SAR (Synthetic Aperture Radar) composite phase modulation interference method based on phase-adjustable metasurface

Abstract

The invention discloses a synthetic aperture radar (SAR) composite phase modulation interference method based on a phase-adjustable metasurface, and relates to the technical field of signal processing. The designed phase-adjustable metasurface adopts the design of multiple layers of metal substrates and butterfly-shaped structure units, so that the whole structure is compact and can be easily integrated on the surface of a protection target; the variable capacitance diode is introduced as a regulation and control element, and the equivalent capacitance of the variable capacitance diode can be regulated and controlled in real time by changing the voltage applied to the two sides of the first butterfly-shaped structure unit and the second butterfly-shaped structure unit, so that the continuous change regulation and control of the incident electromagnetic wave phase can be realized; according to the invention, the modulation of the continuous phase of the incident electromagnetic wave can be realized only by designing the first butterfly-shaped structure unit and the second butterfly-shaped structure unit with high adaptability and simultaneously regulating and controlling the equivalent capacitance of the variable capacitance diodes on the first butterfly-shaped structure unit and the second butterfly-shaped structure unit; the modulation accuracy of the regulation and control metasurface during electromagnetic wave modulation is greatly improved, so that the effect of SAR radar interference is improved.

Description

Technical Field

[0001] The present invention relates to the field of signal processing technology, and in particular to a SAR composite phase modulation interference method, device, equipment and medium based on a phase-adjustable metasurface. Background Art

[0002] Synthetic aperture radar (SAR) has the advantages of all-day, all-weather, strong penetration, long-distance, and high-resolution earth observation. It can provide rich information on the electromagnetic scattering characteristics of the earth's surface. It is an important component of strategic reconnaissance and battlefield surveillance systems, and plays an important role in electronic countermeasures, target reconnaissance, combat mapping and other fields. The development and application of SAR systems pose a serious threat to the military deployment, combat status, and wartime survival of important targets of one's own side. Therefore, studying effective interference countermeasures based on the characteristics of SAR imaging has become a top priority in the field of electronic countermeasures.

[0003] According to the different sources of interference energy, SAR interference mainly includes active interference and passive interference; among them, active interference has the characteristics of high flexibility, multiple interference styles and good interference effect; according to the different implementation methods of interference, active interference is divided into suppression interference and deception interference. Among them, suppression interference refers to the use of a jammer to transmit high-power incoherent interference signals to the SAR system, which greatly reduces the signal-to-noise power ratio received by the radar. However, this type of method has high power requirements; passive interference mainly relies on reflecting or absorbing enemy electromagnetic waves to form interference, so its interference effect is often limited by many factors. For example, when the frequency, polarization or intensity of the enemy's electromagnetic waves changes, passive interference equipment usually cannot provide effective interference effects.

[0004] The emergence and development of electromagnetic metasurfaces have provided a new design method for improving SAR jamming technology. Thanks to the ability of electromagnetic metasurfaces to flexibly control important parameters such as electromagnetic wave delay, amplitude, phase, and frequency, electromagnetic metasurfaces only need to modulate the incident electromagnetic wave to achieve interference. The current controllable metasurfaces mainly include transmission phase type, geometric phase type, and circuit structure type. The transmission phase type is mainly achieved by controlling the dynamic phase during the transmission of electromagnetic waves. When the electromagnetic wave propagates in a material with a specific dielectric constant and magnetic permeability, its dynamic phase will change, thereby achieving phase control. The geometric phase type generates a geometric phase by rotating a graphic structure, thereby achieving phase control of the electromagnetic wave. The circuit structure type mainly uses the circuit phase generated by the equivalent LC resonance of the graphic structure to achieve phase control of the electromagnetic wave. However, this type of control metasurface usually requires the design of a highly coordinated and complex structure to achieve modulation of the dynamic phase and circuit phase during the modulation process, which will reduce the modulation accuracy of the control metasurface when modulating electromagnetic waves, thereby reducing the effect of interference on SAR radars. Summary of the invention

[0005] The embodiment of the present invention provides a SAR composite phase modulation interference method based on a phase-adjustable metasurface, which can solve the problem in the prior art that the current methods usually require the design of a highly coordinated and complex structure to achieve modulation of the dynamic phase and circuit phase in the modulation process, which will reduce the modulation accuracy of the control metasurface when performing electromagnetic wave modulation, thereby reducing the effect of interference on the SAR radar.

