Metasurface unit for conformal design
By setting perforations and metal patches on the metal layer, the distribution of the dielectric layer is optimized, which solves the contradiction between conformal capability and electromagnetic performance of metasurface units, and realizes compact conformal design and real-time electromagnetic control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIDIAN UNIV
- Filing Date
- 2025-07-21
- Publication Date
- 2026-05-19
AI Technical Summary
Existing metasurface units present a contradiction between conformal capability and electromagnetic performance, making it difficult to achieve real-time control and efficient electromagnetic wave control.
A metasurface unit structure is designed by setting perforations in a metal layer and placing metal patches in the perforation areas, combined with active control elements, to optimize the area distribution of the dielectric layer, reduce the footprint of the metal pattern layer, enhance conformal capability, and maintain good electromagnetic performance.
A compact design of metasurface units was achieved, enhancing conformal capability and enabling real-time control of electromagnetic performance while maintaining good electromagnetic modulation effect.
Smart Images
Figure CN224264271U_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of artificial electromagnetic materials and communication technology, and specifically relates to a metasurface unit for conformal design. Background Technology
[0002] With the advancement of technology, people's requirements for electronic devices and systems are constantly increasing. Traditional electromagnetic devices with regular shapes cannot meet people's needs in special scenarios. Compared with traditional planar metasurfaces, conformal metasurface units can conform to complex curved surfaces, offering significant advantages in terms of space optimization, portability, and reliability. In wearable devices, conformal metasurfaces can better conform to the curves of the human body, enabling more comfortable and efficient functional integration. Conformal coded metasurfaces provide the possibility of achieving high-performance electromagnetic control on carriers with complex shapes.
[0003] There are two existing technical solutions for conformal metasurface design. One involves combining metal and dielectric materials, using microfabrication techniques such as photolithography and electron beam etching to create metal structures with specific patterns on a flexible dielectric substrate. When electromagnetic waves are incident, the metal structure interacts with the electromagnetic waves, achieving conformal performance while simultaneously controlling the electromagnetic waves. The other approach uses a mechanically reconfigurable structure, designing conformal metasurface unit structures with movable parts. By changing the geometry or relative position of the unit structure through mechanical devices, the metal patches within the metasurface unit can rotate or translate, achieving conformal performance while simultaneously controlling the electromagnetic waves. In other words, in the design of metasurface units in related technologies, metasurface units with active devices often struggle to exhibit conformal capabilities, and even those with conformal capabilities often lack real-time control. A key reason for this is the inherent contradiction between the electromagnetic performance and conformal capabilities of metasurface units.
[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this utility model, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content
[0005] To address the aforementioned problems in the prior art, this invention provides a metasurface unit for conformal design. The technical problem to be solved by this invention is achieved through the following technical solution:
[0006] In a first aspect, this utility model provides a metasurface unit for conformal design, comprising a bottom layer, a first dielectric layer, and a metal pattern layer stacked sequentially;
[0007] The metal pattern layer includes a first metal layer, and the first metal layer has a first rectangular hollow hole and a second rectangular hollow hole; a first metal patch is disposed in the middle of the first rectangular hollow hole, and a second metal patch is disposed in the middle of the second rectangular hollow hole, so that a hollow hole in the shape of a Chinese character 'hui' is formed around both the first metal patch and the second metal patch;
[0008] The metal pattern layer further includes a first active control element and a second active control element;
[0009] One end of the first active control element is electrically connected to the first metal layer, the other end of the first active control element is electrically connected to the first metal patch, and the first metal patch has a first conductive through hole, and the first conductive through hole is used to be electrically connected to a control circuit through a bottom layer;
[0010] One end of the second active control element is electrically connected to the first metal layer, the other end of the second active control element is electrically connected to the second metal patch, and the second metal patch has a second conductive through hole, and the second conductive through hole is used to be electrically connected to the control circuit through the bottom layer;
[0011] The first metal layer further has a third conductive through hole, and the third conductive through hole is used to be electrically connected to the bottom layer.
