Radar Imaging Deception and Jamming Method and Device Based on Dual Programmable Metasurfaces

Abstract

This invention relates to a radar imaging deception jamming method and device based on dual programmable metasurfaces. The method includes: S1. controlling the spatial coding of a first programmable metasurface to perform beam scanning and aligning its main lobe of the radiation pattern with the incident direction of a radar signal for reception; S2. enhancing the incident radar signal and transmitting the enhanced radar signal to a second programmable metasurface; S3. controlling the spatial and temporal coding of the second programmable metasurface to modulate the temporal representation and spectral structure of the enhanced radar signal, and transmitting the modulated radar signal with the incident direction aligned. This invention, by employing a dual metasurface architecture, integrates each metasurface with its respective horn antenna to form a radio frequency transceiver assembly. The receiving metasurface determines the direction of the incident radar signal through spatial beam scanning, and the transmitting metasurface transmits the modulated signal in the same direction, thus solving the problem of sensitivity to the incident angle.

Description

Technical Field

[0001] This invention relates to the field of novel artificial electromagnetic materials technology, and in particular to a radar imaging deception jamming method and jamming device based on dual programmable metasurfaces. Background Technology

[0002] Programmable electromagnetic metasurfaces are composed of a series of subwavelength units, which are loaded with active devices and arranged periodically to form a planar array structure. Due to their unique electromagnetic wave manipulation capabilities, programmable metasurfaces have been widely studied in the fields of wireless communication and electronic countermeasures. By encoding in the time domain, programmable metasurfaces can modulate the amplitude, phase, and frequency of incident signals, thereby changing the waveform pattern and spectral structure of the original signal. For example, Ke, JC, Dai, JY, Zhang, JW, Chen, Z., Chen, MZ, Lu, Y., ... & Cui, TJ (2022). Frequency-modulated continuous waves controlled by space-time-coding metasurface with nonlinearly periodic phases. Light: Science & Applications, 11(1), 273. discloses the ability to generate a predetermined waveform (spectral structure) in terms of waveform design. Wang, J., Feng, D., Xu, Z., Wu, Q., & Hu, W. (2020). Time-domain digital-coding active frequencyselective surface absorber / reflector and its imaging characteristics. IEEE Transactions on Antennas and Propagation, 69(6), 3322-3331. This paper discloses the ability to modulate artificially induced information in electronic countermeasures, thereby enabling enemy radar to acquire false target characteristics.

[0003] However, existing research on signal modulation using programmable metasurfaces typically relies on the assumption that the signal is normally incident on the metasurface plane. This assumption ensures that each programmable metasurface unit has a uniform spatiotemporal response. However, in practical applications, signals are more likely to be obliquely incident on the programmable metasurface plane, especially in electronic warfare environments where the relative position of enemy radar is often unknown. Compared to normal incidence, oblique incidence has two main effects: firstly, it introduces an initial phase difference into the programmable metasurface units, making the outgoing direction of the reflected signal difficult to control; secondly, the spatial dispersion of the reflected signal reduces the energy of the scattered signal in the desired outgoing direction, leading to a decrease in the signal-to-noise ratio and potentially rendering the employed time-coded modulation strategy ineffective. Therefore, addressing the angle sensitivity and scattering enhancement issues of programmable metasurfaces for signal modulation has practical application value. Summary of the Invention

[0004] The purpose of this invention is to provide a radar imaging deception jamming method and jamming device based on dual programmable metasurfaces.

[0005] To achieve the above-mentioned objectives, this invention provides a radar imaging deception and jamming method based on dual programmable metasurfaces, comprising:

[0006] S1. Control the spatial coding of the first programmable metasurface to perform beam scanning, and align its main lobe of the radiation pattern with the direction of radar signal incidence for reception;

[0007] S2. The incident radar signal is enhanced and the enhanced radar signal is transmitted to the second programmable metasurface;

[0008] S3. Control the spatial and temporal coding of the second programmable metasurface to modulate the temporal representation and spectral structure of the enhanced radar signal, and transmit the modulated radar signal in the incident direction.