[0006] The embodiment of the present invention provides a SAR composite phase modulation jamming method based on a phase-adjustable metasurface, comprising the following steps:

[0007] Designing a phase-controlled metasurface and installing it on the surface of a protected target; the phase-controlled metasurface is composed of a plurality of periodically arranged metasurface units;

[0008] The metasurface unit comprises a metal grounding plate, a first metal substrate is disposed on the top surface of the metal grounding plate, a first butterfly structure unit is disposed on the top surface of the first metal substrate, a second metal substrate is disposed on the top surface of the first butterfly structure unit, and a second butterfly structure unit is disposed on the top surface of the second metal substrate; the first butterfly structure unit and the second butterfly structure unit are used to adjust the phase, amplitude and polarization mode of the electromagnetic wave incident on the metasurface unit;

[0009] A varactor diode is provided at the structural intersection of the first butterfly structure unit and the structural intersection of the second butterfly structure unit; by changing the voltage applied on both sides of the first butterfly structure unit and the second butterfly structure unit, the equivalent capacitance of the varactor diode is adjusted in real time to adjust the phase of the electromagnetic wave incident on the metasurface unit to be continuously changed;

[0010] The phase-controlled metasurface receives the transmission signal of the SAR radar, performs slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal and reflects it, and deceives and interferes with the SAR radar through the reflected signal.

[0011] Preferably, the first butterfly structure unit and the second butterfly structure unit are arranged at an angle of 90 degrees, and bias lines are arranged on both sides of the first butterfly structure unit and the second butterfly structure unit, and the bias lines are used to provide a DC voltage or current to the metal square ring to change the capacitance value of the varactor diode to dynamically control the metasurface electromagnetic wave regulation.

[0012] Preferably, the performing slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal comprises:

[0013] When the transmission signal of the SAR radar is incident on the phase control metasurface, the voltages applied to the bias lines on both sides of the first butterfly structure unit and the second butterfly structure unit are changed respectively, so that the voltages on both sides of the varactor diodes on the first butterfly structure unit and the second butterfly structure unit are changed respectively, so as to adjust the equivalent capacitance of the varactor diodes on the first butterfly structure unit and the second butterfly structure unit in real time, and perform slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the desired phase of the electromagnetic wave incident on the phase control metasurface respectively, and obtain cosine phase modulation signals and multi-phase segmented modulation signals respectively;

[0014] The cosine phase modulation signal is:

[0015] p 1 (t m )=exp[jβcos(2πf 1 t m )];

[0016] Where: p 1 (t m ) represents a cosine phase modulated signal; t m represents slow time; β and f 1 Respectively represent the modulation index and modulation frequency of the cosine phase modulation signal;

[0017] The multi-phase segmented modulation signal is:

[0018]

[0019] Where: p 2 (t m ) represents a multi-phase segmented modulation signal; * represents a convolution operation; τ, T, f 2 =1 / T,φ p ,P,N respectively represent the segment duration, modulation period, modulation frequency, modulation phase, number of phase segments within the pulse, and number of repetitions of the multi-phase segment modulation signal;

[0020] The cosine phase modulation signal and the multi-phase segmented modulation signal form a composite phase modulation signal, and the composite phase modulation signal is:

[0021] p(t m )=p 1 (t m )×p 2 (t m );

[0022] Where: p(t m ) represents a complex phase modulated signal.

