CN111969326A - Electric field regulation and control two-dimensional omnidirectional metal-medium composite stealth device and manufacturing method thereof - Google Patents

Abstract

The invention discloses a two-dimensional omnidirectional metal-dielectric composite stealth device with electric field regulation, comprising a stealth device main body and an electric field regulation system. The plate and the second dielectric plate are alternately arranged to form a layered stacking structure, and the layered stacking structure is a circular cylindrical body with a cylindrical space; N layers of annular metal cross arrays are respectively attached to both sides of the first dielectric plate, and each layer of annular metal The cross array includes a plurality of cuboid lattice units; the electric field control system is used to move the frequency characteristic curve of the main body of the stealth device, so as to realize the tuning of the working frequency of the stealth device. The invention realizes the stealth of electromagnetic waves of different frequency bands, has a wide application range, convenient control, simple and reasonable structure, convenient assembly and high structural stability. The invention also discloses a method for manufacturing a two-dimensional omnidirectional metal-dielectric composite stealth device regulated by an electric field.

Description

Electric field-controlled two-dimensional omnidirectional metal-dielectric composite stealth device and fabrication method

technical field

The invention relates to the technical field of electromagnetic wave control, in particular to a two-dimensional omnidirectional metal-dielectric composite stealth device with electric field regulation and a manufacturing method.

Background technique

The traditional stealth technology uses absorbing materials to reduce the reflection of radar waves to achieve stealth, but it is usually difficult to maintain the stealth effect in the face of more advanced detection technologies such as ground-to-air radar and multistatic radar. The emerging stealth technology based on transformation optics in recent years brings hope to solve this problem. Using the anisotropic electromagnetic parameters of a specific spatial distribution, the transforming optical stealth device can control the propagation path of the electromagnetic wave, so that it bypasses the stealth area when it propagates in the stealth medium, and returns to the original incident direction when it exits, so that the The electromagnetic field distribution is the same as when there are no objects in the area, thus achieving perfect stealth in the true sense.

However, stealth devices based on transformation optics require complex electromagnetic parameters that are non-uniform and anisotropic. Currently, the electromagnetic wave stealth devices implemented generally use a phase approximation method to reduce the non-uniformity, and specify the polarization direction of the incident wave. The operating range of the device is reduced from three-dimensional space to two-dimensional space, so that the non-uniform and anisotropic electromagnetic parameters are simplified. Nevertheless, the simplified parameters still need to be realized with the help of artificially constructed electromagnetic metamaterials. Existing metamaterials use electromagnetic resonance to achieve specific equivalent electromagnetic parameters, which have serious dispersion characteristics. Once the structure is determined, the operating frequency band is also fixed, and the operating frequency is difficult to tune; the coupling between electromagnetic resonances in different directions of metamaterials This makes it difficult to precisely control the equivalent anisotropic electromagnetic parameters, and it takes a lot of time and computing resources to optimize the design of the structure; in addition, metamaterials often need to rely on a support frame or substrate to realize the periodic space of the electromagnetic resonance unit. distribution, which easily causes assembly errors and reduces structural stability, limiting the application range of stealth devices.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to propose a two-dimensional omnidirectional metal-dielectric composite stealth device with electric field regulation, which can realize stealth to electromagnetic waves in different frequency bands, has a large application range, is convenient to control, has a simple and reasonable structure, is convenient to assemble and has a structure High stability.

The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to the embodiment of the first aspect of the present invention includes:

a stealth device body, the stealth device body comprising a first dielectric plate, a second dielectric plate and an annular metal cross array; wherein the dielectric constant of the first dielectric plate is higher than that of the second dielectric plate, The first dielectric plate and the second dielectric plate are both circular and cylindrical, the first dielectric plate and the second dielectric plate are alternately arranged to form a layered stack structure, and the layered stack structure has a cylindrical shape A circular cylindrical body in space; N layers of the annular metal cross arrays are respectively attached to both sides of the first dielectric plate, where N is an integer greater than 1, and each layer of the annular metal cross array includes a plurality of cuboid crystals A lattice unit, wherein each of the lattice units includes two metal crosses symmetrically distributed on both sides of the first dielectric plate, and the lattice units of each layer of the annular metal cross array and the The geometric dimensions of the metal crosses are the same, and the lattice units of the annular metal cross arrays of different layers and the geometric dimensions of the metal crosses in the units are different;

An electric field regulation system, the electric field regulation system includes a DC regulated power supply, a DC bias line and a DC voltage controller; wherein, the DC regulated power supply is used to apply a stable DC voltage to the first dielectric plate, so that the The first dielectric plate is in a stable DC electric field; the annular metal cross arrays on both sides of the first dielectric plate are respectively connected to the positive and negative electrodes of the DC regulated power supply through the DC bias line; The DC voltage controller is used to control the output voltage of the DC regulated power supply to adjust the DC electric field applied to the first dielectric plate, so as to change the dielectric constant of the first dielectric plate itself, so that the The frequency characteristic curve of the main body of the stealth device moves, so as to realize the tuning of the operating frequency of the stealth device.

