Electromagnetic vortex wave radar system feed network delay measurement and correction method
By establishing a model of the feed network length and signal delay, and using matched filtering and Lagrange interpolation methods for signal delay correction, the problem of inconsistent signal delay between channels in the electromagnetic vortex wave radar system was solved, thus improving signal accuracy and quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN INSTITUE OF SPACE RADIO TECH
- Filing Date
- 2025-12-22
- Publication Date
- 2026-04-17
AI Technical Summary
In existing multi-channel electromagnetic vortex wave radar systems, inconsistent feed network lengths between channels result in different signal delays, affecting signal consistency and coherence.
A model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system is established. A signal delay measurement system is designed, and the integer and fractional parts of the signal delay are corrected by matched filtering and Lagrange interpolation.
It improves the signal accuracy of the multi-channel electromagnetic vortex wave radar system, solves the problem of inconsistent signal delay between channels, and enhances the signal quality of the system.
Smart Images
Figure CN121878622A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of radar system technology, and in particular relates to a method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system. Background Technology
[0002] Electromagnetic vortex wave radar, with its ability to transmit and receive unique vortex waves carrying orbital angular momentum, offers new degrees of freedom in observation compared to traditional plane wave radar. To simultaneously acquire multi-mode electromagnetic vortex waves, a multi-channel electromagnetic vortex wave radar system needs to be designed. Currently, commonly used multi-channel electromagnetic vortex wave radar systems are concentric ring array antenna systems. While the design of concentric ring array antennas ensures that antenna elements on the same ring have the same feed network length, the feed network lengths differ between different channels (i.e., rings with different radii). This inconsistency in feed network lengths between channels leads to different signal delays, reduces signal consistency, and may result in decreased signal coherence, thus affecting the application of the electromagnetic vortex wave radar system. Summary of the Invention
[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, so as to realize the measurement and compensation of signal delay inconsistency between channels of a multi-channel electromagnetic vortex wave radar system.
[0004] The objective of this invention is achieved through the following technical solution: a method for measuring and correcting feed network delay in an electromagnetic vortex wave radar system, comprising: establishing a model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system; establishing an inter-channel signal delay measurement system for the electromagnetic vortex wave radar system based on the model of the feed network length and signal delay of the multi-channel electromagnetic vortex wave radar system; performing matched filtering on the multi-channel echo signals in the inter-channel signal delay measurement system to obtain a one-dimensional range image; obtaining an integer part compensation sequence for the inter-channel signal delay based on the one-dimensional range image; upsampling the one-dimensional range image to obtain a fractional part compensation sequence for the inter-channel signal delay; correcting the integer part compensation sequence for the inter-channel signal delay using a signal delay integer part correction method; and correcting the fractional part compensation sequence for the inter-channel signal delay using a Lagrange interpolation fractional part signal delay correction method.
[0005] In the above-mentioned method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the feed network length and signal delay model of the multi-channel electromagnetic vortex wave radar system are obtained through the following formula: ; in, For signal delay, Let be the length of the feed network for the m-th channel. At the speed of light, Let m be the dielectric constant of the signal transmission line, where m = 1, 2, ..., M, and M is the total number of channels.
[0006] In the above-mentioned method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the signal delay measurement system between channels of the electromagnetic vortex wave radar system includes a multi-channel electromagnetic vortex wave radar system and a corner reflector target; wherein, the multi-channel electromagnetic vortex wave radar system transmits signals to the corner reflector target and receives the echo signals from the corner reflector target.
[0007] In the above-mentioned method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the echo signal from the corner reflector target is matched and filtered to obtain the one-dimensional range image of the corner reflector target in the m-th channel. ,in, These are the sampling points corresponding to fast time intervals. Let be the sampling point corresponding to the one-dimensional range image imaging position of the corner reflector target in the m-th channel; where, ,in, The sampling rate.
[0008] In the above method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the matched filter function is: ; in, For matched filtering functions, For distance frequency, To adjust the frequency.
[0009] In the above-mentioned electromagnetic vortex wave radar system feed network delay measurement and correction method, the correction of the inter-channel signal delay integer part compensation sequence by the signal delay integer part correction method includes: constructing a time shift function in the frequency domain for the inter-channel signal delay integer part compensation sequence; performing range-to-frequency FFT transformation on the transmitted signal to the range frequency domain, multiplying it with the time shift function, and then performing range-to-frequency IFFT to return to the range time domain.