[0009] According to one aspect of the present invention, step S1, which involves controlling the spatial coding of the first programmable metasurface to perform beam scanning and aligning its main lobe of the radiation pattern with the incident direction of the radar signal for reception, includes:

[0010] S11. Control the first programmable metasurface to perform spatial beam scanning and acquire the incident radar signal through the first horn antenna;

[0011] S12. Detect the signal strength of the radar signal incident on the first programmable metasurface when the beam direction is different to determine the angle information of the incident radar signal;

[0012] S13. Based on the angle information, control the spatial encoding of the first programmable metasurface so that its main lobe of the radiation pattern is aligned with the incident direction.

[0013] According to one aspect of the present invention, step S11, which involves controlling the first programmable metasurface to perform spatial beam scanning and acquiring the incident radar signal through the first horn antenna, includes:

[0014] S111. Establish a near-field feeding model of the first horn antenna that uses the first programmable metasurface to perform phase compensation on the first horn antenna;

[0015] S112. Construct the spatial coding model of the first programmable metasurface;

[0016] S113. Based on the spatial coding model and the near-field feeding model of the first horn antenna, control the first programmable metasurface to perform spatial beam scanning to obtain the incident signal.

[0017] According to one aspect of the present invention, in step S112, the step of constructing the spatial coding model of the first programmable metasurface, wherein the spatial coding model is represented as:

[0018]

[0019]

[0020]

[0021] in, This represents the additional phase difference between the first metasurface units in the first programmable metasurface caused by the first horn antenna. Let represent the initial phase difference between the first row and first column cells of the first programmable metasurface and the (m,n)th first metasurface cell, with reference to the first row and first column cells of the first programmable metasurface, where m represents the row number of the first metasurface cells in the first programmable metasurface, and n represents the column number of the first metasurface cells in the first programmable metasurface, (x mn y mn ,0) and (x h y h , z h (k) represents the three-dimensional coordinates of the first metasurface element and the first horn antenna, respectively. c d represents the signal wavenumber. x and d y These represent the distances between the first metasurface units that are uniformly spaced on the x-axis and y-axis, respectively. This indicates the desired beam direction.

[0022] According to one aspect of the present invention, in step S12, in the step of detecting the signal strength of the radar signal incident on the first programmable metasurface when the beam direction is different to determine the angle information of the incident radar signal, the angle information of the incident radar signal is determined based on the maximum signal strength among the signal strengths of the incident radar signals.

[0023] According to one aspect of the invention, in step S2, the incident radar signal is enhanced and the enhanced radar signal is transmitted to the second programmable metasurface. The enhanced radar signal is emitted based on a second horn antenna disposed near the second programmable metasurface and reflected to the far field radar direction based on the second programmable metasurface.

[0024] According to one aspect of the present invention, step S3, which involves controlling the spatial and temporal coding of the second programmable metasurface to modulate the temporal domain characterization and spectral structure of the enhanced radar signal, and aligning the modulated radar signal with the incident direction for transmission, includes:

[0025] S31. Control the spatial coding of the second programmable metasurface to adjust the main emission direction of the enhanced radar signal;

[0026] S32. Control the time encoding of the second programmable metasurface to adjust the time-domain characterization and spectral structure of the enhanced radar signal, and transmit the modulated radar signal in the incident direction.

[0027] According to one aspect of the present invention, in step S32, the step of controlling the time encoding of the second programmable metasurface to adjust the temporal representation and spectral structure of the enhanced radar signal is performed by controlling the second programmable metasurface based on an interaction model between the radar signal and the programmable metasurface to adjust the temporal representation and spectral structure of the enhanced radar signal; wherein, the interaction model is expressed as:

[0028]

[0029] Where, θ and Let represent the elevation and azimuth angles of the radar signal relative to the far-field direction of the metasurface plane, respectively; τ represents the fast time; and s(τ) represents the radar signal. This represents the modulation term of a programmable metasurface;

[0030] The modulation term of a programmable metasurface is represented as:

[0031]

[0032]

[0033] Where k0 represents the wavenumber corresponding to the frequency of the modulated radar signal when it is reflected. This represents the spatial scattering characteristics of metasurface units in a programmable metasurface. This indicates the distance between metasurface units in a programmable metasurface in the far-field observation direction. Phase difference caused by spatial path difference, p mn(τ) represents the time-domain modulation signal encoded by the programmable metasurface, i.e., time-coded. When the time-domain modulation signal of the programmable metasurface is periodic, it can be expressed as:

[0034]

[0035] Where, α u Here are the Fourier transform coefficients, u represents the harmonic order, and f... s It is the time-domain periodic modulation frequency.