According to the electric field control two-dimensional omnidirectional metal-dielectric composite stealth device according to the embodiment of the first aspect of the present invention, the first dielectric plate and the second dielectric plate are alternately arranged to form a layered stack structure, and two sides of the first dielectric plate are respectively attached with annular The metal cross array 12, the metal cross will generate magnetic resonance in the alternating magnetic field, in this way, the equivalent anisotropic permeability along the direction of the two metal arms of the metal cross can be achieved through the magnetic resonance of the metal cross, through the first dielectric The layered stack structure of the plate and the second dielectric plate realizes the equivalent permittivity along the stacking direction, when the stealth device realizes the equivalent permittivity of the specific anisotropy required by the transformation optics theory in a specific frequency band and so on When the magnetic permeability is effective, the stealth device can control the requirements of the electromagnetic wave propagation path and phase, so that the obstacles in the cylindrical space can realize the arbitrary waveforms including plane waves and cylindrical waves in the two-dimensional plane and the electromagnetic waves in any incident direction. Stealth; control the output voltage of the DC regulated power supply through the DC voltage controller, adjust the DC voltage on both sides of the first dielectric plate, that is, adjust the DC electric field where the first dielectric plate is located, thereby changing the dielectric constant of the first dielectric plate, By changing the resonance characteristics of the metal cross, the equivalent permeability dispersion curve of the annular metal cross array 12 is shifted, and the operating frequency of the stealth device can be tuned, thereby realizing stealth of electromagnetic waves in different frequency bands. In addition, the stealth device adopts a layered stack structure without the need for additional support frames or substrates. To sum up, the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to the first aspect of the present invention can achieve stealth to electromagnetic waves of different frequency bands, has a large application range, is convenient to control, has a simple and reasonable structure, is convenient to assemble, and has a stable structure. high.

According to an embodiment of the first aspect of the present invention, the dielectric constant of the first dielectric plate varies with the electric field, and the value of the dielectric constant of the first dielectric plate is greater than 50.

According to a further embodiment of the first aspect of the present invention, the dielectric constant of the second dielectric plate ranges from 0.8 to 2.0.

According to an embodiment of the first aspect of the present invention, when the stealth device body takes the zrθ cylindrical coordinate system as a reference, the z-axis is the axial direction of the stealth device body, and the r-axis is the diameter of the stealth device body. The θ-axis is the tangential direction of the cloak body, and the two metal arms of the metal cross in the annular metal cross array are respectively parallel to the r-axis direction and the theta-axis direction.

According to a further embodiment of the first aspect of the present invention, the electromagnetic parameters of the anisotropy and gradient distribution required by the stealth device under the condition that the electric field always polarizes the incident wave in the Z-axis direction are obtained according to the following formula:

Among them, μ _r is the radial permeability;

μ _θ is the tangential permeability;

ε _z is the dielectric constant of the axial direction;

r _a is the radius of the inner boundary of the body of the stealth device;

r _b is the radius of the outer boundary of the stealth device body;

r is an annular radius of the metal cross annular array in any one of the first to Nth layers in the stealth device body.

According to a further embodiment of the first aspect of the present invention, the lengths of the two metal arms along the r-axis and the θ-axis direction of a single metal cross in the annular metal cross array are different.

According to a further embodiment of the first aspect of the present invention, the geometric size of the lattice unit is less than 1/5 of the wavelength of the electromagnetic wave at the working frequency.

According to an embodiment of the first aspect of the present invention, the annular metal cross arrays on both sides of the first dielectric plate serve as positive and negative electrodes to provide the first dielectric plate with the DC electric field correspondingly.

The second aspect of the present invention also provides a method for manufacturing a two-dimensional omnidirectional metal-dielectric composite stealth device regulated by an electric field.

According to a method for fabricating an electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to an embodiment of the second aspect of the present invention, the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device is any one of the embodiments of the first aspect of the present invention For the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device, the fabrication method includes the following steps:

Process the first dielectric plate and the second dielectric plate with required geometrical dimensions by machining;

The annular metal cross arrays and the DC bias lines are processed on both sides of the first dielectric plate, and the annular metal cross arrays on both sides of the first dielectric plate are respectively connected through the DC bias lines. into the positive and negative poles of the DC regulated power supply;

The first dielectric plate and the second dielectric plate attached with the annular metal cross array and the DC bias line are alternately arranged to form a layered stack structure.

According to the method for fabricating the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the second aspect of the present invention, a dielectric plate with a high dielectric constant is selected, and a first dielectric with a required geometric size is processed by machining board, select a low dielectric constant dielectric board, and process the second dielectric board of the required geometric size by machining; process the two sides of the first dielectric board by means of printed circuit board, micromachining or 3D printing, etc. To obtain the required annular metal cross array and DC bias line, the first dielectric plate and the second dielectric plate attached with the annular metal cross array and the DC bias line are alternately arranged to form a layered stack structure to obtain the main body of the stealth device, a plurality of DC One end of the bias line is respectively connected to the annular metal cross array on both sides of the first dielectric plate in a one-to-one correspondence, and the other end is respectively connected to the positive or negative pole of the DC regulated power supply. Therefore, the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device is simple to manufacture and easy to assemble. The output voltage of the DC regulated power supply is controlled by the DC voltage controller, and the DC voltage on both sides of the first dielectric plate is adjusted, that is, the first dielectric plate is adjusted. The DC electric field where the dielectric plate is located changes the permittivity of the first dielectric plate, changes the resonance characteristics of the metal cross, and moves the equivalent permeability dispersion curve of the annular metal cross array, which can adjust the operating frequency of the stealth device. Tuning, thereby realizing the stealth of electromagnetic waves in different frequency bands.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic structural diagram of an electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to an embodiment of the first aspect of the present invention.

