A multi-layer terahertz metamaterial absorber based on dielectric microspheres
By designing a multilayer terahertz metamaterial absorber based on dielectric microspheres, the problems of complex structure and poor absorption performance of existing absorbers are solved by utilizing the resonance and coupling superposition effect of microspheres, and the effect of multi-frequency broadband absorption is achieved.
Patent Information
- Application Number
- CN202210472931.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-04-29
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2042-04-29
AI Technical Summary
Existing terahertz absorbers suffer from problems such as complex structure, difficult manufacturing, poor absorption performance, and poor adjustability.
Design a multilayer terahertz metamaterial absorber based on dielectric microspheres, including a metal reflector and multiple microsphere layers. By the resonance of the upper and lower microsphere layers and the coupling superposition effect between the units, the number of absorption peaks is increased and the absorption bandwidth of the absorber is extended.
It achieves a multi-frequency broadband absorption effect with simple structure and easy fabrication, with excellent absorption performance and the desired absorption effect can be obtained by adjusting the microsphere material and size.
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Figure CN114944556B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of terahertz wave absorption and terahertz device, in particular to a multilayer terahertz metamaterial absorber based on dielectric microspheres. BACKGROUND
[0002] The emergence of electromagnetic metamaterials opens up a new method for controlling electromagnetic waves. Its unique electromagnetic properties include negative refractive index, perfect absorption, etc., which have attracted widespread attention and in-depth research. Most of the current metamaterial absorbers are based on artificial "atomic" structures of metal, which face problems such as complex structure, difficult processing, poor tunability, etc., hindering the development of device. The dielectric metamaterial based on Mie resonance theory provides a new idea for the design of metamaterials. A series of electromagnetic responses can be obtained by using dielectric particles, thereby realizing various special electromagnetic properties, including perfect absorption, while avoiding the problems encountered by metal structures.
[0003] Terahertz waves usually refer to electromagnetic waves with a frequency range of 0.1 THz-10 THz, i.e. a wavelength range of 0.03 mm-3 mm. This band of electromagnetic waves has the advantages of low photon energy, high penetration, and transient nature, and has broad application space in imaging technology, broadband communication, radar, and security detection. Terahertz technology is a breakthrough and challenging emerging technology, and is listed as one of the "top ten technologies that will change the future world". As an important device in terahertz technology, the absorber has in-depth research and application value. The existing absorber has the shortcomings of complex structure, difficult processing, poor absorption performance, and poor tunability. SUMMARY
[0004] In order to solve the above problems, the purpose of the present application is to provide a multilayer terahertz metamaterial absorber based on dielectric microspheres, comprising a metal reflector and a multilayer microsphere layer, the multilayer microsphere layer is a microsphere layer stacked in turn, the number of layers is greater than or equal to two; the microsphere layer comprises a dielectric substrate and a dielectric microsphere resonant unit; the metal reflector is placed on top of the microsphere layer stacked in turn. The multilayer terahertz metamaterial absorber based on dielectric microspheres is designed with a multilayer structure, which increases the number of absorption peaks and expands the absorption bandwidth of the absorber through the resonance of the upper and lower two microspheres and the coupling superposition effect between the units, realizing the multi-frequency broadband absorption of the absorber.
[0005] The purpose of the present application can be realized by the following technical scheme:
[0006] The present application provides a multilayer terahertz metamaterial absorber based on dielectric microspheres, comprising a metal reflector and a multilayer microsphere layer, the multilayer microsphere layer is a microsphere layer stacked in turn, the number of layers is greater than or equal to two;
[0007] The microsphere layer comprises a dielectric substrate and dielectric microsphere resonant units.
[0008] The metal reflection plate top is sequentially stacked with the microsphere layer.
[0009] In one embodiment of the present application, the dielectric microsphere resonant unit is composed of several microspheres.
[0010] In one embodiment of the present application, the diameter of the microspheres is 60-135 μm.
[0011] In one embodiment of the present application, the diameters of the microspheres in the same microsphere layer are the same.
[0012] In one embodiment of the present application, the diameters of the microspheres in different microsphere layers are allowed to be the same or different.
[0013] In one embodiment of the present application, the material of the microspheres is selected from one of alumina or zirconia.
[0014] In one embodiment of the present application, the material of the dielectric substrate is a flexible adjustable insulating polymer, which includes but is not limited to a biaxially oriented polypropylene film tape.
[0015] The dielectric constant of the flexible adjustable insulating polymer is 1.20-1.30.
[0016] In one embodiment of the present application, the thickness of the dielectric substrate is 30-60 μm.