[0036] To achieve the above-mentioned objectives, the present invention provides an interference device for the aforementioned radar imaging deception interference method, comprising: a receiving unit, a transmitting unit, and a control unit;

[0037] The receiving unit includes: a first programmable metasurface, and a first horn antenna disposed in the near field of the first programmable metasurface;

[0038] The transmitting unit includes: a second programmable metasurface, and a second horn antenna disposed in the near field of the second programmable metasurface;

[0039] The control unit includes: a radio frequency channel component and a control channel component;

[0040] The radio frequency channel assembly is connected to the first horn antenna and the second horn antenna respectively to serve as a signal transmission path;

[0041] The control channel assembly is connected to the first programmable metasurface and the second programmable metasurface, respectively.

[0042] According to one aspect of the invention, the radio frequency channel assembly includes: a detector and a power amplifier;

[0043] The detector is connected to the power amplifier;

[0044] The detector is connected to the first horn antenna;

[0045] The power amplifier is connected to the second horn antenna;

[0046] The control channel component uses an FPGA controller.

[0047] According to one aspect of the present invention, the present invention adopts a dual metasurface architecture, which is integrated with its respective horn antenna to form a radio frequency transceiver assembly. The receiving metasurface determines the direction of the incident radar signal through spatial beam scanning, and the transmitting metasurface transmits the modulated signal in the same direction, thus solving the problem of sensitivity to incident angle.

[0048] According to one aspect of the present invention, by employing a direct connection between the detector and the power amplifier, the scattering intensity of the original target under oblique incidence conditions is improved, thus solving the problem of low backscattering intensity.

[0049] According to one aspect of the present invention, the transmitting metasurface (i.e., the second programmable metasurface) modulates the phase, amplitude, and frequency information of the radar signal in real time through time coding, and uses space-time modulation technology to generate multiple synthetic false targets around the original target on the high-resolution range image obtained by the imaging radar, thereby achieving deception interference of the high-resolution range image.

[0050] According to one aspect of the present invention, the beam of the receiving metasurface (i.e., the first programmable metasurface) can be dynamically aligned with the direction of the incident wave, achieving real-time self-tracking within the system. Furthermore, the incident signal from the receiving metasurface is amplified by a power amplifier and transmitted by the transmitting metasurface, thereby directly modulating the radar signal at the radio frequency through the time coding of the transmitting metasurface, thus adding artificially modulated false target information. Attached Figure Description

[0051] Figure 1 This is a schematic diagram illustrating the steps of a radar imaging deception jamming method according to an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram illustrating the structural architecture of an interference device according to an embodiment of the present invention;

[0053] Figure 3 The diagram illustrates the high-resolution range image measurement results of the actual experiment in Example 1, where (a) is the result of the radar signal incident at 0° onto a single metasurface, (b) is the result of the radar signal incident at 30° onto a single metasurface, (c) is the result of the radar signal incident at 0° onto a double metasurface with the power amplifier off and only the direction of the spatially encoded control signal is applied, (d) is the result of the radar signal incident at 30° onto a double metasurface with the power amplifier off and only the direction of the spatially encoded control signal is applied, (e) is the result of the radar signal incident at 0° onto a double metasurface with the power amplifier on and only the direction of the spatially encoded control signal is applied, (f) is the result of the radar signal incident at 30° onto a double metasurface with the power amplifier on and only the direction of the spatially encoded control signal is applied, (g) is the result of the radar signal of modulation pulse 1 incident at 30° onto a double metasurface with the power amplifier on and both spatially and temporally encoded modulation is applied, and (h) is the result of the radar signal of modulation pulse 2 incident at 30° onto a double metasurface with the power amplifier on and both spatially and temporally encoded modulation is applied. Detailed Implementation

[0054] 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 described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0055] In describing embodiments of the present invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" express orientations or positional relationships based on the orientations or positional relationships shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the present invention.

[0056] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described in detail here, but the embodiments of the present invention are not limited to the following embodiments.

