CN110707410A

CN110707410A - Metamaterial, radome and aircraft

Info

Publication number: CN110707410A
Application number: CN201910716009.5A
Authority: CN
Inventors: 刘若鹏; 文革; 赵治亚; 安迪; 田华; 商院芳
Original assignee: Shenzhen Guangqi High-End Equipment Technology Research And Development Co Ltd
Current assignee: Shenzhen Guangqi High-End Equipment Technology Research And Development Co Ltd
Priority date: 2019-08-05
Filing date: 2019-08-05
Publication date: 2020-01-17

Abstract

The invention provides a metamaterial which comprises a base material layer and a metal micro-structure layer superposed on the base material layer, wherein the metal micro-structure layer is provided with a single-direction communication structure which is periodically arranged, the base material layer and the metal micro-structure layer form a whole together, the end part of the whole in a single direction is connected with a wiring terminal, and the whole is communicated with an external power supply through the wiring terminal to form a conductive path so as to carry out electric heating by utilizing the characteristic of metal power-on heating. In addition, the invention also provides the radome and the aircraft. The technical scheme provided by the invention is that the metal micro-structural layer is subjected to specific structural design, so that the metal micro-structural layer is used as an electric heating unit and has an electric heating deicing function, and is also used as an electromagnetic modulation structure, electromagnetic signal transmission in the working frequency range of an electromagnetic transceiver is allowed, electromagnetic waves outside the working frequency range are shielded, and interference of clutter signals is inhibited.

Description

Metamaterial, radome and aircraft

Technical Field

The invention relates to the field of materials, in particular to a metamaterial, a radome and an aircraft.

Background

Icing of an aviation aircraft in the flying process is a physical phenomenon which widely exists, and is one of the major hidden dangers of flight safety accidents. When the aircraft flies under the condition of lower than icing weather, supercooled water drops in the atmosphere impact the surface of the aircraft, and are easy to desublimate and form ice on the surfaces of parts of the protruding parts of the aircraft body, such as wing leading edges, rotors, tail rotor leading edges, an engine air inlet, an airspeed tube, aircraft windshield glass, an antenna housing and the like. The icing of the aircraft can not only increase the weight, but also destroy the aerodynamic appearance of the aircraft surface, change the streaming flow field, destroy the aerodynamic performance, cause the maximum lift force of the aircraft to be reduced, increase the flight resistance, reduce the flight performance, and cause fatal threat to the flight safety under severe conditions. In addition, for military aircraft, like unmanned aerial vehicle, cargo airplane etc. icing will directly restrict its flight area, very big influence its operational capability. Therefore, the critical parts which are easy to freeze must be protected from deicing.

The existing deicing method mainly comprises the following steps: hot air deicing, mechanical deicing, microwave deicing and electrothermal deicing. However, the hot gas deicing method using the engine to bleed air needs to design a complex air supply pipeline, distribute the hot gas bled by the compressor of the engine to the part needing deicing, and affect the power and the working efficiency of the engine; the pneumatic appearance of the aircraft can be damaged by a mechanical deicing method of crushing an ice layer by adopting contraction and expansion of the air bag and the expansion pipe, and the deicing is not thorough; microwave deicing is easy to be captured by radar; in addition, the conventional electrothermal deicing generally adopts metal foils, metal wires, conductive metal films, resistance wires and the like as an electric heating unit, and is not suitable for parts needing an electromagnetic transmission function.

Therefore, how to realize deicing and having an electromagnetic modulation function on an aircraft to ensure transmission of electromagnetic signals has become a pain point problem that needs to be solved urgently in the industry.

Disclosure of Invention

In view of the above problems, the present invention provides a metamaterial, wherein the metamaterial includes a base material layer and a metal micro-structure layer stacked on the base material layer, the metal micro-structure layer has a unidirectional communication structure periodically arranged, wherein the base material layer and the metal micro-structure layer form a whole together, and an end of the whole in a unidirectional direction is connected with a connection terminal and is connected with an external power supply through the connection terminal to form a conductive path for electrical heating by using a metal electrical heating characteristic.

Preferably, the metamaterial further comprises a first prepreg layer, and the first prepreg layer is bonded with the metal microstructure layer through a layer of adhesive.

Preferably, the metamaterial further comprises a second prepreg layer bonded to the base material layer by a layer of adhesive.

Preferably, the metamaterial further comprises a sandwich layer, and the sandwich layer is bonded with the second prepreg layer through a glue film.

Preferably, the metamaterial further comprises a third prepreg layer, and the third prepreg layer is bonded with the sandwich layer through a glue film.

Preferably, at least one metal communication line exists in a plurality of metal periodic units which are periodically arranged between the wiring terminals.

Preferably, any one metal communication line comprises a plurality of periodic metal units which are sequentially connected in the horizontal direction, the metal units are V-shaped, and the opening angle of the V-shape is greater than 0 degree and less than or equal to 180 degrees.

