A broadband on-off adjustable low-scattering metamaterial antenna cover
Patent Information
- Application Number
- CN202521614824.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-07-31
AI Technical Summary
[0004]本发明实施例提出一种宽频段通断可调的低散射天线罩，解决了如何使天线罩在至少一个开关控制元件“开”状态下实现低频宽频范围通带，以及在至少一个开关控制元件“关”状态下实现强截止，通带内透波率高的技术问题
本发明所述宽频段通断可调的低散射超材料天线罩，可以实现L波段宽频透波/截止通断控制。通过合理设计有源层和无源层，可以在开关二极管“开”状态时(即导通状态)实现低频宽频范围通带(即实现0.89~1.38GHz宽频范围通带)；在开关二极管“关”状态时实现0~18GHz频段的强截止，降低天线带内及带外雷达散射截面，可应用于兼具有隐身功能和辐射功能的雷达罩、电子战天线罩。且透波/反射状态的隔离度高；通带内透波率高。
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Figure CN224862470U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metamaterials, and more specifically, to a low-scattering metamaterial radome with adjustable on / off bandwidth. Background Technology
[0002] Traditional passive frequency selective surfaces (FSTs) cannot alter their frequency response once fabricated, thus presenting certain limitations. For example, while FSTs effectively achieve out-of-band stealth, incoming waves within the radome can enter the radome, causing strong scattering of the antenna and limiting its stealth capabilities. Active frequency selective surfaces (AMSs), on the other hand, offer a solution to this problem, enabling the switching of frequency conversion, frequency stabilization, wave transmission, and reflection using metamaterials. This provides a method for achieving in-band stealth of radomes and is also a promising approach to realizing intelligent aircraft.
[0003] Besides the tunable effect of resonance, active metamaterials can also achieve miniaturization of microstructures. By changing the capacitance and inductance between or within microstructures, the resonant frequency of traditional passive devices can be reduced, thus achieving miniaturization. This is significant for stabilizing the incident angle, reducing gate lobes, and minimizing edge scattering of metamaterials. F. Bayatpur et al. designed a novel miniaturized controllable metamaterial with X-band resonance, with a unit size 1 / 12 of the wavelength, six times smaller than traditional microstructure units. Subsequently, they used through-holes to connect two strip microstructures, designing a 2.5D bandpass active metamaterial switch in an air-based environment. This structure achieved switching at an 8 GHz resonant frequency with a unit period of only 4.8 mm. The upper and lower metal strips of this structure are both part of the microstructure and act as feeders for diodes, effectively reducing structural complexity and avoiding the influence of the feed network on the structure's electrical performance. However, due to the high resonant frequency of these structures, achieving S-band switching requires a larger period or a larger voltage. A. Ebrahimi et al. designed a multi-layered active frequency selective surface (PFS) with a passband that can shift between 4 and 5 GHz, but it has poor transmission. SC Bakshi et al. designed a two-layered PF with loaded diodes and resistors, achieving switching between transmission cutoff states in the S-band and exhibiting high isolation, but it also has poor transmission and a large period. Therefore, there is significant design potential for structures that are low-frequency adjustable and switchable, small in size, have high isolation, and good transmission. Summary of the Invention
[0004] This invention proposes a wideband on / off adjustable low-scattering radome, which solves the technical problem of how to achieve a low-frequency wideband passband when at least one switch control element is "on", and how to achieve strong cutoff and high transmittance within the passband when at least one switch control element is "off".
[0005] This invention provides a wideband on / off adjustable low-scattering metamaterial radome, characterized in that the radome is stacked in the following order from the outside to the inside: a first frequency selective surface layer, a first substrate layer, a second frequency selective surface layer, a core material layer, a third frequency selective surface layer, a second substrate layer, and a fourth frequency selective surface layer. The first, second, third, and fourth frequency selective surface layers each include a substrate and conductive microstructures disposed on the substrate. The conductive microstructure of the first frequency selective surface layer is provided with at least one switching control element. When the at least one switching control element is turned on, electromagnetic waves of a predetermined low frequency band in the preset frequency band penetrate the radome. When the at least one switching control element is turned off, the radome blocks the electromagnetic waves of the preset frequency band.
