Microwave-infrared regulation structure and design method thereof

Abstract

This application provides a microwave infrared control structure and its design method, comprising: a metal reflective substrate for reflecting incident microwaves; a microwave control composite layer disposed on the metal reflective substrate; the microwave control composite layer for scattering normally incident microwave energy to non-normal regions; and an infrared control composite layer disposed on the microwave control composite layer. The infrared control composite layer includes at least two metal patterns with different infrared emissivity in the target infrared band. The at least two metal patterns have equivalent impedance characteristics matched in the target microwave operating frequency band, or the reflection phase response deviation introduced by the at least two metal patterns is within a preset threshold range, forming a novel functional structure that can both achieve flexible control of the microwave beam and freely define the infrared radiation distribution of the surface like display pixels, thereby meeting the dual needs of infrared camouflage electromagnetic control and information communication.

Description

Technical Field

[0001] This application relates to the field of electromagnetic functional materials and multi-spectral compatible modulation technology, specifically to a microwave infrared modulation structure and its design method. Background Technology

[0002] With the rapid development of modern electronic information technology, the utilization and countermeasures of electromagnetic spectrum resources are becoming increasingly complex. Among them, microwaves and infrared, as two core spectrum windows, have extremely high application value due to the effective control of their radiation characteristics. On the one hand, facing multi-band detection such as radar detection and infrared imaging, achieving dual electromagnetic control of targets in the microwave and infrared bands is the key to improving performance. On the other hand, utilizing the spatial distribution differences of electromagnetic radiation characteristics to load specific information has become an important emerging means of cryptographic communication, secure data transmission, and identification.

[0003] Traditional approaches often involve directly spraying an infrared low-emissivity coating onto the surface of a microwave absorber, or stacking microwave structures beneath an infrared electromagnetic modulation layer. This simple physical stacking often results in a significant increase in overall thickness, and strong electromagnetic coupling exists between different functional layers. For example, the metallic components of the infrared layer may block microwaves from entering the absorber layer, or alter the impedance matching of the microwave structure, leading to a substantial decrease in the microwave modulation performance of traditional microwave infrared modulation schemes. Secondly, most current compatible materials aim to achieve low infrared emissivity across the entire surface. However, this all-surface low emissivity characteristic can actually expose the target by creating a "thermal black hole" effect when facing complex backgrounds (such as forests, deserts, or mottled ground).

[0004] Therefore, developing a novel functional material capable of flexibly customizing and compatiblely controlling both microwave scattering fields and infrared radiation textures is of great practical significance for meeting the dual requirements of multi-spectral electromagnetic control and secure communication. Summary of the Invention

[0005] The purpose of this application is to provide a microwave infrared modulation structure and its design method, so as to provide a new type of functional material that can flexibly customize and compatibly control both microwave scattering field and infrared radiation texture, thereby meeting the dual requirements of Doppler electromagnetic modulation and secure communication.

[0006] In a first aspect, this application provides a microwave infrared modulation structure, comprising: a metal reflective substrate for reflecting incident microwaves; a microwave modulation composite layer disposed on the metal reflective substrate; the microwave modulation composite layer for scattering normally incident microwave energy to a non-normal region; and an infrared modulation composite layer disposed on the microwave modulation composite layer; the infrared modulation composite layer includes at least two metal patterns with different infrared emissivity in the target infrared band; wherein the equivalent impedance characteristics of the at least two metal patterns are matched in the target microwave operating frequency band, or the reflection phase response deviation introduced by the at least two metal patterns is within a preset threshold range.

[0007] The microwave infrared modulation structure provided in this solution adopts a planar multi-layered structure, consisting of an infrared modulation composite layer, a microwave modulation composite layer, and a metal reflective bottom layer from top to bottom. The top layer, designed with at least two different infrared emissivity metal patterns, allows for flexible adjustment of emissivity parameters (duty cycle, shape, etc.) to meet the customized requirements of different target infrared textures. Simultaneously, the microwave modulation composite layer in the middle layer scatters normally incident microwave energy into non-normal regions, significantly reducing the microwave echo energy in the normal direction due to destructive interference. This results in the radar receiving little or no microwave echo, thus reducing the target's vulnerability to radar. This approach achieves a high probability of detection. Furthermore, by controlling the impedance matching or phase deviation of the metal pattern in the infrared-controlled composite layer, the metal pattern's control effect is limited to the infrared band, maintaining a consistent electromagnetic response in the microwave band without interfering with the phase control effect of the microwave-controlled composite layer. Moreover, the structural design of the microwave-controlled composite layer does not affect the infrared emissivity differences of the metal pattern, achieving functional decoupling and compatibility. This ensures that infrared control and microwave control do not interfere with each other, resulting in a novel functional structure that allows for flexible microwave beam control and the free definition of surface infrared radiation distribution, similar to display pixels. This fulfills the dual requirements of electromagnetic control and information communication in infrared camouflage. In addition, the microwave-infrared control structure designed in this approach is thin, lightweight, and simple to implement in engineering.

[0008] In an optional embodiment of the first aspect, the infrared modulation composite layer includes a metal pattern layer formed by arranging at least two metal patterns in a plane and a first dielectric layer; the metal pattern layer is disposed on the first dielectric layer, and the first dielectric layer is disposed on the microwave modulation composite layer.

[0009] The above-described implementation scheme provides a layered design of the metal pattern layer and the first dielectric layer, which allows the parameters of the metal pattern (shape, size, duty cycle) and the parameters of the first dielectric layer (thickness, dielectric constant) to be adjusted independently without considering the direct coupling effect between the two and the microwave control composite layer. This facilitates the optimization of infrared emissivity and microwave scattering effect according to the requirements of the target microwave frequency band and infrared band, improving the adaptability of the structure. At the same time, the insulating isolation effect of the first dielectric layer blocks the electromagnetic coupling between the metal pattern layer and the microwave control composite layer, avoiding interference from the conductivity of the metal pattern on microwave phase control, and also preventing microwave energy leakage to the metal pattern layer, which would lead to a decrease in microwave control efficiency. This makes the independence of microwave control and infrared control stronger and the effect more stable. In addition, the first dielectric layer provides a flat and stable support for the metal pattern layer, and mature photolithography and etching processes can be used to prepare the metal pattern on the surface of the dielectric layer, improving the dimensional accuracy and uniformity of the metal pattern and facilitating mass production.