Preferably, in the metal microstructure layer, any one of the metal connecting lines includes a plurality of periodic metal units sequentially connected in a single direction, and the metal units are in a rectangular wave shape.

In addition, the invention also provides a radome, wherein the radome comprises the metamaterial.

Furthermore, the invention also provides an aircraft, wherein the aircraft comprises the metamaterial.

According to the technical scheme provided by the invention, through designing the conducted metal passage and the specific design of the metal passage, the problem that the electromagnetic signal transmission cannot be realized due to the fact that the metal layer shields the electromagnetic signal in the conventional electric heating deicing mode is solved, and meanwhile, the interference of external electromagnetic signals outside the working frequency band of an electromagnetic transceiver inside a component can be inhibited, so that the electromagnetic transceiver, such as a microwave millimeter wave antenna and the like, can be arranged at a part with a good electromagnetic transmission visual field, and further, the foundation is laid for the development of the airplane towards the trends of multi-sensor integration, full airspace sensing and the like, and the full information chain penetration of high-end aviation equipment is further improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a multi-layer structure comprising a metamaterial according to a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of another multi-stack structure included in a metamaterial according to a second embodiment of the present invention;

FIG. 3 is a two-dimensional cross-sectional view of another multi-layer stack comprised of a metamaterial according to a second embodiment of the present invention;

fig. 4 is a schematic view illustrating a periodic arrangement of a linear metal microstructure on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 5 is a diagram illustrating the variation of the S21 curve of a metamaterial under TE polarization with the incident angle theta according to a second embodiment of the present invention;

FIG. 6 is a diagram illustrating the variation of the S21 curve of the metamaterial under TM polarization with the incident angle theta according to the second embodiment of the present invention;

fig. 7 is another schematic view of a periodic arrangement of a linear metal microstructure on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 8 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 7 in TE polarization with the incident angle theta according to the second embodiment of the present invention;

FIG. 9 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 7 in TM polarization with the incident angle theta according to the second embodiment of the present invention;

FIG. 10 is a schematic diagram illustrating a periodic arrangement of V-shaped metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 11 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 10 in TE polarization with the incident angle theta according to the second embodiment of the present invention;

FIG. 12 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 10 in TM polarization with the incident angle theta according to the second embodiment of the present invention;

fig. 13 is a schematic view of another periodic arrangement of V-shaped metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 14 is a graph illustrating the variation of the S21 curve of the metamaterial of FIG. 13 under TE polarization at an incident angle theta of 0 degree according to a second embodiment of the present invention;

FIG. 15 is a diagram illustrating the variation of the S21 curve of the metamaterial of FIG. 13 in TM polarization at an incident angle theta equal to 0 deg. according to the second embodiment of the present invention;

fig. 16 is a schematic view of a third periodic arrangement of V-shaped metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 17 is a graph illustrating the change of the S21 curve under TE polarization of the metamaterial of FIG. 16 at an incident angle theta of 0 degree according to the second embodiment of the present invention;

FIG. 18 is a diagram illustrating the variation of the S21 curve of the metamaterial of FIG. 16 in TM polarization at an incident angle theta equal to 0 deg. according to the second embodiment of the present invention;

FIG. 19 is a schematic diagram illustrating the periodic arrangement of the semicircular metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 20 is a graph illustrating the change of the S21 curve under TE polarization of the metamaterial according to FIG. 19 in the second embodiment of the present invention when the incident angle theta is 0 deg.;

FIG. 21 is a graph showing the variation of the S21 curve under TM polarization for the metamaterial according to FIG. 19 at an incident angle theta of 0 ° in the second embodiment of the present invention;

fig. 22 is a schematic view illustrating the periodic arrangement of sinusoidal metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention;

FIG. 23 is a graph illustrating the change of the S21 curve under TE polarization for the metamaterial of FIG. 22 under the second embodiment of the present invention at an incident angle theta of 0 deg.;

fig. 24 is a diagram illustrating a variation of the S21 curve of the metamaterial of fig. 22 in TM polarization at an incident angle theta of 0 ° according to the second embodiment of the present invention.

Detailed Description

The following examples are presented to enable those skilled in the art to more fully understand the present invention and are not intended to limit the invention in any way.

FIG. 1 is a schematic cross-sectional view of a multi-layer structure including a metamaterial according to an embodiment of the present invention.