[0057] Combination Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, a radar imaging deception and jamming method based on dual programmable metasurfaces includes:

[0058] S1. Control the spatial coding of the first programmable metasurface to perform beam scanning, and align its main lobe of the radiation pattern with the direction of radar signal incidence for reception;

[0059] S2. The incident radar signal is enhanced and the enhanced radar signal is transmitted to the second programmable metasurface;

[0060] S3. Control the spatial and temporal coding of the second programmable metasurface to modulate the temporal representation and spectral structure of the enhanced radar signal, and transmit the modulated radar signal in the direction of incidence.

[0061] Combination Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, step S1, which involves controlling the spatial coding of the first programmable metasurface to perform beam scanning and aligning its main lobe of the radiation pattern with the incident direction of the radar signal for reception, includes:

[0062] S11. Controlling the first programmable metasurface to perform spatial beam scanning and acquiring the incident radar signal through the first horn antenna; in this embodiment, it includes:

[0063] S111. Establish a near-field feeding model of the first horn antenna with phase compensation using a first programmable metasurface;

[0064] S112. Construct a spatial coding model for the first programmable metasurface; in this embodiment, the spatial coding model is represented as:

[0065]

[0066]

[0067]

[0068] in, This represents the additional phase difference between the first metasurface units in the first programmable metasurface caused by the first horn antenna, which is crucial for achieving spatial wide-angle beam pointing. This represents the initial phase difference between the (m,n)th first metasurface unit and the first row and first column unit of the first programmable metasurface, which is caused by the far-field spatial beam pointing. m represents the row number of the first metasurface unit in the first programmable metasurface, and n represents the column number of the first metasurface unit in the first programmable metasurface. (x mn y mn ,0) and (x h y h , z h (k) represents the three-dimensional coordinates of the first metasurface element and the first horn antenna, respectively. c d represents the signal wavenumber. x and d y These represent the distances between the first metasurface units that are uniformly spaced on the x-axis and y-axis, respectively. This indicates the desired beam direction.

[0069] S113. Based on the spatial coding model and the near-field feeding model of the first horn antenna, the first programmable metasurface is controlled to perform spatial beam scanning to obtain the incident signal.

[0070] S12. Detect the signal strength of the radar signal incident on the first programmable metasurface when the beam direction is different to determine the angle information of the incident radar signal; In this embodiment, the first programmable metasurface realizes spatial beam scanning based on spatial coding of different time slots. In different time slots, a signal strength value will be obtained. When scanning at a certain angle interval until the entire airspace is covered, the direction of the main lobe of the radiation pattern corresponding to the highest signal strength value is the incident angle (i.e., angle information) of the signal emitted by the radar.

[0071] S13. Based on the angle information, control the spatial encoding of the first programmable metasurface so that its main lobe of the radiation pattern is aligned with the incident direction. In this embodiment, based on the angle information obtained in the preceding steps, the spatial encoding of the first programmable metasurface is fixed to the state corresponding to the incident angle, ensuring that the main lobe of the radiation pattern of the first programmable metasurface is aligned with the incident direction of the signal.

[0072] Combination Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, in step S2, the incident radar signal is enhanced and the enhanced radar signal is transmitted to the second programmable metasurface. The enhanced radar signal is emitted based on a second horn antenna disposed near the second programmable metasurface and reflected by the second programmable metasurface to the far-field radar direction. In this embodiment, the incident signal is enhanced by power amplification and then reflected by the second programmable metasurface to the far-field radar direction. This effectively avoids the passively reflected modulation signal being submerged in background noise due to low energy, thus ensuring the effectiveness of deception jamming.

[0073] Combination Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, step S3, which involves controlling the spatial and temporal coding of the second programmable metasurface to modulate the temporal domain characterization and spectral structure of the enhanced radar signal, and then aligning the modulated radar signal with the incident direction for transmission, includes:

[0074] S31. Control the spatial coding of the second programmable metasurface to adjust the main emission direction of the enhanced radar signal; In this embodiment, the main emission direction of the enhanced radar signal can be controlled by designing spatial coding. The design method of the spatial coding is consistent with the design method of the spatial coding of the first programmable metasurface, and will not be described again here.

[0075] S32. Control the time coding of the second programmable metasurface to adjust the time-domain characterization and spectral structure of the enhanced radar signal, and transmit the modulated radar signal in the direction of incidence.