[0010] In an alternative embodiment of the first aspect, at least two metal patterns include three metal patterns with different metal duty cycles; wherein the three metal patterns with different metal duty cycles include a solid metal pattern structure, an X-shaped metal pattern structure, and a ring-shaped metal pattern structure.

[0011] The above-described implementation scheme provides a clear duty cycle gradient for the three metal patterns, corresponding to three different levels of infrared emissivity. Compared to the two-level emissivity of only two metal patterns, this results in richer infrared grayscale levels, enabling the simulation of more complex natural background infrared textures and improving the realism of infrared camouflage. Simultaneously, the multi-level emissivity provides more coding dimensions for information loading, increasing the capacity of information loading. Furthermore, the infrared emissivity corresponding to the three metal patterns can be continuously adjusted from low to high, adapting to the control requirements of different target infrared bands. The emissivity gradient can be flexibly adjusted according to actual application scenarios (such as infrared camouflage against different backgrounds). Additionally, through optimization of the geometric dimensions of the three metal patterns and their dielectric constant / thickness with the first dielectric layer, equivalent impedance matching or phase deviation within the target microwave operating frequency band is ensured. This guarantees the three-level difference in infrared emissivity while avoiding interference from pattern differences on microwave control, making the dual-band control effect more stable and reliable.

[0012] In an alternative embodiment of the first aspect, at least two metal patterns are arranged to form a target information pattern; wherein the target information pattern includes any one of infrared camouflage texture, QR code, barcode or character encoding.

[0013] The above-described implementation scheme, through the arrangement of metal patterns to form target information patterns, can simultaneously achieve microwave stealth and infrared camouflage while loading information such as QR codes and character codes. This allows for use in scenarios such as secure communication, anti-counterfeiting identification, and target marking, giving the structure dual functions of stealth and information transmission, thus enhancing its practicality and added value. Furthermore, all metal patterns used to form the information patterns meet microwave compatibility requirements, and the pattern arrangement does not introduce additional microwave phase distortion. The microwave-controlled composite layer can still normally scatter microwave energy to illegal regions, ensuring that microwave stealth and infrared information loading functions are simultaneously achieved.

[0014] In an optional embodiment of the first aspect, the microwave control composite layer includes a microwave control layer and a second dielectric layer; the microwave control layer includes a plurality of microwave control units arranged in a target arrangement; wherein the microwave control layer is disposed between the infrared control composite layer and the second dielectric layer.

[0015] In the above-described implementation scheme, the second dielectric layer can provide a stable phase delay, which works in synergy with the phase modulation of the microwave modulation layer to achieve more precise microwave phase modulation and make the scattering direction of microwave energy more controllable. At the same time, the microwave modulation layer is composed of multiple independent microwave modulation units, and the direction and intensity of microwave scattering can be flexibly adjusted by adjusting the parameters and arrangement of each unit to adapt to different microwave modulation requirements.

[0016] In an optional embodiment of the first aspect, the target arrangement of the multiple microwave control units is any one of a checkerboard arrangement, a striped arrangement, or a pseudo-random sequence arrangement.

[0017] The above-described implementation scheme of this design, with its chessboard and pseudo-random sequence arrangement, can avoid the concentration of microwave energy in the normal or specific direction, reducing the echo energy received by the radar; the stripe arrangement can scatter microwave energy in a directional manner to non-detection directions, further reducing the probability of being identified by the radar. Compared with the random arrangement, the scattering effect of the three typical arrangement methods is more stable and controllable, and the stealth performance is better.

[0018] In an alternative embodiment of the first aspect, the scattered fields of adjacent microwave control units in the microwave normal direction are out of phase.

[0019] In the above implementation scheme, multiple microwave control units are arranged with opposite phases between adjacent microwave control units. The microwaves reflected by adjacent microwave control units form two scattered fields with a phase difference of approximately 180° in the normal direction. The two fields interfere and cancel each other out, resulting in a significant reduction in the microwave echo energy in the normal direction. The normal echo energy approaches zero, and the microwave energy is redistributed to the non-normal region, thereby maximizing the reduction of the normal RCS.

[0020] In an optional embodiment of the first aspect, each microwave control unit includes a plurality of first coding units and a plurality of second coding units arranged according to a preset digital coding sequence; wherein the first coding units and the second coding units have equal reflection amplitudes and reflection phase differences within a preset phase difference threshold range in the target microwave frequency band.

[0021] In the above-described implementation scheme, the first and second coding units form a microwave control unit through the design of a digital coding sequence. The arrangement and combination of the first and second coding units can be flexibly adjusted to flexibly control the microwave reflection phase distribution and achieve different microwave scattering effects. At the same time, the reflection amplitudes of the first and second coding units are equal and the phase difference is stable, ensuring the stability of the microwave phase distribution corresponding to the coding sequence. This makes the microwave scattering effect stable and controllable, avoiding fluctuations in the scattering effect caused by differences in unit characteristics.

[0022] In an optional embodiment of the first aspect, both the first coding unit and the second coding unit are metallic conductive structures; wherein the first coding unit and the second coding unit have different geometric dimensions or different metallic structure shapes.

[0023] The aforementioned implementation scheme allows for the mass production of the metallic conductive structure using mature processes such as photolithography and etching, eliminating the need for complex materials or processing procedures. Compared to other phase modulation structures, it offers lower fabrication difficulty and greater cost advantages. Furthermore, the geometric parameters of the metallic conductive structure are easily controlled for precise processing accuracy, enabling accurate achievement of preset phase differences. The electromagnetic properties of the metallic structure are stable and less affected by environmental factors, ensuring long-term reliable phase modulation of the encoding unit.

[0024] Secondly, this application provides a microwave infrared modulation structure design method, comprising: constructing a parameterized model of the modulation structure including an infrared modulation composite layer, a microwave modulation composite layer, and a metal reflective underlayer; obtaining the target microwave operating frequency band and the target infrared operating frequency band; performing joint simulation of the geometric parameters of the infrared modulation composite layer and the structural parameters of the microwave modulation composite layer based on the parameterized model of the modulation structure, the target microwave operating frequency band, and the target infrared operating frequency band, to obtain at least two types of metal patterns and the coding units of the microwave modulation composite layer that meet the target conditions; wherein, the target conditions are: at least two types of metal patterns have different infrared emissivity in the target infrared operating frequency band and their equivalent impedance characteristics are matched in the target microwave operating frequency band, or the reflection phase response deviation introduced by at least two metal patterns is within a preset threshold range; the coding units have equal reflection amplitude in the target microwave operating frequency band and the reflection phase difference is within a preset phase difference threshold range; arranging the coding units of the microwave modulation composite layer on the array surface according to a preset digital coding sequence; and mapping the coding units at each array position to metal patterns with corresponding infrared emissivity levels.

