Amplitude and phase measuring and correcting system for phased array radar

Abstract

The invention discloses a phased array radar amplitude and phase measurement and calibration system, which comprises a measurement and calibration signal source and an amplitude and phase measurement and calibration instrument, and is characterized in that the measurement and calibration signal source is controlled by the amplitude and phase measurement and calibration instrument to generate radar echo signals required by a test, amplitude and phase errors of a plurality of receiving channels of a radar are automatically measured, and a radar system is guided to perform correction. Automatic amplitude and phase testing and correction of the multiple receiving channels of the phased array radar are achieved, the method can be really applied to automatic equipment for production and maintenance support, and the amplitude and phase testing and correction efficiency of the receiving channels of the phased array radar in batch production and the guarantee capacity of a maintenance mechanism in the using process can be improved.

Description

Technical Field

[0001] The present application belongs to the field of testing technology, and in particular relates to an amplitude and phase measurement and calibration system for a phased array radar. Background Art

[0002] Phased array radars generally contain multiple receiving channels, and the consistency of channel amplitude and phase is an important indicator of the radar. If the amplitude and phase of each channel are inconsistent, the radar tracking accuracy will be reduced or even unable to complete the tracking task. The debugging of the whole machine during the radar production process, the failure of the receiving channel during use or the replacement of parts and repairs, etc., all require the testing and correction of the amplitude and phase of the receiving channel. In addition, if the radar has a receiving channel failure during use, most of them cannot be solved by themselves because there is no special equipment support. They often request the manufacturer to provide support for repair or return to the factory for repair, which requires a lot of repair funds and repair time.

[0003] At present, the amplitude and phase test and calibration of the phased array radar receiving channel are mainly completed by radar manufacturers. The calibration equipment consists of simple radar debugging tools, oscilloscopes, RF signal sources and wireless walkie-talkies. Generally, 2 to 3 operators are required, and they need to have certain professional knowledge and engineering experience. The calibration process is mainly manual. It takes at least 1 day to complete the amplitude and phase calibration of a set of radars. The operation time is long, the process is complicated, and the efficiency is low. Summary of the invention

[0004] The embodiment of the present application provides a phased array radar amplitude and phase measurement and calibration system to at least solve the problem of high complexity and low efficiency of radar amplitude and phase measurement and calibration in the related art.

[0005] The embodiment of the present application provides a phased array radar amplitude and phase measurement and calibration system, which is applied to a phased array radar mass production receiving channel. The system includes: The calibration signal source is configured to generate a radar echo signal required for the test and send it to the radar phased array antenna in response to receiving a control signal from the amplitude and phase calibrator, so that the radar phased array antenna mixes, amplifies, phase-detects and AD-converts the radar echo signal and then outputs an I-channel signal and a Q-channel signal corresponding to the radar echo signal; The amplitude and phase calibrator is configured to measure the amplitude and phase errors of multiple receiving channels of the radar by collecting the I-channel signal and Q-channel signal output by the radar phased array antenna, so as to guide the radar system to make corrections.

[0006] The phased array radar amplitude and phase calibration system of the embodiment of the present application includes a calibration signal source and an amplitude and phase calibrator. The amplitude and phase calibrator controls the calibration signal source to generate the radar echo signal required for the test, and automatically measures the amplitude and phase errors of multiple receiving channels of the radar, thereby guiding the radar system to make corrections, thereby realizing automated amplitude and phase testing and calibration of multiple receiving channels of the phased array radar. The system can be truly applied to automated equipment for production and maintenance support, and can improve the amplitude and phase calibration efficiency of the receiving channels of batch production of phased array radars and the support capability of maintenance organizations during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0008] Figure 1 It is a structural schematic diagram of a phased array radar amplitude and phase measurement and calibration system provided in an embodiment of the present application; Figure 2 It is a diagram of the internal structure layout of the amplitude and phase calibration instrument of the phased array radar amplitude and phase calibration system provided in an embodiment of the present application; Figure 3 It is a block diagram of the working principle of the central control board of the amplitude and phase calibration instrument provided in the embodiment of the present application; Figure 4 It is a block diagram of the working principle of the data acquisition board of the amplitude and phase calibration instrument provided in the embodiment of the present application. DETAILED DESCRIPTION

[0009] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0010] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0011] Phased array radars generally contain multiple receiving channels, and the consistency of channel amplitude and phase is an important indicator of the radar. If the amplitude and phase of each channel are inconsistent, the radar tracking accuracy will be reduced or even unable to complete the tracking task. The debugging of the whole machine during the radar production process, the failure of the receiving channel during use or the replacement of parts and repairs, etc., all require the testing and correction of the amplitude and phase of the receiving channel. In addition, if the radar has a receiving channel failure during use, most of them cannot be solved by themselves because there is no special equipment support. They often request the manufacturer to provide support for repair or return to the factory for repair, which requires a lot of repair funds and repair time.

