A Design Method for an OTA Test System of a Spaceborne Multi-Beam Communication Payload

Abstract

The present invention belongs to the technical field of wireless testing of satellite communication payloads. In order to solve the technical problems such as the shortage of site resources, low testing efficiency, and inability to meet the coverage of testing scenarios caused by the long antenna testing distance in the existing design methods, a design method for an on-orbit multi-beam communication payload OTA testing system is proposed. The azimuth angle and off-axis angle of each terminal test antenna target relative to the digital multi-beam antenna are calibrated, and the calibration data of each test target are obtained and stored. When the satellite payload under test sends beam pointing information to the digital multi-beam phased array antenna, the digital phased array automatically matches and calls the calibration data corresponding to the beam pointing, realizes the separate focusing of multiple beams at close range, and completes the multi-beam and multi-wave position parallel OTA testing of the satellite payload under test, solving the problems such as the strict requirements for the site in the existing testing methods, and can be applied in batches during the ground OTA testing process of the on-orbit communication payload system.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite communication payload wireless testing, and particularly relates to a design method for an on-board multi-beam communication payload OTA testing system. Background Art

[0002] Satellite OTA (Over The Air) testing is used to test the performance of wireless communication devices, including the total radiated power of the transmitter, i.e., the ability of the device to send information; and the composite omnidirectional receiving sensitivity of the receiver, i.e., the ability to receive information; the comprehensive ability of the communication payload to provide peak services to multiple users simultaneously through multiple beams and multiple wave positions of the digital phased array antenna; and multi-beam interference, intermodulation, etc.

[0003] Currently, there are two existing methods for designing an OTA testing system for a communication payload with multi-frequency multi-beams and multi-wave positions:

[0004] One is to place multiple terminal antennas at multiple positions that meet the far-field conditions outdoors. However, the outdoor test environment has strict requirements for shielding interference signals. At the same time, the far-field test distance of the on-board phased array antenna is relatively long, making it difficult to find a suitable test environment; it is also difficult to obtain terminal test data and analyze test results, reducing the test efficiency and being unfavorable for mass production. The other is to use the indoor compact range method indoors, where a far-field condition is established within a short distance through multiple reflector systems. However, the reflector system is expensive, and it is difficult to align multiple beams and multiple wave positions simultaneously, with complex operations.

[0005] Currently, satellite communication is carried out through a digital multi-beam phased array antenna, which facilitates real-time and high-frequency time slot scheduling communication between a communication satellite and multiple ground terminals, and flexibly assigns appropriate beams to multiple communication terminals through the cooperation of the on-board base station and the digital phased array, and zeros the beams as needed to achieve anti-interference ability and improve communication quality.

[0006] However, in most current digital multi-beam phased array antennas, there is often only one set of calibration data, and all multi-beams use the same set of calibration data, unable to use different sets of calibration data for multi-beams, resulting in problems such as difficulty in finding a ground test site, low efficiency, and incomplete coverage of test scenarios. Summary of the Invention

[0007] In order to solve the problems of the existing communication satellite payload system OTA testing being demanding on the site, having low test efficiency, and incomplete scenario coverage, the present invention proposes the following technical solutions:

[0008] A design method for an on-board multi-beam communication payload OTA testing system, as Figure 1 shown, includes the following steps:

[0009] S1. Place the satellite payload under test in a shielded and anechoic test site, on which a digital multi-beam phased array antenna is installed. The test site also includes multiple test targets for placing the terminal test antennas.

[0010] S2. Calibrate to obtain the azimuth angle and off-axis angle of each terminal test antenna corresponding to the test target relative to the satellite payload under test.

[0011] S3. Sequentially obtain the calibration data of multiple test targets, number them, and then store them in the digital multi-beam phased array antenna.

[0012] S4. The satellite payload under test sends the beam pointing information to the digital multi-beam phased array antenna.

[0013] S5. The digital multi-beam phased array antenna matches the received beam pointing information with the calibration data written in S3, thereby calling the corresponding calibration data to achieve multi-beam separate focusing at close range and complete the multi-beam and multi-wave position parallel OTA test of the satellite payload under test.

[0014] Technical effects:

[0015] The present invention solves the problems of the existing OTA test of communication satellite payloads, which has strict requirements for the test site and high economic costs. It can achieve all-weather testing without being affected by interference signals. Through the joint design of the ground terminal test antenna and the communication payload under test, it can meet the air interface test requirements of the communication payload for multi-beam and multi-wave position simultaneous parallel testing. Similar to ordinary OTA tests, the ground test system site needs to ensure a shielded and anechoic environment. The test system includes multiple test targets for placing the terminal test antennas. The distance from each test target to the payload under test does not need to meet the far-field condition. For example, the existing far-field test distance of digital phased arrays is more than 130 meters, and the test distance using the test site of the present invention can be shortened to 20 meters or even shorter. By storing and calling multiple sets of calibration data, it can realize the multi-beam and multi-wave position simultaneous test scenario, efficiently complete the full-load assessment of the satellite communication payload satellite-ground system indicators, and can be applied in batches during the ground OTA test process of the spaceborne communication payload system. Description of the drawings

[0016] Figure 1 It is a schematic diagram of the overall process of the present invention.

