A digital TR component amplitude-phase calibration method

Abstract

The application discloses a kind of digital TR component amplitude-phase calibration methods, it is related to the amplitude-phase calibration field of TR component, including: building near-field microwave darkroom;Digital acquisition system and TR component fixing device are constructed in the near-field microwave darkroom, the TR component fixing device is used to ensure that the digital TR component is fastened, and the digital acquisition system is used to generate the radio frequency signal of the digital TR component calibration;The amplitude and phase of the digital acquisition system are calibrated using the calibrated standard digital TR component, to obtain the calibrated digital acquisition system;The amplitude and phase of the transmission link of the digital TR component to be measured are calibrated using the calibrated digital acquisition system;The amplitude and phase of the receiving link of the digital TR component to be measured are calibrated using the calibrated digital acquisition system.The application uses near-field method, is not influenced by external environment, and calibration precision is high.

Description

Technical Field

[0001] This invention relates to the field of amplitude and phase calibration of TR components, and in particular to a method for amplitude and phase calibration of digital TR components. Background Technology

[0002] This invention addresses the TR component, which integrates the active transceiver section with the passive calibration network, and employs a method based on a near-field digital amplitude and phase calibration TR component.

[0003] In conventional phased array radar designs, the active transceiver section and the passive calibration network are designed separately. When the active transceiver section is damaged, only the active transceiver section needs to be replaced. After replacement, the amplitude and phase of the replaced active transceiver section are recalibrated through the original internal monitoring network. If the passive calibration network is damaged, only the passive calibration network needs to be replaced, and the amplitude and phase data of the calibration network are updated at the same time. For TR modules where the active and passive transceiver components are integrated into a single design, the entire TR module must be replaced regardless of whether the active or passive component fails. Once both active and passive components are replaced, the lack of a necessary phase reference makes it impossible to compensate the original TR module's amplitude and phase with the replaced one. Furthermore, phased array radars, due to the use of multiple spatial links, have high requirements for link amplitude and phase consistency. The large number of TR modules inevitably leads to increased failure rates and maintenance / replacement issues. It is well known that to ensure the original array's radiation pattern remains unchanged, the amplitude and phase of the replaced TR module should be consistent with those of the replaced TR module. Common amplitude and phase calibration methods used to solve this problem include:

[0004] 1) Whole-machine far-field external calibration method,

[0005] 2) Whole-machine near-field external calibration method,

[0006] 3) Internal calibration method for the whole machine.

[0007] This invention patent proposes a calibration method using the near-field amplitude and phase of a single digital TR component, which can ensure the absolute amplitude and phase consistency requirements of all digital TR components. After replacement, it is not necessary to recalibrate the entire system to ensure that the radiation pattern of the entire system does not deteriorate. Summary of the Invention

[0008] The purpose of this invention is to provide a method for calibrating the amplitude and phase of digital TR components to ensure that all digital TR components have consistent absolute amplitude and phase.

[0009] To achieve the above objectives, the present invention provides the following solution:

[0010] A method for amplitude and phase calibration of a digital TR component, comprising:

[0011] Construct a near-field microwave anechoic chamber;

[0012] A digital acquisition system and a TR component fixing device are constructed in the near-field microwave anechoic chamber. The TR component fixing device is used to ensure that the digital TR component is securely fastened, and the digital acquisition system is used to generate radio frequency signals for calibration of the digital TR component.

[0013] The amplitude and phase of the digital acquisition system are calibrated using a calibrated standard digital TR component to obtain a calibrated digital acquisition system;

[0014] The amplitude and phase of the transmit link of the digital TR component under test are calibrated using the calibrated digital acquisition system.

[0015] The amplitude and phase of the receiving link of the digital TR component under test are calibrated using the calibrated digital acquisition system.

[0016] Optionally, the digital TR component transmitter and the digital acquisition system receiver on the TR component fixing device are opposite each other.

[0017] Optionally, the near-field microwave anechoic chamber is a closed space constructed using microwave absorbing materials.