[0006] The beneficial effects of this invention are as follows: The wideband adjustable low-scattering metamaterial radome of this invention can achieve wideband L-band transmission / cutoff control. Through the rational design of the active and passive layers, a low-frequency wideband passband (i.e., a wideband passband of 0.89~1.38GHz) can be achieved when the switching diode is in the "on" state (i.e., the conducting state); and a strong cutoff of the 0~18GHz frequency band can be achieved when the switching diode is in the "off" state, reducing the radar cross-section both inside and outside the antenna band. It can be applied to radomes and electronic warfare radomes that combine stealth and radiation functions. Furthermore, it exhibits high isolation between transmission and reflection states and high transmittance within the passband. Attached Figure Description
[0007] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0008] Figure 1 This is a schematic diagram of the structure of a wideband on / off adjustable low-scattering metamaterial radome according to an embodiment of the present invention.
[0009] Figure 2 yes Figure 1 The diagram shows the specific structure of the first frequency-selective surface layer and the second frequency-selective surface layer.
[0010] Figure 3 yes Figure 1 The diagram shows the specific structures of the third and fourth frequency-selective surface layers.
[0011] Figure 4 yesFigure 1 The diagram shows the transmittance curves of the radome in the on and off states of the switching diode. Detailed Implementation
[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.
[0013] Figure 1 The illustration shows a wideband on / off adjustable low-scattering metamaterial radome 100 according to an embodiment of the present invention. The radome 100 is stacked in the following order from the outside to the inside: a first frequency selective surface layer 10, a first substrate layer 20, a second frequency selective surface layer 30, a core layer 40, a third frequency selective surface layer 50, a second substrate layer 60, and a fourth frequency selective surface layer 80.
[0014] The first frequency selective surface layer 10, the second frequency selective surface layer 30, the third frequency selective surface layer 50, and the fourth frequency selective surface layer 80 all include a substrate and conductive microstructures disposed on the substrate. At least one switching diode is disposed in the conductive microstructure of the first frequency selective surface layer 10. When the at least one switching diode is turned on, electromagnetic waves of a predetermined low frequency band in the preset frequency band penetrate the radome 100. When the at least one switching diode is turned off, the radome 100 cuts off the electromagnetic waves of the preset frequency band.
[0015] In this embodiment of the invention, both the first substrate layer 20 and the second substrate layer 60 are made of FR4 material (i.e., glass fiber reinforced epoxy resin), and the substrates of the first frequency selective surface layer 10, the second frequency selective surface layer 30, the third frequency selective surface layer 50, and the fourth frequency selective surface layer 80 are all PI films (i.e., polyimide films). The core layer 40 is a foam layer or a honeycomb layer; preferably, the core layer 40 is a PMI foam layer.
[0016] In this embodiment of the invention, the substrates of the first frequency selective surface layer 10, the second frequency selective surface layer 30, the third frequency selective surface layer 50, and the fourth frequency selective surface layer 80 all have a dielectric constant of 3.5 and a loss tangent of 0.002. The first base layer 20 and the second base layer 60 both have a dielectric constant of 4.3 and a loss tangent of 0.025. The core layer 40 has a dielectric constant of 1.11 and a loss tangent of 0.005.
[0017] In this embodiment of the invention, the thicknesses of the first frequency selective surface layer 10, the second frequency selective surface layer 30, the third frequency selective surface layer 50, and the fourth frequency selective surface layer 80 are all 0.025 mm, the thicknesses of the first substrate layer 20 and the second substrate layer 60 are both 1 mm, and the thickness of the core material layer 40 is 10 mm.
