Active metasurface considering electromagnetic performance and thermal management and optimization method thereof

Abstract

This invention belongs to the field of metasurface structure technology, and particularly relates to an active metasurface that balances electromagnetic performance and thermal management, and its optimization method. It includes a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer, a fourth metal layer, a fourth dielectric layer, and a fifth metal layer arranged sequentially from top to bottom along the thickness direction. The second and fourth metal layers have identical structures, each including a first metal sheet with a hollow region in the center. First T-slots are formed around the perimeter of the first metal sheet, and the horizontal arms of the first T-slots are connected to the hollow region through first through holes. The four corners of the inner periphery of the hollow region formed by the first metal sheet are rounded. This invention significantly reduces ohmic losses caused by strong electric fields, resulting in a significant decrease in the overall operating temperature of the structure, and exhibits significant advantages in electromagnetic-thermal synergistic management.

Description

Technical Field

[0001] This invention belongs to the field of metasurface structure technology, and particularly relates to active metasurfaces that balance electromagnetic performance and thermal management, and their optimization methods. Background Technology

[0002] Metasurfaces are two-dimensional planar devices composed of subwavelength artificial microstructures arranged in a specific spatial pattern. They can precisely control the amplitude, phase, polarization, and frequency of electromagnetic waves within a subwavelength thickness, exhibiting frequency-dependent transmission and reflection characteristics. This allows them to achieve bandpass filtering functionality, enabling wave transmission within a specific frequency band and reflection outside that band. Based on this characteristic, metasurfaces play a crucial role in high-power radar antennas, electromagnetic low-scattering, and wireless communication.

[0003] Advances in multi-standard communication systems have driven the demand for and growth of active metasurface structures. Active / tunable components such as diodes are integrated into these structures, and their electrical states can be altered by external bias voltages. Active metasurfaces can dynamically and in real-time control their filtering characteristics over a wide frequency range, including resonant frequency, bandwidth, transmission / reflection amplitude, and even polarization response, providing crucial technical support for cutting-edge applications such as low electromagnetic scattering and reconfigurable antennas. However, under high-power electromagnetic wave excitation, the temperature of active metasurfaces rapidly rises to over 250 °C, thus necessitating thermal management of active metasurfaces.

[0004] Rapid temperature rise in active metasurfaces can lead to electromagnetic performance drift, and the accumulation of large amounts of electromagnetic heat can easily trigger local or overall thermal runaway, posing a serious threat to device safety and lifespan. Current technologies largely focus on maintaining the stability of electromagnetic performance, lacking systematic exploration and overall technical solution design for electromagnetic-thermal coupling suppression. This research status quo, prioritizing electromagnetic performance over thermal efficiency, has become a bottleneck restricting the transition of active metasurfaces from theoretical concepts to high-power, high-reliability practical applications. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides an active metasurface that balances electromagnetic performance and thermal management, and its optimization method. This not only maintains high stability of the electromagnetic performance of the active metasurface structure, such as the resonant frequency and bandwidth, but also significantly reduces ohmic losses caused by strong electric field regions, resulting in a significant decrease in the overall operating temperature of the structure. This achieves low loss, high thermal stability, and high reliability, and has significant advantages in electromagnetic-thermal synergistic management.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions: The first aspect of the present invention provides an active metasurface that balances electromagnetic properties and thermal management.

[0007] An active metasurface that balances electromagnetic performance and thermal management includes at least one active metasurface structural unit. The active metasurface structural unit comprises, from top to bottom along the thickness direction, a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer, a fourth metal layer, a fourth dielectric layer, and a fifth metal layer. The second and fourth metal layers have identical structures, each including a first metal sheet. A hollow region is formed in the center of the first metal sheet, and first T-slots are formed around the perimeter of the first metal sheet. The horizontal arms of the first T-slots are connected to the hollow region through first through holes. The four corners of the inner periphery of the hollow region formed by the first metal sheet are rounded.

[0008] As an alternative technical solution, each of the first T-slots is located at the center of the corresponding side of the first metal sheet, and a PIN diode is embedded between the vertical arms of each of the first T-slots.

