the four-port vector network, and the scanning frame 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, the status of the four-port vector network, and the scanning frame status in real time; The amplitude and phase data of each position returned by the four-port vector network and the amplitude and phase data of the calibration channel are read and saved, and the data is processed to generate an analysis report and an amplitude and phase truth table, which can be sent to the phased array antenna to complete the amplitude and phase compensation of the channel.

6. The phased array antenna darkroom testing method according to claim 1, characterized in that: The phase-stable cable has high amplitude and phase stability, which can ensure that the amplitude and phase errors of the test cable will not be introduced into each test of the antenna under test.

7. The phased array antenna darkroom testing method according to claim 1, characterized in that: The data stream A is a radio frequency signal. When the antenna under test is undergoing a receiving test, it is connected to port 1 of the four-port vector network. When the antenna under test is undergoing a transmitting test, it is connected to port 2 of the four-port vector network. Data stream B: is the RF signal. When the antenna under test is doing a receiving test, it is connected to port 2 of the four-port vector network. When the antenna under test is doing a transmitting test, it is connected to port 1 of the four-port vector network. Data stream C: is the RF signal, calibration signal, connected to port 3 of the four-port vector network; 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 four-port vector network, which controls the four-port 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 four-port vector network, which is returned to the PC for data processing; Data stream H: digital signal, remote control and telemetry data between ground inspection and PC.

8. The phased array antenna darkroom testing method according to claim 1, characterized in that: In the antenna configuration under test in step four, 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 is the receiving amplitude modulation test wave position; wave position 128-wave position 327 is the code word for different scanning angles in azimuth, starting from -2°, stepping 0.02°, and ending at 2°. The code word needs to be obtained after the amplitude modulation and phase modulation calibration is completed; wave position 328-wave position 527 is the code word for different scanning angles in range, starting from -8°, stepping 0.08°, and ending at 8°. The code word needs to be obtained after the amplitude modulation and phase modulation calibration is completed.

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