W-band active calibration system and active calibration method

Abstract

The invention relates to the technical field of radar calibration, in particular to a W-band active calibration system and an active calibration method. Comprising an antenna feeder combination, a receiving combination, a control combination and a transmitting combination which are connected in sequence, and the antenna feeder combination is used for receiving W-band radio frequency signals transmitted by a measuring radar and directionally forwarding calibration echo signals; the receiving combination is used for performing gain control and down-conversion on the W-band radio frequency signal; the control combination realizes time delay of signals after down-conversion through sequential logic design; and the transmitting combination is used for performing up-conversion and amplification on the delayed radio frequency signal. According to the scheme, the control combination is adopted to carry out delay control on radar signals, compared with a traditional delay device which determines delay duration by using an optical fiber delay line, the scheme can obtain delay precision as low as ns magnitude, the delay precision is far higher than that of the optical fiber delay line, high-precision calibration of a W wave band can be realized, and the method is suitable for large-scale popularization and application. And meanwhile, the problem that the W-band radio-frequency signal is not coherent after being delayed is solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of radar calibration, and in particular to a W-band active calibration system and an active calibration method. Background Art

[0002] Compared to passive calibration, active calibration methods offer the advantages of strong clutter suppression, high calibration accuracy, flexible configuration, a wide calibration range, and ease of use. However, in W-band calibration research, due to the higher frequencies of the W-band, higher requirements are placed on the calibration accuracy of the calibration system. Traditional active calibration systems have low delay accuracy and signal incoherence in the delay modules, resulting in calibration accuracy that cannot meet the W-band accuracy requirements.

[0003] Therefore, there is an urgent need for a W-band active calibration system and an active calibration method. Summary of the Invention

[0004] In order to solve the problems of low active calibration accuracy and signal incoherence during W-band calibration measurement, embodiments of the present invention provide a W-band active calibration system and active calibration method.

[0005] In a first aspect, an embodiment of the present invention provides a W-band active calibration system, the system comprising: an antenna feed assembly, a receiving assembly, a control assembly, and a transmitting assembly connected in sequence;

[0006] The antenna-feed combination is used to receive the W-band radio frequency signal transmitted by the measurement radar, and to transmit a calibration echo to the measurement radar;

[0007] The receiving assembly is used to perform gain control and down-conversion on the W-band radio frequency signal;

[0008] The control assembly is used to delay the down-converted signal, generate corresponding instructions according to external input parameters and issue them to each assembly, and collect feedback information from each assembly;

[0009] The transmitting assembly is used to perform up-conversion and power amplification processing on the delayed radio frequency signal, and obtain a radio frequency signal which is fed into the antenna feed assembly to be transmitted back to the measurement radar.

[0010] In a second aspect, an embodiment of the present invention further provides an active calibration method based on the system described in any embodiment of the specification, the method comprising:

[0011] The antenna-feed combination is used to receive the W-band radio frequency signal transmitted by the measurement radar;

[0012] performing gain control and down-conversion on the W-band radio frequency signal using a receiving combination;

[0013] Use the control combination to delay the down-converted signal, generate corresponding instructions based on external input parameters and issue them to each combination, and collect feedback information from each combination;

[0014] The delayed radio frequency signal is subjected to up-conversion and power amplification processing by using the transmitting assembly to obtain a radio frequency signal which is fed into the antenna feed assembly and then transmitted back to the measuring radar by using the antenna feed assembly.

[0015] An embodiment of the present invention provides an active calibration system for the W band, which uses a control combination to control the delay of radar signals. Compared with traditional delay devices that use optical fiber delay lines to determine the delay duration, this solution can achieve delay accuracy as low as nanoseconds, which is much higher than that of optical fiber delay devices. It also eliminates the problem of signal incoherence and can achieve high-precision calibration in the W band. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 1 is a schematic diagram of the composition of a W-band active calibration system provided by one embodiment of the present invention;

[0018] Figure 2 This is a flow chart of a W-band active calibration method provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] Please refer to Figure 1 , an embodiment of the present invention provides a W-band active calibration system, the system comprising: an antenna feed assembly, a receiving assembly, a control assembly, and a transmitting assembly connected in sequence;

[0021] The antenna-feed combination is used to receive the W-band radio frequency signal transmitted by the measurement radar and transmit calibration echoes to the measurement radar;

[0022] The receiving combination is used to perform gain control and down-conversion on the W-band RF signal;

[0023] The control combination is used to delay the down-converted signal, generate corresponding instructions based on external input parameters and issue them to each combination, and collect feedback information from each combination;

[0024] The transmitting combination is used to up-convert and power-amplify the delayed RF signal, and the obtained RF signal is fed into the antenna-feed combination to be transmitted back to the measurement radar.