[0009] As an alternative technical solution, the size of the first through hole is smaller than the length of the first T-slot cross arm.

[0010] As an alternative technical solution, a slender rectangular connecting strip is formed between the cross arm of the first T-slot and the hollow area of ​​the first metal sheet.

[0011] As an alternative technical solution, the first metal layer, the third metal layer and the fifth metal layer have the same structure, all including a second metal sheet; a second through hole is provided at the center of each side of the second metal sheet, and the end of the second through hole is connected to a second T-shaped groove.

[0012] As an alternative technical solution, the second through hole connects to the horizontal arm of the second T-slot, and the vertical arm of the second T-slot extends toward the center of the second metal sheet.

[0013] As an alternative technical solution, the four corners of the outer periphery of the second metal sheet are all rounded.

[0014] As an alternative technical solution, the first, third, and fifth metal layers are centrally symmetric and axially symmetric, while the second and fourth metal layers are axially symmetric.

[0015] As an alternative technical solution, a PIN diode, under forward bias, is equivalent to a series connection of a resistor and a parasitic inductance; under reverse bias, it is equivalent to a series connection of a capacitor and a parasitic inductance.

[0016] The second aspect of this invention provides an optimization method for active metasurfaces that balance electromagnetic performance and thermal management.

[0017] The optimization method for active metasurfaces that balance electromagnetic performance and thermal management, as described in Example 1, includes the following steps: Based on the equivalent circuit model, an initial active metasurface structure was constructed, and electromagnetic-thermal multiphysics coupling analysis was carried out. Targeted optimizations were made for the two main heat sources: metal loss and dielectric loss. By introducing temperature field and electromagnetic performance parameters, an electromagnetic-thermal multi-objective optimization model is constructed. Under the constraint of electromagnetic performance index, the structural parameters of the active metasurface structure are globally optimized by simulation-driven topology iterative optimization method, and the optimized set of structural physical parameters is obtained.

[0018] The above one or more technical solutions have the following beneficial effects: This invention provides an active metasurface that balances electromagnetic performance and thermal management, along with its optimization method. By specifically designing the second and fourth metal layers in the active metasurface structural unit, a hollow region is set in the center of the first metal sheet, and a "T"-shaped grid slot is provided. Combined with rounded corners around the outer edges of the first, third, and fifth metal layers, as well as the inner edges of the second and fourth metal layers, the electromagnetic performance and thermal management of the active metasurface structure are balanced. This significantly reduces ohmic losses caused by strong electric field regions, lowers the sensitivity of the structure temperature to the incident angle of electromagnetic waves, and significantly reduces the overall operating temperature of the structure, thereby improving the reliability of the active device.

[0019] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a three-dimensional view of an active metasurface that combines electromagnetic performance and thermal management according to Embodiment 1 of the present invention.

[0022] Figure 2 This is a three-dimensional view of the active metasurface structure unit of Embodiment 1 of the present invention.

[0023] Figure 3 This is a side view of the active metasurface structure unit of Embodiment 1 of the present invention.

[0024] Figure 4 This is a front view of the first, third, and fifth metal layers of the active metasurface structure unit according to Embodiment 1 of the present invention.

[0025] Figure 5This is a front view of the second and fourth metal layers of the active metasurface structure unit in Embodiment 1 of the present invention.

[0026] Figure 6 This is a schematic diagram of the method flow of Embodiment 2 of the present invention.

[0027] Figure 7 This is a simulation diagram of the filtering performance of Embodiment 1 of the present invention under the diode conduction and cutoff states.

[0028] Figure 8 This is a simulation diagram of the filtering performance of different incident angles in TE polarization mode according to Embodiment 1 of the present invention.

[0029] Figure 9 This is a simulation diagram of the filtering performance of different incident angles in TM polarization mode according to Embodiment 1 of the present invention.

[0030] Figure 10 This is the response curve of the maximum temperature with incident frequency in both diode conduction and cutoff states according to Embodiment 1 of the present invention.

[0031] Figure 11 This is the response curve of the maximum temperature at different incident angles with incident frequency in TE polarization mode according to Embodiment 1 of the present invention.