[0012] In an embodiment of the present invention, the bottom layer includes a second metal layer, a second dielectric layer and a third metal layer which are sequentially stacked;
[0013] The third metal layer is located on a side of the second metal layer away from the metal pattern layer;
[0014] The second metal layer is a grounding layer, and the third conductive through hole is electrically connected to the second metal layer;
[0015] Both the first conductive through hole and the second conductive through hole are electrically connected to the third metal layer.
[0016] In an embodiment of the present invention, the bottom layer further includes a bias line, and the bias line is used to be electrically connected to a control circuit;
[0017] The third metal layer is a fan-shaped metal layer, and the fan-shaped metal layer and the second metal layer form a capacitor; the bias line is electrically connected to the fan-shaped metal layer.
[0018] In an embodiment of the present invention, the first dielectric layer includes a first composite material layer on a side close to the metal pattern layer and a prepreg layer on a side away from the metal pattern layer; the second dielectric layer is a second composite material layer; and the materials of both the first composite material layer and the second composite material layer are glass fiber reinforced polytetrafluoroethylene;
[0019] The thickness of the first composite material layer is 2 to 4 mm, and the thickness of the second composite material layer is 0.1 to 0.2 mm.
[0020] In one embodiment of this utility model, the first metal layer, the second metal layer and the third metal layer are all made of copper.
[0021] In one embodiment of this utility model, both the first active control element and the second active control element are PIN diodes.
[0022] In one embodiment of this utility model, the ratio of the surface area of the metal pattern layer to the surface area of the first dielectric layer is 1:(1.2~1.6); the ratio of the surface area of the first dielectric layer to the surface area of the bottom layer is 1:(2~2.5).
[0023] In one embodiment of this utility model, the area ratio of the first rectangular hollow hole to the area of the first metal patch is (3-5):1; the area ratio of the second rectangular hollow hole to the area of the second metal patch is (3-5):1.
[0024] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0025] The metasurface unit provided by this invention features perforations in the first metal layer and metal patches in the perforation areas. This moves the connection between the active control element and the first metal layer and the metal patches from the outer region of the first metal layer to the middle region, improving the compactness of the two active control element structures and significantly reducing the overall area occupied by the metal pattern layer. The reduced area occupied by the metal pattern layer on the first dielectric layer provides a foundation for designing a first dielectric layer with a smaller surface area. By analyzing the mechanism of the metasurface unit's interaction with electromagnetic waves during operation, and identifying the dielectric regions with minimal impact on the unit's electromagnetic properties, the surface area of the first dielectric layer is reduced, enhancing the conformal capability of the metasurface unit while maintaining good electromagnetic performance.
[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0027] Figure 1 A schematic diagram of a metasurface unit in related technologies;
[0028] Figure 2 This is a schematic diagram of the conformal state three-dimensional structure of the metasurface unit in one embodiment of the present utility model;
[0029] Figure 3This is a schematic diagram of the unfolded structure of the metasurface unit in one embodiment of the present invention;
[0030] Figure 4 This is a three-dimensional structural schematic diagram of a metasurface unit in one embodiment of the present invention;
[0031] Figure 5 yes Figure 4 Enlarged view of region B in the middle;
[0032] Figure 6 This is a simulation characterization diagram of a metasurface unit in one embodiment of this utility model;
[0033] Figure 7 This is a schematic diagram showing the comparison before and after cutting of the first dielectric layer of the metasurface unit in one embodiment of this utility model;
[0034] Figure 8 This is a graph representing the change of electromagnetic wave amplitude of a metasurface unit with frequency in one embodiment of the present invention.
[0035] Figure 9 This is a characterization curve of the electromagnetic wave reflection phase change of the metasurface unit in one embodiment of the present invention.