[0023] Preferably, the forming of the reflection signal comprises:

[0024] The phase control metasurface on the stationary target receives the transmission signal of the SAR radar, and performs slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal, respectively, to obtain a cosine phase modulation signal and a multi-phase segmented modulation signal, so as to generate a composite phase modulation signal;

[0025] The spectrum of the composite phase modulated signal in the frequency domain is extracted, and the spectrum of the composite phase modulated signal is replicated multiple times in the azimuth direction of the protected target. The spectrum of the composite phase modulated signal is replaced with the replicated multiple different spectra in sequence to form multiple harmonic components of the composite phase modulated signal, and the multiple harmonic components are synthesized into a composite phase interference signal, which is a reflected signal.

[0026] Preferably, the composite phase interference signal is:

[0027]

[0028] Among them: J n (β) represents the first-kind n-th-order Bessel function; f 1 represents the modulation frequency of the cosine phase modulated signal; f 2 Indicates the modulation frequency of the multi-phase segmented modulation signal; nf 1 +mf 2 Indicates the spectrum deviation of the composite phase interference signal.

[0029] Preferably, the deceptive interference to the SAR radar includes:

[0030] The SAR radar receives the composite phase interference signal, and performs range matching filtering, range migration correction and clutter suppression on the interference signal, forming a two-way false target string along the azimuth of the protected target in the interference image to achieve interference to the SAR radar;

[0031] The offset of the mnth false target in the azimuth dimension is:

[0032]

[0033] Where: nf 1 +mf 2 Represents the spectrum offset of the composite phase interference signal; f 1 represents the modulation frequency of the cosine phase modulated signal; f 2 It represents the modulation frequency of the multi-phase segmented modulation signal; γ represents the Doppler modulation frequency.

[0034] The embodiment of the present invention also provides a SAR composite phase modulation jammer based on a phase-adjustable metasurface, comprising:

[0035] A design module, used for designing a phase-controlled metasurface and installing it on a protected target surface; the phase-controlled metasurface is composed of a plurality of periodically arranged metasurface units;

[0036] The metasurface unit comprises a metal grounding plate, a first metal substrate is disposed on the top surface of the metal grounding plate, a first butterfly structure unit is disposed on the top surface of the first metal substrate, a second metal substrate is disposed on the top surface of the first butterfly structure unit, and a second butterfly structure unit is disposed on the top surface of the second metal substrate; the first butterfly structure unit and the second butterfly structure unit are used to adjust the phase, amplitude and polarization mode of the electromagnetic wave incident on the metasurface unit;

[0037] A varactor diode is provided at the structural intersection of the first butterfly structure unit and the structural intersection of the second butterfly structure unit; by changing the voltage applied on both sides of the first butterfly structure unit and the second butterfly structure unit, the equivalent capacitance of the varactor diode is adjusted in real time to adjust the phase of the electromagnetic wave incident on the metasurface unit to be continuously changed;

[0038] SAR radar jammer module, the phase-controlled metasurface receives the transmission signal of the SAR radar, performs slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal and reflects it, and deceives and jams the SAR radar through the reflected signal.

[0039] An embodiment of the present invention further provides an electronic device, including a memory and a processor;

[0040] The memory is used to store computer programs;

[0041] The processor is used to implement the steps of the SAR composite phase modulation interference method based on the phase-adjustable metasurface as described above when executing the computer program stored in the memory.

[0042] An embodiment of the present invention further provides a computer-readable storage medium for storing a computer program, which, when executed by a processor, implements the steps of the SAR composite phase modulation interference method based on a phase-adjustable metasurface as described above.