[0032] Figure 12 This is the response curve of the maximum temperature at different incident angles with incident frequency in Embodiment 1 of the present invention under TM polarization mode.

[0033] Figure 13 This is the response curve of the maximum temperature over time under high-power resonant frequency incident light according to Embodiment 1 of the present invention.

[0034] Figure 14 This is a temperature contour map comparing the initial structure under high-power resonant frequency incident light according to Embodiment 1 of the present invention.

[0035] Figure label: 1. First metal layer; 2. First dielectric layer; 3. Second metal layer; 4. Second dielectric layer; 5. Third metal layer; 6. Third dielectric layer; 7. Fourth metal layer; 8. Fourth dielectric layer; 9. Fifth metal layer; 10. PIN diode; 11. First metal sheet; 12. Hollow region; 13. First T-slot; 14. First through-hole; 15. Inner peripheral corner; 16. Second metal sheet; 17. Second through-hole; 18. Second T-slot; 19. Outer peripheral corner; 20. Active metasurface; 21. Active metasurface structural unit. Detailed Implementation

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, 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 invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0038] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0039] Example 1 This embodiment discloses an active metasurface that balances electromagnetic performance and thermal management.

[0040] An active metasurface that balances electromagnetic performance and thermal management includes at least one active metasurface structural unit 21. Specifically, the active metasurface structural unit 21 is arranged in an array to form the aforementioned active metasurface structure that balances electromagnetic performance and thermal management, in order to meet the surface arrangement requirements of different types of high-power radar antennas.

[0041] Please see Figure 1 , Figure 1 This is a perspective view of a multi-layer active metasurface multi-unit structure provided by an embodiment of the present invention. The active metasurface 20 includes N×M periodically arranged low-profile tunable active metasurface structural units 21, where M and N are integers greater than or equal to 1. In this embodiment, the low-profile tunable active metasurface structural unit 21 includes a 5*5 unit structure. In other embodiments, the active metasurface 20 may include 10*10, 20*20, 40*40, or even more of the above-mentioned unit structures.

[0042] Please see Figures 2 to 5 , Figure 2 This is a perspective view of a multilayer active metasurface unit structure based on a PIN diode 10 provided in an embodiment of the present invention; Figure 3 This is a side view of a multilayer active metasurface unit structure based on a PIN diode 10 provided in an embodiment of the present invention; Figure 4 This is a front view of the first, third, and fifth metal layers of a multilayer active metasurface unit structure based on a PIN diode 10 provided in an embodiment of the present invention. Figure 5 This is a front view of the second and fourth metal layers of a multilayer active metasurface unit structure based on a PIN diode 10 provided in an embodiment of the present invention.

[0043] like Figure 2 and Figure 3As shown, the active metasurface structure unit 21 includes a first metal layer 1, a first dielectric layer 2, a second metal layer 3, a second dielectric substrate, a third metal layer 5, a third dielectric substrate, a fourth metal layer 7, a fourth dielectric substrate, and a fifth metal layer 9 arranged sequentially from top to bottom along the thickness direction. The second metal layer 3 and the fourth metal layer 7 have the same structure, and the first metal layer 1, the third metal layer 5, and the fifth metal layer 9 have the same structure.

[0044] To further improve the angular stability of the active metasurface, especially to mitigate the sensitivity of its out-of-band suppression characteristics to the incident angle, this embodiment employs a miniaturized active metasurface 20 and introduces a specific trench structure to reduce the unit cell electrical size, thereby enhancing its stability to changes in the incident angle. To ensure the optimized structure maintains the X-band transmission characteristics of the initial structure, the equivalent capacitance and inductance values ​​of the structure are further precisely adjusted and improved through parametric reconstruction and iterative optimization of the trench structure. Simulation-driven design is performed with corresponding frequency band optimization targets set, ultimately determining the optimal topology.

[0045] In general, the first, third, and fifth metal layers all include a metal layer body and a square slot structure penetrating the metal layer body; the second and fourth metal layers both include a metal layer body and a mesh slot structure penetrating the metal layer body; such as Figure 4 and Figure 5 As shown, all slotted structures are "T" shaped slotted structures.