[0036] Explanation of reference numerals in the attached figures:
[0037] 01-Ground layer; 02-Dielectric layer; 03-Upper metal layer; 031-Diode; 032-Metal sheet; 033-Conductive via;
[0038] 1-Bottom layer; 11-Second metal layer; 12-Second dielectric layer; 13-Third metal layer; 14-Offset line; 2-First dielectric layer; 21-First composite material layer; 22-Prepreg material layer; 3-Metal pattern layer; 30-First metal layer; 31-First rectangular cutout hole; 32-First metal patch; 33-First conductive via; 34-First active control element; 35-Second rectangular cutout hole; 36-Second metal patch; 37-Second conductive via; 38-Second active control element; 39-Third conductive via. Detailed Implementation
[0039] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the following detailed description of a metasurface unit for conformal design based on this utility model is provided in conjunction with the accompanying drawings and specific embodiments.
[0040] The foregoing and other technical contents, features, and effects of this utility model will be clearly presented in the following detailed description of the specific embodiments with reference to the accompanying drawings. Through the description of the specific embodiments, a more in-depth and specific understanding can be gained of the technical means and effects adopted by this utility model to achieve the intended purpose. However, the accompanying drawings are only provided for reference and illustration and are not intended to limit the technical solution of this utility model.
[0041] In the description of this utility model, it should be understood that the terms "thickness", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise expressly specified. Moreover, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed.
[0043] In related technologies, such as Figure 1 As shown, the metasurface unit includes an upper metal layer 03, a dielectric layer 02, and a ground layer 01. The upper metal layer 03 includes a copper layer and a metal sheet 032 located on the side of the copper layer but not directly connected to it. A diode 031 is electrically connected to both the metal sheet 032 and the copper layer. The metal sheet 032 has a conductive via 033. Because the diode 031 and the metal sheet 032 are located outside the copper layer, the upper metal layer 03 occupies a large area, thus requiring a large dielectric layer to support it. Generally, the dielectric layer 02 is relatively thick, which limits the flexibility and conformality of the metasurface unit.
[0044] To address the aforementioned problems, this utility model provides a metasurface unit for conformal design, such as... Figure 2 and Figure 3As shown in the figure, the metasurface unit includes a bottom layer 1, a first dielectric layer 2, and a metal pattern layer 3 that are sequentially stacked. The metal pattern layer 3 includes a first metal layer 30, and the first metal layer 30 has a first rectangular hollow hole 31 and a second rectangular hollow hole 35; a first metal patch 32 is provided in the middle of the first rectangular hollow hole 31, and a second metal patch 36 is provided in the middle of the second rectangular hollow hole 35, so that "hui"-shaped hollow holes are formed around both the first metal patch 32 and the second metal patch 36. The metal pattern layer 3 further includes a first active control element 34 and a second active control element 38. One end of the first active control element 34 is electrically connected to the first metal layer 30, the other end of the first active control element 34 is electrically connected to the first metal patch 32, and the first metal patch 32 has a first conductive via 33, and the first conductive via 33 is used to be electrically connected to the control circuit through the bottom layer 1. One end of the second active control element 38 is electrically connected to the first metal layer 30, the other end of the second active control element 38 is electrically connected to the second metal patch 36, and the second metal patch 36 has a second conductive via 37, and the second conductive via 37 is used to be electrically connected to the control circuit through the bottom layer 1. The first metal layer 30 further has a third conductive via 39, and the third conductive via 39 is used to be electrically connected to the bottom layer 1.
[0045] In this embodiment, by providing hollow holes on the first metal layer 30 and arranging metal patches in the hollow hole areas, the connection of the active control elements to the first metal layer 30 and the metal patches is moved from the peripheral area of the first metal layer 30 to the middle area of the first metal layer 30, improving the compactness of the structures of the two active control elements and greatly reducing the overall area occupation of the metal pattern layer 3. Thus, the occupied area of the metal pattern layer 3 on the first dielectric layer 2 is reduced, providing a basic condition for designing a first dielectric layer 2 with a smaller surface area. By analyzing the mechanism of the interaction between the metasurface unit and electromagnetic waves during operation, the dielectric areas with less influence on the electromagnetic characteristics of the unit are analyzed and identified, so that the surface area of the first dielectric layer 2 is reduced, enhancing the conformal ability of the metasurface unit, and at the same time the metasurface unit still has good electromagnetic performance.