[0010] In the above method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the time shift function is obtained by the following formula: ; in, It is a time-shift function. Sampling rate, This is the compensation sequence for the integer part of the inter-channel signal delay. For distance frequency.
[0011] In the above-mentioned method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the method for correcting the fractional signal delay of the inter-channel signal delay fractional part compensation sequence using Lagrange interpolation includes: designing a Lagrange interpolation filter and using the Lagrange interpolation filter to correct the fractional signal delay of the transmitted signal.
[0012] In the above method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, the Lagrange interpolation filter is obtained through the following formula: ; ; in, For the interpolation sampling point location, This is a partial compensation sequence for the signal delay between channels. Let the filter order be . For Lagrange interpolation filters, For the fractional delay portion, For the number of channels, This is the upsampling factor.
[0013] A feed network delay measurement and correction system for an electromagnetic vortex wave radar system includes: a first module for establishing a model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system; a second module for establishing an inter-channel signal delay measurement system for the electromagnetic vortex wave radar system based on the feed network length and signal delay model; a third module for performing matched filtering on the multi-channel echo signals in the inter-channel signal delay measurement system to obtain a one-dimensional range image, obtaining an integer part compensation sequence for the inter-channel signal delay based on the one-dimensional range image, and upsampling the one-dimensional range image to obtain a fractional part compensation sequence for the inter-channel signal delay; and a fourth module for correcting the integer part compensation sequence for the inter-channel signal delay using an integer part correction method, and correcting the fractional part compensation sequence for the inter-channel signal delay using a fractional part signal delay correction method using Lagrange interpolation.
[0014] Compared with the prior art, the present invention has the following advantages: (1) This invention establishes a model of the length of the feed network and the signal delay of a multi-channel electromagnetic vortex wave radar system, designs a signal delay measurement system and method between channels, and solves the measurement problem of inconsistent signal delay between multiple channels in an electromagnetic vortex wave radar system. (2) This invention designs a signal delay integer part correction method and a signal delay fractional part signal delay correction method based on Lagrange interpolation. By correcting the integer part and fractional part of the signal delay separately, it solves the problems of large upsampling factor or high Lagrange interpolation order that would be encountered when directly correcting the two parts of the delay, resulting in large computational load and poor frequency response. It effectively solves the signal delay problem caused by inconsistent delay of multi-channel feed network in electromagnetic vortex wave radar system, improves the signal accuracy of multi-channel electromagnetic vortex wave radar system, and provides a solution for the testing and application of electromagnetic vortex wave radar system. Attached Figure Description
[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a flowchart illustrating the method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the electromagnetic vortex wave radar system feed network delay measurement system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the echo data distance pulse compression result without inter-channel feeder delay compensation provided in an embodiment of the present invention; Figure 4 This is an enlarged view of the corner reflector target in the echo data range pulse compression result without inter-channel feed network delay compensation provided in an embodiment of the present invention; Figure 5 This is an enlarged view of the corner reflector target after inter-channel feed network delay compensation using the method provided in this embodiment of the invention. Detailed Implementation
[0016] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0017] Figure 1 This is a schematic flowchart of the electromagnetic vortex wave radar system feed network delay measurement and correction method provided in an embodiment of the present invention. Figure 1As shown, the method for measuring and correcting the feed network delay of the electromagnetic vortex wave radar system includes: establishing a model of the feed network length and signal delay of the multi-channel electromagnetic vortex wave radar system; establishing a signal delay measurement system between channels of the electromagnetic vortex wave radar system based on the feed network length and signal delay model; and performing matched filtering on the multi-channel echo signals in the signal delay measurement system between channels to obtain a one-dimensional range profile. According to one-dimensional distance image Obtain the integer part compensation sequence of inter-channel signal delay For one-dimensional distance images Upsampling was performed to obtain the inter-channel signal delay fractional compensation sequence. The integer part compensation sequence of inter-channel signal delay is corrected using the integer part correction method of signal delay, and the fractional part compensation sequence of inter-channel signal delay is corrected using the fractional part signal delay correction method of Lagrange interpolation.