[0017] In one embodiment of the present application, the material of the metal reflection plate includes but is not limited to aluminum, iron, and copper.
[0018] In one embodiment of the present application, the thickness of the metal reflection plate is 80-200 μm.
[0019] The present application designs a multi-layer terahertz metamaterial wave absorber based on dielectric microspheres, which has simple structure, excellent performance, and good adjustability.
[0020] Compared with the prior art, the present application has the following beneficial effects:
[0021] (1) The multi-layer terahertz metamaterial wave absorber based on dielectric microspheres uses dielectric microspheres as resonant units, which has a simple structure and is easy to obtain.
[0022] (2) The multi-layer terahertz metamaterial wave absorber based on dielectric microspheres has a multi-layer structure, which increases the number of absorption peaks, expands the absorption bandwidth of the wave absorber, and realizes multi-frequency broadband absorption of the wave absorber through the resonance of the microspheres in each layer and the coupling superposition effect between the units.
[0023] (3) The multilayer structure of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres is simple in structure, easy to prepare, and flexible in design, and the wave absorption performance can be regulated by changing the materials and sizes of the microspheres in each layer to obtain the desired effect. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a perspective view of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres of the application.
[0025] Figure 2 It is a front view of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres of the application.
[0026] Figure 3 It is an absorption rate spectrum of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres in Example 1 of the application;
[0027] Figure 4 It is an absorption rate spectrum of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres in Example 2 of the application;
[0028] Figure 5 It is an absorption rate spectrum of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres in Example 3 of the application;
[0029] Figure 6 It is an absorption rate spectrum of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres in Example 4 of the application;
[0030] Figure 7 It is an absorption rate spectrum of the multilayer terahertz metamaterial wave absorber based on dielectric microspheres in Example 5 of the application;
[0031] Label in the figure: 1, upper microsphere layer; 11, first dielectric microsphere resonant unit; 12, first dielectric substrate; 2, lower microsphere layer; 21, second dielectric microsphere resonant unit; 22, second dielectric substrate; 3, metal reflection plate. DETAILED DESCRIPTION
[0032] The application provides a multilayer terahertz metamaterial wave absorber based on dielectric microspheres, which comprises a metal reflection plate and a multilayer microsphere layer, the multilayer microsphere layer is a microsphere layer stacked in sequence, and the number of layers is greater than or equal to two.
[0033] The microsphere layer comprises a dielectric substrate and a dielectric microsphere resonant unit.
[0034] The metal reflection plate is sequentially stacked with the microsphere layer at the top.
[0035] In an embodiment of the application, the dielectric microsphere resonant unit is composed of a plurality of microspheres.
[0036] In one embodiment of the present application, the diameter of the microspheres is 60-135 μm.
[0037] In one embodiment of the present application, the diameters of the microspheres in the same microsphere layer are the same.
[0038] In one embodiment of the present application, the diameters of the microspheres in different microsphere layers are allowed to be the same or different.
[0039] In one embodiment of the present application, the material of the microspheres is selected from one of alumina or zirconia.
[0040] In one embodiment of the present application, the material of the medium substrate is a flexible adjustable insulating polymer, which includes but is not limited to a biaxially oriented polypropylene film tape.
[0041] The dielectric constant of the flexible adjustable insulating polymer is 1.20-1.30.
[0042] In one embodiment of the present application, the thickness of the medium substrate is 30-60 μm.
[0043] In one embodiment of the present application, the material of the metal reflecting plate includes but is not limited to aluminum, iron, copper.
[0044] In one embodiment of the present application, the thickness of the metal reflecting plate is 80-200 μm.
[0045] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0046] During the test, the terahertz wave is incident along the -z direction, and the absorption rate is calculated by the formula A = 100 - R - T. In the formula, R is the reflectivity (%), and T is the transmittance (%). Since the bottom layer is a metal reflecting plate, T = 0, and thus A = 100 - R.
[0047] Based on the Mie resonance theory, the upper and lower dielectric microsphere layers can produce strong absorption peaks at their electric and magnetic resonance frequencies, respectively. The coupling superposition between the upper and lower microsphere layers can increase the number of absorption peaks, expand the absorption bandwidth of the wave absorber, and achieve multi-frequency broadband absorption of the wave absorber. Therefore, by designing the structure of the wave absorber, such as changing the material and size of the microspheres, the wave absorption performance can be controlled to obtain the desired wave absorption effect.
[0048] Example 1
[0049] As shown in Figures 1-2 The present embodiment provides a multi-layer terahertz metamaterial wave absorber based on dielectric microspheres, which includes a metal reflecting plate 3, an upper microsphere layer 1, and a lower microsphere layer 2.