[0076] Combination Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, in step S32, the step of controlling the time encoding of the second programmable metasurface to adjust the time-domain representation and spectral structure of the enhanced radar signal is performed by controlling the second programmable metasurface based on the interaction model between the radar signal and the programmable metasurface to adjust the time-domain representation and spectral structure of the enhanced radar signal; wherein, the interaction model is expressed as:

[0077]

[0078] Where, θ and Let represent the elevation and azimuth angles of the radar signal relative to the far-field direction of the metasurface plane, respectively; τ represents the fast time; and s(τ) represents the radar signal. Modulation terms of programmable metasurfaces;

[0079] In this embodiment, due to the changes in the encoded control signals of the planar distributed metasurface units, the modulation of the programmable metasurface is generated simultaneously in the spatial and temporal domains. Therefore, the modulation term of the programmable metasurface is represented as:

[0080]

[0081]

[0082] Where k0 represents the wavenumber corresponding to the frequency of the modulated radar signal when it is reflected. This represents the spatial scattering characteristics of metasurface units in a programmable metasurface. This indicates the distance between metasurface units in a programmable metasurface in the far-field observation direction. Phase difference caused by spatial path difference, p mn (τ) represents the time-domain modulation signal encoded by the programmable metasurface, i.e., time coding.

[0083] In this embodiment, the time-domain modulation signal encoded by the programmable metasurface can be described as a pulse sequence, which represents:

[0084]

[0085] Where rect(·) is a rectangular pulse signal, when hour, T0 is the state duration, which is also the encoding switching cycle. It is a convolution operation, δ(·) is the impulse function, A mn (l) represents the reflection characteristics of the metasurface unit in the l-th time slot.

[0086] Furthermore, when the time-domain modulation signal of the programmable metasurface is periodic, the time-domain modulation signal can be expressed as:

[0087]

[0088] Where, α u Here are the Fourier transform coefficients, u represents the harmonic order, and f... s It is the time-domain periodic modulation frequency.

[0089] Therefore, the time-coding design of the second programmable metasurface can be realized through the above interaction model, so as to achieve modulation of the spectral structure of the emitted signal.

[0090] According to an embodiment of the present invention, a radar transmits a broadband linear frequency modulation (LFM) signal, which can be expressed as:

[0091]

[0092] where T p represents the signal pulse width, K r = B / T p represents the frequency modulation rate, B represents the signal bandwidth, and f c represents the carrier frequency for radar signal processing.

[0093] When the radar signal modulated by the metasurface is received by the radar, it is mixed from radio frequency to intermediate frequency, then band-pass filtered, and finally enters the baseband. After pulse compression, the output of the matched filter, that is, the high-resolution range profile (HRRP) can be expressed as:

[0094]

[0095] where U depends on the cut-off frequency of the band-pass filter and the relative relationship between the modulation frequency and the bandwidth. When the modulation frequency satisfies the condition 0 < f s < B, the radar signal modulated by the metasurface contains a series of false targets. The u-th harmonic corresponds to a false target with a range offset of ΔR u = -cuf s / 2K r .

[0096] As Figure 2 shown, according to an embodiment of the present invention, an interference device for the aforementioned radar imaging deception interference method includes: a receiving unit 1, a transmitting unit 2, and a regulation unit 3. In this embodiment, the receiving unit 1 includes: a first programmable metasurface 11 and a first horn antenna 12 disposed in the near field of the first programmable metasurface 11; wherein, the first horn antenna 12 is used to receive the incident signal reflected by the first programmable metasurface 11. In this embodiment, the transmitting unit 2 includes: a second programmable metasurface 21 and a second horn antenna 22 disposed in the near field of the second programmable metasurface 21; wherein, the second horn antenna 22 acts as a feed to realize transmitting the outgoing signal to the second programmable metasurface 21. In this embodiment, the regulation unit 3 includes: a radio frequency channel component 31 and a control channel component 32; wherein, the radio frequency channel component is respectively connected to the first horn antenna 11 and the second horn antenna 21 to serve as a signal transmission path; the control channel component is respectively connected to the first programmable metasurface and the second programmable metasurface.

[0097] As Figure 2As shown, according to one embodiment of the present invention, the radio frequency channel assembly 31 includes a detector 311 and a power amplifier 312; in this embodiment, the detector 311 and the power amplifier 312 are connected; wherein, the detector 311 is connected to a first horn antenna 11 for detecting the signal strength of the incident signal when the beam direction is different. The power amplifier 312 is connected to a second horn antenna 21 for amplifying the incident signal so that the generated outgoing signal is sent to the second horn antenna 21 for transmission.