[0025] This solution provides a microwave infrared control structure design method. First, a parameterized model of the control structure is constructed based on the layered design of the microwave infrared control structure. Then, based on the parameterized model, the parameters of the metal pattern and the coding unit are precisely controlled through co-simulation. This ensures that the differences in infrared emissivity, the phase difference of the coding unit, and the amplitude deviation all meet preset thresholds. Furthermore, precise coordination at the array level is achieved through mapping relationships, improving the control accuracy of microwave scattering and infrared radiation. Simultaneously, it ensures that the metal pattern and the coding unit meet both infrared emissivity differences and microwave compatibility requirements, avoiding mutual interference from the design source and improving the synergy and stability of dual-band control. Therefore, the microwave infrared control structure designed using this method can achieve flexible control of the microwave beam and freely define the infrared radiation distribution on the surface, similar to display pixels. This results in a novel functional structure that meets the dual needs of infrared camouflage electromagnetic control and information communication.

[0026] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a first structural schematic diagram of the microwave infrared modulation structure provided in the embodiments of this application; Figure 2 This is a schematic diagram of the second structure of the microwave infrared modulation structure provided in the embodiments of this application; Figure 3 Examples of the structure of various metal patterns provided in the embodiments of this application; Figure 4 An example structural diagram of the microwave control layer provided in the embodiments of this application; Figure 5 The microwave reflection amplitude and phase curve of the encoding unit provided in the embodiments of this application; Figure 6 RCS attenuation curve of the microwave control structure provided in the embodiment of this application relative to a metal plate of the same size; Figure 7A flowchart illustrating the design method of the microwave infrared modulation structure provided in this application embodiment.

[0029] Icons: 10-Metallic reflective base layer; 20-Microwave control composite layer; 210-Microwave control layer; 220-Second dielectric layer; 30-Infrared control composite layer; 310-Metal pattern layer; 320-First dielectric layer; An-Metal pattern; A1-Solid metal pattern structure; A2-X-shaped metal pattern structure; A3-Ring metal pattern structure; Ln-Microwave control unit; L1-First encoding unit; L2-Second encoding unit. Detailed Implementation

[0030] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0032] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0035] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0036] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to 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, they should not be construed as limitations on the embodiments of this application.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] With the rapid development of modern electronic information technology, the utilization and countermeasures of electromagnetic spectrum resources are becoming increasingly complex. Among them, microwaves and infrared, as two core spectrum windows, have extremely high application value due to the effective control of their radiation characteristics. On the one hand, facing multi-band detection such as radar detection and infrared imaging, achieving dual electromagnetic control of targets in the microwave and infrared bands is the key to improving performance. On the other hand, utilizing the spatial distribution differences of electromagnetic radiation characteristics to load specific information has become an important emerging means of cryptographic communication, secure data transmission, and identification.

[0039] Therefore, developing a novel functional material capable of flexibly customizing and compatiblely controlling both microwave scattering fields and infrared radiation textures is of great practical significance for meeting the dual requirements of multi-spectral electromagnetic control and secure communication.

[0040] To address the aforementioned issues, this application provides a microwave infrared modulation structure and its design method. The structure employs a planar multilayer stacked structure, comprising, from top to bottom, an infrared modulation composite layer, a microwave modulation composite layer, and a metal reflective bottom layer. The top layer, designed with metal patterns containing at least two different infrared emissivity, allows for flexible adjustment of emissivity parameters (duty cycle, shape, etc.) to meet the customized requirements of different target infrared textures. Furthermore, the microwave modulation composite layer in the middle layer scatters normally incident microwave energy into non-normal regions, significantly reducing the microwave echo energy in the normal direction due to destructive interference, resulting in the radar receiving little or no microwave echo energy. The weak microwave echo reduces the probability of the target being detected by radar. In addition, this scheme controls the impedance matching or phase deviation of the metal pattern in the infrared-controlled composite layer so that the metal pattern only modulates the infrared band and has a basically consistent electromagnetic response in the microwave band, without interfering with the phase modulation effect of the microwave-controlled composite layer. At the same time, the structural design of the microwave-controlled composite layer does not affect the difference in infrared emissivity of the metal pattern. The two achieve functional decoupling and compatibility, thus forming a new functional structure that can achieve flexible control of the microwave beam and freely define the infrared radiation distribution of the surface like display pixels, thereby meeting the dual needs of electromagnetic control and information communication in infrared camouflage.

[0041] Based on the above ideas, this application first provides a microwave infrared modulation structure, such as... Figure 1 As shown, the microwave infrared modulation structure includes a metal reflective substrate 10, a microwave modulation composite layer 20, and an infrared modulation composite layer 30. The microwave modulation composite layer 20 is disposed on the metal reflective substrate 10, and the infrared modulation composite layer 30 is disposed on the microwave modulation composite layer 20.

[0042] The microwave infrared modulation structure designed in this scheme uses a continuous conductive metal thin film as the metal reflective substrate 10. Metal materials have excellent conductivity; when microwaves are incident on the surface of the metal reflective substrate 10, the free electrons inside the metal generate an induced current under the influence of the microwave electric field. This induced current then radiates reflected microwaves in the opposite direction to the incident microwaves, achieving total reflection of the incident microwaves. The metal reflective substrate 10 avoids energy loss caused by microwave transmission downwards and provides a stable reflection boundary for the microwave modulation composite layer, ensuring that the microwave modulation composite layer can effectively modulate the phase of the reflected microwaves.