[0018] This embodiment establishes a model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system, designs and constructs a measurement system, and designs an inter-channel delay measurement method. The inter-channel signal delay of the electromagnetic vortex wave radar is obtained through actual measurement. To ensure the accuracy of signal delay calibration, the measured signal delay is upsampled to obtain the signal delay portion at non-integer sampling points, i.e., the fractional signal delay. For the measured signal delay containing the fractional part, to avoid the hardware pressure on digital electronic equipment caused by the computational burden of upsampling processing, a signal delay integer part correction method and a fractional part signal delay correction method based on Lagrange interpolation are designed to complete the inter-channel signal delay correction of the electromagnetic vortex wave radar, thereby improving the signal quality of the multi-channel electromagnetic vortex wave radar system.
[0019] The feed network length and signal delay model of a multi-channel electromagnetic vortex wave radar system are obtained through the following formula: ; in, For signal delay, Let be the length of the feed network for the m-th channel. At the speed of light, Let m be the dielectric constant of the signal transmission line, where m = 1, 2, ..., M, and M is the total number of channels.
[0020] The inter-channel signal delay measurement system of the electromagnetic vortex wave radar system includes a multi-channel electromagnetic vortex wave radar system and a corner reflector target; wherein, the multi-channel electromagnetic vortex wave radar system transmits signals to the corner reflector target and receives the echo signals from the corner reflector target.
[0021] Matched filtering is performed on the echo signal of the diagonal reflector target to obtain the one-dimensional range image of the diagonal reflector target in the m-th channel. ,in, These are the sampling points corresponding to fast time intervals. Let be the sampling point corresponding to the one-dimensional range image imaging position of the corner reflector target in the m-th channel; where, ,in, The sampling rate.
[0022] The matched filter function is: ; in, For matched filtering functions, For distance frequency, To adjust the frequency.
[0023] The correction of the integer part of the inter-channel signal delay compensation sequence by the signal delay integer part correction method includes: constructing a time shift function in the frequency domain for the inter-channel signal delay integer part compensation sequence; performing a range-direction FFT transformation on the transmitted signal to the range frequency domain, multiplying it with the time shift function, and then performing a range-direction IFFT to return to the range time domain.
[0024] The time-shift function is obtained by the following formula: ; in, It is a time-shift function. Sampling rate, This is the compensation sequence for the integer part of the inter-channel signal delay. For distance frequency.
[0025] The method of correcting the fractional signal delay of the inter-channel signal delay fractional part compensation sequence by Lagrange interpolation includes: designing a Lagrange interpolation filter and using the Lagrange interpolation filter to correct the fractional signal delay of the transmitted signal.
[0026] The Lagrange interpolation filter is obtained through the following formula: ; ; in, For the interpolation sampling point location, This is a partial compensation sequence for the signal delay between channels. Let the filter order be . For Lagrange interpolation filters, For the fractional delay portion, For the number of channels, This is the upsampling factor.
[0027] Specifically, the method includes the following steps: (1) Establish a model of the relationship between the length of the feed network and the signal delay of a multi-channel electromagnetic vortex wave radar system; (2) Design of a signal delay measurement system and method for inter-channel electromagnetic vortex wave radar system; (3) Delay the integer part of the radar system's transmitted waveform to construct a time-shift function in the frequency domain, multiply the time-shift functions in the frequency domain, and then return to the time domain; (4) Design the Lagrange interpolation filter coefficients for the fractional part of the signal delay, and use the designed filter to correct the fractional part of the signal delay of the radar system's transmitted waveform.
[0028] The specific implementation of step (1) is as follows: A model is established to show the relationship between the feed network length and signal delay in a multi-channel electromagnetic vortex wave radar system, yielding the signal delay and correlation between the multiple channels. It is assumed that the electromagnetic vortex wave radar system possesses... There are 1 channel, and the feed network length of each channel is 1. ( Therefore, when each channel transmits and receives, the two-way delay of the received signal from channel m through the system link is... ,in At the speed of light, Let be the dielectric constant of the signal transmission line. Signal delay. The corresponding number of sampling points for the acquired signal is ,in This represents the system sampling rate.
[0029] The specific implementation of step (2) is as follows: design an electromagnetic vortex wave radar system channel signal delay measurement system and measurement method.