[0018] like Figure 2 As shown, in one embodiment of the present invention, the at least one switching control element is six switching diodes 16. The conductive microstructure of the first frequency selection surface layer 10 includes a first I-shaped structure 12 and a second I-shaped structure 14 that are orthogonal to each other, six switching diodes 16, and six first feed vias 18. The six switching diodes 16 correspond one-to-one with the six first feed vias 18. The middle of the two parallel sides of the first I-shaped structure 12 is connected to the corresponding first feed via 18 in sequence through the switching diodes 16 and the feed lines. The two ends of the two parallel sides of the second I-shaped structure 14 are connected to the corresponding first feed via 18 in sequence through the switching diodes 16 and the feed lines.
[0019] Please see Figure 2 The conductive microstructure of the second frequency selective surface layer 30 includes six identical first conductive geometric structures 32, second conductive geometric structures 34, and six second power feeding vias 38. The six first conductive geometric structures 32 are connected end to end to form an approximately regular hexagonal structure, and a first gap is formed at the center of the approximately regular hexagonal structure and a second gap is formed between any two adjacent first conductive geometric structures 32. The six second power feeding vias 38 are respectively disposed at the six ends of the approximately regular hexagonal structure.
[0020] Each first conductive geometry 32 includes multiple raised curve segments, the shape of which is the same as that of a rectangular wave in the positive half-cycle. The multiple raised curve segments are arranged in a row in the horizontal direction, and the gap between any two adjacent raised curve segments is the same. The height of the multiple raised curve segments arranged in a row increases in the vertical direction and then decreases in the vertical direction. The first raised curve segment in the multiple raised curve segments arranged in a row is connected to a second power supply through-hole 38 through a feed line, and the last raised curve segment in the multiple raised curve segments arranged in a row is connected to another second power supply through-hole 38 through a gap and a feed line in sequence.
[0021] The second conductive geometry 34 includes a regular hexagonal single-ring structure and six first straight line segments. The regular hexagonal single-ring structure is disposed within the first gap, and the six first straight line segments are respectively disposed within the six second gaps. One end of each of the six first straight line segments is connected to the six endpoints of the single-ring structure, and the other end of each of the six first straight line segments extends into the corresponding second gap. Each first power supply via and each corresponding second power supply via are respectively connected to the positive and negative terminals of the power supply through a feed line to supply power to the corresponding switching diode.
[0022] Specifically, in the first frequency selection surface layer 10, the line width W1 of both the first I-shaped and the second I-shaped is 0.1 mm.
[0023] In the second frequency selection surface layer 30, the length g1 of the high-level continuous line segment of the multiple raised curve segments is 0.15mm, and the line width w2 of the multiple raised curve segments is 0.04mm; the side length r1 of the regular hexagonal single-ring structure is 0.5mm; and the line width w3 of the regular hexagonal single-ring structure and the six straight line segments is 0.2mm.
[0024] like Figure 3 As shown, the conductive microstructure of the third frequency selection surface layer 50 is a regular hexagonal single-ring structure.
[0025] Please see Figure 3 The conductive microstructure of the fourth frequency selective surface layer 80 includes six identical third conductive geometric structures 82 and six identical fourth conductive geometric structures 84. The six third conductive geometric structures 82 are connected end to end in sequence to form an approximately ring structure, and a third gap is formed at the center of the approximately ring structure. The six fourth conductive geometric structures 84 are all disposed in the third gap and are arranged end to end in sequence to form an approximately regular hexagonal structure. Each third conductive geometry 82 includes a bent portion in the form of a rectangular wave and two bend lines, the two bend lines being respectively connected to the two ends of the bent portion; Each fourth conductive geometry 84 includes a triangular open-loop structure and two second straight segments. The two second straight segments are respectively connected to the two ends of the opening of the triangular open-loop structure. The ends of the two second straight segments of each fourth conductive geometry 84 away from the opening are respectively connected to the bend lines of the two adjacent third conductive geometries 82.
[0026] Specifically, in the third frequency selection surface layer 50, the side length r2 and line width w4 of the regular hexagonal single-ring structure are 2.45 mm and 0.17 mm, respectively.
[0027] In the fourth frequency-selective surface layer 80, the linewidth w5 of each third conductive geometry 82 and each fourth conductive geometry 84 is 0.05 mm, and the lengths of the high-level continuous line segment and the low-level continuous line segment g2 of the bend of the rectangular wave are both 0.08 mm.