[0043] The microwave-controlled composite layer 20 receives microwaves reflected from the metallic reflective substrate 10. It contains subwavelength structures with phase-modulation capabilities. By designing the parameters of these structures, the reflected phase of the microwaves can be discretely or continuously controlled. When normally incident microwaves pass through the microwave-controlled composite layer, the reflected phases at different locations change differentially, causing interference effects in space. This results in a significant reduction in the energy of the microwave reflected wave in the normal direction due to destructive interference, and the microwave energy is redistributed to the non-normal region. This achieves control over the microwave scattering direction, reducing the echo energy detected by radar, i.e., reducing the radar cross section (RCS).

[0044] An infrared modulation composite layer 30 is disposed on a microwave modulation composite layer 20. It contains at least two metal patterns An with different infrared emissivity. The emissivity difference between the metal patterns An is determined by the geometric parameters of the metal patterns (such as duty cycle, shape, and size). For example, the higher the duty cycle of a metal pattern (the larger the metal area ratio), the lower its infrared emissivity; conversely, the lower the duty cycle, the higher the infrared emissivity. Thus, by setting metal patterns with different geometric parameters on the infrared modulation composite layer 30, this scheme can form at least two different emissivity levels in the target infrared band, thereby achieving customized infrared texture. Simultaneously, to avoid interference from the metal patterns in the infrared modulation composite layer on the microwave modulation effect, this scheme designs at least two metal patterns with equivalent impedance characteristics matched within the target microwave operating frequency band. At this point, the microwave reflection characteristics (amplitude and phase) of different metal patterns are basically consistent, and no additional microwave phase distortion is introduced due to pattern differences; or the reflection phase response deviation introduced by the at least two metal patterns designed in this scheme is within a preset threshold range, ensuring that the effect of phase deviation on microwave interference effect is negligible, thereby achieving compatibility between infrared emissivity differentiation and microwave scattering modulation.

[0045] The microwave infrared modulation structure provided in this solution adopts a planar multi-layered structure, consisting of an infrared modulation composite layer, a microwave modulation composite layer, and a metal reflective bottom layer from top to bottom. The top layer, designed with at least two different infrared emissivity metal patterns, allows for flexible adjustment of emissivity parameters (duty cycle, shape, etc.) to meet the customized requirements of different target infrared textures. Simultaneously, the microwave modulation composite layer in the middle layer scatters normally incident microwave energy into non-normal regions, significantly reducing the microwave echo energy in the normal direction due to destructive interference. This results in the radar receiving little or no microwave echo, thus reducing the target's vulnerability to radar. This approach achieves a high probability of detection. Furthermore, by controlling the impedance matching or phase deviation of the metal pattern in the infrared-controlled composite layer, the metal pattern's control effect is limited to the infrared band, maintaining a consistent electromagnetic response in the microwave band without interfering with the phase control effect of the microwave-controlled composite layer. Moreover, the structural design of the microwave-controlled composite layer does not affect the infrared emissivity differences of the metal pattern, achieving functional decoupling and compatibility. This ensures that infrared control and microwave control do not interfere with each other, resulting in a novel functional structure that allows for flexible microwave beam control and the free definition of surface infrared radiation distribution, similar to display pixels. This fulfills the dual requirements of electromagnetic control and information communication in infrared camouflage. In addition, the microwave-infrared control structure designed in this approach is thin, lightweight, and simple to implement in engineering.

[0046] In an optional implementation of this embodiment, such as Figure 2 As shown, the infrared control composite layer 30 designed in this scheme includes a metal pattern layer 310 formed by arranging at least two metal patterns An in a plane and a first dielectric layer 320; the metal pattern layer 310 is disposed on the first dielectric layer 320, and the first dielectric layer 320 is disposed on the microwave control composite layer 20.

[0047] In the above-described implementation scheme, the first dielectric layer 320 is made of an insulating dielectric material. For example, this scheme can use a dielectric material with a relative permittivity of approximately 2.65 and a dielectric loss tangent of approximately 0.001, which can provide a stable support for the metal pattern layer 310, facilitating the fabrication of metal patterns through photolithography, while also meeting the requirements for miniaturization of electromagnetic dimensions. Furthermore, the dielectric constant and thickness of the first dielectric layer 320 can be jointly optimized with the microwave-controlled composite layer and the metal reflective underlayer, ensuring that the reflection phase influence of at least two metal patterns on the underlying microwave-controlled composite layer is substantially consistent within the target microwave frequency band. This avoids interference from the metal patterns on the phase modulation of the microwave-controlled composite layer, while also reducing microwave energy leakage from the microwave-controlled composite layer to the metal pattern layer, ensuring the independence of microwave modulation and infrared modulation.

[0048] Metal patterns with different geometric parameters on the metal pattern layer 310 form at least two different emissivity levels in the target infrared band, thereby achieving customization of the infrared texture.

[0049] The above-described implementation scheme provides a layered design of the metal pattern layer and the first dielectric layer, which allows the parameters of the metal pattern (shape, size, duty cycle) and the parameters of the first dielectric layer (thickness, dielectric constant) to be adjusted independently without considering the direct coupling effect between the two and the microwave control composite layer. This facilitates the optimization of infrared emissivity and microwave scattering effect according to the requirements of the target microwave frequency band and infrared band, improving the adaptability of the structure. At the same time, the insulating isolation effect of the first dielectric layer blocks the electromagnetic coupling between the metal pattern layer and the microwave control composite layer, avoiding interference from the conductivity of the metal pattern on microwave phase control, and also preventing microwave energy leakage to the metal pattern layer, which would lead to a decrease in microwave control efficiency. This makes the independence of microwave control and infrared control stronger and the effect more stable. In addition, the first dielectric layer provides a flat and stable support for the metal pattern layer, and mature photolithography and etching processes can be used to prepare the metal pattern on the surface of the dielectric layer, improving the dimensional accuracy and uniformity of the metal pattern and facilitating mass production.

[0050] In an optional implementation of this embodiment, such as Figure 2 As shown, the at least two metal patterns An designed in this scheme include three metal patterns with different metal duty cycles. Among them, the three metal patterns An with different metal duty cycles include a solid metal pattern structure A1, an X-shaped metal pattern structure A2, and a ring-shaped metal pattern structure A3. The metal duty cycle represents the ratio of the area of ​​the metal pattern to the total area of ​​the unit (or region) in which the metal pattern is located, and is one of the core parameters that determine the infrared emissivity of the metal pattern.