[0046] Exemplarily, both the first active control element 34 and the second active control element 38 are PIN diodes.
[0047] In an embodiment provided by the present utility model, the bottom layer 1 includes a second metal layer 11, a second dielectric layer 12, and a third metal layer 13 that are sequentially stacked. The third metal layer 13 is located on the side of the second metal layer 11 away from the metal pattern layer 3; the second metal layer 11 is a grounding layer, and the third conductive via 39 is electrically connected to the second metal layer 11; both the first conductive via 33 and the second conductive via 37 are electrically connected to the third metal layer 13.
[0048] Exemplarily, the materials of the first metal layer 30, the second metal layer 11, and the third metal layer 13 are all copper.
[0049] In one embodiment of this invention, the bottom layer 1 further includes a bias line 14 for electrical connection to the control circuit. The third metal layer 13 is a fan-shaped metal layer, which forms a capacitor with the second metal layer 11; the bias line 14 is electrically connected to the fan-shaped metal layer. That is, one end of the first active control element 34 (diode) is electrically connected to the ground layer through the third conductive via 39; the other end of the first active control element 34 (diode) is electrically connected to the third metal layer 13 through the first conductive via 33, and then connected to the control circuit through the bias line 14 to achieve real-time control of the first active control element 34. One end of the second active control element 38 (diode) is electrically connected to the ground layer through the third conductive via 39; the other end of the second active control element 38 (diode) is electrically connected to the third metal layer 13 through the second conductive via 37, and then connected to the control circuit through the bias line 14 to achieve real-time control of the second active control element 38. Thus, the metasurface unit in this embodiment has high conformal capability and can be controlled in real time.
[0050] In one example, the first dielectric layer 2 includes a first composite material layer 21 near the metal pattern layer 3 and a prepreg material layer 22 away from the metal pattern layer 3. The second dielectric layer 12 is a second composite material layer; both the first composite material layer 21 and the second composite material layer are made of glass fiber reinforced polytetrafluoroethylene. The thickness of the first composite material layer 21 is 2-4 mm, and the thickness of the second composite material layer is 0.1-0.2 mm. That is, the thickness of the first composite material layer 21 in the first dielectric layer 2 is relatively large. If the area of the first dielectric layer 2 is large, then the metasurface unit will not easily conform to the curved surface, or the accuracy of electromagnetic control will be reduced after conforming to the curved surface. The metasurface unit in this embodiment of the present invention reduces the surface area of the metal pattern layer 3 through structural design. According to electric field simulation, the area with greater electromagnetic influence is concentrated in the edge region of the metal pattern. Thus, when designing the metasurface unit, the area with less electromagnetic influence can be cut off, reducing the overall footprint of the first dielectric layer 2 and improving the conformal capability of the metasurface unit.
[0051] For example, the prepreg layer 22 may include a resin matrix and a reinforcing material. The resin matrix may be epoxy resin (such as FR-4), polytetrafluoroethylene (PTFE), or modified cyanate, etc., and the reinforcing material may be fiberglass cloth or nonwoven fabric. The prepreg layer 22 mainly serves to provide insulation, adhesion, and control electromagnetic properties.
[0052] In one embodiment of this utility model, the surface area ratio of the metal pattern layer 3 to the surface area of the first dielectric layer 2 is 1:(1.2~1.6); the surface area ratio of the first dielectric layer 2 to the surface area of the bottom layer 1 is 1:(2~2.5). Figure 4 As shown, the surface area of the metal pattern layer 3 is mx * my The surface area of the first dielectric layer 2 is ls * ls In this example, the upper surface of the first dielectric layer 2 is square. It can be understood that the first dielectric layer 2 can be rectangular or other shapes. The surface area of the bottom layer 1 is... a * a .