As shown in fig. 1, the metamaterial of the present invention adopts a multi-stack structure design, specifically, the metamaterial includes a base material layer 1 and a metal micro-structure layer 2 stacked on the base material layer 1, the metal micro-structure layer 2 has a single square direction communication structure periodically arranged, wherein the base material layer 1 and the metal micro-structure layer 2 form a whole together, and an end of the whole in a single direction is connected with a connection terminal 3, and is connected with an external power supply through the two connection terminals 3 to form a conductive path, and the characteristic of metal electrical heating is utilized to perform electrical heating. The base material layer 1 may be a flexible base material layer or a rigid base material layer, and the specific requirement is determined according to an actual application scenario, for example, if the metamaterial is applied to a curved surface, the flexible base material layer is required, and if the metamaterial is applied to a plane, the rigid base material layer or the flexible base material layer may be selected. Wherein, the base material layer 1 has the characteristics of excellent insulating property, high and low temperature resistance, good mechanical properties such as stretching and the like, the base material layer 1 and the metal microstructure layer 2 form a whole which is called as a metal soft board, the end part of the metal soft board in the horizontal direction is connected with a connecting terminal 3, the connecting terminal 3 can be connected with the metal on the metal microstructure layer 2 in a welding way, or other connection modes, as long as the metal electric connection between the wiring terminal 3 and the metal micro-structure layer 2 is satisfied, the two wiring terminals 3 are respectively connected with the positive electrode and the negative electrode of the external power supply through the power line, so that a conductive path structure can be formed among the metal on the metal micro-structure layer 2, the two wiring terminals 3, the power line and the external power supply, and the external power supply performs electric heating through the conductive path structure by utilizing the characteristic of the electric heating of the metal micro-structure layer 2.

As shown in fig. 1, in the metal flexible board, the metal on the base material layer 1 is etched by an etching process, and then various metal microstructure patterns required actually are processed, the metal is retained in the area that is not etched in the metal microstructure layer 2, and the retained metal in the metal microstructure layer 2 forms a communication structure in a single direction, where the communication structure is a communication structure in a single direction with periodic arrangement, for example, the communication structure in a single direction may be a linear horizontal communication structure such as a straight line, a V-shape, a rectangular waveform, or a curved horizontal communication structure such as a sine waveform, a semicircle.

In the metal microstructure layer 2, each metal periodic unit includes two ends, one of the ends of two adjacent metal periodic units is connected, specifically, the end of the first metal periodic unit is connected with the end of the second adjacent metal periodic unit, the other end of the second metal periodic unit is connected with the end of the third adjacent metal periodic unit, and the other end of the third metal periodic unit is connected with the end of the fourth adjacent metal periodic unit, …, and according to the rule, the two metal periodic units are sequentially connected in sequence to form a communicating structure in the horizontal direction. In the metal microstructure layer 2, at least one metal communication line exists in a plurality of metal periodic units periodically arranged between two wiring terminals 3, so that the two wiring terminals 3 at two ends of the metal flexible board can be ensured to form a conduction path after being electrified and serve as heating units, the metamaterial structure has an electric heating deicing function, any one metal communication line comprises a plurality of metal periodic units which are sequentially connected in a single direction, the metal periodic units are in a linear shape or a V shape, the opening angle of the V shape is larger than 0 degree and smaller than or equal to 180 degrees, or any one metal communication line comprises a plurality of metal periodic units which are sequentially connected in a horizontal direction, and the metal periodic units are in a rectangular wave shape.

As shown in fig. 1, the metamaterial further includes a first prepreg layer 4 and a second prepreg layer 5, which are respectively bonded to the front surface and the back surface of the metal flexible board through two layers of adhesives 6, specifically, the first prepreg layer 4 is bonded to the front surface of the metal micro-structure layer 2 through one layer of adhesive 6, the back surface of the metal micro-structure layer 2 is overlapped with the front surface of the base material layer 1, and the second prepreg layer 5 is bonded to the back surface of the base material layer 1 through another layer of adhesive 6. The prepregs in the first prepreg layer 4 and the second prepreg layer 5 are glass or quartz fiber prepregs, so that the effects of insulation, strength support and the like are achieved, and the two layers of the adhesive 6 are used for better adhering the first prepreg layer 4 and the second prepreg layer 5 to the front surface and the back surface of the metal soft board.

In this embodiment, the metal microstructure layer 2 has a periodically arranged unidirectional connection structure, and the periodically arranged unidirectional connection structure is prepared by etching the metal on the base material layer 1 in the metal flexible board through an etching process to further process into various actually required metal microstructure patterns, wherein the metal microstructure patterns are connected in a single direction. The electrons generated by the band-grid type metal structure pattern under the irradiation of the electromagnetic wave can flow without restriction, and from the aspect of frequency response characteristics, the band-grid type metal structure pattern has a high-pass type electromagnetic modulation function of low-frequency cut-off under the incidence of the electromagnetic wave of which the electric field polarization direction is parallel to the band-grid direction, and basically does not influence the field of the other orthogonal polarization direction, and specifically, the mechanism of the high-pass type electromagnetic modulation function of the low-frequency cut-off is represented as follows:

a) when the low-frequency electromagnetic wave with the electric field polarization direction parallel to the band-grid direction irradiates the surface of the band-grid type metal structure pattern, electrons with large-range free quantity are excited to move towards the same direction in a long time, and therefore, larger kinetic energy is obtained. The lower the frequency of the incident electromagnetic wave is, the more energy the electrons absorb, so the weaker the transmission capability of the incident electromagnetic wave is, the smaller the transmission coefficient is;

b) when high-frequency electromagnetic waves are incident, the direction of an electric field is changed rapidly, the reaching speed of electrons is low, and the energy absorbed by the electrons is low, so that the incident electromagnetic waves have high transmission capability and high transmission coefficient.