[0043] The embodiment of the present invention provides a SAR composite phase modulation jamming method based on a phase-adjustable metasurface. Compared with the prior art, the method has the following beneficial effects:

[0044] The phase-control metasurface designed by the present invention adopts a multi-layer metal substrate and a butterfly structure unit design, so that the entire structure is compact and easy to integrate into the surface of the protection target, and introduces a varactor diode as a control element. By changing the voltage applied on both sides of the first butterfly structure unit and the second butterfly structure unit, the equivalent capacitance of the varactor diode can be controlled in real time, thereby realizing continuous change control of the phase of the incident electromagnetic wave; the present invention only designs a first butterfly structure unit and a second butterfly structure unit with a high degree of coordination, and simultaneously controls the equivalent capacitance of the varactor diode on the first butterfly structure unit and the second butterfly structure unit, that is, realizes the modulation of the continuous phase of the incident electromagnetic wave, greatly improves the modulation accuracy of the control metasurface when performing electromagnetic wave modulation, thereby improving the effect of interference to SAR radar.

[0045] In addition, the phase-controlled metasurface can receive the transmission signal of the SAR radar, and process the signal through slow-time cosine phase modulation and slow-time multi-phase segmented modulation and then reflect it back. This processing method can generate a radar image different from the real target, thereby achieving deception interference to the SAR radar. At the same time, it has the characteristics of high efficiency and concealment, and can effectively protect the target from the threat of radar detection and identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the overall process of a SAR composite phase modulation jamming method based on a phase-adjustable metasurface provided in an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of an interference model of a SAR composite phase modulation interference method based on a phase-adjustable metasurface provided in an embodiment of the present invention;

[0048] Figure 3 A schematic diagram of the design of a phase-adjustable metasurface for a SAR composite phase modulation interference method based on a phase-adjustable metasurface provided in an embodiment of the present invention; (a) is a schematic diagram of the structure of the metasurface; (b) is a schematic diagram of a metasurface array;

[0049] Figure 4 A schematic diagram of the original SAR imaging result without interference using the SAR composite phase modulation interference method based on the phase-adjustable metasurface provided in an embodiment of the present invention;

[0050] Figure 5 A schematic diagram of the composite modulation phase distribution of the SAR composite phase modulation interference method based on the phase-adjustable metasurface provided in an embodiment of the present invention;

[0051] Figure 6 A schematic diagram of interference imaging results of a SAR composite phase modulation interference method based on a phase-adjustable metasurface provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0053] See also Figure 1 The embodiment of the present invention provides a SAR composite phase modulation interference method based on a phase-adjustable metasurface, comprising the following steps:

[0054] Step 1: Design of phase-tunable metasurface.

[0055] Step 2: Establishment of a composite phase modulation signal model based on phase-adjustable metasurface.

[0056] Step 3: Construction of SAR interference signal model based on phase-adjustable metasurface.

[0057] Step 4: SAR imaging processing and imaging interference effect analysis.

[0058] The design of the phase-tunable metasurface in step 1 is as follows:

[0059] First, a double-layer butterfly metal structure is designed, and a lumped element, a varactor diode, is added between the butterfly metal gap structures. The voltage on both sides of the varactor diode is adjusted to change the equivalent capacitance, so that the phase of the incident electromagnetic wave can be continuously changed. The designed electromagnetic metasurface unit structure and array structure are as follows: Figure 3 As shown, the array structure layout is achieved by performing a two-dimensional periodic translation of the unit structure, thereby realizing a complete two-dimensional electromagnetic metasurface array structure.

[0060] The establishment of the composite phase modulation signal model in step 2 is as follows:

[0061] Cosine phase modulation and multi-phase segmented modulation have superior interference effects in traditional active interference methods. The present invention uses a phase-adjustable metasurface to combine cosine phase modulation with multi-phase segmented modulation to generate a composite phase modulation signal, which can be expressed as:

[0062] p(t m )=p 1 (t m )×p 2 (t m );

[0063] Where: t mIndicates slow time; p 1 (t m ) and p 2 (t m ) represent the cosine phase modulation signal and the multi-phase segmented modulation signal respectively, and their expressions are as follows:

[0064] p 1 (t m )=exp[jβcos(2πf 1 t m )];

[0065]

[0066] Among them: β and f 1 Respectively represent the modulation index and modulation frequency of the cosine phase modulation signal; * represents the convolution operation; τ, T, f 2 =1 / T,φ p ,P,N represent the segment duration, modulation period, modulation frequency, modulation phase, number of phase segments within the pulse, and number of repetitions of the multi-phase segment modulation signal respectively.