[0053] In one embodiment of this utility model, the area of the first rectangular perforated hole 31 and the area of the first metal patch 32 are in a ratio of (3-5):1; the area of the second rectangular perforated hole 35 and the area of the second metal patch 36 are in a ratio of (3-5):1. For example, such as Figure 5 As shown, Figure 4 A partially enlarged schematic diagram of the second rectangular perforated hole 35 in region B. The area of the second rectangular perforated hole 35 is... cw * cl The area of the second metal patch 36 is tl * tw .
[0054] The following section provides further explanation using specific metasurface unit structures.
[0055] like Figure 4 and Figure 5 As shown, the dimensions of the metasurface unit structure are: a = 30mm, d = 3mm, mx = 15.92mm, my =17mm, ls = 20mm, dp = 0.2mm, p 1 = 2.9mm p 2 = 2.1mm, cw = 2mm, cl = 2.95mm, tl = 1.45mm, tw =1mm, rk = 0.5mm. d The thickness of the first composite material layer 21 dp The thickness of the prepreg layer 22 p 1 represents the distance from the first active control element 34 to the third conductive via 39.p 2 represents the distance from the second active control element 38 to the third conductive via 39. rk The radius of the second conductive via 37 is given. The first composite material layer 21 (glass fiber reinforced polytetrafluoroethylene layer, F4B layer) has a thickness of 3 mm and a dielectric constant of 3.5; the prepreg material layer 22 has a thickness of 0.2 mm and a dielectric constant of 2.55. The second composite material layer (glass fiber reinforced polytetrafluoroethylene layer, F4B layer) has a thickness of 0.127 mm; the third metal layer 13 is a fan-shaped metal sheet with a radius rc = 9.7 mm.
[0056] In this embodiment, the PIN diode used in the metasurface unit is model SMP1345-079LF, which has a small turn-off capacitance, ensuring excellent conduction and turn-off characteristics. When the PIN diode is in the conducting state, its circuit characteristics can be equivalent to a resistor and an inductor in series; where the resistance value is Ron = 3Ω and the inductance value is Lon = 0.7nH. When the PIN diode is in the turn-off state, its circuit characteristics can be roughly equivalent to a resistor and a capacitor in series; the turn-off resistance is Roff = 10Ω and the turn-off capacitance is Coff = 0.165pF. To minimize design complexity, the capacitor used in this embodiment has a 0201-inch package specification (the first two digits "02" indicate the length (0.02 inches) and the last two digits "01" indicate the width (0.01 inches)).
[0057] 1. Electric field simulation and detection of metasurface units
[0058] The metasurface elements were simulated using the commercial software CST, and the results are as follows: Figure 6 As shown, the electric field is mainly distributed in the edge region of the metal pattern in metal pattern layer 3, while the electric field distribution is smaller outside the metal pattern. This indicates that the area outside the metal pattern has little impact on the electromagnetic properties of the metasurface unit. Therefore, in subsequent simulations of the metasurface unit, the first dielectric layer 2 outside the metal pattern was removed. Figure 7 As shown ( Figure 7 (The schematic diagram on the left side of the middle section does not show the diodes, metal patches, and other structures on the metal pattern layer 3.) During the fabrication of the metasurface unit, unnecessary first dielectric layer 2 is removed using laser cutting, retaining only the flexible bottom layer 1 and the area of first dielectric layer 2 required for microwave resonance. Reducing the area of first dielectric layer 2 leaves almost no impact on the microwave performance of the metasurface unit. Ultimately, the area of the retained first dielectric layer 2 is only 4 / 9 of the original area. This compact structural design provides excellent conditions for the conformal design of the metasurface unit.