[0025] In an embodiment of the present invention, a control combination performs delay control on radar signals. Compared with a traditional delay device that uses an optical fiber delay line to determine the delay duration, this solution can obtain a delay accuracy as low as nanoseconds. The delay accuracy is much higher than that of an optical fiber delay device, and there is no signal incoherence problem, which can achieve high-precision calibration of the W band.

[0026] In some embodiments, the antenna feed combination includes: a receiving antenna and a transmitting antenna;

[0027] The receiving antenna is used to receive the W-band radio frequency signal transmitted by the measurement radar;

[0028] The transmitting antenna is used to transmit the calibration echo back to the measuring radar.

[0029] In this embodiment, the antenna-feed combination uses separate transmitting and receiving antennas, which effectively improves the isolation between the transmitting and receiving antennas, thereby improving the calibration test accuracy of the high frequency band.

[0030] In some embodiments, a receiving assembly includes: a receiving module and a down-conversion component;

[0031] The receiving module is used to perform gain control on the W-band radio frequency signal based on the gain control command sent by the control combination to simulate a calibration body with different RCS values;

[0032] The down-conversion component is used to down-convert the W-band RF signal after gain control to a low frequency band based on the down-conversion instruction sent by the control combination, so that the down-converted signal is within the operating frequency range of the control combination.

[0033] In this embodiment, the receiving assembly primarily comprises a receiving module and a downconversion component. The receiving module receives the W-band RF signal received directionally by the receiving antenna, performs low-noise amplification and filtering, and adjusts the amplitude of the filtered W-band RF signal accordingly, thereby simulating the different RCS values ​​of multiple standard calibration bodies. The downconversion component primarily converts the gain-controlled W-band RF signal into a low-frequency signal through multiple stages, which is then fed into the control assembly to meet the operating frequency requirements of the control assembly's input signal.

[0034] In this embodiment, the control combination includes a timing controller, a storage unit, etc. Compared with the traditional optical fiber delay unit, it has a timing control function and can realize delay design. It does not need to use the length of the optical fiber delay line to determine the delay time, which can greatly improve the delay accuracy.

[0035] In some embodiments, the control assembly is used to utilize the timing logic of the digital board to perform delay timing, separate the calibration echo signal, the radar target body reflection, and the surrounding environment echo signal by adjusting the step, and output an incoherent calibration echo signal.

[0036] In this embodiment, the control assembly has two functions. First, it receives external input parameters and generates corresponding instructions. After receiving these instructions, the receiving and transmitting assemblies adjust the corresponding operating parameters and record operating status information. The control assembly is responsible for completing the acquisition. Second, it performs RF delay. The down-converted signal is fed into the control assembly, which receives delay instructions from the host computer software and performs signal delay, with adjustable step sizes. This delay function separates the calibration echo signal, the radar target body reflection, and the surrounding environment echo signal. This delay method has two advantages: first, it can achieve delay accuracy down to the nanosecond level; second, it overcomes the issue of non-coherence of W-band RF signals after delayed forwarding, which occurred in previous tests. In specific implementation, the control assembly is equipped with hardware boards and host computer software to issue instructions and store the returned information.

[0037] In an embodiment of the present invention, the control assembly converts the analog signal into a digital signal through ADC conversion and stores it in a storage module, and achieves time delay by controlling the read and write timing of the memory. Finally, the delayed digital signal is restored to an analog signal through DAC output.

[0038] In an embodiment of the present invention, the control combination delay time is calculated as follows:

[0039] t=N / fs

[0040] Where t is the delay time, N is the number of storage points, and fs is the sampling frequency.

[0041] In this embodiment, time delay is achieved by calculating the delay time based on the number of storage points and the sampling frequency, and then controlling the read and write timing of the memory based on the delay time. Compared with the traditional optical fiber delay unit, the delay design is achieved by controlling the read and write timing of the memory. There is no need to use the length of the optical fiber delay line to determine the delay time, which can greatly improve the delay accuracy and solve the problem of incoherence of W-band RF signals after delayed forwarding.

[0042] In some embodiments, the transmitting assembly includes: an up-conversion component and a power amplifier module;

[0043] The up-conversion component is used to up-convert the delayed RF signal to the W band;

[0044] The power amplifier module is used to amplify the power of the up-converted W-band signal based on the control instructions sent by the control combination, and obtain the RF signal to feed the antenna feed combination for transmission back to the measurement radar.

[0045] In this embodiment, the transmitting assembly mainly includes an up-conversion component and a power amplifier module. The up-conversion component is used to up-convert the delayed low-frequency signal to the W band; the power amplifier module amplifies the power of the signal and then feeds it into the transmitting antenna, sending the calibration echo to the measurement radar.