[0028] In this way, the following technical effects can be achieved: when all six switching diodes 16 are turned on, electromagnetic waves in a predetermined low-frequency band of the preset frequency band can penetrate the radome 100; when all six switching diodes 16 are turned off, the radome 100 can cut off the electromagnetic waves in the preset frequency band.
[0029] The preset frequency band is 0~18GHz, and the predetermined low frequency band within the preset frequency band is 0.89~1.38GHz; that is, please refer to... Figure 4 The simulation diagram of the wave transmission curve of the radome 100 shows that, with all six switching diodes 16 turned on, electromagnetic waves in the frequency range of 0.89~1.38GHz penetrate the radome 100 (specifically, the wave transmission rate of the radome 100 for electromagnetic waves in the frequency range of 0.89~1.38GHz is greater than or equal to 73%, that is, high wave transmission is achieved); Figure 4 (As shown). With all six switching diodes 16 turned off, the radome 100 blocks electromagnetic waves in the 0-18 GHz frequency range, and the transmittance in the cutoff section is less than 10%. Figure 4 As shown.
[0030] Optionally, in another embodiment of the present invention, the at least one switching control element is four switching diodes, and the conductive microstructure of the second frequency selection surface layer includes four identical first conductive geometric structures, second conductive geometric structures, and four second power feed vias. The four first conductive geometric structures are connected end to end to form an approximately square structure, and a first gap is formed at the center of the approximately square structure and a second gap is formed between any two adjacent first conductive geometric structures; the four second power feed vias are respectively disposed at the four ends of the approximately square structure. Each first conductive geometry includes multiple raised curve segments, the shape of which is the same as that of a rectangular wave in the positive half-cycle. The multiple raised curve segments are arranged in a row in the horizontal direction, and the gap between any two adjacent raised curve segments is the same. The height of the multiple raised curve segments arranged in a row increases and then decreases in the vertical direction. The first raised curve segment in the multiple raised curve segments arranged in a row is connected to a second feed through hole through a feed line, and the last raised curve segment in the multiple raised curve segments arranged in a row is connected to another second feed through hole through a gap and a feed line in sequence. The second conductive geometry includes a regular quadrilateral single-ring structure and four first straight line segments. The regular quadrilateral single-ring structure is disposed in the first gap, and the four first straight line segments are respectively disposed in the four second gaps. One end of each of the four first straight line segments is connected to the four endpoints of the single-ring structure, and the other end of each of the four first straight line segments extends into the four second gaps.
[0031] Correspondingly, the conductive microstructure of the first frequency selective surface layer 10 includes the four switching diodes, four first feed vias, and mutually orthogonal first and second I-shaped structures (that is, the at least one switching control element is four switching diodes). Each of the four switching diodes corresponds one-to-one with one of the four first feed vias; the middle of each of the two parallel sides of the first I-shaped structure is connected to the corresponding first feed via in sequence through a switching diode and a feed line; one end of each of the two parallel sides of the second I-shaped structure is connected to the corresponding first feed via in sequence through a switching diode and a feed line.
[0032] The third frequency selection surface layer 50 has a conductive microstructure that is a single ring structure in the shape of a regular quadrilateral.
[0033] The conductive microstructure of the fourth frequency-selective surface layer 80 includes four identical third conductive geometric structures and four identical fourth conductive geometric structures. The four third conductive geometric structures are connected end-to-end to form an approximately ring-shaped structure, and a third gap is formed at the center of the approximately ring-shaped structure. The four fourth conductive geometric structures are all disposed within the third gap and are arranged end-to-end to form an approximately square structure. Each third conductive geometry includes a bent portion in the form of a rectangular wave and two bend lines, the two bend lines being connected to the two ends of the bent portion respectively; Each fourth conductive geometry includes a triangular open-loop structure and two second straight segments. The two second straight segments are respectively connected to the two ends of the opening of the triangular open-loop structure. The ends of the two second straight segments of each fourth conductive geometry away from the opening are respectively connected to the bend lines of the two adjacent third conductive geometries.