[0046] like Figure 5 As shown, both the second metal layer 3 and the fourth metal layer 7 include a first metal sheet 11. A hollow region 12 is provided in the center of the first metal sheet 11. A first T-shaped groove 13 is provided around the first metal sheet 11. The horizontal arm of the first T-shaped groove 13 is connected to the hollow region 12 through a first through hole 14. like Figure 4 As shown, the first metal layer 1, the third metal layer 5 and the fifth metal layer 9 each include a second metal sheet 16; a second through hole 17 is provided at the center of each side of the second metal sheet 16, and the end of the second through hole 17 is connected to a second T-slot 18.

[0047] Furthermore, each of the first T-slots 13 is located at the center of the corresponding side of the first metal sheet 11, and a PIN diode 10 is embedded between the vertical arms of each of the first T-slots 13. Figure 2 In, and combined Figure 5As shown, a PIN diode 10 is embedded in the center of each of the four sides of the second metal layer 3 and the fourth metal layer 7. By controlling the bias voltage of the PIN diode 10, its equivalent circuit parameters can be dynamically changed: under forward bias, the PIN diode 10 is equivalent to a series connection of a resistor and a parasitic inductance; under reverse bias, it is equivalent to a series connection of a capacitor and a parasitic inductance. This characteristic allows the resonant frequency of the entire structure to be electrically tuned within a certain range, thereby achieving dynamic tuning of X-band communication signals and effectively shielding out-of-band interference.

[0048] The active metasurface provided in this embodiment, which balances electromagnetic performance and thermal management, has a PIN diode 10 embedded in the center of each of the four sides of the second and fourth metal layers. Under forward bias, the PIN diode 10 is modeled as a series combination of a 1 Ω resistor and a 1.5 nH parasitic inductance, while under reverse bias, it is modeled as a series combination of a 0.1 pF capacitor and a 1.5 nH parasitic inductance.

[0049] A DC bias voltage is applied to the lower left and upper right corners of the second metal layer 3 and the fourth metal layer 7. When the bias voltage is negative, all PIN diodes 10 on the first metal sheet 11 are in the off state, achieving a transmittance of over 80% in the X-band. When the bias voltage is positive, all PIN diodes 10 on the first metal sheet 11 are in the on state, achieving efficient electromagnetic wave absorption in the low-frequency band through impedance matching.

[0050] exist Figure 5 In the middle, the first metal sheet 11 is a connected structure in which the central hollow area 12 is connected to the outer periphery.

[0051] On each side of the first metal sheet 11, the horizontal arm of the first T-slot 13 extends outward from the center of the corresponding side. The size of the first through hole 14 is smaller than the length of the horizontal arm of the first T-slot 13. Thus, the first through hole 14 forms a connection between the hollow region 12 in the center of the first metal sheet 11 and the outer periphery of the first metal sheet 11. The advantage of this design is: Adding rectangular apertures significantly lengthens the current path on the metal patch surface, forcing the current to flow along a narrow metal strip. This introduces a larger equivalent series inductance into the structure, enabling miniaturization. Simultaneously, the extended current path allows for more flexible input impedance adjustment, improving impedance matching characteristics and reducing return loss.

[0052] Figure 5 In the middle, a slender rectangular connecting strip is formed between the horizontal arm of the first T-slot 13 and the hollow area 12 of the first metal sheet 11.

[0053] Figure 4The diagram shows the structure of the second metal sheet 16 and the second T-slot 18. Unlike the first metal sheet 11, the second metal sheet 16 has a solid center, and a second T-slot 18 is provided near each edge of the second metal sheet 16. A second through hole 17 is provided at the center of each edge, and the second through hole 17 communicates with the horizontal arm of the second T-slot 18 near the corresponding edge. The vertical arm of the second T-slot 18 extends towards the center of the second metal sheet 16. The advantage of this design is that: By introducing an equivalent capacitance through slotting, the structure can be miniaturized. At the same time, slotting changes the current path on the surface of the patch, which can effectively control the input impedance, improve impedance matching characteristics, reduce return loss, and thus significantly broaden the operating bandwidth of the active metasurface.