FIG. 2 is an enlarged schematic view of A in FIG. 1 .

3 is a schematic structural diagram of a cuboid lattice unit in an electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to an embodiment of the first aspect of the present invention.

FIG. 4 is a schematic diagram of the assembly of the first dielectric plate and the metal cross in the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to the first aspect of the present invention.

FIG. 5 is a schematic structural diagram of a layered stack structure in an electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to an embodiment of the first aspect of the present invention.

6 is a diagram showing the stealth effect of the two-dimensional omnidirectional metal-dielectric composite stealth device regulated by the electric field to planar electromagnetic waves according to the embodiment of the first aspect of the present invention.

7 is a diagram showing the stealth effect of the two-dimensional omnidirectional metal-dielectric composite stealth device regulated by the electric field to cylindrical electromagnetic waves according to the embodiment of the first aspect of the present invention.

和等效介电常数

的色散曲线。FIG. 8 is the equivalent magnetic permeability of a cuboid lattice unit in the stealth device main body of the two-dimensional omnidirectional metal-dielectric composite stealth device according to the embodiment of the first aspect of the present invention.

and the equivalent dielectric constant

dispersion curve.

Fig. 9 is a schematic diagram of the scattering cross section of an obstacle as a function of frequency, in which the solid line is the curve of the scattering cross section with frequency when the obstacle is located in a cylindrical space, and the dashed line is the scattering cross section when there is only an obstacle but no stealth device. Frequency change curve.

Reference number:

Stealth Device 1000

Stealth device body 1

Layered Stacked Structure 11

cylindrical space 111 annular cylindrical body 112 first dielectric plate 113 second dielectric plate 114

Circular Metal Cross Array 12

Metal Cross 121 Metal Arm 1211

Lattice cell 13

Electric field control system 2

DC stabilized power supply 21 DC bias line 22 DC voltage controller 23

Planar electromagnetic wave emission source 3 Planar electromagnetic wave 31

Cylindrical electromagnetic wave emission source 4 Cylindrical electromagnetic wave 41

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

The following describes the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the embodiment of the first aspect of the present invention with reference to FIGS. 1 to 9 .

As shown in FIGS. 1 to 7 , an electric field control two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to an embodiment of the first aspect of the present invention includes a stealth device body 1 and an electric field control system 2 . The stealth device body 1 includes a first The dielectric plate 113, the second dielectric plate 114 and the annular metal cross array 12; wherein the dielectric constant of the first dielectric plate 113 is higher than that of the second dielectric plate 114, the first dielectric plate 113 and the second dielectric plate 114 They are all circular columnar shapes, the first dielectric plates 113 and the second dielectric plates 114 are alternately arranged to form a layered stack structure 11 , and the layered stack structure 11 is a circular columnar body 112 with a cylindrical space 111 ; N layers of annular metal cross arrays 12 are respectively attached on both sides, where N is an integer greater than 1, and each layer of annular metal cross array 12 includes a plurality of cuboid lattice units 13 , wherein each cuboid lattice unit 13 includes two The metal crosses 121 symmetrically distributed on both sides of the first dielectric plate 113, the geometrical dimensions of the rectangular parallelepiped lattice unit 13 of the annular metal cross array 12 of each layer and the metal cross 121 in the unit are the same, and the rectangular parallelepiped crystal of the annular metal cross array 12 of different layers The geometric dimensions of the grid unit 13 and the metal cross 121 in the unit are different; the electric field regulation system 2 includes a DC regulated power supply 21, a DC bias line 22 and a DC voltage controller 23; The dielectric plate 113 applies a stable DC voltage, so that the first dielectric plate 113 is in a stable DC electric field; the annular metal cross arrays 12 on both sides of the first dielectric plate 113 are respectively connected to the DC regulated power supply 21 through the DC bias line 22 . The positive and negative electrodes are connected to each other; the DC voltage controller 23 is used to control the output voltage of the DC regulated power supply 21 to adjust the DC electric field applied to the first dielectric plate 113, thereby changing the permittivity of the first dielectric plate 113 itself, making it invisible The frequency characteristic curve of the device main body 1 is shifted to realize the tuning of the working frequency of the stealth device 1000 .