In this embodiment, the surface of the metal structure pattern with the gate may be freely combined with non-connected annular metal surface micro-elements and patch-type metal surface micro-elements, thereby realizing the required electromagnetic modulation characteristics. The invention combines the electromagnetic response characteristic and the requirements of structure and strength of the electromagnetic transceiver, selects materials for the composite layer with the functions of electric heating and electromagnetic modulation, and carries out integrated design of thickness, metal structure patterns and the like, thereby realizing the integrated component with the functions of structure, strength and composite electric heating and electromagnetic modulation.

In this embodiment, according to the requirements of structural strength, electromagnetic control performance, and the like, a new combined dielectric layer may be further added to the metamaterial, as shown in fig. 2.

FIG. 2 is a schematic cross-sectional view of another multi-stack structure included in a metamaterial according to an embodiment of the present invention.

As shown in fig. 2, a dotted frame a represents the meta-material in fig. 1, and a dotted frame B represents the added combined dielectric layer. On the basis of the metamaterial structure shown in fig. 1, the metamaterial in fig. 2 further includes a sandwich layer 7 and a third prepreg layer 8, wherein one surface of the sandwich layer 7 is bonded to the second prepreg layer 5 through one adhesive film 9, and the third prepreg layer 8 is bonded to the other surface of the sandwich layer 7 through another adhesive film 9. In the present embodiment, in order to achieve more excellent electromagnetic modulation performance, the present invention may also embed a metal soft sheet (i.e., an integral body formed by the base material layer 1 and the metal microstructure layer 2 together) shown in fig. 1 alone in the core layer 7 or the third prepreg layer 8 as an electromagnetic modulation layer.

FIG. 3 is a two-dimensional cross-sectional view of another multi-layer stack comprised of a metamaterial according to a second embodiment of the present invention.

Fig. 3 is a schematic two-dimensional cross-sectional view of a multi-layer metamaterial formed by laminating the multi-layer structures shown in fig. 2, where the metamaterial structure shown in fig. 3 is a sandwich structure integrating functions of deicing and electromagnetic modulation and a structure bearing function, and includes 9 layers, and specifically, the first prepreg layer 4 has a thickness d from top to bottom₁A layer of adhesive 6 having a thickness d₂The thickness of the metal flexible board (comprising the base material layer 1 and the metal microstructure layer 2) is d₃The other layer of adhesive 6 has a thickness d₄The second prepreg layer 5 has a thickness d₅The thickness of one layer of glue film 9 is d₆The thickness of the sandwich layer 7 is d₇The thickness of the other glue film 9 is d₈The thickness of the third prepreg layer 8 is d₉。

Wherein, the prepregs in the first prepreg layer 4, the second prepreg layer 5 and the third prepreg layer 8 are low-dielectric and low-loss quartz fiber cyanate ester prepregs, which have high wave-transmitting and bearing functions, and meanwhile, the first prepreg layer 4, the second prepreg layer 5 and the third prepreg layer 8 are all good skin materials, the first prepreg layer 4 and the second prepreg layer 5 can be used as outer skin materials, the third prepreg layer 8 can be used as inner skin materials, the two layers of adhesives 6 can be bonded by adhesive films, the metal soft plate is used as an electric heating layer and mainly comprises heating materials and insulating materials, the metal microstructure layer 2 in the invention is a heating material which is made of metal copper with high resistivity and high electric conductivity, the substrate material layer 1 in the invention is an insulating material which is mainly a Polyimide (PI) film with excellent comprehensive performance, the sandwich layer 7 is used as a honeycomb layer to realize electromagnetic performance optimization and bearing functions.

The thickness of the metal layer in the metal microstructure layer 2 is determined according to the actual required resistance, the thicker the metal layer, the smaller the resistance, and the thinner the metal layer, the larger the resistance. In the present embodiment, the thickness of the metal layer in the metal microstructure layer 2 is 18 μm, and the thickness of the base material layer 1 (i.e. PI film) is 25 μm, so the metal soft plate formed by the two in the present invention has flexibility as an electrical heating layer, and is easy to be attached to a curved surface part, and the metal copper can be designed into different topological hollow patterns to realize the electromagnetic modulation function of frequency selection, meanwhile, the metal microstructure layer 2 is a communication structure, so as to ensure that the metal in the metal microstructure layer 2 can form a conductive path after being powered up, so as to realize the power-on heating deicing function, and in order to realize the high-pass frequency selection function of single-polarized low-frequency cutoff, the metal microstructure layer 2 also needs to have a periodic arrangement structure and a horizontal communication structure. The adhesive film is used for realizing the adhesion between the layers. Among the materials used above, the skin material had a dielectric constant of 3.15 and a loss tangent of 0.006, the prepreg had a dielectric constant of 2.7 and a loss tangent of 0.0065, the PI film material had a dielectric constant of 3.2 and a loss tangent of 0.002, and the honeycomb material had a dielectric constant of 1.11 and a loss tangent of 0.006.