[0012] At present, the amplitude and phase test and calibration of the phased array radar receiving channel are mainly completed by radar manufacturers. The calibration equipment consists of simple radar debugging tools, oscilloscopes, RF signal sources and wireless walkie-talkies. Generally, 2 to 3 operators are required, and they need to have certain professional knowledge and engineering experience. The calibration process is mainly manual. It takes at least 1 day to complete the amplitude and phase calibration of a set of radars. The operation time is long, the process is complicated, and the efficiency is low.

[0013] In the related technology, Lv Guizhou and Liu Limin. Design of PXI bus amplitude and phase consistency test module. "Measurement and Control Technology", Vol. 33, No. 1, 2014, proposed a design for using PXI bus technology to implement the amplitude and phase consistency error test of the receiving channel. This design mainly completes the measurement and calculation of the amplitude and phase errors of the intermediate frequency receiving channel, and cannot realize the measurement and calibration of the front end of the phased array antenna (such as the antenna array, T / R components, etc.), nor can it complete the automatic switching and calibration of various frequency points of the entire phased array antenna, and cannot meet the production and maintenance guarantee needs.

[0014] In order to solve the problems of the related art, the embodiment of the present application provides a phased array radar amplitude and phase calibration system. It should be noted that the phased array radar amplitude and phase calibration system of the embodiment of the present application is applied to the mass production receiving channel of the phased array radar.

[0015] The phased array radar amplitude and phase calibration system provided in the embodiment of the present application is described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0016] refer to Figure 1 , is a schematic diagram of the structure of a phased array radar amplitude and phase calibration system according to an embodiment of the present application. Figure 1 As shown, the phased array radar amplitude and phase calibration system includes a calibration signal source and an amplitude and phase calibrator. Specifically, the calibration signal source is configured to generate a radar echo signal required for the test in response to receiving a control signal from the amplitude and phase calibrator and send it to the radar phased array antenna, so that the radar phased array antenna mixes, amplifies, phase-detects and AD-converts the radar echo signal and then outputs an I-channel signal and a Q-channel signal corresponding to the radar echo signal; the amplitude and phase calibrator is configured to measure the amplitude and phase errors of multiple receiving channels of the radar by collecting the I-channel signal and the Q-channel signal output by the radar phased array antenna, so as to guide the radar system to make corrections.

[0017] It should be understood that both the amplitude and phase calibrator and the calibration signal source are portable devices, wherein the amplitude and phase calibrator is constructed by using automatic testing technology based on embedded computer ETX modules, and the calibration signal source is constructed by using automatic control technology based on single chip microcomputers.

[0018] It should be noted that, in the embodiment of the present application, the amplitude and phase calibrator is connected to the radar center computer, the calibration signal source is set at a preset distance from the radar vehicle and the horn antenna of the calibration signal source is facing the center of the radar antenna.

[0019] It should be noted that, in the embodiment of the present application, the output frequency of the radar echo signal is 0.5 MHz higher than the radar transmission frequency.

[0020] Next, the specific structure and configuration of the amplitude and phase calibration instrument are described in detail. Figure 1 As shown, the amplitude and phase calibrator includes: a central control board, a data acquisition board, a wireless communication module, a touch screen, a shortwave antenna, a standard computer interface, a test interface and a power module.

[0021] Furthermore, Figure 2 The internal structure layout of the amplitude and phase calibration instrument is shown in FIG. Figure 2 As shown, the portable device has a central control board, a data acquisition board and a power supply inserted into the chassis. The standard interface and the test interface are designed on the right side of the device. A fan is designed on the left side. Forced air cooling is used in the chassis.