[0067] p(t m ) is expressed in the frequency domain as:

[0068]

[0069] Among them: J n (β) represents the first-kind n-order Bessel function; the expression of B(m) is:

[0070]

[0071] It can be seen from the above formula that the spectrum of the composite phase modulated signal is composed of J n The “comb” spectrum is formed by jointly weighting the amplitudes of B(β) and B(m).

[0072] The construction of the SAR interference signal model in step 3 is as follows:

[0073] The interference model of SAR imaging based on phase-adjustable metasurface is as follows: Figure 2 As shown in the figure, a two-dimensional rectangular coordinate system XOR is established on the SAR data acquisition plane. The SAR system moves from the origin O along the X-axis at a constant speed V, and the distance direction perpendicular to the flight trajectory to the center of the observation scene is recorded as the R axis. The phase-adjustable metasurface is placed on the surface p of the protected target in the observation scene. t (x 0 ,R 0 ), where (x 0 ,R 0 ) represents the target position; the instantaneous slant range between the SAR system and the protected target can be expressed as:

[0074]

[0075] Where: t m Indicates the azimuth slow time; R B =minR(t m ).

[0076] Assume that the LFM signal emitted by the SAR system is expressed as:

[0077]

[0078] in: Indicates distance to fast time; T r represents the pulse width; rect(·) represents the rectangular function; f 0 represents the center frequency of the transmitted signal; μ represents the modulation frequency of the transmitted LFM signal.

[0079] The phase-adjustable metasurface on the target surface intercepts the signal transmitted by the radar and performs interference modulation on it. Since the metasurface itself does not actively radiate high-power signals to the outside world, it avoids the shortcomings of traditional active interference methods, which are high cost and easy to expose the target area. Under the control of external bias voltage, the phase-adjustable metasurface can realize real-time modulation of the phase information of the transmitted signal and forward the modulated signal to the SAR imaging system. The SAR system performs detection and demodulation on the received interference echo signal, and its complex baseband interference signal can be expressed as:

[0080]

[0081] in: represents the unmodulated echo signal, and its expression is:

[0082]

[0083] Where: A represents the complex reflection coefficient of the target; T a represents the synthetic aperture time; λ and c represent the wavelength and the speed of light, respectively.

[0084] The interference signal can be expressed in the Doppler frequency domain as:

[0085]

[0086] From the above formula, we can see that the spectrum of the interference signal is a multiple spectral replication of the original echo signal spectrum in the azimuth direction, and the spectrum offset is nf 1 +mf 2 ; At the same time, the amplitude of each harmonic component is affected by J n Joint modulation of (β) and B(m).

[0087] The SAR imaging processing and imaging interference effect analysis in step 4 are as follows:

[0088] The SAR interference signal is processed by range-Doppler SAR imaging. The interference signal after range matched filtering and range migration correction can be expressed as:

[0089]

[0090] Among them: B r Indicates the transmit signal bandwidth.

[0091] The above interference signal is processed by azimuth matched filtering to obtain the final interference SAR image, which is expressed as:

[0092]

[0093] in:

[0094] Among them: B a represents the signal Doppler bandwidth; γ represents the Doppler modulation frequency.

[0095] It can be seen that multiple false targets are generated along the azimuth direction in the jamming SAR image, and the offset of the mnth false target in the azimuth dimension is:

[0096]

[0097] The specific tests are:

[0098] A reference target RT and three protected targets PT1-3 are set in the center of the imaging scene; the unmodulated radar echo is processed by range-Doppler SAR imaging to obtain the unmodulated original SAR imaging result, such as Figure 4 As shown, it can be observed that four targets with high focus quality can be seen in the SAR image.