[0018] Optionally, the digital acquisition system includes an FPGA, a DDS, an AD converter, an optical fiber module, a data analysis module, a frequency up / down conversion module, a frequency source module, and a PRT synchronous output circuit.

[0019] The FPGA serves as the control core, controlling the DDS to generate baseband signals, controlling the AD to acquire the input calibration signals, and transmitting the calibration signals to the data analysis module via the fiber optic module.

[0020] The data analysis module is used to analyze the amplitude and phase information of the transmit and receive links;

[0021] The up-conversion and down-conversion modules are used to generate the excitation signal required for the calibration of the digital TR component's receiving link, and also to down-convert the calibration signal transmitted by the digital TR component's transmitting link.

[0022] The frequency source module is used to provide the reference clock for the FPGA and the up-conversion and down-conversion modules;

[0023] The PRT synchronous output circuit is used to generate the synchronous acquisition pulses required by the digital TR component.

[0024] Optionally, the digital acquisition system further includes an N-channel selection switch, which is connected to the up and down frequency conversion module.

[0025] Optionally, the digital acquisition system further includes a display and control software module, which is used to control the working logic and timing of the digital acquisition system.

[0026] Optionally, after the step of "calibrating the amplitude and phase of the transmit link of the digital TR component under test using the calibrated digital acquisition system", the method further includes:

[0027] The first calibration value is stored in the FLASH memory of the digital TR component under test.

[0028] Optionally, after the step of "calibrating the amplitude and phase of the receiving link of the digital TR component under test using the calibrated digital acquisition system", the method further includes:

[0029] The second calibration value is stored in the FLASH memory of the digital TR component under test.

[0030] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0031] This invention uses a near-field method, which is unaffected by the external environment and has high calibration accuracy. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart of the amplitude and phase calibration method for the digital TR component of the present invention;

[0034] Figure 2 This is a block diagram illustrating the principle of the digital acquisition system of the present invention.

[0035] Figure 3 This is a schematic diagram of the self-calibration process of the digital acquisition system of the present invention;

[0036] Figure 4 This is a schematic diagram of the transmission link calibration process for the digital TR component of the present invention;

[0037] Figure 5 This is a schematic diagram of the receiving link calibration process for the digital TR component of the present invention. Detailed Implementation

[0038] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] The purpose of this invention is to provide a method for calibrating the amplitude and phase of digital TR components to ensure that all digital TR components have consistent absolute amplitude and phase.

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Figure 1 This is a flowchart of the amplitude and phase calibration method for the digital TR component of the present invention, as shown below. Figure 1 As shown, a digital TR component amplitude and phase calibration method includes:

[0042] Step 1: Construct a near-field microwave anechoic chamber.

[0043] The purpose of building a near-field microwave anechoic chamber is to meet the operating frequency range of radar. By using absorbing materials to create a closed space, an interference-free electromagnetic environment can be created in the anechoic chamber.

[0044] Step 2: Construct a digital acquisition system and a TR component fixing device in the near-field microwave anechoic chamber. The TR component fixing device is used to ensure that the digital TR component is securely fastened, and the digital acquisition system is used to generate radio frequency signals for calibration of the digital TR component.

[0045] The digital acquisition system typically includes an N-channel selector switch, an FPGA, a DDS, an AD converter, an optical fiber module, a frequency source module, up and down conversion modules, N antennas, a display and control module, a PRT synchronous output circuit, and a data analysis module, which can generate radio frequency signals for digital TR component calibration.

[0046] Digital acquisition system such as Figure 2As shown, the system uses an FPGA as the control core, controlling the DDS to generate baseband signals and the AD acquisition input calibration signals, and sending the acquired digital echo signals to the data analysis module through an optical fiber module. The frequency source module provides the reference clock required by the FPGA and the up-conversion and down-conversion modules. The up-conversion and down-conversion modules generate the excitation signals required for the calibration of the digital TR component receiving link, and simultaneously down-convert the received calibration signals of the digital TR component transmitting link. The PRT synchronization output circuit is used to generate the synchronization acquisition pulses required by the digital TR component to synchronize the transmission and acquisition times. The data analysis module performs FFT processing on the received echo data with PRT as the beat, finds the frequency corresponding to the point of maximum amplitude in the frequency domain, and records the phase of that frequency point. The amplitude and phase at this time are the amplitude and phase information of the transmission or receiving link. The display and control software controls the working logic and timing of the entire system through the network port.