[0022] Optionally, the wireless communication module is connected to the central control board using a standard RS232 serial communication interface. The transmission frequency uses the open ISM band 433MHz, the RF output power is 500mW, the maximum transmission distance is 600 meters, and it is configured to send frequency and power saving and other control commands to the calibration signal source.

[0023] Optional, standard computer interfaces include 2 USB2.0, 1 VGA, 2 PS / 2, and 1 Ethernet port.

[0024] Optionally, the test interface is the interface between the test equipment and the radar, including a DOC disk interface, a data acquisition interface, a serial communication port, etc.

[0025] Optionally, the LCD screen uses an 8-inch TFT true color screen with a wide viewing angle; the touch screen uses a five-wire resistive screen with a wide operating temperature range; the touch / LCD screen adopts a wide-temperature reinforced structure to meet field working conditions.

[0026] It can be understood that the central control panel is the control core of the amplitude and phase calibration instrument. Figure 3 The block diagram of its working principle is shown in Figure 2. Figure 3 As shown, the central control board includes: ETX computer module, eight serial port board, CPLD circuit and drive circuit. Among them, the eight serial port board includes eight programmable serial communication ports; the CPLD circuit is configured to generate various control signals and interfaces.

[0027] Optionally, for the eight serial port board, the RS232, RS485 or RS422 serial communication mode can be set through the jumper, the working mode can be programmed to be duplex, half-duplex, etc., and the baud rate can be set to the standard baud rate. In this way, the radar main control board can be controlled through the serial communication port to make the radar work in calibration mode.

[0028] Furthermore, in some embodiments, the data acquisition board is configured to provide working timing to the A / D board of the radar receiving channel, read the conversion result of the A / D board on the radar echo signal and save it in the dual-port RAM to obtain the amplitude and phase data of the receiving channel. Therefore, the test system pre-connected with the amplitude and phase calibrator can read, process, analyze and display the amplitude and phase data of the receiving channel.

[0029] Specifically, Figure 4 The working principle block diagram of the data acquisition board in the amplitude and phase calibration instrument is shown. Figure 4As shown, the data acquisition board includes: a high-speed signal processing chip DSP, a programmable logic chip FPGA, a differential chip (differential receiving chip and differential transmitting chip), and a power module, etc. Among them, the programmable logic chip is configured to complete the working timing logic control corresponding to the high-speed signal processing chip, and perform electrical reset and watchdog reset based on the reset signal; a voltage conversion chip is provided between the differential chip and the programmable logic chip.

[0030] Optionally, the address lines A0~A18 and data lines D16~D47 of the DSP chip are all connected to the FPGA, which is configured by the FPGA to connect to the A / D board data bus or the data and address bus of the dual-port RAM; IRQ0~IRQ3, FLAG0~FLAG3, DMAR1, DMAR2, read, write, chip select and other signals are all connected to the FPGA, which completes the timing logic control of the DSP operation; the reset signal is connected to the FPGA, which completes its power-on reset and watchdog reset.

[0031] Optionally, the I / O pin voltage of the FPGA chip is 3.3V, and the core voltage is 1.5V. It has 1 million gates, 575 pins, of which 328 are user I / O pins. The external clock input is 40M, and the operating voltage of the matching configuration chip is 3.3V.

[0032] Optionally, the operating voltage of the differential chip is 5V, and the I / O operating voltage of the FPGA is 5V, so a voltage conversion chip is provided between the differential chip and the FPGA.

[0033] Optionally, the power module has an input voltage of 5V, an output voltage of 3.3V, and an output current of 3A. It is mainly used to power DSP chips, voltage conversion chips, FPGA chips and their configuration chips; the TPS75515 has an input of 5V and an output of 1.5V, which is used to power XC2V1000.

[0034] Therefore, the amplitude and phase calibrator is based on the central control board, data acquisition board, wireless communication module, touch screen, shortwave antenna, standard computer interface and test interface to control the measurement and calibration signal source to generate the radar echo signal required for the test, and automatically measure the amplitude and phase errors of multiple receiving channels of the radar, guide the radar system to make corrections, and realize the automated amplitude and phase testing and calibration of multiple receiving channels of the phased array radar. It can be truly applied to automated equipment for production and maintenance support, and can improve the efficiency of amplitude and phase measurement and calibration of batch production receiving channels of phased array radars and the support capability of maintenance organizations during use.