Specifically, as shown in FIGS. 1 and 4 , the stealth device body 1 includes a first dielectric plate 113 , a second dielectric plate 114 and an annular metal cross array 12 ; wherein the dielectric constant of the first dielectric plate 113 is higher than that of the second dielectric plate 113 . The dielectric constant of the dielectric plate 114, the first dielectric plate 113 and the second dielectric plate 114 are both circular and cylindrical, the first dielectric plate 113 and the second dielectric plate 114 are alternately arranged to form the layered stack structure 11, and the layered stack structure 11 N-layer annular metal cross arrays 12 are respectively attached to both sides of the first dielectric plate 113, N is an integer greater than 1, and each layer of annular metal cross arrays 12 includes a plurality of cuboids The lattice unit 13, wherein each cuboid lattice unit 13 includes two metal crosses 121 symmetrically distributed on both sides of the first dielectric plate 113, the cuboid lattice unit 13 of each layer of the annular metal cross array 12 and the inner The geometrical dimensions of the metal crosses 121 are the same, and the geometrical dimensions of the cuboid lattice cells 13 of the annular metal cross arrays 12 of different layers and the metal crosses 121 in the cells are different. It can be understood that the first dielectric plates 113 and the second dielectric plates 114 are alternately arranged to form the layered stack structure 11 , and the two sides of the first dielectric plate 113 are respectively attached with the annular metal cross arrays 12 . The resonance can realize the equivalent anisotropic permeability along the direction of the two metal arms 1211 of the metal cross 121, and the equivalent anisotropic permeability along the stacking direction can be achieved through the layered stack structure 11 of the first dielectric plate 113 and the second dielectric plate 114 dielectric constant, the stealth device 1000 can meet the requirements of transforming optics theory to control the propagation path and phase of electromagnetic waves, so as to achieve stealth from obstacles in the cylindrical space 111; preferably, the dielectric constant of the first dielectric plate 113 is much higher than The dielectric constant of the second dielectric plate 114 .

The electric field regulation system 2 includes a DC regulated power supply 21, a DC bias line 22 and a DC voltage controller 23; wherein, the DC regulated power supply 21 is used to apply a stable DC voltage to the first dielectric plate 113, so that the first dielectric plate 113 is in a stable DC electric field; the annular metal cross arrays 12 on both sides of the first dielectric plate 113 are respectively connected to the positive and negative poles of the DC regulated power supply 21 through the DC bias line 22; the DC voltage controller 23 is used to control the DC The output voltage of the regulated power supply 21 is used to adjust the DC electric field applied to the first dielectric plate 113, thereby changing the dielectric constant of the first dielectric plate 113 itself, so as to move the frequency characteristic curve of the main body 1 of the stealth device, so as to realize the control of the stealth device 1000. Tuning of the operating frequency. It can be understood that the annular metal cross arrays 12 on both sides of the first dielectric plate 113 are respectively connected together through the DC bias line 22 and connected to the positive or negative pole of the DC regulated power supply 21, so as to apply a stable voltage to the first dielectric plate 113. The DC electric field of the first dielectric plate 113 itself changes with the change of the DC electric field, the DC voltage controller 23 controls the output voltage of the DC regulated power supply 21, and adjusts the two sides of the first dielectric plate 113. The DC voltage of the first dielectric plate 113 is adjusted, so that the dielectric constant of the first dielectric plate 113 is changed, and the resonance characteristics of the metal cross 121 are changed, so that the equivalent permeability of the annular metal cross array 12 is dispersed. The curve moves, and the operating frequency of the stealth device 1000 can be tuned to achieve stealth to electromagnetic waves in different frequency bands.

According to the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the embodiment of the first aspect of the present invention, the first dielectric plates 113 and the second dielectric plates 114 are alternately arranged to form a layered stack structure 11 . A ring-shaped metal cross array 12 is attached to the side respectively. The metal cross 121 will generate magnetic resonance in the alternating magnetic field. In this way, through the magnetic resonance of the metal cross 121, the equivalent iso-direction of the two metal arms 1211 of the metal cross 121 can be realized. Anisotropic permeability, through the layered stack structure 11 of the first dielectric plate 113 and the second dielectric plate 114 to achieve the equivalent permittivity along the stacking direction, when the stealth device 1000 realizes the requirements of the theory of transformation optics in a certain frequency band When the equivalent dielectric constant and equivalent magnetic permeability of the specific anisotropy are set, the stealth device 1000 can control the requirements of the propagation path and phase of the electromagnetic wave, so that the obstacles in the cylindrical space 111 can affect the two-dimensional plane including plane waves and Arbitrary waveforms including cylindrical waves and electromagnetic waves in any incident direction realize stealth; the DC voltage controller 23 controls the output voltage of the DC regulated power supply 21 to adjust the DC voltage on both sides of the first dielectric plate 113, that is, to adjust the first dielectric The direct current electric field in which the plate 113 is located, thereby changing the permittivity of the first dielectric plate 113, changing the resonance characteristics of the metal cross 121, so that the equivalent permeability dispersion curve of the annular metal cross array 12 is shifted, which can affect the stealth device 1000. The working frequency is tuned to realize the stealth of electromagnetic waves in different frequency bands. Furthermore, the stealth device 1000 employs the stacked stack structure 11 without requiring additional support frames or substrates. To sum up, the electric field control two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the first aspect of the present invention can achieve stealth to electromagnetic waves of different frequency bands, has a large application range, is convenient to control, has a simple and reasonable structure, is convenient to assemble, and has a stable structure Sex is high.