[0099] The phase-adjustable metasurface is used to perform composite phase modulation on the echo signal of the protected target, and the modulation parameters are set to β = 1, f 1 =10Hz, f 2 =37.5Hz,φ p =0, 0.2π, 0.35π, 0.8π, and its composite modulation phase is as follows Figure 5 As shown; after range-Doppler imaging processing, the interference imaging result is obtained, as shown Figure 6 As shown, it can be seen that after the composite phase modulation processing based on the phase-adjustable metasurface, the protected target PTi, (i=1, 2, 3) can generate a false target string in the azimuth direction, thereby interfering with the subsequent SAR target detection and recognition, achieving the purpose of deception interference.

[0100] The present invention utilizes a phase-adjustable metasurface to perform slow-time phase modulation on a radar signal through an external control system to generate a SAR composite phase interference signal; by performing range-Doppler imaging processing on the SAR composite phase interference signal, theoretical analysis and experimental results show that the present invention generates a false target string with flexibly controllable azimuth position and amplitude in azimuth, has a highly flexible, high-fidelity, low-cost interference imaging effect, and has strong practical application value.

[0101] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A SAR composite phase modulation jamming method based on phase-adjustable metasurface, characterized in that: The following steps are involved: Designing a phase-controlled metasurface and installing it on the surface of a protected target; the phase-controlled metasurface is composed of a plurality of periodically arranged metasurface units; The metasurface unit comprises a metal grounding plate, a first metal substrate is disposed on the top surface of the metal grounding plate, a first butterfly structure unit is disposed on the top surface of the first metal substrate, a second metal substrate is disposed on the top surface of the first butterfly structure unit, and a second butterfly structure unit is disposed on the top surface of the second metal substrate; the first butterfly structure unit and the second butterfly structure unit are used to adjust the phase, amplitude and polarization mode of the electromagnetic wave incident on the metasurface unit; A varactor diode is provided at the structural intersection of the first butterfly structure unit and the structural intersection of the second butterfly structure unit; by changing the voltage applied on both sides of the first butterfly structure unit and the second butterfly structure unit, the equivalent capacitance of the varactor diode is adjusted in real time to adjust the phase of the electromagnetic wave incident on the metasurface unit to be continuously changed; The phase-controlled metasurface receives the transmission signal of the SAR radar, performs slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal and reflects it, and deceives and interferes with the SAR radar through the reflected signal.

2. The SAR composite phase modulation jamming method based on phase-adjustable metasurface according to claim 1 is characterized in that: The first butterfly structure unit is arranged at an angle of 90 degrees to the second butterfly structure unit, and bias lines are arranged on both sides of the first butterfly structure unit and the second butterfly structure unit. The bias lines are used to provide a DC voltage or current to the metal square ring to change the capacitance value of the varactor diode to dynamically control the metasurface electromagnetic wave regulation.

3. The SAR composite phase modulation jamming method based on phase-adjustable metasurface according to claim 1 is characterized in that: The step of performing slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal comprises: When the transmission signal of the SAR radar is incident on the phase control metasurface, the voltages applied to the bias lines on both sides of the first butterfly structure unit and the second butterfly structure unit are changed respectively, so that the voltages on both sides of the varactor diodes on the first butterfly structure unit and the second butterfly structure unit are changed respectively, so as to adjust the equivalent capacitance of the varactor diodes on the first butterfly structure unit and the second butterfly structure unit in real time, and perform slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the desired phase of the electromagnetic wave incident on the phase control metasurface respectively, and obtain cosine phase modulation signals and multi-phase segmented modulation signals respectively; The cosine phase modulation signal is: p1(t m )=exp[jβcos(2πf1t m )]; Where: p1(t m ) represents a cosine phase modulated signal; t m represents slow time; β and f1 represent the modulation index and modulation frequency of the cosine phase modulation signal respectively; The multi-phase segmented modulation signal is: Where: p2(t m ) represents a multi-phase segmented modulation signal; * represents a convolution operation; τ,T,f2=1 / T,φ p ,P,N respectively represent the segment duration, modulation period, modulation frequency, modulation phase, number of phase segments within the pulse, and number of repetitions of the multi-phase segment modulation signal; The cosine phase modulation signal and the multi-phase segmented modulation signal form a composite phase modulation signal, and the composite phase modulation signal is: p(t m )=p1(t m )×p2(t m ); Where: p(t m ) represents a complex phase modulated signal.