[0050] The upper microsphere layer 1 comprises a first dielectric substrate 12 and a first dielectric microsphere resonant unit 11; the lower microsphere layer 2 comprises a dielectric substrate and a second dielectric microsphere resonant unit 21 (composed of first dielectric microspheres); the lower microsphere layer 2 comprises a second dielectric substrate 22 and a second dielectric microsphere resonant unit 21 (composed of second dielectric microspheres);
[0051] The first dielectric microsphere resonant unit 11 is arranged above the first dielectric substrate 12, and the second dielectric microsphere resonant unit 21 is arranged above the second dielectric substrate 22.
[0052] The multilayer terahertz metamaterial wave absorber based on dielectric microspheres comprises, from top to bottom, the upper microsphere layer 1, the lower microsphere layer 2, and the metal reflection plate 3.
[0053] The first dielectric microspheres and the second dielectric microspheres are arranged in a periodic array, and the dielectric microspheres in the same layer have the same diameter. The diameters of the first dielectric microspheres and the second dielectric microspheres are denoted as a and b, respectively.
[0054] The materials of the first dielectric microspheres and the second dielectric microspheres are both alumina, the first dielectric substrate 12 and the second dielectric substrate 22 are both biaxially oriented polypropylene (BOPP) film adhesive tapes with a dielectric constant of 1.27 and a thickness of 40 μm; the material of the metal reflection plate 3 is aluminum with a thickness of 100 μm; the diameter of the first dielectric microspheres is a = 135 μm, and the diameter of the second dielectric microspheres is b = 135 μm.
[0055] In the absorption spectrum of the absorber in the terahertz frequency band, multiple strong absorption peaks and absorption bands are generated due to the Mie resonance of the dielectric microspheres and the coupling superposition effect between the two layers of microspheres. Four obvious absorption peaks are located at 0.68 THz, 0.79 THz, 0.94 THz, and 1.12 THz, and the maximum absorption rates are 98.36%, 95.96%, 98.15%, and 99.69%, respectively. Five frequency bands with an absorption rate greater than 90% are 0.67 THz-0.69 THz, 0.78 THz-0.80 THz, 0.88 THz-0.98 THz, 1.08 THz-1.18 THz, and the most eye-catching 1.34 THz-2.00 THz. The absorber achieves a multi-frequency broadband wave absorption effect. Figure 3 )。
[0056] Embodiment 2
[0057] The embodiment provides a multilayer terahertz metamaterial wave absorber based on dielectric microspheres, which is different from embodiment 1 in that the diameter of the first dielectric microspheres is a = 77 μm, the diameter of the second dielectric microspheres is b = 77 μm, the thickness of the first dielectric substrate 12 and the second dielectric substrate 22 is 30 mm, and the thickness of the metal reflection plate 3 is 200 mm.
[0058] In the absorption spectrum of the wave absorber in the terahertz band, due to the Mie resonance of the dielectric microspheres and the coupling superposition effect between the two layers of microspheres, multiple strong absorption peaks and absorption bands are generated. Two obvious absorption peaks are located at 1.07 THz and 1.53 THz, and the maximum absorption rates are 57.54% and 99.96%, respectively. It is remarkable that the excellent wave absorption performance of the latter absorption peak is generated, and the frequency band with an absorption rate greater than 90% is 1.34 THz-2.00 THz. The wave absorber also achieves a wide frequency band wave absorption effect. Figure 4
[0059] Embodiment 3
[0060] The embodiment provides a multilayer terahertz metamaterial wave absorber based on dielectric microspheres, and different from embodiment 1, the diameter a of the first dielectric microspheres is 90 μm, and the diameter b of the second dielectric microspheres is 135 μm in the embodiment; the thicknesses of the first dielectric substrate 12 and the second dielectric substrate 22 are both 60 mm, and the thickness of the metal reflection plate 3 is 80 mm.
[0061] In the absorption spectrum of the wave absorber in the terahertz band, due to the Mie resonance of the dielectric microspheres and the coupling superposition effect between the two layers of microspheres, multiple strong absorption peaks and absorption bands are generated. Four obvious absorption peaks are located at 0.85 THz, 1.24 THz, 1.37 THz and 1.65 THz, and the maximum absorption rates are 98.09%, 97.50%, 99.77% and 99.94%, respectively. Three frequency bands with an absorption rate greater than 90% are 0.84 THz-0.87 THz, 1.22 THz-1.27 THz and 1.34 THz-1.71 THz Figure 5
[0062] Embodiment 4
[0063] The embodiment provides a multilayer terahertz metamaterial wave absorber based on dielectric microspheres, and different from embodiment 1, the materials of the first dielectric microspheres and the second dielectric microspheres are both zirconium oxide in the embodiment, the diameter a of the first dielectric microspheres is 77 μm, and the diameter b of the second dielectric microspheres is 77 μm.