[0054] In this embodiment, a specific slotted structure is designed on the second metal layer 3 and the fourth metal layer 7: "T"-shaped square slots are formed on the square patches of the first, third, and fifth metal layers; "T"-shaped grid slots are also formed on the grid structure of the second and fourth metal layers. This slotted structure, combined with the overall miniaturization design, reduces the electrical size of the unit, and the equivalent capacitance and inductance of the structure are adjusted through parametric optimization, so that the resonant frequency and bandwidth of the structure can remain highly stable in both TE and TM polarization modes, even at large angles of oblique incidence, with minimal performance changes.

[0055] Furthermore, this embodiment addresses the issue of electric field concentration at the edges and corners of the metal patch by introducing rounded corners at key locations around the basic structure. This design smooths the distribution of electric field lines, significantly reducing the maximum electric field intensity, thereby minimizing ohmic losses caused by strong field regions at the source.

[0056] The four corners of the inner periphery of the first metal sheet 11 forming the hollow region 12 are rounded, and the four corners of the outer periphery of the second metal sheet 16 are rounded.

[0057] That is, the outer perimeter corners of the first, third, and fifth metal layers are rounded at 19mm, and the inner perimeter corners of the second and fourth metal layers are rounded at 15mm. The chamfer radius can be 0.1mm.

[0058] This embodiment introduces a rounded corner design at the edges and corners of the metal patch. This design smooths the electric field distribution, reduces charge concentration and tip discharge effects, thereby significantly reducing ohmic losses caused by strong electric field regions, resulting in a significant decrease in the overall operating temperature of the structure and improving the reliability of active devices.

[0059] Furthermore, the first, third, and fifth metal layers are centrally symmetric and axially symmetric, while the second and fourth metal layers are axially symmetric.

[0060] The metal layer pattern exhibits centrosymmetry and rotational symmetry in orthogonal directions, resulting in excellent polarization stability. When electromagnetic waves are incident perpendicularly, the resonant frequencies of both transverse electric (TE) and transverse magnetic (TM) polarized waves are completely identical, and the filtering performance is unaffected by the polarization mode.

[0061] Regarding the materials used in the preparation, the first metal layer, the second metal layer 3, the third metal layer, the fourth metal layer 7, and the fifth metal layer in this embodiment are made of materials that have both high electrical conductivity and high thermal conductivity, including but not limited to one or more of copper, aluminum, and gold.

[0062] The first dielectric layer 2, the second dielectric layer 4, the third dielectric layer 6, and the fourth dielectric layer 8 are all made of a composite material with a low loss tangent to significantly reduce the dielectric loss of electromagnetic waves in the structure. Optionally, the above-mentioned dielectric layers are made of a composite material with a relative permittivity of 3.75 and a loss tangent of 0.0004, with a surface size of 6 mm * 6 mm and a thickness of 1 mm.

[0063] In this embodiment, the thickness of all metal layers is 0.017 mm. Within the range of 0.035mm. The active metasurface unit structure of this embodiment has a very small size, referencing... Figure 4 The surface dimensions of the square patch unit structure consisting of the first, third, and fifth metal layers can be 4.63 mm * 4.63 mm; (Reference) Figure 5 The surface dimensions of the second and fourth metal mesh layers are 6 mm*6 mm, and the width can be 0.4 mm, which meets the current trend of miniaturized device structures and processing technology requirements.

[0064] The active metasurface structure unit 21 features a compact size design in the planar direction, specifically with a surface dimension of 6*6 mm and a thickness of 1 mm. This size meets the requirements of electrical dimensions, frequency response, and layout adaptability for mainstream applications such as the X-band, while also aligning with the current trend of miniaturization and integration in electronic systems.

[0065] Please see also Figure 4-5 Table 1 contains the geometric parameters of the preferred metal layers provided in the embodiments.