4. The SAR composite phase modulation jamming method based on phase-adjustable metasurface according to claim 1 is characterized in that: The formation of the reflection signal comprises: The phase control metasurface on the stationary target receives the transmission signal of the SAR radar, and performs slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal, respectively, to obtain a cosine phase modulation signal and a multi-phase segmented modulation signal, so as to generate a composite phase modulation signal; The spectrum of the composite phase modulated signal in the frequency domain is extracted, and the spectrum of the composite phase modulated signal is replicated multiple times in the azimuth direction of the protected target. The spectrum of the composite phase modulated signal is replaced with the replicated multiple different spectra in sequence to form multiple harmonic components of the composite phase modulated signal, and the multiple harmonic components are synthesized into a composite phase interference signal, which is a reflected signal.

5. The SAR composite phase modulation jamming method based on phase-adjustable metasurface according to claim 4 is characterized in that: The composite phase interference signal is: Among them: J n (β) represents the first kind of n-th order Bessel function; f1 represents the modulation frequency of the cosine phase modulation signal; f2 represents the modulation frequency of the multi-phase segmented modulation signal; nf1+mf2 represents the spectrum offset of the composite phase interference signal.

6. The SAR composite phase modulation jamming method based on phase-adjustable metasurface according to claim 5 is characterized in that: The deceptive interference to the SAR radar includes: The SAR radar receives the composite phase interference signal, and performs range matching filtering, range migration correction and clutter suppression on the interference signal, forming a two-way false target string along the azimuth of the protected target in the interference image to achieve interference to the SAR radar; The offset of the mnth false target in the azimuth dimension is: Wherein: nf1+mf2 represents the frequency spectrum offset of the composite phase interference signal; f1 represents the modulation frequency of the cosine phase modulation signal; f2 represents the modulation frequency of the multi-phase segmented modulation signal; γ represents the Doppler modulation frequency.

7. SAR composite phase modulation jammer based on phase-adjustable metasurface, characterized in that: include: A design module, used to design a phase-controlled metasurface and install it on the target surface; The phase control metasurface is composed of a plurality of periodically arranged metasurface units; The metasurface unit comprises a metal grounding plate, a first metal substrate is disposed on the top surface of the metal grounding plate, a first butterfly structure unit is disposed on the top surface of the first metal substrate, a second metal substrate is disposed on the top surface of the first butterfly structure unit, and a second butterfly structure unit is disposed on the top surface of the second metal substrate; the first butterfly structure unit and the second butterfly structure unit are used to adjust the phase, amplitude and polarization mode of the electromagnetic wave incident on the metasurface unit; A varactor diode is provided at the structural intersection of the first butterfly structure unit and the structural intersection of the second butterfly structure unit; by changing the voltage applied on both sides of the first butterfly structure unit and the second butterfly structure unit, the equivalent capacitance of the varactor diode is adjusted in real time to adjust the phase of the electromagnetic wave incident on the metasurface unit to be continuously changed; SAR radar jammer module, the phase-controlled metasurface receives the transmission signal of the SAR radar, performs slow-time cosine phase modulation and slow-time multi-phase segmented modulation on the transmission signal and reflects it, and deceives and jams the SAR radar through the reflected signal.

8. An electronic device, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is used to implement the steps of the SAR composite phase modulation interference method based on the phase-adjustable metasurface as described in any one of claims 1 to 6 when executing the computer program stored in the memory.

9. A computer-readable storage medium, characterized in that: Used to store a computer program, which, when executed by a processor, implements the steps of the SAR composite phase modulation interference method based on a phase-adjustable metasurface as described in any one of claims 1 to 6.

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