[0051] In the above-described implementation scheme, the infrared emissivity of the metal material is much lower than that of the insulating medium. When the duty cycle of the metal pattern changes, the infrared radiation capability of the metal pattern surface will change accordingly. For example, the higher the metal duty cycle, the larger the metal area ratio, the higher the proportion of infrared radiation reflected by the metal, the less infrared energy radiated outward, and the lower the infrared emissivity. Conversely, the lower the metal duty cycle, the smaller the metal area ratio, the lower the proportion of infrared radiation reflected, the more infrared energy radiated outward, and the higher the infrared emissivity.

[0052] In this embodiment, the duty cycles of the three metal patterns present a clear gradient relationship: the duty cycle of the solid metal pattern structure A1 > the duty cycle of the X-shaped metal pattern structure A2 > the duty cycle of the annular metal pattern structure A3. Therefore, the corresponding infrared emissivities of the three present an inverse gradient relationship: the emissivity of the solid metal pattern structure A1 < the emissivity of the X-shaped metal pattern structure A2 < the emissivity of the annular metal pattern structure A3 is the highest, forming a three-level infrared emissivity gradient. In this way, by arranging the three metal patterns in a certain rule within the plane of the metal pattern layer 310 and utilizing the differences in the three-level infrared emissivity gradient, richer infrared gray levels are formed, and thus more complex infrared texture customization is realized.

[0053] In addition, although the duty cycles of the three metal pattern structures are different, in the design process, in this solution, by adjusting the geometric dimensions of each pattern (such as the arm length of the X shape and the inner and outer diameters of the ring), the equivalent impedance characteristics of the three patterns within the target microwave operating frequency band are matched, or the reflection phase response deviation is within a preset threshold range, ensuring that the interference of the three patterns on microwave regulation is negligible and does not affect the microwave scattering effect, while realizing the three-level differentiation of infrared emissivity. For example, Figure 3 As an implementation, as a specific example, the solid metal pattern structure A1 designed in this solution can specifically be a solid metal square patch with a side length p = 3.75 mm. The long side S2 of the two intersecting metal strips of the X-shaped metal pattern structure A2 is 5.0 mm and the short side S1 is 1.063 mm. The annular metal pattern structure A3 designed in this solution can specifically be a metal square ring structure with an outer ring side length w1 of 3.4 mm and an inner ring side length w2 of 2.75 mm. Within the target infrared band of 8 - 14 μm, due to the differences in metal duty cycle and local resonance of the three types of top units, significantly different effective emissivities are exhibited, thus forming three distinguishable infrared emissivity levels of "low, medium, high", and within the target microwave frequency band of 6 - 18 GHz, the equivalent impedance characteristics are matched, or the reflection phase response deviation is within a preset threshold range.

[0054] It should be noted here that the specific parameters of the three metal patterns in the above example are only a specific example. The metal pattern structure designed in this solution and the specific geometric parameters of the metal pattern structure can be adaptively adjusted according to the actual application scenario, as long as the designed different metal patterns have different infrared emissivities within the target infrared operating band and the equivalent impedance characteristics within the target microwave operating frequency band are matched, or the reflection phase response deviation is within a preset threshold range.

[0055] The above-described implementation scheme provides a clear duty cycle gradient for the three metal patterns, corresponding to three different levels of infrared emissivity. Compared to the two-level emissivity of only two metal patterns, this results in richer infrared grayscale levels, enabling the simulation of more complex natural background infrared textures and improving the realism of infrared camouflage. Simultaneously, the multi-level emissivity provides more coding dimensions for information loading, increasing the capacity of information loading. Furthermore, the infrared emissivity corresponding to the three metal patterns can be continuously adjusted from low to high, adapting to the control requirements of different target infrared bands. The emissivity gradient can be flexibly adjusted according to actual application scenarios (such as infrared camouflage against different backgrounds). Additionally, through optimization of the geometric dimensions of the three metal patterns and their dielectric constant / thickness with the first dielectric layer, equivalent impedance matching or phase deviation within the target microwave operating frequency band is ensured. This guarantees the three-level difference in infrared emissivity while avoiding interference from pattern differences on microwave control, making the dual-band control effect more stable and reliable.

[0056] In an optional embodiment of this scheme, at least two metal patterns An are arranged to form a target information pattern; wherein, the target information pattern includes any one of infrared camouflage texture, QR code, barcode or character encoding.

[0057] The above-described implementation method provided by this solution treats metal patterns with different infrared emissivity as infrared pixels. The metal patterns with higher emissivity correspond to brighter pixels in infrared imaging, and the metal patterns with lower emissivity correspond to darker pixels. According to the rules of the target information pattern (such as the distribution of camouflage texture, the modular arrangement of QR codes, and the shape of characters), these infrared pixels are arranged in the plane of the metal pattern layer to form a target information pattern that can be identified under infrared imaging equipment.

[0058] It should be noted that regardless of how the metal patterns are arranged to form the target information pattern, all metal patterns meet the condition that the equivalent impedance matching or reflection phase response deviation is within the preset threshold range within the target microwave operating frequency band. Therefore, the arrangement of the metal patterns will not affect the phase modulation effect of the microwave modulation composite layer, and microwave energy can still be scattered to the non-directional region, achieving dual-function compatibility.

[0059] The above-described implementation method provided in this solution forms a target information pattern through the arrangement of metal patterns. This allows for the simultaneous loading of information such as QR codes and character codes, achieving both microwave stealth and infrared camouflage. This enables applications in secure communication, anti-counterfeiting identification, and target marking, giving the structure dual functions of stealth and information display, thus enhancing its practicality and added value. Furthermore, all metal patterns used to form the information pattern meet microwave compatibility requirements. The pattern arrangement does not introduce additional microwave phase distortion, and the microwave-controlled composite layer can still normally scatter microwave energy to illegal regions, ensuring that microwave stealth and infrared information loading functions are simultaneously achieved.

[0060] In an optional implementation of this embodiment, such as Figure 2 As shown, the microwave control composite layer 20 designed in this scheme includes a microwave control layer 210 and a second dielectric layer 220.

[0061] The microwave control layer 210 is disposed between the infrared control composite layer 30 and the second dielectric layer 220. Specifically, the microwave control layer 210 is disposed between the first dielectric layer 320 and the second dielectric layer 220.