[0030] (2a) Build as Figure 2 The test link shown depicts a corner reflector target positioned in the scene, with a multi-channel electromagnetic vortex wave radar system simultaneously transmitting signals towards the corner reflector target. And receive the echo signal from the corner reflector target; (2b) Perform matched filtering on the received multi-channel echo signals to form a one-dimensional range image of channel m relative to the corner reflector target. ,in These are the sampling points corresponding to fast time intervals. These are the sampling points corresponding to the one-dimensional range image imaging positions of the corner reflector target in channel m. and All integers are used. The matched filter function is designed in the distance-frequency domain as follows: ,in For distance frequency, To adjust the frequency; (2c) The one-dimensional distance image obtained from step (2b) This yields the feed network delay sequence for M channels. To achieve inter-channel delay compensation, the signals from all channels need to be compensated towards the channel with the longest delay. Therefore, the integer part compensation sequence for the inter-channel feed network delay is obtained as follows: ,in ; (2d) In order to improve the accuracy of inter-channel feeder delay compensation, the one-dimensional range image obtained in step (2b) is... After performing upsampling by N times, we obtain the upsampled one-dimensional distance image. ,in These are the sampling points corresponding to the distance over time after upsampling by N times. Let M be the sampling points corresponding to the one-dimensional range image imaging positions of the corner reflector target in channel m after upsampling by N times. The feed network delay of M channels compared to the non-integer sampling points before upsampling is... , The measurement obtained in step (2c) The integer part is called the inter-channel feed network delay compensation sequence.
[0031] The specific implementation of step (3) is as follows: For the integer part of the radar system's transmitted waveform, a time-shift function is constructed in the frequency domain to delay the signal. After multiplying the time-shift functions in the frequency domain, the result is returned to the time domain. This applies to the integer part of the inter-channel feed network delay compensation sequence obtained in step (2c). The time shift function for the m-th channel in the distance-frequency domain is constructed as follows:
[0032] in, The sampling rate.
[0033] Transmit signal of channel m After performing a range-to-FFT transform to the range-frequency domain, and then combining it with the time-shift function... Multiplying and then performing a distance-to-time IFFT to return to the distance-time domain, the delay compensation of the integer part of the transmitted signal of channel m is completed by delay alignment of the transmitted signal, thus obtaining the transmitted signal of channel m. .
[0034] The specific implementation of step (4) is as follows: for the signal delay of the fractional part, design the Lagrange interpolation filter coefficients, and use the designed filter to correct the signal delay of the fractional part of the radar system's transmitted waveform.
[0035] (4a) Design the Lagrange interpolation filter as follows
[0036] in, For the interpolation sampling point location, Let the filter order be . The delay is for the non-integer part.
[0037] (4b) Transmit signal for channel m ,make The output of the Lagrange interpolation filter designed in step (4a) is:
[0038] After Lagrange interpolation, the delay compensation correction of the electromagnetic vortex wave radar system feed network is completed at the transmitting signal end.
[0039] This embodiment uses field measurement results for verification, and the correctness of all steps and conclusions is verified on MatlabR2017b.
[0040] The measured radar system parameters of this embodiment are shown in the table below:
[0041] The application scenario of this embodiment is as follows: This invention can be applied to feed network delay correction in multi-channel electromagnetic vortex wave radar systems. The feed network delay model and measurement system are suitable for electromagnetic vortex wave radar systems with simultaneous multi-mode transmission and reception. This method solves the inter-channel delay problem caused by inconsistent feed network lengths in multi-channel electromagnetic vortex wave radar systems by establishing an inter-feed network delay model and building a measurement system, designing an integer part delay compensation function and a fractional part delay compensation method based on Lagrange interpolation. The specific implementation steps are as follows: Step (1): Establish a model of the relationship between the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system, and obtain the signal delay and correlation between the multiple channels. Assume the electromagnetic vortex wave radar system has... There are 1 channel, and the feed network length of each channel is 1. ( Therefore, when each channel transmits and receives, the two-way delay of the received signal from channel m through the system link is... ,in At the speed of light, Let be the dielectric constant of the signal transmission line. Signal delay. The corresponding number of sampling points for the acquired signal is ,in This represents the system sampling rate.
[0042] Step (2): Design the signal delay measurement system and measurement method between channels of the electromagnetic vortex wave radar system.