Fig. 4 is a schematic view illustrating a periodic arrangement of linear metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention.

As shown in fig. 4, the basic unit of the metal microstructure on the metal microstructure layer 2 is in a straight shape, and includes two ends, one of the ends of two adjacent straight metal microstructures is connected, specifically, in the first row, the end of the first straight metal microstructure is connected to the end of the second adjacent straight metal microstructure, the other end of the second straight metal microstructure is connected to the end of the third adjacent straight metal microstructure, the other end of the third straight metal microstructure is connected to the end of the fourth adjacent straight metal microstructure, …, according to the rule, the two ends are sequentially connected in sequence to form a communicating structure in the horizontal direction, that is, the whole in the horizontal direction also presents a straight shape; in the second row, the connection mode of the plurality of linear metal microstructures is the same as that of the first row; in the third row, the fourth row and the … Nth row, the connection mode of the plurality of in-line metal microstructures is the same as that of the first row; in this way, the metal microstructures on the metal microstructure layer 2 are arranged in a one-dimensional communication manner, a communication structure is arranged in the horizontal direction, and an electrifying loop can be formed through the wiring terminals on both sides, that is, two tail ends of the communication structure in the horizontal direction of each row are respectively connected with two wiring terminals 3. As shown in fig. 4, the metal line widths of the linear metal microstructures are ww, the distances between two adjacent rows of metal microstructures are p, and the metal line widths are ww.

In this embodiment, the periodic arrangement of the metal microstructures on the metal microstructure layer 2 shown in fig. 4 is applied to the stacked structure shown in fig. 3, wherein the main structure dimensions are designed as shown in table 1 below:

TABLE 1 major structural dimensions

Parameter(s)	Numerical value (mm)
		d₁	0.3
d₂	0.1
		d₃	0.043
d₄	0.1
		d₅	0.3
d₆	0.2
		d₇	5.6
d₈	0.2
		d₉	0.3
ww	0.04
		p	10

The metamaterial in fig. 3 was then simulated according to the dimensions in the above table, and the results are shown in fig. 5 and 6.

As can be seen from FIGS. 5 and 6, when the incident angle theta is 0-70 degrees, the TM polarization shows high-pass characteristic at 4-18GHz, and the wave-transparent is greater than-0.8 dB; when the incident angle theta is 0-60 degrees, TM polarization shows a cut-off characteristic at 0-0.6GHz, and wave-transmitting is smaller than-9 dB; when the TE polarization is at an incident angle theta of 0-60 degrees, the wave-transparent property is basically the pure medium property, and the wave-transparent property is larger than-0.834 dB at 0-20 GHz.

From the simulation results, it can be seen that the metal line continuous in the horizontal direction is equivalent to a high-pass frequency selection structure for TM polarization low-frequency cut-off, and can realize relatively independent modulation on TM waves without affecting the other polarization. Similarly, by changing the periodic arrangement of the metal lines along the continuous direction in the vertical direction, as shown in fig. 7, at this time, the metal lines continuous along the vertical direction are equivalent to a high-pass frequency-selective structure for the low-frequency cut-off of the TE polarization, and the TE wave can be relatively independently modulated, and the specific dimensions are shown in table 1.

The metamaterial in fig. 7 was then simulated according to the dimensions in the above table, and the results are shown in fig. 8 and 9.

FIG. 8 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 7 in TE polarization with the incident angle theta according to the second embodiment of the present invention.

FIG. 9 is a diagram illustrating the variation of the S21 curve of the metamaterial of FIG. 7 under TM polarization with the incident angle theta according to the second embodiment of the present invention.

As can be seen from FIGS. 8 and 9, when the incident angle theta is 0-70 degrees, the TE polarization shows high-pass characteristic at 8-16GHz, and the wave-transparent is greater than-1.3 dB; when the incident angle theta is 0-80 degrees, the TE polarization shows a cut-off characteristic at 0-1.3GHz, and the wave-transmitting is less than-10 dB; when the incidence angle theta is 0-70 degrees, the TM polarized wave-transparent basically shows the pure dielectric property, and the wave-transparent is larger than-0.8 dB at 0-18 GHz.

Therefore, as shown in the simulation results of fig. 5, 6, 8, and 9, the metamaterial according to the present invention realizes a high-frequency wave-transmitting function, and such a linear horizontal direction communication structure formed by unidirectional continuous metal wires can be combined with an electromagnetic modulation function on the basis of realizing electrical heating deicing, thereby realizing a single-polarization low-frequency cut-off function.