[0064] In the absorption spectrum of the absorber in the terahertz band, due to the Mie resonance of the dielectric microspheres and the coupling superposition effect between the two layers of microspheres, multiple strong absorption peaks and absorption bands are generated. Six obvious absorption peaks are located at 0.61 THz, 0.86 THz, 0.97 THz, 1.19 THz, 1.31 THz, 1.56 THz, and the maximum absorption rates are 98.19%, 94.73%, 91.20%, 98.01%, 96.95%, and 99.91%, respectively. Five absorption bands with an absorption rate greater than 90% are 0.60 THz-0.63 THz, 0.84 THz-0.87 THz, 0.94 THz-0.98 THz, 1.14 THz-1.35 THz, and 1.40 THz-1.70 THz. Figure 6 )。
[0065] Embodiment 5
[0066] The embodiment provides a multilayer terahertz metamaterial absorber based on dielectric microspheres, and the difference between the embodiment and embodiment 1 is that the materials of the first dielectric microspheres and the second dielectric microspheres in the embodiment are both zirconia, the diameter a of the first dielectric microspheres is 60 μm, and the diameter b of the second dielectric microspheres is 90 μm.
[0067] In the absorption spectrum of the absorber in the terahertz band, due to the Mie resonance of the dielectric microspheres and the coupling superposition effect between the two layers of microspheres, multiple strong absorption peaks and absorption bands are generated. Three obvious absorption peaks are located at 0.57 THz, 0.94 THz, and 0.1.33 THz, and the maximum absorption rates are 99.79%, 99.92%, and 99.96%, respectively. Four absorption bands with an absorption rate greater than 90% are 0.55 THz-0.59 THz, 0.90 THz-0.97 THz, 1.22 THz-1.41 THz, and 1.57 THz-2.00 THz. Figure 7 )。
[0068] In summary, the multilayer terahertz metamaterial absorber based on dielectric microspheres has excellent wave-absorbing performance, flexible design, and strong functionality.
[0069] The above description of the embodiments is for the purpose of enabling a person of ordinary skill in the art to understand and use the application. Those skilled in the art can easily make various modifications to the embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the application is not limited to the above embodiments, and improvements and modifications made by those skilled in the art within the scope of the application without departing from the scope of the application should be within the protection scope of the application.
Claims
1. A multi-layer terahertz metamaterial absorber based on dielectric microspheres, characterized in that, The metal reflection plate and a multilayer microsphere layer, the multilayer microsphere layer is a microsphere layer stacked in sequence, and the number of layers is greater than or equal to two; The microsphere layer comprises a dielectric substrate and a dielectric microsphere resonant unit; The microsphere layer is stacked in sequence on the top of the metal reflection plate; The dielectric microsphere resonant unit is composed of a plurality of microspheres, and the diameter of the microspheres is 60-135 μm; In the same microsphere layer, the diameters of the microspheres are the same; In different microsphere layers, the diameters of the microspheres can be the same or different; The material of the microspheres is selected from one of alumina or zirconia; The Mie resonance of the dielectric microspheres and the coupling superposition effect between the microspheres of different layers can generate a plurality of strong absorption peaks and absorption bands.
2. The multi-layer terahertz metamaterial absorber based on dielectric microspheres according to claim 1, characterized in that, The material of the dielectric substrate is a flexible adjustable insulating polymer, and the flexible adjustable insulating polymer is selected from a biaxially oriented polypropylene film tape; The dielectric constant of the flexible adjustable insulating polymer is 1.20-1.
30.
3. The multi-layer terahertz metamaterial absorber based on dielectric microspheres of claim 1, wherein, The thickness of the dielectric substrate is 30-60 μm.
4. The multi-layer terahertz metamaterial absorber based on dielectric microspheres of claim 1, wherein, The material of the metal reflection plate is selected from one of aluminum, iron or copper.
5. The multi-layer terahertz metamaterial absorber based on dielectric microspheres of claim 1, wherein, The thickness of the metal reflection plate is 80-200 μm.
Citation Information
Patent Citations
Double-layer terahertz wave absorber based on vanadium dioxide and cavity resonance
CN210040564U