[0043] (2a) Build as Figure 2 The test link shown depicts a corner reflector target positioned in the scene, with a multi-channel electromagnetic vortex wave radar system simultaneously transmitting signals towards the corner reflector target. And receive the echo signal from the corner reflector target; (2b) Perform matched filtering on the received multi-channel echo signals to form a one-dimensional range image of channel m relative to the corner reflector target. ,in These are the sampling points corresponding to fast time intervals. These are the sampling points corresponding to the one-dimensional range image imaging positions of the corner reflector target in channel m. and All integers are used. The matched filter function is designed in the distance-frequency domain as follows: ,in For distance frequency, To adjust the frequency; (2c) The one-dimensional distance image obtained from step (2b) This yields the feed network delay sequence for M channels. To achieve inter-channel delay compensation, the signals from all channels need to be compensated towards the channel with the longest delay. Therefore, the integer part compensation sequence for the inter-channel feed network delay is obtained as follows: ,in ; (2d) In order to improve the accuracy of inter-channel feeder delay compensation, the one-dimensional range image obtained in step (2b) is... After performing upsampling by N times, we obtain the upsampled one-dimensional distance image. ,in These are the sampling points corresponding to the distance over time after upsampling by N times. Let M be the sampling points corresponding to the one-dimensional range image imaging positions of the corner reflector target in channel m after upsampling by N times. The feed network delay of M channels compared to the non-integer sampling points before upsampling is... , The measurement obtained in step (2c) The integer part is called the inter-channel feed network delay compensation sequence.
[0044] Step (3): Construct a time-shift function in the frequency domain for the integer part of the radar system's transmitted waveform signal delay, multiply the time-shift functions in the frequency domain, and then return to the time domain. For the integer part of the inter-channel feed network delay compensation sequence obtained in step (2c). The time shift function for the m-th channel in the distance-frequency domain is constructed as follows:
[0045] in, The sampling rate.
[0046] Transmit signal of channel m After performing a range-to-FFT transform to the range-frequency domain, and then combining it with the time-shift function... Multiplying and then performing a distance-to-time IFFT to return to the distance-time domain, the delay compensation of the integer part of the transmitted signal of channel m is completed by delay alignment of the transmitted signal, thus obtaining the transmitted signal of channel m. .
[0047] Step (4): Design the Lagrange interpolation filter coefficients for the fractional part of the signal delay, and use the designed filter to correct the fractional part of the signal delay in the radar system's transmitted waveform.
[0048] (4a) Design the Lagrange interpolation filter as follows
[0049] in, For the interpolation sampling point location, Let the filter order be . The delay is for the non-integer part.
[0050] (4b) Transmit signal for channel m ,make The output of the Lagrange interpolation filter designed in step (4a) is:
[0051] After Lagrange interpolation, the delay compensation correction of the electromagnetic vortex wave radar system feed network is completed at the transmitting signal end.
[0052] Figure 3 This is a one-dimensional range image containing the echoes from corner reflectors, actually measured by an electromagnetic vortex wave radar system. The point target with the strongest energy is the one-dimensional range image of the corner reflector target. The electromagnetic vortex wave radar system has 7 simultaneous transmit and receive channels. Figure 4 The magnified view of the corner reflector target shows a positional shift in the one-dimensional range image of the same corner reflector target across different channels. Figure 4 The integer part compensation sequence for inter-channel feeder delay can be obtained. and fractional partial compensation sequence The upsampling factor N=10. Figure 5 To achieve the results of compensating for the feed network delay of the integer and fractional parts of the channels using the method of this invention, the one-dimensional range image position of the same corner reflector target in the seven channels remains consistent, and the feed network delay between channels is fully compensated.
[0053] This embodiment also provides a system for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system. The system includes: a first module for establishing a model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system; a second module for establishing a signal delay measurement system between channels of the electromagnetic vortex wave radar system based on the feed network length and signal delay model; and a third module for performing matched filtering on the multi-channel echo signals from the signal delay measurement system between channels to obtain a one-dimensional range profile. According to one-dimensional distance image Obtain the integer part compensation sequence of inter-channel signal delay For one-dimensional distance images Upsampling was performed to obtain the inter-channel signal delay fractional compensation sequence. The fourth module is used to correct the integer part compensation sequence of inter-channel signal delay using the integer part correction method, and to correct the fractional part compensation sequence of inter-channel signal delay using the fractional part signal delay correction method of Lagrange interpolation.
[0054] This embodiment establishes a model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system, designs a signal delay measurement system and method between channels, and solves the measurement problem of inconsistent signal delays between multiple channels in an electromagnetic vortex wave radar system. This embodiment designs a method for correcting the integer part of the signal delay and a method for correcting the fractional part of the signal delay based on Lagrange interpolation. By correcting the integer and fractional parts of the signal delay separately, it solves the problems of large upsampling factors or excessively high Lagrange interpolation orders that would lead to large computational loads and poor frequency response when directly correcting the two parts of the delay. This effectively solves the signal delay problem caused by inconsistent feed network delays in multi-channel electromagnetic vortex wave radar systems, improves the signal accuracy of multi-channel electromagnetic vortex wave radar systems, and provides a solution for the testing and application of electromagnetic vortex wave radar systems.