[0034] Thus, alternatively, in another embodiment of the present invention, the following technical effects can also be achieved: when all four switching diodes are turned on, electromagnetic waves of a predetermined low frequency band in the preset frequency band penetrate the radome 100; when all four switching diodes are turned off, the radome 100 cuts off the electromagnetic waves of the preset frequency band.
[0035] This invention relates to an active low-scattering switch-type composite metamaterial radome (i.e., a wide-band on / off adjustable low-scattering radome), which can achieve resonance modulation and on / off control in the electromagnetic wave band. It features a short period, high isolation, thinness, simple structure, and ease of implementation, which is beneficial for the stealth and resonance modulation of radomes and antennas, and can be applied to radomes in electronic warfare, communications, and other types of applications.
[0036] This invention relates to a low-frequency, low-scattering, switch-type composite metamaterial radome (i.e., a wideband adjustable on / off low-scattering metamaterial radome), which can achieve L-band wideband transmission / cutoff control. By rationally designing the active and passive layers, full cutoff in the 0-18 GHz frequency band can be achieved when the switching diode is "off," reducing the in-band and out-of-band radar cross-section of the antenna. It can be applied to radomes and electronic warfare radomes that combine stealth and radiation functions.
[0037] This invention features a simple structure and is easy to fabricate. Miniaturization is achieved through wire winding and the introduction of switching diodes. By rationally designing the microstructure and the arrangement of the switching diodes' operating states, a low-frequency wideband passband is achieved in the "on" (conducting) state of the switching diodes, and a strong cutoff is achieved in the "off" (turn-off) state. It exhibits high isolation between transmission and reflection states and high transmittance within the passband.
[0038] The most difficult part of this invention is (1) the design of achieving a large degree of isolation between the two "on" and "off" states of the switching diode; (2) the miniaturized structure design of the low-frequency band (L-band); (3) the low-frequency wideband passband with stable angle; and (4) the full-band cutoff in the "off" state.
[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A low-scattering metamaterial radome with adjustable on / off bandwidth, characterized in that, The radome is stacked in the following order from the outside to the inside: first frequency selective surface layer, first substrate layer, second frequency selective surface layer, core material layer, third frequency selective surface layer, second substrate layer and fourth frequency selective surface layer. The first frequency selection surface layer, the second frequency selection surface layer, the third frequency selection surface layer and the fourth frequency selection surface layer all include a substrate and a conductive microstructure disposed on the substrate. The conductive microstructure of the first frequency selection surface layer is provided with at least one switching control element. When at least one switch control element is turned on, electromagnetic waves in a predetermined low-frequency band within a preset frequency band penetrate the radome; when at least one switch control element is turned off, the radome blocks electromagnetic waves in the preset frequency band.
2. The radome according to claim 1, characterized in that, Both the first and second base layers are made of FR4 material; the substrates of the first, second, third, and fourth frequency selective surface layers are all PI films; and the core layer is a foam layer or a honeycomb layer. The substrates of the first frequency selective surface layer, the second frequency selective surface layer, the third frequency selective surface layer, and the fourth frequency selective surface layer all have a dielectric constant of 3.5 and a loss tangent of 0.002; the first base layer and the second base layer both have a dielectric constant of 4.3 and a loss tangent of 0.025; the core material layer has a dielectric constant of 1.11 and a loss tangent of 0.
005.
3. The radome according to claim 2, characterized in that, The thickness of the first frequency selective surface layer, the second frequency selective surface layer, the third frequency selective surface layer and the fourth frequency selective surface layer is 0.025 mm, the thickness of the first base layer and the second base layer is 1 mm, and the thickness of the core material layer is 10 mm.