[0066] Table 1. Preferred geometric parameters of the metal layer (unit: mm)

[0067] This embodiment proposes a multilayer active metasurface 20 designed based on the principle of isotropic geometric symmetry, which features high transmittance, wide transmission angle, and polarization stability. Under TE and TM polarized electromagnetic wave incident conditions, it can maintain a transmittance of over 80% in the 8–12 GHz frequency band. By integrating active devices, dynamic control of the electromagnetic response of the structural unit is achieved, ensuring efficient transmission of communication signals in the target frequency band while effectively suppressing interference from other frequency signals.

[0068] Furthermore, by optimizing the unit structure parameters and the electromagnetic coupling relationship between multiple layers, phase compensation and impedance matching under wide-angle incident conditions are achieved, enabling the structure to maintain stable transmittance, operating bandwidth and out-of-band suppression performance under large-angle oblique incident and dual polarization conditions, thereby significantly improving its application stability and reliability in complex electromagnetic environments.

[0069] This embodiment offers significant advantages in electromagnetic-thermal synergistic management, effectively suppressing the formation of local hot spots and significantly improving the overall temperature uniformity of the structure. Based on rounded corners at key locations and overall miniaturization, the electromagnetic losses of the structure are effectively reduced. The rounded corner design significantly reduces charge concentration and local electric field intensity at boundaries, smooths the current distribution path, and suppresses ohmic and dielectric losses caused by structural discontinuities and edge effects.

[0070] Meanwhile, miniaturization not only reduces the physical size of the structure but also shortens the transmission path of electromagnetic energy within it, further reducing transmission losses and heat dissipation. Lowering the operating temperature not only improves the reliability and lifespan of active devices but also maintains the long-term stability of the structure's electromagnetic performance, making it particularly suitable for integrated applications with high power density or stringent thermal management requirements.

[0071] Furthermore, in order to verify the electromagnetic and thermal properties of the active metasurface 20 in this embodiment, a number of performance analyses were performed on the structure.

[0072] refer to Figures 7 to 9 , Figure 7 This is a simulation diagram of the filtering performance of a multilayer active metasurface 20 based on a PIN diode 10 under diode conduction and cutoff states, provided by an embodiment of the present invention. Figure 8 This is a simulation diagram of the filtering performance of a multilayer active metasurface 20 based on a PIN diode 10 under different incident angles in TE polarization mode, provided by an embodiment of the present invention. Figure 9 This is a simulation diagram of the filtering performance of a multilayer active metasurface 20 based on a PIN diode 10 under different incident angles in TM polarization mode, provided by an embodiment of the present invention.

[0073] from Figure 7As can be seen from the scattering parameters, the resonant frequency of the active metasurface 20 in this embodiment shifts with the switching of the state of the PIN diode 10. In the off state, the resonant frequency of this structure is always within the 8-12 GHz band, exhibiting excellent transmission performance in the X-band and effectively resisting interference from out-of-band signals.

[0074] Furthermore, from Figure 8 and Figure 9 As can be seen from the insertion loss and return loss, the active metasurface structure in this embodiment maintains "reflection" under both TE and TM polarization. transmission It exhibits filtering characteristics of "reflection", maintains a stable resonant frequency, and has excellent polarization stability.

[0075] Furthermore, to investigate the angular stability of the active metasurface structure in this embodiment, its electromagnetic properties were obtained by irradiating it with incident waves at incident angles of 0°, 15°, 30°, 45°, and 60° under TE and TM polarization. This active metasurface structure exhibits good angular stability; under electromagnetic incident wave irradiation at different angles, the frequency deviation remains within an acceptable range, and it maintains high transmittance in the X-band, demonstrating excellent signal transmission and anti-interference capabilities.