[0055] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.
Claims
1. A method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, characterized in that... include: Establish a model for the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system; A signal delay measurement system between channels of an electromagnetic vortex wave radar system is established based on the feed network length and signal delay model of a multi-channel electromagnetic vortex wave radar system. A one-dimensional range profile is obtained by matching filtering the multi-channel echo signal in the inter-channel signal delay measurement system of the electromagnetic vortex wave radar system. The integer part compensation sequence of the inter-channel signal delay is obtained based on the one-dimensional range profile. The fractional part compensation sequence of the inter-channel signal delay is obtained by upsampling the one-dimensional range profile. The integer part compensation sequence of inter-channel signal delay is corrected using the integer part correction method, and the fractional part compensation sequence of inter-channel signal delay is corrected using the fractional part signal delay correction method of Lagrange interpolation.
2. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 1, characterized in that: The feed network length and signal delay model of a multi-channel electromagnetic vortex wave radar system are obtained through the following formula: ； in, For signal delay, Let be the length of the feed network for the m-th channel. At the speed of light, Let m be the dielectric constant of the signal transmission line, where m = 1, 2, ..., M, and M is the total number of channels.
3. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 1, characterized in that: The inter-channel signal delay measurement system for an electromagnetic vortex wave radar system includes a multi-channel electromagnetic vortex wave radar system and a corner reflector target; among which, The multi-channel electromagnetic vortex wave radar system transmits signals to the corner reflector target and receives the echo signals from the corner reflector target.
4. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 3, characterized in that: Matched filtering is performed on the echo signal of the diagonal reflector target to obtain the one-dimensional range image of the diagonal reflector target in the m-th channel. ,in, These are the sampling points corresponding to fast time intervals. Let be the sampling point corresponding to the one-dimensional range image imaging position of the corner reflector target in the m-th channel; where, ,in, The sampling rate.
5. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 4, characterized in that: The matched filter function is: ； in, For matched filtering functions, For distance frequency, To adjust the frequency.
6. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 1, characterized in that: The signal delay integer part compensation sequence between channels is corrected using the signal delay integer part correction method, including: Construct a time-shift function in the frequency domain for the compensation sequence of the integer part of the inter-channel signal delay; The transmitted signal is transformed into the range frequency domain by range-directed FFT, multiplied by the time shift function, and then transformed back into the range time domain by range-directed IFFT.
7. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 6, characterized in that: The time-shift function is obtained by the following formula: ； in, It is a time-shift function. Sampling rate, This is the compensation sequence for the integer part of the inter-channel signal delay. For distance frequency.
8. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 1, characterized in that: The fractional signal delay compensation sequence between channels is corrected using a fractional signal delay correction method based on Lagrange interpolation, including: Design a Lagrange interpolation filter and use it to correct the fractional delay of the transmitted signal.
9. The method for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system according to claim 8, characterized in that: The Lagrange interpolation filter is obtained through the following formula: ； ； in, The location of the interpolation sampling point. This is a partial compensation sequence for the signal delay between channels. Let the filter order be . For Lagrange interpolation filters, For the fractional delay portion, For the number of channels, This is the upsampling factor.
10. A system for measuring and correcting the feed network delay of an electromagnetic vortex wave radar system, characterized in that... include: The first module is used to establish a model of the feed network length and signal delay of a multi-channel electromagnetic vortex wave radar system. The second module is used to establish a signal delay measurement system between channels of the electromagnetic vortex wave radar system based on the feed network length and signal delay model of the multi-channel electromagnetic vortex wave radar system. The third module is used to perform matched filtering on the multi-channel echo signals in the electromagnetic vortex wave radar system inter-channel signal delay measurement system to obtain a one-dimensional range image, obtain an integer part compensation sequence for inter-channel signal delay based on the one-dimensional range image, and upsample the one-dimensional range image to obtain a fractional part compensation sequence for inter-channel signal delay. The fourth module is used to correct the integer part compensation sequence of the inter-channel signal delay using the integer part correction method, and to correct the fractional part compensation sequence of the inter-channel signal delay using the fractional part signal delay correction method of Lagrange interpolation.