In addition, the invention not only can realize the electric heating deicing function and the electromagnetic modulation function by the periodic arrangement of the linear horizontal direction communication structures like the linear metal microstructures, but also can realize the electric heating deicing function and the electromagnetic modulation function by other linear horizontal direction communication structures, for example, any edge of the metal wire can be bent (such as V-shaped) or converted into any polygonal periodic boundary (such as rectangular waveform), and the bent metal wire can form the communication structure to realize the conductive path as long as the one-dimensional continuous arrangement in the horizontal direction is met, so that the deicing function can be realized when the metal wire is used as an electric heating layer for electrifying, and the electromagnetic modulation function can be realized by designing the main structure size in the laminated structure.

as shown in fig. 10, the basic unit of the metal microstructure on the metal microstructure layer 2 is V-shaped, and has two sides that are bilaterally symmetrical, and includes two ends, where one end of two adjacent V-shaped metal microstructures is connected, specifically, in the first row, the end of the first V-shaped metal microstructure is connected to the end of the second V-shaped metal microstructure, the other end of the second V-shaped metal microstructure is connected to the end of the third V-shaped metal microstructure, and the other end of the third V-shaped metal microstructure is connected to the end of the fourth V-shaped metal microstructure, …, which are sequentially connected according to the rule to form a connection structure in the horizontal direction, that is, the whole in the horizontal direction also presents a V shape; in the second row, the connection mode of the V-shaped metal microstructures is the same as that of the first row; in the third row, the fourth row and the … Nth row, the connection mode of the V-shaped metal microstructures is the same as that of the first row; in this way, the metal microstructures on the metal microstructure layer 2 are arranged in a one-dimensional communication manner, a communication structure is arranged in the horizontal direction, and an electrifying loop can be formed through the wiring terminals on both sides, that is, two tail ends of the communication structure in the horizontal direction of each row are respectively connected with two wiring terminals 3. As shown in fig. 10, the metal line widths of the V-shaped metal microstructures are ww, the distances between two adjacent rows of metal microstructures are p, the side lengths of the left and right sides of the V-shaped metal microstructures are a, and the opening angle of the V-shaped metal microstructures is greater than 0 degree and less than or equal to 180 degrees.

In the present embodiment, the periodic arrangement of the metal microstructures on the metal microstructure layer 2 shown in fig. 10 is applied to the stacked structure shown in fig. 3, wherein the main structural dimension design is as shown in the following table 2:

TABLE 2 major structural dimensions

The metamaterial in fig. 3 was then simulated according to the dimensions in the above table, and the results are shown in fig. 11 and 12.

FIG. 11 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 10 in TE polarization with the incident angle theta according to the second embodiment of the present invention.

FIG. 12 is a graph showing the variation of the S21 curve of the metamaterial of FIG. 10 in TM polarization with the incident angle theta according to the second embodiment of the present invention.

As can be seen from FIGS. 11 and 12, when the incident angle theta is 0-70 deg., the TM polarization shows high-pass characteristic at 7-20GHz, and the wave-transparent is greater than-1 dB; when the incident angle theta is 0-70 degrees, TM polarization shows a cut-off characteristic at 0-0.8GHz, and wave-transmitting is smaller than-9.8 dB; when the incident angle theta is 0-60 degrees, the TE polarization wave-transparent basically shows the pure dielectric property, and the wave-transparent is larger than-0.64 dB at 0-18 GHz.

Fig. 13 is another schematic view of the periodic arrangement of the V-shaped metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention.

As shown in fig. 13, the basic unit of the metal microstructure on the metal microstructure layer 2 is V-shaped, and the opening angle of the V-shaped metal microstructure is 60 degrees, and other parameters are the same as those shown in fig. 10.

In the present embodiment, the periodic arrangement of the metal microstructures on the metal microstructure layer 2 shown in fig. 13 is applied to the stacked structure shown in fig. 3, wherein the main structural dimension design is as shown in the following table 3:

TABLE 3 major structural dimensions

The metamaterial in fig. 13 was then simulated according to the dimensions in the above table, and the results are shown in fig. 14 and 15.

Fig. 14 is a diagram illustrating a variation of the S21 curve of the metamaterial under TE polarization of fig. 13 at an incident angle theta of 0 ° according to the second embodiment of the present invention.

Fig. 15 is a diagram illustrating a variation of the S21 curve of the metamaterial of fig. 13 under TM polarization at an incident angle theta equal to 0 ° according to the second embodiment of the present invention.

As can be seen from fig. 14 and 15, the TE polarization is greater than-0.64 dB at 0-16GHz at an incident angle theta of 0 °; the TM polarization shows high-pass characteristic, wave transmission is larger than-0.66 dB at 3-20GHz, and the low-frequency polarization has a cut-off function. Therefore, the periodic arrangement of the linear horizontal direction communication structures like the V-shaped metal microstructures can realize the electric heating deicing function and the electromagnetic modulation function.

