Large phased-array antenna calibration test system

Abstract

The invention discloses a large phased-array antenna calibration test system, which belongs to the technical field of antenna microwaves and comprises a scanning frame servo system, a first circulator, a second circulator, a first vector network, a second vector network, a signal generator, an antenna upper computer, a servo computer and a plurality of matched cables. The scanning frame servo system is connected with the first vector network and the second vector network through the first circulator and the second circulator; the signal generator receives an instruction of the antenna upper computer, generates a differential signal for antenna control, and provides TTL signals for the first vector network and the second vector network; the antenna upper computer is connected with the servo computer; the radar antenna pulse working system is utilized, receiving and transmitting calibration is completed through one-time testing, the testing efficiency is doubled, and the larger the array plane scale is, the more obvious the effect is.

Description

Technical Field

[0001] This invention relates to the field of antenna microwave technology, and more specifically to a calibration and testing system for a large phased array antenna. Background Technology

[0002] In recent years, radar applications have developed towards multi-functionality, integration, low cost, and lightweight design. As a crucial component of radar systems, phased array antennas are seeing continuous increases in their electrical aperture and transmit power. Furthermore, with the ever-evolving demands of radar applications, the development cycle for phased array antennas has been significantly shortened. Calibration and testing are critical to ensuring the performance of phased array antennas in terms of scanning, sidelobes, and beamforming. Large phased array antennas, with their numerous channels and narrow beamwidths, require even higher efficiency and accuracy in calibration. Aperture field single-open calibration offers high accuracy and is a commonly used calibration method for phased array antennas in spaceborne applications; however, its low calibration and testing efficiency is particularly pronounced for large arrays.

[0003] To date, phased array antennas have employed a separate calibration method for reception and transmission. Specifically, during reception calibration testing, the antenna samples data in continuous wave reception mode, while during transmission calibration testing, data is sampled within the transmission modulation timing pulse. Four calibration tests are required to complete both reception and transmission calibration and verification.

[0004] Radars can be divided into two main categories according to their signal form: continuous wave radar and pulse radar. Most radars operate in a pulse mode, meaning that reception and transmission are time-division multiplexed within a single PRT. Therefore, performing reception and transmission calibration tests separately wastes twice the probe travel time. If the radar pulse mode is utilized properly, the calibration efficiency of large phased array antennas can be significantly improved. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a large phased array antenna calibration and testing system that utilizes the radar antenna pulse operating mode to complete both transmission and reception calibration in a single test, thereby doubling the calibration and testing efficiency. Furthermore, during the acquisition of calibration data, the antenna more closely approximates its actual operating conditions.

[0006] To achieve the above objectives, the technical solution adopted by this invention is as follows: a large-scale phased array antenna calibration and testing system, comprising a scanning frame servo system, a first circulator, a second circulator, a first vector network, a second vector network, a signal generator, an antenna host computer, a servo computer, and multiple matching cables; the scanning frame servo system is connected to the first and second vector networks through the first circulator and the second circulator; the signal generator receives instructions from the antenna host computer, generates differential signals for antenna control, and provides TTL signals for the first and second vector networks; the antenna host computer is connected to the servo computer.

[0007] In a preferred embodiment of the present invention, the scanning frame servo system is controlled by a servo computer. After receiving the arrival information sent by the servo computer via a serial port, the antenna host computer sends a control command to the phased array antenna to control the channel selection, and displays the transmit and receive amplitude and phase after completing data sampling.

[0008] In a preferred embodiment of the present invention, the antenna host computer is connected to the signal generator via a network port and to the servo computer via a serial port.

[0009] As a preferred structure of the present invention, the signal generator generates a differential signal for antenna control by sending a working timing and control command word to the phased array antenna.

[0010] As a preferred structure of the present invention, the phased array antenna operates in pulse mode, that is, within a single PRT, the antenna inside the pulse is in the transmitting state and the antenna outside the pulse is in the receiving state.

[0011] As a preferred structure of the present invention, the first circulator is used for the separation of the antenna transceiver link, and the second circulator is used for the separation of the probe transceiver link.