[0035] As an optional embodiment, the amplitude and phase calibrator is specifically configured to collect I-path signals and Q-path signals output by the radar phased array antenna through a data acquisition board.

[0036] As an optional embodiment, the amplitude and phase calibrator is specifically configured to send frequency and power saving control signals to the calibration signal source through a wireless communication module.

[0037] As an optional embodiment, the amplitude and phase calibrator is specifically configured to calculate the phase difference of the receiving channel according to the radar echo signal through the central control board when performing phase calibration; and update the radar center phase difference compensation file according to the phase difference to perform phase correction on the receiving channel.

[0038] As an optional embodiment, the amplitude and phase calibrator is specifically configured to, when performing amplitude calibration, calculate the channel echo signal amplitude based on the radar echo signal through the central control board; calculate the channel gain based on the channel echo signal amplitude; determine whether the channel gain meets the preset conditions, and if the channel gain does not meet the preset conditions, adjust the corresponding potentiometer in the radar gain control board until the gain of each receiving channel meets the preset conditions.

[0039] Next, the specific structure and configuration of the calibration signal source are described in detail. Figure 1 As shown in the figure, the calibration signal source includes: display control panel, microwave signal source, digital display, horn antenna, shortwave antenna, keypad and power supply. In this way, the amplitude and phase calibrator controls the calibration signal source through the shortwave antenna; the calibration signal source receives the wireless communication control signal from the amplitude and phase calibrator, simulates the radar echo, and sends it to the radar phased array antenna.

[0040] In another embodiment, when the amplitude and phase calibration system of this embodiment is used for phase calibration, the amplitude and phase calibrator is set next to the radar cabinet, and its interface is connected to the radar center and the A / D output interface. The calibration signal source is set at 300 meters away from the radar vehicle, and there should be no obstacle between the calibration signal source and the radar vehicle. The horn antenna of the calibration signal source is directly opposite to the center of the radar antenna. The test system connected to the central control panel of the calibrator is operated to calibrate the phase of the radar multiple receiving channels. First, the amplitude and phase calibrator controls the calibration signal source to output an echo signal with a frequency 0.5MHz higher than the radar transmission frequency. The radar antenna receives the signal, and after mixing, amplification, and phase detection, it outputs an orthogonal I and Q orthogonal signal with a frequency of 0.5MHz, which is then converted into a digital signal by the AD conversion board. Then, the data acquisition board of the calibrator is used to collect the I and Q signals output by the radar A / D conversion board, and transmit them to the main control board for processing, and the phase difference of the test channel is calculated. Finally, the phase correction of the receiving channel is realized by updating the phase difference compensation file of the radar center.

[0041] Specifically, the phase can be calculated according to the following formulas (1)-(5): ; (1) When testing the linear sum and difference channels, the phase difference is: ; (2) When testing subarray 1 channel, the phase difference is: ; (3) When testing subarray 2 channels, the phase difference is: ; (4) When testing the logarithmic sum and difference channels, the phase difference is: ; (5) in, Indicates the phase of a certain receiving channel; I indicates the amplitude of the signal on the I channel of a certain receiving channel; Q indicates the amplitude of the signal on the Q channel of a certain receiving channel; , , , , , Respectively represent the phases of the linear sum, linear difference, subarray 1, subarray 2, logarithmic sum, and logarithmic difference channels; Indicates the phase difference.

[0042] In another embodiment, when the amplitude and phase calibration system of this embodiment is used for amplitude calibration, the calibration signal source is set next to the radar antenna, and its output port is connected to the signal input end of the radar high-frequency receiving component test channel through a fixed attenuator. The output signal frequency of the calibration signal source is 0.5MHz higher than the corresponding frequency point transmission frequency. After mixing, amplification, and phase detection in the radar receiving channel, the orthogonal I and Q signals with an output frequency of 0.5MHz are converted into digital signals through the AD conversion board. The I and Q signals output by the A / D conversion board are collected by the data acquisition board, processed by the main control board, and the channel echo signal amplitude is calculated according to the following formula (6), and then the channel gain is calculated. If the gain does not meet the requirements, the corresponding potentiometer in the radar gain control board is adjusted to make the gain meet the requirements until the gain of each receiving channel meets the requirements.