It should be noted that, when the geometrical dimensions of the cuboid lattice unit 13 and the metal cross 121 and the thicknesses of the first dielectric plate 113 and the second dielectric plate 114 are kept unchanged, the annular cylindrical body of the cylindrical space 111 of the stealth device 1000 is If the area of 112 is proportionally enlarged, or the number of periods of the cuboid lattice cells 13 in the z-axis direction of the stealth device 1000 is increased, the space size of the cylindrical space can be increased, and the stealth of larger-sized obstacles can be realized.

According to an embodiment of the first aspect of the present invention, the dielectric constant of the first dielectric plate 113 varies with the electric field, and the value of the dielectric constant of the first dielectric plate 113 is greater than 50. It can be understood that, since the dielectric constant of the high dielectric constant dielectric plate will obviously change with the change of the electric field, the first dielectric plate 113 should be selected as a high dielectric constant dielectric plate with a larger coefficient of change in the dielectric constant with the applied electric field. The dielectric constant of the first dielectric plate 113 can be obviously adjusted by adjusting the electric field. For example, the first dielectric plate 113 can be a ferroelectric ceramic material with a dielectric constant greater than 50.

According to a further embodiment of the first aspect of the present invention, the dielectric constant of the second dielectric plate 114 ranges from 0.8 to 2.0. Specifically, the dielectric constant of the second dielectric board 114 may be 0.8, 1.0 or 1.2, and the second dielectric board 114 should be a low-k dielectric board with a dielectric constant much lower than that of the first dielectric board 113, such as balsa wood Or fluoropolymer foam, etc., which can effectively reduce the interference to incident electromagnetic waves.

和

According to an embodiment of the first aspect of the present invention, when the stealth device body 1 takes the zrθ cylindrical coordinate system as a reference, the z axis is the axial direction of the stealth device body, the r axis is the radial direction of the stealth device body, and the θ axis Being the tangential direction of the cloak body, the two metal arms 1211 of the metal cross 121 in the annular metal cross array 12 are parallel to the r-axis direction and the θ-axis direction, respectively. Specifically, when the stealth device body 1 takes the zrθ cylindrical coordinate system as a reference, the metal arms 1211 in the metal cross 121 parallel to the r-axis direction are used to realize magnetic resonance in the θ-axis direction, and the metal arms 1211 parallel to the θ-axis direction are used for The magnetic resonance in the r-axis direction is realized, which makes the cuboid lattice unit 13 have anisotropic equivalent magnetic permeability in the r-axis and θ-axis directions, respectively. The equivalent magnetic permeability of the anisotropy in the θ axis direction is

and

According to a further embodiment of the first aspect of the present invention, the electromagnetic parameters of the anisotropy and gradient distribution required by the stealth device 1000 under the condition that the electric field always polarizes the incident wave in the Z-axis direction are obtained according to the following formula:

Among them, μ _r is the radial permeability;

μ _θ is the tangential permeability;

ε _z is the dielectric constant of the axial direction;

r _a is the radius of the inner boundary of the stealth device body 1;

r _b is the radius of the outer boundary of the stealth device body 1;

r is the annular radius of the annular array of metal crosses 121 in any one of the first to Nth layers in the stealth device body 1 .

It can be understood that, according to the principle of transformation optics, when the radii _{ra and r b of} the inner and outer boundaries of the stealth device body 1 are determined, the specific anisotropy required by the body 1 of the stealth device can be calculated through the ideal electromagnetic parameter formula. As well as the permittivity and permeability of gradient distribution, the ideal electromagnetic parameter formula is expressed in the form of cylindrical coordinates. When the electric field is always polarized in the z-axis direction, the stealth device 1000 needs electromagnetic parameters of anisotropy and gradient distribution according to The following ideal electromagnetic parameter formula is obtained:

The ideal electromagnetic parameter changes continuously with the position, which cannot be realized by using metamaterials. Therefore, it is necessary to discretize the electromagnetic parameters in the stealth device body 1, that is, the stealth device body 1 is divided into multi-layer annular regions. Let the electromagnetic parameters in the annular region of each layer remain unchanged and equal to the electromagnetic parameter value in the middle between the inner boundary and the outer boundary of the annular region.

According to Lenz's law and the law of electromagnetic induction, an alternating current will be generated in the metal cross 121 in the alternating electromagnetic field. Therefore, magnetic resonance can be generated in two directions perpendicular to the metal arm 1211. Therefore, the metal arm 1211 in the circular metal cross array 12 parallel to the r-axis direction is used to realize the magnetic permeability μ _θ in the θ-axis direction. The metal arm 1211 in the array 12 parallel to the θ-axis direction realizes the magnetic permeability μ _r in the r-axis direction, and the layered stack structure 11 of the first dielectric plate 113 and the second dielectric plate 114 is used to realize the magnetic permeability in the z-axis direction. Conductivity ε _z .