Fig. 16 is a schematic view of a third periodic arrangement of V-shaped metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention.

As shown in fig. 16, the basic unit of the metal microstructure on the metal microstructure layer 2 is V-shaped, the opening angle of the V-shaped metal microstructure is 90 degrees, the distance p between two adjacent rows of metal microstructures is 12mm, other parameters are the same as those shown in fig. 10, and a plurality of metal microstructures in any row are sequentially connected in the horizontal direction to form a rectangular wave shape.

In the present embodiment, the periodic arrangement of the metal microstructures on the metal microstructure layer 2 shown in fig. 16 is applied to the stacked structure shown in fig. 3, wherein the main structural dimension design is as shown in table 4 below:

TABLE 4 major structural dimensions

The metamaterial in fig. 16 was then simulated according to the dimensions in the above table, and the results are shown in fig. 17 and 18.

Fig. 17 is a diagram illustrating a variation of the S21 curve of the metamaterial of fig. 16 under TE polarization at an incident angle theta of 0 ° according to the second embodiment of the present invention.

Fig. 18 is a diagram illustrating a variation of the S21 curve of the metamaterial of fig. 16 under TM polarization at an incident angle theta of 0 ° according to the second embodiment of the present invention.

As can be seen from fig. 17 and 18, the TE polarization is greater than-0.54 dB at 0-18GHz at an incident angle theta of 0 °; TM polarization shows high-pass characteristic, wave-transmitting is larger than-0.95 dB at 3-20GHz, and the low-frequency polarization has a cut-off function. Therefore, the linear horizontal direction communication structure, such as the linear metal microstructure, the V-shaped bent metal microstructure, the rectangular wave-shaped bent metal microstructure and the like, can form the communication structure to realize the conductive path as long as the one-dimensional continuous arrangement in the horizontal direction is met, and further can realize the deicing function when being used as an electric heating layer for electrifying, and can also have the electromagnetic modulation function by designing the main structure size in the laminated structure.

In addition, the invention not only can realize the electric heating deicing function and the electromagnetic modulation function by the periodic arrangement of the linear type unidirectional communication structure, but also can realize the electric heating deicing function and the electromagnetic modulation function by the periodic arrangement of the curved type unidirectional communication structure.

Fig. 19 is a schematic diagram illustrating a periodic arrangement of semicircular metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention.

As shown in fig. 19, the basic unit of the metal microstructure on the metal microstructure layer 2 is semicircular, and includes a plurality of rows of semicircular metal microstructures which are continuously and periodically arranged in the horizontal direction, in any row, the plurality of semicircular metal microstructures are sequentially connected in the horizontal direction to form a curved horizontal direction communicating structure, the distance between the rows is p, the diameter of the semicircle is a, and the line width of the semicircular metal microstructures is ww.

In this embodiment, the periodic arrangement of the metal microstructures on the metal microstructure layer 2 shown in fig. 19 is applied to the stacked structure shown in fig. 3, in which the main structural dimension design is as shown in table 5 below:

TABLE 5 major structural dimensions

Parameter(s)	Numerical value (mm)
		d₁	0.3
d₂	0.1
		d₃	0.043
d₄	0.1
		d₅	0.3
d₆	0.2
		d₇	5.6
d₈	0.2
		d₉	0.3
ww	0.04
		p	8
a	4

The metamaterial in fig. 19 was then simulated according to the dimensions in the above table, and the results are shown in fig. 20 and 21.

Fig. 20 is a diagram illustrating a variation of the S21 curve of the metamaterial under TE polarization of fig. 19 under an incident angle theta of 0 ° in the second embodiment of the present invention.

Fig. 21 is a diagram illustrating a variation of the S21 curve of the metamaterial of fig. 19 in TM polarization at an incident angle theta of 0 ° according to the second embodiment of the present invention.

As can be seen from fig. 20 and 21, the TE polarization is greater than-0.35 dB at 0-20GHz at an incident angle theta of 0 °; TM polarization shows high-pass characteristic, wave-transmitting is larger than-1 dB at 6-20GHz, and low frequency has a cut-off function.

Fig. 22 is a schematic diagram illustrating the periodic arrangement of sinusoidal metal microstructures on the metal microstructure layer 2 included in the metamaterial according to the second embodiment of the present invention.

As shown in fig. 22, the basic unit of the metal microstructure on the metal microstructure layer 2 is a sine waveform, and includes a plurality of rows of sine waveform metal microstructures which are continuously and periodically arranged in the horizontal direction, in any row, the plurality of sine waveform metal microstructures are sequentially connected in the horizontal direction to form a curved horizontal direction communication structure, the distance between the rows is p, the period of the sine waveform is a, and the line width of the semicircular metal microstructure is ww.