[0062] The second dielectric layer 220 in this design can be made of an insulating dielectric material. Its thickness and dielectric constant are designed according to the target microwave operating frequency band. For example, the second dielectric layer 220 in this design can also be made of a dielectric material with a relative dielectric constant of approximately 2.65 and a dielectric loss tangent of approximately 0.001. The total thickness of the first dielectric layer 320 and the second dielectric layer 220 is 2 mm, thereby achieving miniaturization of the electromagnetic dimensions while ensuring mechanical strength. When the microwaves reflected by the metal reflective substrate 10 pass through the second dielectric layer 220, a certain phase delay will occur. This phase delay can work in conjunction with the phase modulation effect of the microwave modulation layer to achieve more precise microwave phase modulation. At the same time, the insulating properties of the second dielectric layer 220 can block the transmission of induced current between the microwave modulation layer and the metal reflective substrate, avoiding interference from the current of the metal reflective substrate with the phase modulation of the microwave modulation layer, and ensuring the stability of microwave modulation.

[0063] like Figure 4 As shown, the microwave control layer 210 designed in this scheme includes multiple microwave control units Ln arranged according to the target arrangement. Each microwave control unit can change its reflection phase of microwaves. When microwaves pass through the microwave control layer, microwave control units Ln at different positions generate different phase modulations on the microwaves, causing the microwave energy to produce an interference effect in space, thereby scattering the normally incident microwave energy to the non-normal region.

[0064] In the above-described implementation scheme, the second dielectric layer can provide a stable phase delay, which works in synergy with the phase modulation of the microwave modulation layer to achieve more precise microwave phase modulation and make the scattering direction of microwave energy more controllable. At the same time, the microwave modulation layer is composed of multiple independent microwave modulation units, and the direction and intensity of microwave scattering can be flexibly adjusted by adjusting the parameters and arrangement of each unit to adapt to different microwave modulation requirements.

[0065] In an optional embodiment of this scheme, the target arrangement of the multiple microwave control units Ln can be any one of a checkerboard arrangement, a striped arrangement, or a pseudo-random sequence arrangement. Specifically, a checkerboard arrangement means that the multiple microwave control units are arranged according to the rules of a checkerboard grid, i.e., adjacent microwave control units are arranged alternately (like the black and white squares of a chessboard), and the phase control characteristics of adjacent units are opposite; a striped arrangement means that the multiple microwave control units are arranged according to the rules of parallel stripes, i.e., microwave control units with the same phase control characteristics form a stripe, multiple stripes are arranged in parallel, and different stripes have different phase control characteristics; a pseudo-random sequence arrangement means that the multiple microwave control units are arranged according to a preset pseudo-random sequence, the phase control characteristics of the units are randomly distributed but follow certain pseudo-random rules, and there is no obvious periodicity.

[0066] The above-described implementation scheme provides that the chessboard arrangement and pseudo-random sequence arrangement can avoid the concentration of microwave energy in the normal or specific direction, thereby reducing the echo energy received by the radar; the stripe arrangement can scatter microwave energy in a directional manner to non-detection directions, further reducing the probability of being identified by the radar. Compared with the random arrangement, the scattering effect of the three typical arrangement methods is more stable and controllable, and the stealth performance is better.

[0067] In an optional embodiment of this scheme, the scattered fields of adjacent microwave control units in the microwave normal direction are designed to be out of phase. That is, in the multiple microwave control units, the phase difference of the scattered fields generated by two adjacent microwave control units in the microwave normal direction is close to 180° (within ±37°). In other words, the phase of the scattered field of one unit is 0°, and the phase of the scattered field of adjacent units is close to 180°.

[0068] In the above implementation scheme, multiple microwave control units are arranged with adjacent microwave control units having opposite phases. The microwaves reflected by adjacent microwave control units form two scattered fields with a phase difference of approximately 180° in the normal direction. The two fields interfere and cancel each other out, resulting in a significant reduction in the microwave echo energy in the normal direction. The normal echo energy approaches zero, and the microwave energy is redistributed to the non-normal region, thereby maximizing the reduction of the normal RCS.

[0069] In an optional implementation of this embodiment, such as Figure 4 As shown, each microwave control unit Ln designed in this scheme may include multiple first coding units L1 and multiple second coding units L2 arranged according to a preset digital coding sequence; wherein, the first coding units L1 and the second coding units L2 have equal reflection amplitudes and reflection phase differences within a preset phase difference threshold range in the target microwave frequency band.

[0070] In the implementation of the above design, this scheme adopts the design concept of a digital binary encoded metasurface. The first encoding unit L1 is defined as a "0" code unit, and the second encoding unit L2 is defined as a "1" code unit. By different arrangements and combinations of the "0" code units and the "1" code units, the digital control of the microwave reflection phase is achieved. Since the reflection amplitudes of the first encoding unit L1 and the second encoding unit L2 are equal and the phase difference is within a preset threshold range, the scattering direction and intensity of the microwave can be flexibly controlled through the design of the encoding sequence.

[0071] Specifically, the first coding unit L1 and the second coding unit L2 have equal reflection amplitudes within the target microwave operating frequency band, ensuring consistent microwave energy reflected by the two units and avoiding unstable interference effects due to amplitude differences. Simultaneously, the reflection phase difference between the first coding unit L1 and the second coding unit L2 is within a preset threshold range (e.g., 180°±37°), ensuring that the microwaves reflected by the two coding units can produce effective destructive or constructive interference effects, thereby achieving control over the microwave scattering direction.

[0072] As a specific example, taking a period of 5 mm for the first coding unit L1 or the second coding unit L2, this scheme designs the side length of the metal patch in the first coding unit L1 to be 3.9 mm and the side length of the metal patch in the second coding unit L2 to be 5.0 mm. The latter is close to the unit period. Through full-wave electromagnetic simulation, it can be found that in the target microwave operating frequency band of 6 to 18 GHz, the reflection amplitude of both types of units is close to 1. In the target microwave operating frequency band, the reflection phase difference between the two is basically maintained within the range of 180°±37°, which meets the design requirements that the reflection phases of the two coding units are approximately opposite and the reflection amplitudes are basically consistent. Based on this, this scheme can arrange the first coding unit L1 and the second coding unit L2 in a 16×16 pattern to form a microwave control unit Ln with a size of approximately 80 mm×80 mm, containing a total of 256 units. Based on this, 4×4 adjacent microwave control units Ln are combined to form a microwave control layer 210. A total of 16 microwave control units Ln are obtained in the entire microwave control layer 210. Along the x and y directions, the first coding unit L1 and the second coding unit L2 are arranged in a typical "1, 0, 1, 0, ..." checkerboard pattern, so that the scattered fields of adjacent microwave control units Ln in the normal direction are approximately opposite in phase, thereby achieving the cancellation of the mirror direction scattering components in the far field.