It should be noted that each pair of metal crosses 121 and the first dielectric plate 113 and the second dielectric plate 114 in the cuboid region constitute a cuboid lattice unit 13, and the equivalent magnetic field of a cuboid lattice unit 13 Conductivity is a function of the frequency of the incident electromagnetic wave, while the equivalent permittivity hardly changes with frequency in the operating frequency band. Using the magnetic resonance characteristics of the metal cross 121, adjust the geometric parameters of the annular metal cross array 12 (the length of the metal arm 1211, the line width of the metal arm 1211, the period length of the annular metal cross array 12, etc.), so that under a certain operating frequency band , the equivalent magnetic permeability and equivalent permittivity of the metal-dielectric composite metamaterial cuboid lattice unit 13 in several different directions simultaneously reach the values required by the theory of transformation optics, and the discretized ring shape of different layers In the area, metal crosses 121 and cuboid lattice units 13 of different sizes are used to construct an annular array to achieve the required gradient electromagnetic parameters. At this time, the electromagnetic waves in the stealth device body 1 will bypass the cylindrical space 111 and exit, and when exiting Return to the original propagation direction, thereby realizing the stealth of electromagnetic waves. In the alternating electromagnetic field, an alternating current is generated inside the metal cross 121, which is equivalent to an RLC series resonant circuit. The equivalent inductance L and equivalent capacitance C of the series circuit are both the same as the dielectric constant of the first dielectric plate 113 itself. Therefore, by adjusting the electric field to change the dielectric constant of the first dielectric plate 113 itself, the equivalent inductance value and equivalent capacitance value of the RLC series resonant circuit can be changed, so that the resonance characteristic curve of the metal cross 121 is shifted. The operating frequency corresponding to a metal-dielectric composite metamaterial cuboid lattice unit 13 also shifts accordingly. For any two different lattice units 13, the ratio of their operating frequencies is only related to the ratio of the lengths of their metal arms 1211, and has nothing to do with the dielectric constant of the first dielectric plate 113 itself. The dielectric constant of the dielectric plate 113 itself and the operating frequency of each lattice unit 13 are shifted, but the operating frequencies of any two lattice units 13 are the same, so as to achieve the purpose of tuning the operating frequency of the main body 1 of the stealth device.

和等效介电常数

的色散曲线。由环形金属十字阵列12实现的各向异性等效磁导率

和

在磁谐振频率处具有洛仑兹线型的色散曲线，由第一电介质板113与第二电介质板114的层状堆叠结构11实现的等效介电常数

具有几乎非色散的常数值，能够实现一定范围内的等效磁导率和等效介电常数，并且该超材料结构不同方向上的电磁谐振间不存在耦合，能够实现对等效电磁参数的精准设计。It should be noted that, as shown in FIG. 8 , is the equivalent magnetic permeability of a cuboid lattice unit 13 in the stealth device body 1

and the equivalent dielectric constant

dispersion curve. Anisotropic Equivalent Permeability Realized by Annular Metal Cross Array 12

and

Equivalent permittivity achieved by the layered stack structure 11 of the first dielectric plate 113 and the second dielectric plate 114 having a Lorentzian line-type dispersion curve at the magnetic resonance frequency

With almost non-dispersive constant value, it can achieve equivalent permeability and equivalent permittivity within a certain range, and there is no coupling between electromagnetic resonances in different directions of the metamaterial structure, which can realize the adjustment of equivalent electromagnetic parameters. Precise design.

The following three specific examples are used to describe the anisotropic electromagnetic parameters required by each layer in the body 1 of the stealth device from the inside to the outside when _ra and _rb are different.

Taking _ra as 30mm and _rb as 60mm, and discretizing the main body of the stealth device 1 into 5-layer annular areas, the anisotropic electromagnetic parameters required by each layer of the main body of the stealth device 1 from the inside to the outside are as follows:

layers 1 2 3 4 5 μ_r 0.017 0.107 0.222 0.339 0.449 μ_θ 2.000 2.000 2.000 2.000 2.000 ε_z 2.000 2.000 2.000 2.000 2.000

Further, taking _{ra as 30 mm and r b as} 60 mm, and discretizing the stealth device body 1 into 10-layer annular regions, the anisotropic electromagnetic parameters required by each layer of the stealth device body 1 from the inside to the outside are as follows:

layers 1 2 3 4 5 6 7 8 9 10 μ_r 0.005 0.034 0.080 0.134 0.193 0.252 0.310 0.367 0.422 0.475 μ_θ 2.000 2.000 2.000 2.000 2.000 2.000 2.000 2.000 2.000 2.000 ε_z 2.000 2.000 2.000 2.000 2.000 2.000 2.000 2.000 2.000 2.000

Further, taking _ra as 30mm and _rb as 90mm, and discretizing the main body of the stealth device 1 into 10-layer annular regions, the anisotropic electromagnetic parameters required by each layer of the main body of the stealth device 1 from the inside to the outside are as follows:

layers 1 2 3 4 5 6 7 8 9 10 μ_r 0.012 0.080 0.167 0.254 0.337 0.412 0.479 0.540 0.595 0.644 μ_θ 1.500 1.500 1.500 1.500 1.500 1.500 1.500 1.500 1.500 1.500 ε_z 1.500 1.500 1.500 1.500 1.500 1.500 1.500 1.500 1.500 1.500

The two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the embodiment of the first aspect of the present invention will be described below based on two specific examples.

The obstacle is placed in the cylindrical area in the stealth device 1000 , for the plane electromagnetic wave 31 emitted by the plane electromagnetic wave emission source 3 and incident in any direction in the two-dimensional plane, the electric field controls the two-dimensional omnidirectional metal-dielectric composite stealth device 1000 The effect of stealth to the plane electromagnetic wave 31 is shown in FIG. 6 , the stealth device 1000 can control the iso-phase plane of the outgoing electromagnetic wave to remain flat, and the propagation direction is consistent with the incident electromagnetic wave, that is, the stealth of the plane electromagnetic wave 31 is realized.