[0017] Figure 2 It is a schematic diagram of the multi-beam simultaneous test scenario of the test system designed by the present invention.

[0018] Figure 3 It is a schematic diagram of the beam pointing of the digital multi-beam phased array. Detailed implementation manners

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts in using the embodiments of the present invention belong to the scope of protection of the present invention.

[0020] A design method for an on-orbit multi-beam communication payload OTA test system in an embodiment of the present invention is as Figure 1 shown

[0021] S1. Place the satellite payload to be tested in a shielded and anechoic test site, on which a digital multi-beam phased array antenna is installed. The test site also includes multiple test positions for placing terminal test antennas.

[0022] In this embodiment, the multiple test positions are arranged in an arc distribution as a whole, and the distance between each test position is greater than or equal to 3 m (ensuring no mutual interference).

[0023] S2. Calibrate to obtain the azimuth angle and off-axis angle of the terminal test antennas corresponding to the test positions relative to the satellite payload to be tested;

[0024] Calibrate the azimuth angle θ and off-axis angle by a total station instrument. As Figure 3 shown, establish a coordinate system with the center of the digital phased array surface as the origin, and the position of the test position as the beam pointing target point. The azimuth angle θ is the clockwise angle between the projection of the beam pointing on the XOY plane and the positive X axis, and the off-axis angle is the angle between the beam pointing and the positive Z axis.

[0025] S3. Obtain the calibration data of multiple test positions in sequence, number them, and then store them in the digital multi-beam phased array antenna;

[0026] Among them, during the calibration process, the transceiver calibration channels of the satellite payload to be tested are sequentially connected to the terminal test antennas corresponding to multiple test positions, and the multi-channel external calibration function of the digital multi-beam phased array antenna is used to accurately obtain multiple groups of calibration data in combination with the terminal test antennas, and the azimuth angle and off-axis angle obtained in S2 are grouped with the calibration data and then stored in the satellite payload to be tested.

[0027] S4. The satellite payload to be tested sends the beam pointing information to the digital multi-beam phased array antenna; the beam pointing information is the azimuth angle and off-axis angle of the test position relative to the satellite payload to be tested.

[0028] S5. The digital multi-beam phased array antenna matches the received beam pointing information with the calibration data written in S3, thereby calling the corresponding calibration data, and uses the digital multi-beam phased array to control the focal point to achieve separate focusing of multiple beams at close range, completing the multi-beam and multi-wave position parallel OTA test of the payload of the satellite under test.

[0029] As Figure 2 shown, when using the OTA test system designed by the present invention, in this embodiment, the shielded and anechoic test site is an anechoic chamber. The distance from the digital multi-beam phased array antenna to the test antenna is less than the far-field distance of the antenna, and the multi-beam and multi-wave position tests are realized in parallel. Through the present invention, subsequent test operations can be conveniently carried out, and the test data is transmitted to the data analysis and processing system server through the terminal test antenna for recording and analysis.

[0030] Contents not described in detail in this specification are all well-known prior arts to those skilled in the art. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A design method for an on-orbit multi-beam communication payload OTA test system, characterized in that It includes the following steps: S1. Place the satellite payload under test in a shielded and anechoic test site, on which a digital multi-beam phased array antenna is installed. The test site also includes multiple test positions for placing the terminal test antennas; S2. Calibrate to obtain the azimuth angle and off-axis angle of each terminal test antenna corresponding to the test position relative to the satellite payload under test; S3. Sequentially obtain the calibration data of multiple test positions, number them, and then store them in the digital multi-beam phased array antenna; S4. The satellite payload under test sends the beam pointing information to the digital multi-beam phased array antenna; S5. The digital multi-beam phased array antenna matches the received beam pointing information with the calibration data written in S3, thereby calling the corresponding calibration data to achieve separate focusing of multiple beams at close range and complete the multi-beam and multi-wave position parallel OTA test of the satellite payload under test.

2. The design method of an on-board multi-beam communication payload OTA test system according to claim 1, characterized in that, The multiple test positions are arranged in an arc distribution as a whole, and the interval between each test position is greater than or equal to 3 m.

3. The design method of an on-board multi-beam communication payload OTA test system according to claim 1, characterized in that, Taking the center of the digital phased array surface as the origin, a coordinate system is established. Taking the position where the test position is located as the beam pointing target point, the azimuth angle is the clockwise angle between the projection of the beam pointing on the XOY plane and the positive X axis, and the off-axis angle is the angle between the beam pointing and the positive Z axis.

4. The design method of an on-board multi-beam communication payload OTA test system according to claim 1, characterized in that The specific content of S3 is as follows: During the calibration process, the transceiver calibration channels of the satellite payload under test are sequentially connected to the terminal test antennas corresponding to multiple test positions, and multiple groups of calibration data are accurately obtained through the external calibration function of the digital multi-beam phased array antenna. After grouping the azimuth angle and off-axis angle obtained in S2 with the calibration data, they are stored in the digital multi-beam phased array antenna.

5. The design method of an on-orbit multi-beam communication payload OTA test system according to claim 1, characterized in that, The shielded and anechoic test site is an anechoic chamber. The distance between the digital multi-beam phased array antenna and the test antenna is less than the far-field distance of the antenna, and the multi-beam and multi-wave position tests are realized in parallel.

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