[0012] As a preferred structure of the present invention, within a single PRT, the signal transmitted from port 1 of the first vector network enters the antenna after passing through the first circulator. After the signal is received by the probe, it enters port 2 of the first vector network after passing through the second circulator. The falling edge / rising edge of the TTL signal generated by the signal generator is within the antenna transmission operation modulation signal pulse. At this time, the first vector network performs transmission calibration data sampling within the pulse. The signal transmitted from port 1 of the second vector network enters the probe after passing through the second circulator. After the antenna receives the signal, it enters port 2 of the second vector network after passing through the first circulator. The rising / falling edge of the TTL signal generated by the signal generator is outside the antenna's transmitting modulation signal pulse. At this time, the second vector network performs receive calibration data sampling outside the pulse.

[0013] As a preferred embodiment of the present invention, it is recommended that the falling edge of the external trigger signal be delayed by 2 seconds from the falling edge of the modulated signal pulse width. The pulse width is the same as the transmitted modulation signal.

[0014] Compared with the prior art, the technical solution adopted in this invention has the following beneficial effects: 1. High efficiency: Utilizing the radar antenna pulse working mode, the receiving and transmitting calibrations are completed in one test, doubling the testing efficiency. The larger the array size, the more obvious the effect. 2. High precision: During the calibration data acquisition process, the antenna more closely approximates the actual working conditions, resulting in high test accuracy; 3. High versatility: Most radars operate in pulse mode, making this method suitable for calibration and testing. Even continuous wave mode radars can be designed with pulse test modes, thus improving calibration efficiency. Attached Figure Description

[0015] Figure 1 This is a block diagram of a large phased array antenna calibration and testing system provided in this embodiment.

[0016] Figure 2 This is a schematic diagram of the working principle of a large phased array antenna calibration and testing system provided in this embodiment.

[0017] The components include: a scanning gantry servo system 1; a first circulator 2; a second circulator 3; a first vector network 4; a second vector network 5; a signal generator 6; an antenna host computer 7; and a servo computer 8. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Any modifications made to the technical solutions based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

[0019] like Figure 1 As shown in the diagram, this embodiment provides a block diagram of a large phased array antenna calibration and testing system, including a scanning frame servo system 1, a first circulator 2, a second circulator 3, a first vector network 4, a second vector network 5, a signal generator 6, an antenna host computer 7, a servo computer 8, and multiple matching cables; the scanning frame servo system 1 is connected to the first vector network 4 and the second vector network 5 through the first circulator 2 and the second circulator 3; the signal generator 6 receives instructions from the antenna host computer 7, generates differential signals for antenna control, and provides TTL signals for the first vector network 4 and the second vector network 5; the antenna host computer 7 is connected to the servo computer 8.

[0020] In a preferred embodiment, the scanning frame servo system 1 is controlled by the servo computer 8. After receiving the arrival information sent by the servo computer 8 via a serial port, the antenna host computer 7 sends control commands to the phased array antenna to control channel selection, and displays the transmit and receive amplitudes and phases after data sampling is completed.

[0021] In a preferred configuration of this embodiment, the antenna host computer 7 is connected to the signal generator 6 via a network port and to the servo computer 8 via a serial port.

[0022] As a preferred structure in this embodiment, the phased array antenna operates in pulse mode, that is, within a single PRT, the antenna inside the pulse is in the transmitting state and the antenna outside the pulse is in the receiving state.

[0023] As a preferred structure in this embodiment, the first circulator 2 is used for the separate antenna transceiver link, and the second circulator 3 is used for the separate probe transceiver link.

[0024] The working principle of a large phased array antenna calibration and testing system in this embodiment is as follows: In routine calibration tests, receive and transmit calibrations are performed separately. During receive calibration tests, the antenna operates in continuous wave mode, and receive calibration data sampling is triggered within the vector network interface (VNA). Figure 2 As shown in the routine transmission calibration test section, during the routine transmission calibration test, the antenna pulse is activated, and external vector network sampling is triggered. Transmission calibration data is sampled within the transmission modulation signal pulse.