The obstacle is placed in the cylindrical area in the stealth device 1000 , for the cylindrical electromagnetic wave 41 emitted by the cylindrical electromagnetic wave emission source 4 at any position in the two-dimensional plane, the electric field controls the two-dimensional omnidirectional metal-dielectric composite stealth device 1000 The effect of stealth to the cylindrical electromagnetic wave 41 is shown in FIG. 7 . The stealth device 1000 can control the iso-phase surface of the outgoing electromagnetic wave to remain a cylinder, and the propagation direction is the same as the incident electromagnetic wave, which also realizes the stealth of the cylindrical electromagnetic wave 41 .

According to a further embodiment of the first aspect of the present invention, the lengths of the two metal arms 1211 of a single metal cross 121 in the annular metal cross array 12 along the r-axis and θ-axis directions are different. Specifically, as shown in FIG. 3 and FIG. 4 , the length of the metal arm 1211 of the metal cross 121 of the j-th layer along the r-axis direction is L _r,j , the length of the metal arm 1211 of the metal cross 121 along the θ-axis direction is L _{θ, j} , the distribution period of the annular metal cross array 12 along the r-axis direction is the length _Pr,j of the unit along the r-axis direction, the distribution period of the annular metal cross array 12 along the θ-axis direction is the unit length P _{θ along the θ-axis direction, j} .

According to a further embodiment of the first aspect of the present invention, the geometric size of the cuboid lattice unit 13 is less than 1/5 of the wavelength of the electromagnetic wave at the working frequency. It can be understood that the geometric size of the cuboid lattice unit 13 is limited to less than 1/5 of the electromagnetic wave wavelength of the operating frequency, which can meet the theoretical requirements of the equivalent medium of metamaterials, so that the cuboid lattice unit 13 can be equivalent to a kind of It is a homogeneous medium, and its electromagnetic properties can be described by equivalent permeability and equivalent permittivity.

According to an embodiment of the first aspect of the present invention, the annular metal cross arrays 12 on both sides of the first dielectric plate 113 serve as positive and negative electrodes to provide a DC electric field to the first dielectric plate 113 correspondingly. It can be understood that the annular metal cross arrays 12 on both sides of the first dielectric plate 113 are respectively connected together through the DC bias lines 22 and connected to the positive and negative poles of the DC regulated power supply 21, so as to apply a stable voltage to the first dielectric plate 113. Since the first dielectric plate 113 has the characteristic that its own dielectric constant changes with the change of the DC electric field, the output voltage of the DC regulated power supply 21 is controlled by the DC voltage controller 23, so that the first dielectric plate 113 The annular metal cross arrays 12 on both sides can adjust the DC voltage on both sides of the first dielectric plate 113 , that is, adjust the DC electric field where the first dielectric plate 113 is located, thereby changing the dielectric constant of the first dielectric plate 113 .

The second aspect of the present invention also provides a method for fabricating the two-dimensional omnidirectional metal-dielectric composite stealth device 1000 regulated by an electric field.

According to the manufacturing method of the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the embodiment of the second aspect of the present invention, the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000 is any one of the embodiments of the first aspect of the present invention The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000, the fabrication method includes the following steps:

Process the first dielectric plate 113 and the second dielectric plate 114 with required geometrical dimensions by machining;

The annular metal cross arrays 12 and the DC bias lines 22 are processed on both sides of the first dielectric plate 113 , and the annular metal cross arrays 12 on both sides of the first dielectric plate 113 are respectively connected to the DC voltage regulator through the DC bias lines 22 The positive and negative poles of the power supply 21;

The first dielectric plates 113 and the second dielectric plates 114 to which the annular metal cross arrays 12 and the DC bias lines 22 are attached are alternately arranged to form the layered stack structure 11 .

According to the method for fabricating the electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device 1000 according to the second aspect of the present invention, a dielectric plate with a high dielectric constant is selected, and a first dielectric with a required geometric size is processed by machining Board 113, a low dielectric constant dielectric board is selected, and the second dielectric board 114 of the required geometric size is processed by machining; The required annular metal cross arrays 12 and DC bias lines 22 are processed on the side, and the first dielectric plates 113 and the second dielectric plates 114 attached with the annular metal cross arrays 12 and the DC bias lines 22 are alternately arranged to form a layered stack structure. 11. Obtain the main body 1 of the stealth device. One end of the plurality of DC bias lines 22 is respectively connected to the annular metal cross array 12 on both sides of the first dielectric plate 113 in a one-to-one correspondence, and the other end is respectively connected to the positive pole or the positive pole of the DC regulated power supply 21. negative electrode. Therefore, the electric field control two-dimensional omnidirectional metal-dielectric composite stealth device 1000 is simple to manufacture and easy to assemble. The DC voltage controller 23 controls the output voltage of the DC regulated power supply 21, and adjusts the DC voltage on both sides of the first dielectric plate 113. That is, adjusting the DC electric field where the first dielectric plate 113 is located, thereby changing the permittivity of the first dielectric plate 113 and changing the resonance characteristics of the metal cross 121, so that the equivalent permeability dispersion curve of the annular metal cross array 12 moves, The operating frequency of the stealth device 1000 can be tuned, thereby realizing stealth of electromagnetic waves in different frequency bands.