[0098] In this embodiment, the control channel component 32 employs an FPGA controller, which is used to control the spatial coding of the first programmable metasurface 11 for spatial beam scanning, and to control the spatial coding and time coding of the second programmable metasurface 21. The spatial coding is used to control the main emission direction of the emitted signal, and the time coding is used to modulate the signal in the time domain, thereby changing the time domain characterization and spectral structure of the emitted signal, so that the radar can acquire echo signals containing artificially modulated false information.

[0099] To further illustrate this solution, further examples are provided.

[0100] Example 1

[0101] A field experiment was conducted on the jamming device based on the dual metasurface architecture of this invention. The radar's transmitted signal parameters were: LFM signal B = 300MHz, T... p =100us, f c =10GHz; the first programmable metasurface 11 and the second programmable metasurface 21 have the same structure, and their parameters are set as follows: M=N=20, d x =d y =c / 2f c f s =50kHz, the jamming device was placed approximately 9.5m away from the radar;

[0102] In contrast. Figure 3 (a) and Figure 3 (b) Results for a single metasurface at 0° and 30° incident angles are given respectively. It can be seen that the scattering intensity of the target in the high-resolution range image HRRP decreases by about 14dB at 30° incident angle.

[0103] Figure 3 (c) and Figure 3(e) shows the interference results against radar when the present invention is incident at 0 degrees, wherein the present invention only performs spatial coding control of the direction of the signal to achieve angle adaptation, the difference being whether the power amplifier is switched on or off. The results show that when only the direction of the spatial coding control signal is performed, the addition of the power amplifier gain in the dual metasurface architecture of the present invention increases the scattering intensity at the original target.

[0104] Figure 3 (d) and Figure 3 (f) illustrates the interference results against radar at 30 degrees, where the present invention only performs spatial coding to control the direction of the control signal to achieve angle adaptation; the difference lies in whether the power amplifier is switched on or off. Figure 3 (b) shows a significantly enhanced scattering effect. Compared to... Figure 3 (c) and Figure 3 (e) In contrast, the target exhibits an approximate scattering intensity, demonstrating the angle adaptability of the proposed architecture.

[0105] Figure 3 (g) and Figure 3 (h) presents the HRRP results of the double metasurface under 30-degree incidence of two different radar signal pulses, including comparisons. Figure 3 (f) The second programmable metasurface adds time modulation (in the previous embodiments, only spatial coding was used to control the direction of the signal to achieve angle adaptation, and time coding is added to add artificial modulation information). Figure 3 (g) and Figure 3 The results (h) show that the scattering intensity of the original target on the metasurface is significantly reduced, and a series of false targets appear around the original target, the positions of which are marked with vertical lines in the figure, achieving a deception jamming effect. The HRRP results generated by the two different radar pulses are similar, which also indicates the jamming stability of the jammer of the dual metasurface architecture of this invention in the time dimension (wherein, Figure 3 (g) and Figure 3 (h) is equivalent to conducting two experiments, and the results are basically the same.

[0106] The above description is merely an example of a specific solution of the present invention. For any devices and structures not described in detail herein, it should be understood that they are implemented using common devices and methods already available in the art.

[0107] The above is merely one embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for radar imaging deception jamming based on dual programmable hypersurfaces, characterized by, include: S1. Control the spatial coding of the first programmable metasurface to perform beam scanning, and align its main lobe of the radiation pattern with the incident direction of the radar signal for reception; wherein, it includes: S11. Control the first programmable metasurface to perform spatial beam scanning and acquire the incident radar signal through the first horn antenna; S12. Detect the signal strength of the radar signal incident on the first programmable metasurface when the beam direction is different to determine the angle information of the incident radar signal; S13. Based on the angle information, control the spatial encoding of the first programmable metasurface to align its main lobe of the radiation pattern with the incident direction; S2. The incident radar signal is enhanced and the enhanced radar signal is transmitted to the second programmable metasurface; wherein the enhanced radar signal is emitted based on the second horn antenna disposed in the near field of the second programmable metasurface and reflected to the far field radar direction based on the second programmable metasurface; S3. Controlling the spatial and temporal coding of the second programmable metasurface to modulate the temporal representation and spectral structure of the enhanced radar signal, and transmitting the modulated radar signal in the incident direction; wherein: S31. Control the spatial coding of the second programmable metasurface to adjust the main emission direction of the enhanced radar signal; S32. Control the time encoding of the second programmable metasurface to adjust the time-domain characterization and spectral structure of the enhanced radar signal, and transmit the modulated radar signal in the incident direction.