[0059] 2. Electromagnetic wave response detection of metasurface units
[0060] like Figure 4 and Figure 5 As shown, by adjusting the length and width of the metal patch and the positions of the two PIN diodes, the dimensions of the metasurface unit structure are determined, ultimately achieving a precise 90° phase difference across the four operating states of the two diodes ("00", "01", "10", "11", where "0" represents off and "1" represents on). The final metasurface unit is simulated using CST. Figure 8 and Figure 9 The diagram illustrates the amplitude versus frequency curves and the reflection phase curves under four operating conditions. From... Figure 8 It can be seen that the reflection amplitude remains stable over a wide frequency range and is close to 0dB under the four operating conditions, indicating that the amplitude of the reflected wave is basically the same as that of the incident wave. In other words, when using this set of frequency metasurface elements to design a coded metasurface, the error caused by the amplitude of the metasurface elements can be ignored. Figure 9 As can be seen, under the four operating conditions, the metasurface units used for conformal design exhibit a precise phase spacing of 90° at the 5GHz frequency.
[0061] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.
Claims
1. A metasurface unit for conformal design, characterized in that, It includes a bottom layer, a first dielectric layer, and a metal pattern layer that are stacked in sequence; The metal pattern layer includes a first metal layer, and the first metal layer has a first rectangular through-hole and a second rectangular through-hole; a first metal patch is provided in the middle of the first rectangular through-hole, and a second metal patch is provided in the middle of the second rectangular through-hole, so that a "hui"-shaped through-hole is formed around both the first metal patch and the second metal patch; The metal pattern layer further includes a first active control element and a second active control element; One end of the first active control element is electrically connected to the first metal layer, the other end of the first active control element is electrically connected to the first metal patch, and the first metal patch has a first conductive via, and the first conductive via is used to be electrically connected to the control circuit through the bottom layer; One end of the second active control element is electrically connected to the first metal layer, the other end of the second active control element is electrically connected to the second metal patch, and the second metal patch has a second conductive via, and the second conductive via is used to be electrically connected to the control circuit through the bottom layer; The first metal layer further has a third conductive via, and the third conductive via is used to be electrically connected to the bottom layer.
2. The metasurface unit for conformal design of claim 1, wherein, The bottom layer includes a second metal layer, a second dielectric layer, and a third metal layer that are stacked in sequence; The third metal layer is located on the side of the second metal layer away from the metal pattern layer; The second metal layer is a grounding layer, and the third conductive via is electrically connected to the second metal layer; Both the first conductive via and the second conductive via are electrically connected to the third metal layer.
3. The metasurface unit for conformal design of claim 2, wherein, The bottom layer further includes a bias line, and the bias line is used to be electrically connected to the control circuit; The third metal layer is a fan-shaped metal layer, and the fan-shaped metal layer and the second metal layer form a capacitor; the bias line is electrically connected to the fan-shaped metal layer.
4. The metasurface unit for conformal design of claim 3, wherein, The first dielectric layer includes a first composite material layer on the side close to the metal pattern layer and a prepreg layer on the side away from the metal pattern layer; the second dielectric layer is a second composite material layer; the materials of both the first composite material layer and the second composite material layer are glass fiber reinforced polytetrafluoroethylene; The thickness of the first composite material layer is 2 - 4 mm, and the thickness of the second composite material layer is 0.1 - 0.2 mm.
5. The metasurface unit for conformal design of claim 4, wherein, The materials of the first metal layer, the second metal layer, and the third metal layer are all copper.
6. The metasurface cell for conformal design of claim 1, wherein, Both the first active control element and the second active control element are PIN diodes.
7. The metasurface cell for a conformal design of any of claims 1-6, wherein, The ratio of the surface area of the metal pattern layer to the surface area of the first dielectric layer is 1:(1.2 - 1.6); the ratio of the surface area of the first dielectric layer to the surface area of the bottom layer is 1:(2 - 2.5).
8. The metasurface unit for conformal design of claim 7, wherein, The ratio of the area of the first rectangular through-hole to the area of the first metal patch is (3 - 5):1; the ratio of the area of the second rectangular through-hole to the area of the second metal patch is (3 - 5):1.