As shown in FIG. 9 , the solid line in the figure is the variation curve of the scattering cross section with frequency when the obstacle is located in the cylindrical space 111 of the stealth device main body 1 , and the dotted line is the scattering cross section with frequency when there is only an obstacle but no stealth device 1000 . change curve. At the operating frequency, the scattering cross section of the stealth device 1000 reaches the lowest point and is smaller than the scattering cross section of the obstacle, indicating that the stealth device 1000 can effectively stealth from the obstacles located in the cylindrical space 111 .

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, or characteristic described by an example or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, The scope of the invention is defined by the claims and their equivalents.

Claims (9)

1. a two-dimensional omnidirectional metal-dielectric composite stealth device for electric field regulation, is characterized in that, comprises: a stealth device body, the stealth device body comprising a first dielectric plate, a second dielectric plate and an annular metal cross array; wherein the dielectric constant of the first dielectric plate is higher than that of the second dielectric plate, The first dielectric plate and the second dielectric plate are both circular and cylindrical, the first dielectric plate and the second dielectric plate are alternately arranged to form a layered stack structure, and the layered stack structure has a cylindrical shape A circular cylindrical body in space; N layers of the annular metal cross arrays are respectively attached to both sides of the first dielectric plate, where N is an integer greater than 1, and each layer of the annular metal cross array includes a plurality of cuboid crystals A lattice unit, wherein each of the lattice units includes two metal crosses symmetrically distributed on both sides of the first dielectric plate, and the lattice units of each layer of the annular metal cross array and the The geometric dimensions of the metal crosses are the same, and the lattice units of the annular metal cross arrays of different layers and the geometric dimensions of the metal crosses in the units are different; An electric field regulation system, the electric field regulation system includes a DC regulated power supply, a DC bias line and a DC voltage controller; wherein, the DC regulated power supply is used to apply a stable DC voltage to the first dielectric plate, so that the The first dielectric plate is in a stable DC electric field; the annular metal cross arrays on both sides of the first dielectric plate are respectively connected to the positive and negative electrodes of the DC regulated power supply through the DC bias line; The DC voltage controller is used to control the output voltage of the DC regulated power supply to adjust the DC electric field applied to the first dielectric plate, so as to change the dielectric constant of the first dielectric plate itself, so that the The frequency characteristic curve of the main body of the stealth device moves, so as to realize the tuning of the operating frequency of the stealth device. 2 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 1 , wherein the dielectric constant of the first dielectric plate changes with the change of the electric field, and the first dielectric plate changes. 3 . The value of the dielectric constant is greater than 50. 3 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 2 , wherein the dielectric constant of the second dielectric plate ranges from 0.8 to 2.0. 4 . 4 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 1 , wherein the main body of the stealth device takes the zrθ cylindrical coordinate system as a reference, wherein the z-axis is the main body of the stealth device. 5 . , the r axis is the radial direction of the stealth device body, the θ axis is the tangential direction of the stealth device body, and the two metal arms of the metal cross in the annular metal cross array are parallel to each other. in the r-axis direction and the θ-axis direction. 5 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 4 , wherein the stealth device requires anisotropy and gradient distribution under the condition that the electric field always polarizes incident waves in the Z-axis direction. 6 . The electromagnetic parameters of are obtained according to the following formula:

Among them, μ _r is the radial permeability; μ _θ is the tangential permeability; ε _z is the dielectric constant of the axial direction; r _a is the radius of the inner boundary of the body of the stealth device; r _b is the radius of the outer boundary of the stealth device body; r is an annular radius of the metal cross annular array in any one of the first to Nth layers in the stealth device body. 6 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 4 , wherein a single metal cross in the annular metal cross array is two metal crosses along the r-axis and theta-axis directions. 7 . Arm lengths vary. 7 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 4 , wherein the geometric size of the lattice unit is less than 1/5 of the wavelength of the electromagnetic wave at the operating frequency. 8 . 8 . The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device according to claim 1 , wherein the annular metal cross arrays on both sides of the first dielectric plate serve as positive and negative electrodes correspondingly. 9 . The first dielectric plate provides the DC electric field. 9. A method of making a two-dimensional omnidirectional metal-dielectric composite stealth device regulated by an electric field, characterized in that the two-dimensional omnidirectional metal-dielectric composite stealth device regulated by an electric field is the method according to any one of claims 1-8. The electric field regulated two-dimensional omnidirectional metal-dielectric composite stealth device, the fabrication method includes the following steps: Process the first dielectric plate and the second dielectric plate with required geometrical dimensions by machining; The annular metal cross arrays and the DC bias lines are processed on both sides of the first dielectric plate, and the annular metal cross arrays on both sides of the first dielectric plate are respectively connected through the DC bias lines. into the positive and negative poles of the DC regulated power supply; The first dielectric plate and the second dielectric plate attached with the annular metal cross array and the DC bias line are alternately arranged to form a layered stack structure.

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