2. The method of radar imaging deception jamming according to claim 1, characterized in that, Step S11, the step of controlling the first programmable metasurface to perform spatial beam scanning and acquiring the incident radar signal through the first horn antenna, includes: S111. Establish a near-field feeding model of the first horn antenna that uses the first programmable metasurface to perform phase compensation on the first horn antenna; S112. Construct the spatial coding model of the first programmable metasurface; S113. Based on the spatial coding model and the first horn antenna near-field feeding model, control the first programmable metasurface to perform spatial beam scanning to obtain the incident radar signal.

3. The method of radar imaging deception jamming according to claim 2, characterized in that, In step S112, the spatial coding model of the first programmable metasurface is represented as follows: in, This represents the additional phase difference between the first metasurface units in the first programmable metasurface caused by the first horn antenna. This indicates that, with reference to the first row and first column cells of the first programmable metasurface, and the ( m , n The initial phase difference of the first metasurface unit, m This indicates the row number of the first metasurface unit in the first programmable metasurface. n This indicates the column number of the first metasurface unit in the first programmable metasurface. and These represent the three-dimensional coordinates of the first metasurface element and the first horn antenna, respectively. k c Indicates the signal wavenumber. d x and d y They represent x shaft and y The distance between the first metasurface units that are uniformly spaced on the axis This indicates the desired beam direction.

4. The radar imaging deception and jamming method according to claim 3, characterized in that, In step S12, the step of detecting the signal strength of the radar signal incident on the first programmable metasurface when the beam direction is different to determine the angle information of the incident radar signal is determined based on the maximum signal strength among the incident radar signal signals.

5. The radar imaging deception and jamming method according to claim 4, characterized in that, In step S32, the step of controlling the time encoding of the second programmable metasurface to adjust the time-domain representation and spectral structure of the enhanced radar signal involves controlling the second programmable metasurface based on an interaction model between the radar signal and the programmable metasurface to adjust the time-domain representation and spectral structure of the enhanced radar signal; wherein the interaction model is expressed as: in, θ and φ These represent the elevation and azimuth angles of the radar signal relative to the far-field direction of the metasurface plane, respectively. τ Indicates a fast time. Indicates radar signal, This represents the modulation term of a programmable metasurface; The modulation term of a programmable metasurface is represented as: in, k 0 indicates the wavenumber corresponding to the frequency of the modulated radar signal when it is reflected. This represents the spatial scattering characteristics of metasurface units in a programmable metasurface. This indicates the distance between metasurface units in a programmable metasurface in the far-field observation direction. Phase difference caused by spatial path difference, The time-domain modulation signal representing the programmable metasurface encoding, i.e., time-coded, can be expressed as follows when the time-domain modulation signal of the programmable metasurface is periodic: in, These are the Fourier transform coefficients. u Indicates the harmonic order. f s It is the time-domain periodic modulation frequency.

6. An jamming device for the radar imaging deception jamming method according to any one of claims 1 to 5, characterized in that, include: Receiver unit, transmitter unit, and control unit; The receiving unit includes: a first programmable metasurface, and a first horn antenna disposed in the near field of the first programmable metasurface; The transmitting unit includes: a second programmable metasurface, and a second horn antenna disposed in the near field of the second programmable metasurface; The control unit includes: a radio frequency channel component and a control channel component; The radio frequency channel assembly is connected to the first horn antenna and the second horn antenna respectively to serve as a signal transmission path; The control channel assembly is connected to the first programmable metasurface and the second programmable metasurface, respectively.

7. The interference device according to claim 6, characterized in that, The radio frequency channel assembly includes: a detector and a power amplifier; The detector is connected to the power amplifier; The detector is connected to the first horn antenna; The power amplifier is connected to the second horn antenna; The control channel component uses an FPGA controller.

Images