[0076] refer to Figures 10 to 13 , Figure 10 This is a response curve of the maximum temperature of a multilayer active metasurface 20 based on a PIN diode 10 as a function of incident frequency in both diode conduction and cutoff states, provided by an embodiment of the present invention. Figure 11 This is a response curve of the maximum temperature of a multilayer active metasurface 20 based on a PIN diode 10 under different incident angles in TE polarization mode as a function of incident frequency, provided by an embodiment of the present invention. Figure 12 This is a response curve of the maximum temperature of a multilayer active metasurface 20 based on a PIN diode 10 under different incident angles in TM polarization mode as a function of incident frequency, provided by an embodiment of the present invention. Figure 13 This is a response curve of the maximum temperature over time of a multilayer active metasurface 20 based on a PIN diode 10 under high-power resonant frequency incident light, provided by an embodiment of the present invention. The active metasurface 20 in this embodiment exhibits drastically different temperature change trends in the on and off states. This difference stems from the fact that the switching action of the PIN diode 10 alters the resonant characteristics of the entire active metasurface structure, leading to significant changes in its scattering parameters and absorption characteristics.

[0077] Furthermore, from Figure 11 and Figure 12As can be seen, significant and stable temperature rise peaks are formed at 8 GHz and 12 GHz within the 6–16 GHz frequency band. Simultaneously, the temperature response curves are highly consistent across the 0° to 60° incident angle range, exhibiting excellent angle insensitivity and thermal stability. Temperature rise is effectively suppressed in non-target frequency bands (such as 10–11 GHz and 14–16 GHz), achieving selective energy absorption. The overall structure is compact and has high thermal conversion efficiency, making it suitable for electromagnetic wave thermal control applications in various scenarios. This invention solves the technical bottlenecks of traditional electromagnetic thermal structures, such as inconsistent thermal response and low energy efficiency under multi-angle incident conditions, and possesses significant engineering practical value and innovation.

[0078] In addition, from Figure 13 It can be seen that when subjected to continuous high-power electromagnetic wave excitation, its temperature response exhibits stable linear growth without saturation or oscillation, demonstrating excellent thermal stability and structural integrity. This structure can effectively suppress the formation of local hot spots, solving the technical problems of traditional active metasurface structures being prone to thermal failure and difficult thermal management under high-power applications. It significantly improves the power tolerance and long-term operational reliability of the structure, making it suitable for high-energy-density applications such as high-power microwave systems and high-power radar antennas.

[0079] from Figure 14 As can be seen, when the incident power density is 500 kW / m² and the vertical irradiation time is 30 s, the highest temperature of the conventional structure reaches 208 ℃ and the lowest temperature is 196 ℃, exhibiting a significant temperature gradient and generating local hot spots. However, at a similar resonant frequency (approximately 11.7 GHz), the highest temperature of the optimized structure is only 113 ℃, and the overall temperature distribution is more uniform. At other resonant frequencies (such as 8.2 GHz and 10.2 GHz), the Type 2 structure also exhibits lower temperature rise and more uniform temperature distribution. These results demonstrate that by introducing rounded corners and miniaturization into the structure, the electric field concentration effect can be effectively reduced, electromagnetic losses can be decreased, and heat dissipation uniformity can be improved, thereby significantly improving the thermal stability and reliability of the structure under high-power operating conditions while ensuring electromagnetic performance.

[0080] Example 2 The optimization method for active metasurfaces that balance electromagnetic performance and thermal management, as described in Example 1, includes the following steps: Based on the equivalent circuit model, an initial active metasurface was constructed, and electromagnetic-thermal multiphysics coupling analysis was carried out. Targeted optimizations were made for the two main heat sources: metal loss and dielectric loss. By introducing temperature field and electromagnetic performance parameters, an electromagnetic-thermal multi-objective optimization model is constructed. Under the constraint of electromagnetic performance index, the structural parameters of active metasurface 20 are globally optimized by simulation-driven topology iterative optimization method to obtain the optimized set of structural physical parameters.