In this embodiment, the periodic arrangement of the metal microstructures on the metal microstructure layer 2 shown in fig. 22 is applied to the stacked structure shown in fig. 3, in which the main structural dimension design is as shown in table 6 below:

TABLE 6 major structural dimensions

Parameter(s)	Numerical value (mm)
		d₁	0.3
d₂	0.1
		d₃	0.043
d₄	0.1
		d₅	0.3
d₆	0.2
		d₇	5.6
d₈	0.2
		d₉	0.3
ww	0.04
		p	15
a	10

The metamaterial in fig. 22 was then simulated according to the dimensions in the above table, and the results are shown in fig. 23 and 24.

Fig. 23 is a diagram illustrating a variation of the S21 curve of the metamaterial under TE polarization of fig. 22 in the second embodiment of the present invention when the incident angle theta is 0 °.

As can be seen from fig. 23 and 24, at an incident angle theta of 0 °, the TE polarization is greater than-0.02 dB at 0-20 GHz; the TM polarization shows high-pass characteristic, wave transmission is larger than-0.74 dB at 4-20GHz, and the low-frequency polarization has a cut-off function. Therefore, the curved unidirectional communicating structure, such as a semicircular metal microstructure, a sine wave-shaped metal microstructure and the like, can form the communicating structure to realize a conductive path as long as the unidirectional one-dimensional continuous arrangement is met, and further can realize a deicing function when the communicating structure is used as an electric heating layer and is electrified, and the communicating structure can also have an electromagnetic modulation function by designing the main structural size in the laminated structure.

Therefore, the linear and curved unidirectional communication structures are used as basic unit structures to realize the electric heating deicing function under the condition of periodic arrangement, and as long as the unidirectional continuous arrangement is met, the adjacent two unit structures can form a conductive path under the condition of intersection (such as common edges, common points, collinear sections and the like) so as to realize the deicing function when the electric heating layer is electrified, and the electromagnetic modulation function can be realized by designing the main structure size in the laminated structure. The electric heating layer (namely the metal soft plate) with the deicing function is connected with a power line through a welding point to form a wiring terminal besides ensuring that the metal layer is of a communicated structure, the wiring terminal is connected to an airborne power supply on an aircraft through the power line, a thin layer is dissolved between an ice layer and an outer skin by heat generated by the electric heating layer, the adhesive force between the ice layer and the outer skin is reduced, and the ice layer is easily blown down under the action of aerodynamic force or centrifugal force.

The technical scheme provided by the invention combines the electromagnetic modulation function on the basis of meeting the deicing function, solves the problem that the transmission of electromagnetic signals cannot be ensured due to the shielding of electromagnetic signals by a metal layer in the conventional deicing mode by designing the conducted metal channel and the specific design of the metal channel, and simultaneously can inhibit the interference of external electromagnetic signals outside the working frequency band of the electromagnetic transceiver in the part, so that the electromagnetic transceiver can be distributed at the part with good electromagnetic transmission visual field, such as microwave and millimeter wave antennas, and the like, and lays a foundation for the development of the airplane towards the trends of multi-sensor integration, full airspace perception and the like, thereby further improving the full information chain penetration of high-end aviation equipment.

Those skilled in the art will appreciate that the above embodiments are merely exemplary embodiments and that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention.

Claims

1. The metamaterial is characterized by comprising a base material layer and a metal micro-structure layer superposed on the base material layer, wherein the metal micro-structure layer is provided with a single-direction communication structure which is periodically arranged, the base material layer and the metal micro-structure layer jointly form a whole, the end part of the whole in the single direction is connected with a wiring terminal, and the wiring terminal is connected with an external power supply to form a conductive path so as to carry out electric heating by utilizing the characteristic of metal power-on heating.

2. The metamaterial according to claim 1, further comprising a first prepreg layer bonded to the metallic microstructure layer by a layer of adhesive.

3. The metamaterial according to claim 2, further comprising a second prepreg layer bonded to the base material layer by a layer of adhesive.

4. The metamaterial according to claim 3, further comprising a sandwich layer bonded to the second prepreg layer by a glue film.

5. The metamaterial according to claim 4, further comprising a third prepreg layer bonded to the core layer by a glue film.

6. The metamaterial according to claim 1, wherein in the metal microstructure layer, at least one metal communication line exists in a plurality of metal periodic units periodically arranged between the wiring terminals.

7. The metamaterial according to claim 6, wherein in the metal microstructure layer, a plurality of periodic metal units are sequentially connected in a horizontal direction in any one metal communication line, the metal units are V-shaped, and the opening angle of the V-shape is greater than 0 degree and less than or equal to 180 degrees.

8. The metamaterial according to claim 6, wherein in the metal microstructure layer, a plurality of periodic metal units are included in any one metal communication line and are sequentially connected in a horizontal direction, and the metal units are in a rectangular wave shape.

9. A radome, characterized in that it comprises a metamaterial according to any one of claims 1-8.

10. An aircraft, characterized in that it comprises a metamaterial according to any one of claims 1 to 8.