[0047] The digital TR component fixing device is designed and manufactured according to the outer dimensions and fixing position of the digital TR component being tested. However, it is necessary to ensure that each digital TR component is secure and consistent with the spatial position of the digital acquisition system, that is, to ensure that the transmitting end of the digital TR component and the receiving end of the digital acquisition system are opposite each other, and their relative positions remain unchanged.

[0048] Step 3: Use a quasi-digital TR component to calibrate the amplitude and phase of the digital acquisition system to obtain the calibrated digital acquisition system.

[0049] The digital acquisition system self-calibrates, and the self-calibration process is as follows: Figure 3 As shown, the digital acquisition system comprises N antennas and links, each with a different inherent amplitude and phase. Using a calibrated standard digital TR module (the amplitude and phase of each link in the standard digital TR module have been calibrated by other means, and the amplitude and phase of each link are known), the process of acquiring the inherent amplitude and phase of the links in the digital acquisition system is as follows:

[0050] Taking the self-calibration of link 1 in the digital acquisition system as an example: the standard TR component's link 1 is turned on to transmit. After the transmitting signal is radiated in space, it is received by the antenna link 1 of the digital acquisition system. At the same time, the N-way selector switch is switched to antenna 1. At this time, the radio frequency signal transmitted by the digital TR component's link 1 is down-converted by the up-conversion module and acquired by the AD. After being buffered by the FPGA, it is transmitted through the optical fiber module to the data analysis software to analyze the original amplitude and phase information of link 1 in the digital acquisition system, and the original amplitude and phase of link 1 analyzed by the data analysis software are recorded. The self-calibration of the other N-1 links is the same as the self-calibration process of link 1.

[0051] Step 4: Use the calibrated digital acquisition system to calibrate the amplitude and phase of the transmission link of the digital TR component under test.

[0052] The amplitude and phase of the transmit link of the digital TR component are calibrated one by one for each channel and frequency point, and the first calibration value is stored in the FLASH of the digital TR component.

[0053] The calibration process of the digital TR component under test, such as Figure 4 As shown, assuming the digital TR component has N links and M operating frequencies, taking the calibration of the digital TR component's transmit link 1 and frequency 1 as an example:

[0054] The digital TR component operates at frequency 1, with link 1 set to transmit mode. After the transmitted signal is radiated in space, it is received by link 1 of the digital acquisition system. Simultaneously, the N-channel selector switch is switched to antenna 1. At this time, the radio frequency signal transmitted by link 1 of the digital TR component is down-converted by the up-conversion module and acquired by the AD converter. After being buffered by the FPGA, it is transmitted through the fiber optic module to the data analysis software to analyze the amplitude and phase information of link 1. The amplitude and phase of link 1 analyzed by the data analysis software are recorded (the inherent amplitude and phase values ​​during the self-calibration of the digital acquisition system should be subtracted during calculation). The calibration process of the other N-1 transmission links of the digital TR component is the same as that of transmission link 1.

[0055] The transmission calibration process for the other M-1 frequency points is the same as that for frequency point 1.

[0056] Step 5: Use the calibrated digital acquisition system to calibrate the amplitude and phase of the receiving link of the digital TR component under test.

[0057] The amplitude and phase of the receiving link of the digital TR component are calibrated one by one, link by link, and frequency by frequency, and the second calibration value is stored in the FLASH of the digital TR component.