[0081] Specifically: This embodiment proposes a multilayer active metasurface electromagnetic-thermal synergistic optimization method with electromagnetic properties as constraints and temperature field and temperature rise control as optimization objectives: First, an initial active metasurface structure (lacking the technical features of rounded corners and miniaturization) that satisfies the target electromagnetic wave transmission performance is constructed based on an equivalent circuit model. Then, electromagnetic-thermal multiphysics coupling analysis is carried out, and targeted optimizations are performed for the two main heat sources: metal loss and dielectric loss. Selecting dielectric materials with small loss tangent can effectively reduce the proportion of dielectric loss in total electromagnetic loss, improve energy transmission efficiency, and enhance device thermal stability. By rounding the corners of key metal structures, the local electric field concentration effect and peak electric field intensity are reduced, thereby reducing current skin loss and the resulting electromagnetic heat source. Meanwhile, by introducing geometric control methods such as slotting and bending into the structure to increase the equivalent capacitance and inductance, the structure is miniaturized and its sensitivity to changes in the angle of incident electromagnetic waves is reduced. Further, temperature field and electromagnetic performance parameters are introduced to construct an electromagnetic-thermal multi-objective optimization model. Under the constraints of electromagnetic performance indicators such as transmittance, bandwidth and out-of-band suppression, the structural parameters are globally optimized by simulation-driven topology iterative optimization method. Finally, a set of structural physical parameters that take into account electromagnetic transmittance, low electromagnetic loss and low temperature rise characteristics are obtained, thereby realizing the design of a multilayer active metasurface with low loss, high thermal stability and high reliability.

[0082] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0083] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An active metasurface that balances electromagnetic properties and thermal management, characterized in that, The device includes at least one active metasurface structure unit, which comprises, from top to bottom along the thickness direction, a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer, a fourth metal layer, a fourth dielectric layer, and a fifth metal layer; wherein, the second metal layer and the fourth metal layer have the same structure, both including a first metal sheet, a hollow region is provided in the center of the first metal sheet, and a first T-shaped groove is formed around the first metal sheet, the horizontal arm of the first T-shaped groove is connected to the hollow region through a first through hole; the four corners of the inner periphery of the first metal sheet forming the hollow region are rounded.

2. The active metasurface that balances electromagnetic performance and thermal management as described in claim 1, characterized in that, Each of the first T-slots is located at the center of the corresponding side of the first metal sheet, and a PIN diode is embedded between the vertical arms of each of the first T-slots.

3. The active metasurface that balances electromagnetic performance and thermal management as described in claim 1, characterized in that, The size of the first through hole is smaller than the length of the first T-slot cross arm.

4. The active metasurface that balances electromagnetic performance and thermal management as described in claim 1, characterized in that, A slender rectangular connecting strip is formed between the cross arm of the first T-slot and the hollow area of ​​the first metal sheet.

5. The active metasurface that balances electromagnetic performance and thermal management as described in claim 1, characterized in that, The first metal layer, the third metal layer, and the fifth metal layer have the same structure, each including a second metal sheet; a second through hole is provided at the center of each side of the second metal sheet, and the end of the second through hole is connected to a second T-shaped groove.

6. The active metasurface that balances electromagnetic performance and thermal management as described in claim 5, characterized in that, The second through hole connects to the horizontal arm of the second T-slot, and the vertical arm of the second T-slot extends toward the center of the second metal sheet.

7. The active metasurface that balances electromagnetic performance and thermal management as described in claim 5, characterized in that, The four corners of the outer periphery of the second metal sheet are all rounded.

8. The active metasurface that balances electromagnetic performance and thermal management as described in claim 5, characterized in that, The first, third, and fifth metal layers are centrally symmetric and axially symmetric, while the second and fourth metal layers are axially symmetric.

9. The active metasurface that balances electromagnetic performance and thermal management as described in claim 2, characterized in that, When forward biased, a PIN diode is equivalent to a series connection of a resistor and a parasitic inductance; when reverse biased, it is equivalent to a series connection of a capacitor and a parasitic inductance.

10. An optimization method for an active metasurface that balances electromagnetic performance and thermal management, based on any one of claims 1-9, characterized in that, Includes the following steps: Based on the equivalent circuit model, an initial active metasurface structure was constructed, and electromagnetic-thermal multiphysics coupling analysis was carried out. Targeted optimizations were made for the two main heat sources: metal loss and dielectric loss. By introducing temperature field and electromagnetic performance parameters, an electromagnetic-thermal multi-objective optimization model is constructed. Under the constraint of electromagnetic performance index, the structural parameters of the active metasurface structure are globally optimized by simulation-driven topology iterative optimization method, and the optimized set of structural physical parameters is obtained.

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