[0073] Figure 5 This is a graph showing the microwave reflection amplitude and phase of each first coding unit L1 and second coding unit L2 in the embodiments of this application. Figure 5As can be seen from the results, the amplitudes of the first coding unit L1 and the second coding unit L2 obtained by the design are basically consistent, and the phase difference is between 143° and 247°, which meets the requirements of this scheme that the coding units have equal reflection amplitudes in the target microwave operating frequency band and that the reflection phase difference is within the preset phase difference threshold range.

[0074] The above-described implementation scheme provides a microwave control unit formed by designing a digital coding sequence using a first coding unit and a second coding unit. This allows for flexible adjustment of the arrangement and combination of the first and second coding units, thereby flexibly controlling the microwave reflection phase distribution and achieving different microwave scattering effects. Simultaneously, the reflection amplitudes of the first and second coding units are equal and the phase difference is stable, ensuring the stability of the microwave phase distribution corresponding to the coding sequence. This results in a stable and controllable microwave scattering effect, avoiding fluctuations in scattering effects caused by differences in unit characteristics.

[0075] In an optional embodiment of this scheme, both the first encoding unit L1 and the second encoding unit L2 are metallic conductive structures; wherein, the first encoding unit L1 and the second encoding unit L2 have different geometric dimensions or different metallic structure shapes.

[0076] The above-described implementation method provided by this solution features a metal conductive structure with excellent conductivity. When microwaves are incident on the surface of the metal conductive structure, an induced current is generated. The reflected microwaves radiated by the induced current are superimposed on the incident microwaves to form the final reflected microwaves. Based on this, this solution designs the first coding unit L1 and the second coding unit L2 to have different geometric dimensions. When microwaves are incident, the induced current distribution generated by the first coding unit L1 and the second coding unit L2 is different, and the phase of the reflected microwaves is also different. Thus, by reasonably designing the size difference, the phase difference between the reflection of the first coding unit L1 and the second coding unit L2 can be kept within a preset threshold range (such as 180°±37°), while ensuring that the reflection amplitude is equal.

[0077] The above-described embodiments provided in this solution allow for the mass production of metallic conductive structures using mature processes such as photolithography and etching, eliminating the need for complex materials or processing procedures. Compared to other phase modulation structures, these structures offer lower fabrication difficulty and greater cost advantages. Furthermore, the geometric parameters of the metallic conductive structures are easily controlled for precision, enabling accurate achievement of preset phase differences. The electromagnetic properties of the metallic structures are stable and less affected by environmental factors, ensuring long-term reliable phase modulation of the coding unit.

[0078] The microwave infrared modulation structure designed in this scheme can be realized using conventional multilayer printed circuit board (PCB) technology or micro-nano fabrication technology. Taking PCB technology as an example, its fabrication process can include: firstly, forming a metal reflective underlayer 10 on the back of a dielectric substrate by copper plating and lamination; then, preparing a microwave modulation layer 210 on the other side by photolithography and etching; next, stacking and curing a first dielectric layer 320, and preparing a metal pattern layer 310 on its surface using the same photolithography and etching process; finally, achieving the integration of the multilayer structure through lamination, alignment, and curing processes. The metal material used can be copper or other conductive metals, and the dielectric material can be commercially available microwave substrate materials such as F4B, which have mature processes suitable for large-area processing and mass production.

[0079] Figure 6 This is an RCS attenuation curve of the microwave control structure relative to a metal plate of the same size in an embodiment of the present invention. Figure 6 As can be seen from the data, in the target band of 8~16GH, the microwave control structure designed in this scheme attenuates the RCS to below -10dB, which fully meets the requirement of reducing the radar cross section (RCS).

[0080] It should be noted that the specific dimensions, material parameters, array size, and coding sequences given in this solution are merely examples to facilitate understanding of the invention. For different platform sizes and operating frequency bands, adjustments can be made to the unit period, dielectric thickness, metal pattern shape and size, array size, and coding method while maintaining the core design principles of approximately opposite reflection phases and basically consistent reflection amplitudes between the first and second coding units, and the formation of multi-level infrared emissivity in the metal pattern layer without affecting the phase of the microwave control layer. For example, the period of the first coding unit L1 or the second coding unit can be scaled to the range of 3–8 mm, or other shapes such as circular or cross-shaped metal patches and square ring structures can be used. These variations should all be considered to fall within the scope of protection of this application.

[0081] This application also provides a method for designing a microwave infrared modulation structure, such as... Figure 7 As shown, the microwave infrared modulation structure design method can be implemented in the following ways, including: Step S700: Construct a parameterized model of the control structure, which includes an infrared control composite layer, a microwave control composite layer, and a metal reflective substrate.

[0082] Step S710: Obtain the target microwave operating frequency band and the target infrared operating band.

[0083] Step S720: Based on the parameterized model of the control structure, the target microwave operating frequency band, and the target infrared operating frequency band, perform joint simulation of the geometric parameters of the infrared control composite layer and the structural parameters of the microwave control composite layer to obtain at least two types of metal patterns that meet the target conditions and the coding unit of the microwave control composite layer.

[0084] Step S730: Arrange the coding units of the microwave-controlled composite layer on the array surface according to a preset digital coding sequence; and map the coding units at each array position to a metal pattern with a corresponding infrared emissivity level.

[0085] In the above embodiments, this solution constructs a parameterized model of the control structure, including a metal pattern layer, a first dielectric layer, a microwave control layer, a second dielectric layer, and a metal reflective underlayer, and sets the target microwave operating frequency band and the target infrared operating band. Specifically, this solution can specify the preset target microwave operating frequency band and the target infrared operating band according to the actual application scenario (such as radar detection frequency band and infrared detection frequency band). For example, the target microwave operating frequency band can be set as [value], and the target infrared operating band can be set as [value].