[0058] The calibration process of the digital TR component under test, such as Figure 5 As shown, a digital TR module has N receiving links and M operating frequencies. Taking the calibration of receiving link 1 and frequency 1 of the digital TR module as an example:

[0059] The digital TR component operates at frequency 1, and link 1 is set to receive mode. The FPGA of the digital acquisition system controls the DDS to generate a baseband signal. This baseband signal is converted into a radio frequency excitation signal at frequency 1 by up-conversion and down-conversion modules. This excitation signal is radiated through antenna 1 via an N-way selection switch and received by link 1 of the digital TR component. The digital TR component also sends the digital echo to the data analysis software through optical fiber. The data analysis software analyzes the amplitude and phase of this link (the inherent amplitude and phase values ​​during the self-calibration of the digital acquisition system should be subtracted during the calculation). The calibration process of the other N-1 receiving links is the same as that of receiving link 1.

[0060] The transmission calibration process for the other M-1 frequency points is the same as the reception calibration process for frequency point 1.

[0061] The present invention also discloses the following technical effects:

[0062] Traditional calibration methods include: far-field external calibration, near-field external calibration, and internal calibration. These methods rely on the overall system environment. Once the system is delivered, if the original sample is missing or its technical condition changes, it is difficult to guarantee the consistency of amplitude and phase of the digital TR components produced subsequently with those of the original system. Furthermore, after replacing the digital TR components on the system, amplitude and phase calibration on the system is greatly affected by the external natural environment, making it difficult to guarantee calibration accuracy. This invention uses a near-field method, which is not affected by the external environment and has high calibration accuracy.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0064] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for amplitude and phase calibration of a digital TR component, characterized in that, include: Construct a near-field microwave anechoic chamber; A digital acquisition system and a TR component fixing device are constructed in the near-field microwave anechoic chamber. The TR component fixing device is used to ensure that the digital TR component is securely fastened, and the digital acquisition system is used to generate radio frequency signals for calibration of the digital TR component. The amplitude and phase of the digital acquisition system are calibrated using a calibrated standard digital TR component to obtain a calibrated digital acquisition system; the standard digital TR component has been calibrated by other means, and the amplitude and phase of each link are known. The amplitude and phase of the transmit link of the digital TR component under test are calibrated using the calibrated digital acquisition system. The amplitude and phase of the transmit link of the digital TR component are calibrated one by one for each channel and frequency point, and the first calibration value is stored in the FLASH of the digital TR component. The amplitude and phase of the receiving link of the digital TR component under test are calibrated using the calibrated digital acquisition system. The amplitude and phase of the receiving link of the digital TR component are calibrated one by one, link by link, and frequency by frequency, and the second calibration value is stored in the FLASH of the digital TR component.

2. The amplitude and phase calibration method for a digital TR component according to claim 1, characterized in that, The digital TR component transmitter and the digital acquisition system receiver on the TR component fixing device are opposite each other.

3. The amplitude and phase calibration method for a digital TR component according to claim 1, characterized in that, The near-field microwave anechoic chamber is an enclosed space constructed using microwave absorbing materials.

4. The amplitude and phase calibration method for a digital TR component according to claim 1, characterized in that, The digital acquisition system includes an FPGA, a DDS, an AD converter, an optical fiber module, a data analysis module, an up / down conversion module, a frequency source module, and a PRT synchronous output circuit. The FPGA serves as the control core, controlling the DDS to generate baseband signals, controlling the AD to acquire the input calibration signals, and transmitting the calibration signals to the data analysis module via the fiber optic module. The data analysis module is used to analyze the amplitude and phase information of the transmit and receive links; The up-conversion and down-conversion modules are used to generate the excitation signal required for the calibration of the digital TR component's receiving link, and also to down-convert the calibration signal transmitted by the digital TR component's transmitting link. The frequency source module is used to provide the reference clock for the FPGA and the up-conversion and down-conversion modules; The PRT synchronous output circuit is used to generate the synchronous acquisition pulses required by the digital TR component.

5. The amplitude and phase calibration method for a digital TR component according to claim 4, characterized in that, The digital acquisition system also includes an N-channel selection switch, which is connected to the up and down frequency conversion module.

6. The amplitude and phase calibration method for a digital TR component according to claim 4, characterized in that, The digital acquisition system also includes a display and control software module, which is used to control the working logic and timing of the digital acquisition system.

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