4. The radome according to claim 1, characterized in that, The at least one switching control element comprises six switching diodes. The conductive microstructure of the first frequency selective surface layer includes six first feed vias and a first I-shaped and a second I-shaped structure that are orthogonal to each other. The six switching diodes correspond one-to-one with the six first feed vias. The middle of the two parallel sides of the first I-shaped structure is connected to the corresponding first feed via in sequence through a switching diode and a feed line. The two ends of the two parallel sides of the second I-shaped structure are connected to the corresponding first feed via in sequence through a switching diode and a feed line.
5. The radome according to claim 4, characterized in that, The conductive microstructure of the second frequency selective surface layer includes six identical first conductive geometric structures, second conductive geometric structures, and six second power feed vias. The six first conductive geometric structures are connected end to end to form an approximately regular hexagonal structure. A first gap is formed at the center of the approximately regular hexagonal structure, and a second gap is formed between any two adjacent first conductive geometric structures. The six second power feed vias are respectively disposed at the six endpoints of the approximately regular hexagonal structure. Each first conductive geometry includes multiple raised curve segments, the shape of which is the same as that of a rectangular wave in the positive half-cycle. The multiple raised curve segments are arranged in a row in the horizontal direction, and the gap between any two adjacent raised curve segments is the same. The height of the multiple raised curve segments arranged in a row increases and then decreases in the vertical direction. The first raised curve segment in the multiple raised curve segments arranged in a row is connected to a second feed through hole through a feed line, and the last raised curve segment in the multiple raised curve segments arranged in a row is connected to another second feed through hole through a gap and a feed line in sequence. The second conductive geometry includes a regular hexagonal single-ring structure and six first straight line segments. The regular hexagonal single-ring structure is disposed within the first gap, and the six first straight line segments are respectively disposed within the six second gaps. One end of each of the six first straight line segments is connected to the six endpoints of the single-ring structure, and the other end of each of the six first straight line segments extends into the six second gaps. Each first power supply via and each corresponding second power supply via are respectively connected to the positive and negative terminals of the power supply through a feed line to supply power to the corresponding switching diode.
6. The radome according to claim 5, characterized in that, The line width W1 of both the first and second I-shaped shapes is 0.1 mm; The length g1 of the high-level continuous line segment of the plurality of raised curve segments is 0.15mm, and the line width w2 of the plurality of raised curve segments is 0.04mm; the side length r1 of the single-ring structure of the regular hexagon is 0.5mm; the line width w3 of the single-ring structure of the regular hexagon and the six straight line segments is 0.2mm.
7. The radome according to claim 5, characterized in that, The conductive microstructure of the third frequency-selective surface layer is a single-ring structure of regular hexagon or regular quadrilateral.
8. The radome according to claim 7, characterized in that, The conductive microstructure of the fourth frequency-selective surface layer includes six identical third conductive geometric structures and six identical fourth conductive geometric structures. The six third conductive geometric structures are connected end-to-end to form an approximately ring-shaped structure, with a third gap at the center of the approximately ring-shaped structure. The six fourth conductive geometric structures are all disposed within the third gap and are arranged end-to-end to form an approximately regular hexagonal structure. Each third conductive geometry includes a bent portion in the form of a rectangular wave and two bend lines, the two bend lines being connected to the two ends of the bent portion respectively; Each fourth conductive geometry includes a triangular open-loop structure and two second straight segments. The two second straight segments are respectively connected to the two ends of the opening of the triangular open-loop structure. The ends of the two second straight segments of each fourth conductive geometry away from the opening are respectively connected to the bend lines of the two adjacent third conductive geometries.
9. The radome according to claim 8, characterized in that, The side length r2 and line width w4 of the single-ring structure of the regular hexagon are 2.45 mm and 0.17 mm, respectively; The linewidth w5 of each third conductive geometry and each fourth conductive geometry is 0.05 mm, and the lengths of the high-level continuous line segment and the low-level continuous line segment g2 of the bend of the rectangular wave are both 0.08 mm.
10. The radome according to claim 9, characterized in that, The preset frequency band is 0~18GHz, and the predetermined low frequency band within the preset frequency band is 0.89~1.38GHz.
11. The radome according to claim 2, characterized in that, The core material layer is a PMI foam layer.