[0046] In some embodiments, it further includes: a power management combination; the power management combination is connected to the receiving combination, the transmitting combination and the control combination respectively, and is used to supply power to the receiving combination, the transmitting combination and the control combination respectively.

[0047] like Figure 2 As shown, an embodiment of the present invention further provides an active calibration method based on a system of any embodiment of the specification, the method comprising:

[0048] Step 200: using an antenna-feed combination to receive a W-band radio frequency signal transmitted by a measurement radar;

[0049] Step 202: The receiving assembly performs gain control and down-conversion on the W-band RF signal based on the instruction issued by the control assembly;

[0050] Step 204, performing delay design on the down-converted signal using a control combination;

[0051] Step 204: The transmitting assembly up-converts and amplifies the delayed RF signal based on the instruction issued by the control assembly to obtain a RF signal which is fed into the antenna feed assembly to be transmitted back to the measurement radar by the antenna feed assembly.

[0052] The content of the above method is based on the same concept as the embodiment of the system of the present invention. For specific content, please refer to the description in the embodiment of the system of the present invention and will not be repeated here.

[0053] It should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0054] Those skilled in the art will understand that all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk, etc. Various media that can store program codes.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A W-band active calibration system, characterized in that: include: Antenna feed combination, receiving combination, control combination, and transmitting combination connected in sequence; The antenna-feed combination is used to receive the W-band radio frequency signal transmitted by the measurement radar, and to transmit a calibration echo to the measurement radar; The receiving combination is used to perform gain control and down-conversion processing on the W-band radio frequency signal; The control assembly is used to delay the down-converted signal, generate corresponding instructions according to external input parameters and issue them to each assembly, and collect feedback information from each assembly; The transmitting assembly is used to perform up-conversion and power amplification processing on the delayed radio frequency signal, and obtain a radio frequency signal which is fed into the antenna feed assembly to be radiated back to the measurement radar.

2. The system according to claim 1, wherein: The antenna feed combination includes: a receiving antenna and a transmitting antenna; The receiving antenna is used to receive the W-band radio frequency signal transmitted by the measurement radar; The transmitting antenna is used to radiate the calibration echo back to the measuring radar.

3. The system according to claim 1, wherein: The receiving assembly includes: a receiving module and a down-conversion component; The receiving module is used to receive the gain control instruction sent by the control assembly and perform gain control on the W-band radio frequency signal to simulate a calibration body with different RCS values; The down-conversion component is used to down-convert the W-band radio frequency signal after gain control to a low frequency band, so that the down-converted signal is within the operating frequency range of the control combination.

4. The system according to claim 1, wherein: The transmitting assembly includes: an up-conversion component and a power amplifier module; The up-conversion component is used to up-convert the delayed radio frequency signal to the W band; The power amplifier module is used to receive the timing logic sent by the control combination, perform power amplification on the up-converted W-band signal and output it, and obtain a radio frequency signal which is fed into the antenna feed combination to be transmitted back to the measurement radar.

5. The system according to claim 1, wherein: The control combination utilizes the timing logic of the digital board to perform delay design, separates the calibration echo signal, the radar target body reflection and the surrounding environment echo signal by regulating the step, and outputs a coherent calibration echo signal.

6. The system according to claim 1, wherein: The control combination adopts FPGA timing design.

7. The system according to claim 5, characterized in that The control combination is used to convert analog signals into digital signals through ADC conversion. In the process of storing the digital signals in the storage module, the read and write timing of the memory is controlled to achieve time delay. The delayed digital signal is restored to an analog signal output through the DAC.

8. The system according to claim 7, characterized in that The control combination delay time is calculated as follows: t=N / fs Where t is the delay time, N is the number of storage points, and fs is the sampling frequency.

9. The system according to claim 1, wherein: Also includes: A power management assembly; the power management assembly is connected to the receiving assembly, the transmitting assembly and the control assembly respectively, and is used to supply power to the receiving assembly, the transmitting assembly and the control assembly respectively.

10. An active calibration method based on the system according to any one of claims 1 to 9, characterized in that: include: The antenna-feed combination is used to receive the W-band radio frequency signal transmitted by the measurement radar; The receiving assembly performs gain control and down-conversion on the W-band radio frequency signal based on the instruction issued by the control assembly; Use control combination to design delay of down-converted signal; The transmitting assembly performs up-conversion and power amplification processing on the delayed radio frequency signal based on the instruction issued by the control assembly, obtains a radio frequency signal and feeds it into the antenna feed assembly, so as to be radiated back to the measurement radar by the antenna feed assembly.

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