[0025] according to Figure 2 As shown in the high-precision, high-efficiency transceiver calibration test section, the sampling of transmission and reception calibration test data is completed in a time-division multiplexing process within one PRT (Personal Radio Unit). This means that a single sweep of the scanning frame can complete both transmission and reception calibration data sampling, saving 50% of the test time compared to conventional methods, as detailed below: Within a single PRT, the signal transmitted from port 1 of the first vector network 4 enters the antenna after passing through the first circulator 2. After the probe receives the signal, it enters port 2 of the first vector network 4 after passing through the second circulator 3. The falling / rising edge of the TTL signal generated by the signal generator 6 is within the antenna transmission operation modulation signal pulse. At this time, the first vector network 4 performs transmission calibration data sampling within the pulse. The signal transmitted from port 1 of the second vector network 5 enters the probe after passing through the second circulator 3. After the antenna receives the signal, it enters port 2 of the second vector network 5 after passing through the first circulator 2. The rising / falling edge of the TTL signal generated by the signal generator 6 is outside the antenna transmission modulation signal pulse. At this time, the second vector network 5 performs reception calibration data sampling outside the pulse.

[0026] External trigger signal falling edge suggests delay transmit modulation signal pulse width falling edge 2 The pulse width is the same as the transmitted modulation signal.

[0027] Although the present invention has been disclosed above with reference to preferred embodiments, the embodiments and accompanying drawings are not intended to limit the invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention, and these changes will also be within the protection scope of the invention. Therefore, the protection scope of the present invention should be defined by the scope of the claims of this application.

Claims

1. A calibration and testing system for a large phased array antenna, characterized in that: The system includes a scanning gantry servo system (1), a first circulator (2), a second circulator (3), a first vector network (4), a second vector network (5), a signal generator (6), an antenna host computer (7), a servo computer (8), and multiple matching cables. The scanning gantry servo system (1) is connected to the first vector network (4) and the second vector network (5) through the first circulator (2) and the second circulator (3). The signal generator (6) receives instructions from the antenna host computer (7), generates differential signals for antenna control, and provides TTL signals for the first vector network (4) and the second vector network (5). The antenna host computer (7) is connected to the servo computer (8).

2. The large phased array antenna calibration and testing system according to claim 1, characterized in that: The scanning frame servo system (1) is controlled by the servo computer (8). After the antenna host computer (7) receives the arrival information sent by the servo computer (8) via the serial port, it sends a control command to the phased array antenna to control the channel selection, and displays the transmit and receive amplitude and phase after completing data sampling.

3. The large phased array antenna calibration and testing system according to claim 1, characterized in that: The antenna host computer (7) is connected to the signal generator (6) via the network port and to the servo computer (8) via the serial port.

4. The large phased array antenna calibration and testing system according to claim 1, characterized in that, The signal generator (6) generates a differential signal for antenna control, specifically as follows: The signal generator (6) generates differential signals and sends operating timing and control command words to the phased array antenna.

5. A large phased array antenna calibration and testing system according to any one of claims 1-4, characterized in that: The phased array antenna operates on pulses, meaning that within a single pulse (PRT), the antenna inside the pulse is in the transmitting state, while the antenna outside the pulse is in the receiving state.

6. A large phased array antenna calibration and testing system according to any one of claims 1-4, characterized in that: The first circulator (2) is used for the separation of the antenna transceiver link, and the second circulator (3) is used for the separation of the probe transceiver link.

7. A large phased array antenna calibration and testing system according to any one of claims 1-4, characterized in that: Within a single PRT, the signal transmitted from port 1 of the first vector network (4) enters the antenna after passing through the first circulator (2). After the probe receives the signal, it enters port 2 of the first vector network (4) after passing through the second circulator (3). The falling edge / rising edge of the TTL signal generated by the signal generator (6) is within the antenna transmission operation modulation signal pulse. At this time, the first vector network (4) performs transmission calibration data sampling within the pulse. The signal transmitted from port 1 of the second vector network (5) enters the probe after passing through the second circulator (3). After the antenna receives the signal, it enters port 2 of the second vector network (5) after passing through the first circulator (2). The rising / falling edge of the TTL signal generated by the signal generator (6) is outside the antenna transmission modulation signal pulse. At this time, the second vector network (5) performs reception calibration data sampling outside the pulse.

8. The large phased array antenna calibration and testing system according to claim 7, characterized in that: External trigger signal falling edge delay transmit modulation signal pulse width falling edge 2 The pulse width is the same as the transmitted modulation signal.

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