[0086] Based on the above-mentioned completed parameterized model of the control structure, this scheme uses the constructed parameterized model of the control structure, combined with the obtained target microwave operating frequency band and target infrared band, to jointly simulate the geometric parameters of the infrared control composite layer and the structural parameters of the microwave control composite layer. The core is to select at least two types of metal patterns and coding units of the microwave control composite layer that meet the preset target conditions. The target conditions must meet two requirements at the same time: (1) Metal pattern constraint: At least two types of metal patterns have different infrared emissivity in the target infrared operating frequency band, and meet the equivalent impedance characteristic matching in the target microwave operating frequency band, or the introduced reflection phase response deviation is within the preset threshold range, to ensure that the metal patterns do not interfere with the microwave control effect. (2) Coding unit constraint: The coding units have equal reflection amplitude in the target microwave operating frequency band, and the reflection phase difference is within the preset phase difference threshold range (usually 180°±37°), to ensure that the coding units can achieve precise microwave scattering control through interference effect.

[0087] The coding units of the microwave control composite layer selected through joint simulation using the above method are arranged regularly on the array surface according to a preset digital coding sequence to form a complete microwave control layer array. By combining the coding sequences, the preset microwave scattering direction and intensity control can be achieved. At the same time, each coding unit in the array surface is mapped to a metal pattern with a corresponding infrared emissivity level. That is, each coding unit position is corresponding to a metal pattern that meets the target conditions, so that the microwave control array and the infrared texture array correspond one-to-one. Finally, the coordinated work of microwave scattering control and infrared radiation control is achieved, ensuring dual-band compatibility, thereby completing the design of the microwave infrared control structure.

[0088] This solution provides a microwave infrared control structure design method. First, a parameterized model of the control structure is constructed based on the layered design of the microwave infrared control structure. Then, based on the parameterized model, the parameters of the metal pattern and the coding unit are precisely controlled through co-simulation. This ensures that the differences in infrared emissivity, the phase difference of the coding unit, and the amplitude deviation all meet preset thresholds. Furthermore, precise coordination at the array level is achieved through mapping relationships, improving the control accuracy of microwave scattering and infrared radiation. Simultaneously, it ensures that the metal pattern and the coding unit meet both infrared emissivity differences and microwave compatibility requirements, avoiding mutual interference from the design source and improving the synergy and stability of dual-band control. Therefore, the microwave infrared control structure designed using this method can achieve flexible control of the microwave beam and freely define the infrared radiation distribution on the surface, similar to display pixels. This results in a novel functional structure that meets the dual needs of infrared camouflage electromagnetic control and information communication.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A microwave infrared modulation structure, characterized in that, The microwave infrared modulation structure includes: A metallic reflective substrate, used to reflect incident microwaves; A microwave-controlled composite layer is disposed on the metal reflective substrate; the microwave-controlled composite layer is used to scatter normally incident microwave energy to non-normal regions; An infrared modulated composite layer is disposed on the microwave modulated composite layer; the infrared modulated composite layer includes at least two metal patterns with different infrared emissivity in the target infrared band. Wherein, the equivalent impedance characteristics of the at least two metal patterns are matched in the target microwave operating frequency band, or the reflection phase response deviation introduced by the at least two metal patterns is within a preset threshold range.

2. The microwave infrared modulation structure according to claim 1, characterized in that, The infrared-controlled composite layer includes a metal pattern layer formed by arranging the at least two metal patterns in a plane and a first dielectric layer; The metal pattern layer is disposed on the first dielectric layer, and the first dielectric layer is disposed on the microwave-controlled composite layer.

3. The microwave infrared modulation structure according to claim 2, characterized in that, The at least two metal patterns include three metal patterns with different metal duty cycles; The three types of metal patterns with different metal duty cycles include solid metal pattern structures, X-shaped metal pattern structures, and ring-shaped metal pattern structures.

4. The microwave infrared modulation structure according to claim 2, characterized in that, The at least two metal patterns are arranged to form a target information pattern; wherein the target information pattern includes any one of infrared camouflage texture, QR code, barcode or character encoding.

5. The microwave infrared modulation structure according to claim 1, characterized in that, The microwave-controlled composite layer includes a microwave-controlled layer and a second dielectric layer; The microwave control layer includes multiple microwave control units arranged according to the target arrangement. The microwave modulation layer is disposed between the infrared modulation composite layer and the second dielectric layer.

6. The microwave infrared modulation structure according to claim 5, characterized in that, The target arrangement of the multiple microwave control units can be any one of the following: checkerboard arrangement, stripe arrangement, or pseudo-random sequence arrangement.

7. The microwave infrared modulation structure according to claim 5, characterized in that, in, The scattered fields of adjacent microwave control units in the microwave normal direction are out of phase.

8. The microwave infrared modulation structure according to claim 5, characterized in that, Each of the microwave control units includes a plurality of first coding units and a plurality of second coding units arranged according to a preset digital coding sequence; The first coding unit and the second coding unit have equal reflection amplitudes and reflection phase differences within a preset phase difference threshold range in the target microwave frequency band.

9. The microwave infrared modulation structure according to claim 8, characterized in that, Both the first encoding unit and the second encoding unit are metallic conductive structures; The first encoding unit and the second encoding unit have different geometric dimensions or different metal structure shapes.

10. A microwave infrared modulation structure design method, characterized in that, The method includes: constructing a parameterized model of the control structure comprising an infrared control composite layer, a microwave control composite layer, and a metal reflective underlayer; Acquire the target's microwave operating frequency band and the target's infrared operating band; Based on the parameterized model of the control structure, the target microwave operating frequency band, and the target infrared operating frequency band, the geometric parameters of the infrared control composite layer and the structural parameters of the microwave control composite layer are jointly simulated to obtain at least two types of metal patterns and the coding unit of the microwave control composite layer that meet the target conditions. The target conditions are: at least two types of metal patterns have different infrared emissivity in the target infrared operating frequency band and their equivalent impedance characteristics are matched in the target microwave operating frequency band; or the reflection phase response deviation introduced by the at least two metal patterns is within a preset threshold range; the coding units have equal reflection amplitudes in the target microwave operating frequency band and the reflection phase difference is within a preset phase difference threshold range. The coding units of the microwave-controlled composite layer are arranged on the array surface according to a preset digital coding sequence; and the coding units at each array position are mapped to metal patterns with corresponding infrared emissivity levels.

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