[0043] . (6) Therefore, the phased array radar amplitude and phase calibration system in the embodiment of the present application significantly improves the calibration efficiency of the phased array radar's multiple receiving channels. The traditional method is to use instruments and meters and perform calibration manually, and it takes at least one day to complete the calibration of a radar. After using the amplitude and phase calibration system, since the control command sending, test frequency switching, data acquisition, data processing, and data recording are all performed automatically, the test and calibration work can be completed in a maximum of two hours, and the work efficiency is improved by at least 75%.

[0044] In addition, the phased array radar amplitude and phase calibration system in the embodiment of the present application is easy to operate and use, and meets the requirements of production and maintenance. Among them, the calibration equipment adopts a portable structure and can be carried by one person; the signal source adopts a lithium-ion battery and an automatic wireless communication module, which can be unattended; the test and data recording are automatically carried out, reducing the requirements for operators.

[0045] It should be noted that, for the convenience of description, the above device or system is described as various modules according to their functions. Of course, when implementing this application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0046] The functional blocks shown in the structural block diagram described above can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier. "Machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0047] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0048] The above reference is made to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application, and describe various aspects of the present application. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the functions / actions specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0049] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A phased array radar amplitude and phase measurement and calibration system, characterized in that: Applied to the mass production receiving channel of phased array radar, the system includes: The calibration signal source is configured to generate a radar echo signal required for the test and send it to the radar phased array antenna in response to receiving a control signal from the amplitude and phase calibrator, so that the radar phased array antenna mixes, amplifies, phase-detects and AD-converts the radar echo signal and then outputs an I-channel signal and a Q-channel signal corresponding to the radar echo signal; The amplitude and phase calibrator is configured to measure the amplitude and phase errors of multiple receiving channels of the radar by collecting the I-channel signal and Q-channel signal output by the radar phased array antenna, so as to guide the radar system to make corrections.

2. The system according to claim 1, characterized in that The amplitude and phase calibration instrument comprises: a central control panel, a data acquisition panel, a wireless communication module, a touch screen, a shortwave antenna, a standard computer interface and a test interface; The calibration signal source includes: a display control panel, a microwave signal source, a digital display, a horn antenna and a shortwave antenna; The amplitude and phase calibration instrument is connected to the radar center computer, the calibration signal source is arranged at a preset distance from the radar vehicle and the horn antenna of the calibration signal source is directly facing the center of the radar antenna.

3. The system according to claim 2, characterized in that The central control board includes: an ETX computer module, an eight-serial port board, a CPLD circuit and a drive circuit; The eight serial port board includes eight programmable serial communication ports; The CPLD circuit is configured to generate various control signals and interfaces.

4. The system according to claim 2, characterized in that The amplitude and phase calibrator is specifically configured to collect I-channel signals and Q-channel signals output by the radar phased array antenna through a data acquisition board.

5. The system according to claim 2, characterized in that The amplitude and phase calibrator is specifically configured to calculate the phase difference of the receiving channel according to the radar echo signal through the central control board during phase calibration; and update the radar center phase difference compensation file according to the phase difference to perform phase correction on the receiving channel.

6. The system according to claim 2, characterized in that The amplitude and phase calibrator is specifically configured to, when performing amplitude calibration, calculate the channel echo signal amplitude based on the radar echo signal through the central control board; calculate the channel gain based on the channel echo signal amplitude; determine whether the channel gain meets the preset conditions, and if the channel gain does not meet the preset conditions, adjust the corresponding potentiometer in the radar gain control board until the gain of each receiving channel meets the preset conditions.

7. The system according to claim 2, characterized in that The amplitude and phase calibration instrument is specifically configured to send frequency and power saving control signals to the calibration signal source through a wireless communication module.

8. The system according to claim 2, characterized in that The data acquisition board is configured to provide working timing for the A / D board of the radar receiving channel, read the conversion result of the A / D board on the radar echo signal and save it in the dual-port RAM to obtain the amplitude and phase data of the receiving channel.

9. The system according to claim 8, characterized in that The data acquisition board includes: a high-speed signal processing chip, a programmable logic chip and a differential chip; The programmable logic chip is configured to complete the work timing logic control corresponding to the high-speed signal processing chip, and perform electrical reset and watchdog reset based on a reset signal; A voltage conversion chip is provided between the differential chip and the programmable logic chip.

10. The system according to claim 1, characterized in that The output frequency of the radar echo signal is 0.5 MHz higher than the radar transmission frequency.

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