阅读说明：本技术 一种用于产生非共面分离波束的棋盘式石墨烯超表面 (Checkerboard type graphene super surface for generating non-coplanar separation wave beams ) 是由 杨锐 李佳成 于 2021-08-20 设计创作，主要内容包括：本发明提出了一种用于产生非共面分离波束的棋盘式石墨烯超表面,其由M×N个石墨烯超表面单元周期性排布而成,石墨烯超表面单元包括上下层叠的第一介质板和第二介质板,第一介质板的上表面的一条对角线上印制有第一矩形石墨烯贴片,第二介质板的上表面印制有蚀刻了矩形缝隙第二矩形石墨烯贴片,第二介质板的下表面印制有金属地板；通过对部分第一矩形石墨烯贴片施加零费米能级同时对第二矩形石墨烯贴片施加非零费米能级能产生与同极化共面异常反射波束；通过对其余部分第二矩形石墨烯贴片施加零费米能级,同时对第一矩形石墨烯贴片施加非零费米能级能产生同极化异面异常反射波束,能够实现强度可调的非共面高极化纯度波束分离效果。(The invention provides a checkerboard type graphene super-surface for generating non-coplanar separation beams, which is formed by periodically arranging M multiplied by N graphene super-surface units, wherein each graphene super-surface unit comprises a first dielectric plate and a second dielectric plate which are stacked up and down, a first rectangular graphene patch is printed on one diagonal line of the upper surface of the first dielectric plate, a second rectangular graphene patch with rectangular gaps etched is printed on the upper surface of the second dielectric plate, and a metal floor is printed on the lower surface of the second dielectric plate; applying a zero Fermi level to a part of first rectangular graphene patches and simultaneously applying a non-zero Fermi level to second rectangular graphene patches to generate homopolarized coplanar abnormal reflected beams; by applying a zero Fermi level to the rest of the second rectangular graphene patches and applying a non-zero Fermi level to the first rectangular graphene patches, homopolarity and heteroplanar abnormal reflection beams can be generated, and the intensity-adjustable non-coplanar high-polarization purity beam separation effect can be achieved.)

1. A checkerboard type graphene super-surface for generating non-coplanar separation beams is characterized by comprising M x N graphene super-surface units which are periodically arranged, wherein the distance between the adjacent graphene super-surface units is less than one fourth of the working wavelength of incident waves; the graphene super-surface unit comprises a first dielectric plate (1) and a second dielectric plate (2) which are square and stacked up and down, a first rectangular graphene patch (3) is printed on one diagonal line of the upper surface of the first dielectric plate (1), a second rectangular graphene patch (4) is printed on the upper surface of the second dielectric plate (2), a rectangular slot is etched on a connecting line of midpoints of two long sides of the second rectangular graphene patch (4), the connecting line of midpoints of the two short sides of the rectangular slot is perpendicular to the normal direction of an incident wave plane, and a metal floor (5) is printed on the lower surface of the second dielectric plate (2); when a zero Fermi level is applied to a first rectangular graphene patch (3) on H graphene super-surface units contained in the graphene super-surface, and a non-zero Fermi level is applied to a second rectangular graphene patch (4), the H graphene super-surface units are in a same-polarization electromagnetic response state 0 and are used for generating coplanar abnormal reflection beams which are the same as incident wave polarization; when a non-zero Fermi level is applied to the first rectangular graphene patch (3) on the rest M multiplied by N-H graphene super-surface units contained in the graphene super-surface, and a zero Fermi level is applied to the second rectangular graphene patch (4), the M multiplied by N-H graphene super-surface units are in a cross polarization electromagnetic response state 1 and are used for generating an abnormal reflection wave beam with the same incident wave polarization, the H graphene super-surface units corresponding to the same polarization electromagnetic response state 0 and the M multiplied by N-H graphene super-surface units corresponding to the cross polarization electromagnetic response state 1 are distributed randomly or in a cross mode to form a checkerboard structure, wherein M is more than or equal to 2, and N is more than or equal to 2.

2. The checkerboard graphene super-surface for generating non-coplanar split beams according to claim 1, wherein a connecting line of midpoints of two short sides of the rectangular graphene patch (3) is coincident with a diagonal line of the upper surface of the first dielectric plate (1).

3. The checkerboard graphene super-surface for generating non-coplanar split beams as claimed in claim 1, wherein the connecting line of the midpoints of the two short sides of the rectangular slot is coincident with the connecting line of a group of opposite side midpoints of the upper surface of the second dielectric plate (2).

4. The checkerboard graphene super-surface for generating non-coplanar split beams as claimed in claim 1, wherein the thickness of said first dielectric plate (1) is much smaller than the thickness of the second dielectric plate (2).

Technical Field

The invention belongs to the field of super-surfaces, relates to a graphene super-surface, and particularly relates to a checkerboard type graphene super-surface for generating non-coplanar separation beams, which can be used in the fields of electromagnetic beam separation and the like.

Technical Field

As a novel artificial electromagnetic material, the super surface can realize the control of the electromagnetic wave intensity, polarization and propagation direction by designing a micro-unit structure. And through arranging various units according to a certain rule, a chessboard-like super surface is formed, and a more complex electromagnetic regulation and control effect can be realized. For example, a patent application having application publication No. CN112216993A entitled "an ultra-thin ultra-wideband checkerboard RCS reduced super surface" discloses a super surface for RCS reduction comprising two types of microcells, each type of microcell grouping super cells on a scale of 5 × 5, the two types of super cells being arranged in a spaced apart manner to produce a low RCS effect. The existing chessboard-type super-surface technology is limited by the coupling problem between units, and the independence of the resonance states of the two units can not be ensured, so that the super-surface technology can only form a super unit by a plurality of units of the same kind and then carry out array formation. The super cell has a high cancellation lobe level due to the excessively large spacing, which is very beneficial to the reduction of RCS, but cannot achieve an efficient beam splitting effect.

Graphene, as a two-dimensional planar carbon structure, has good conductivity and flexibility, and its electromagnetic parameters can be controlled by the fermi level. The application of graphene to metamaterial design can realize reconfigurable wave splitter design, for example, a patent application with the application publication number of CN111682319A entitled "design method of novel broadband tunable encoding super surface based on metal-graphene" discloses an encoding super surface based on graphene, which can separate incident waves into two symmetrical reflected beams by using a cross-shaped graphene super surface unit, and can change the direction of the separated beams by controlling the phase distribution of the graphene super surface unit. The coding setting mode of the method is only suitable for vertical incidence, so that non-coplanar beam separation under the oblique incidence condition cannot be realized. In addition, although the method can realize reconfigurable control of the direction of the separated wave beam, the intensity of the separated wave beam cannot be independently regulated and controlled due to the fact that a single type of unit is adopted for arraying, and polarization purity of the separated wave beam is low due to the fact that polarization matching is not designed.

Disclosure of Invention

The invention aims to provide a checkerboard type graphene super-surface for generating non-coplanar separated beams, aiming at realizing the non-coplanar characteristic and the intensity reconfigurable characteristic of the separated beams and improving the polarization purity of the separated beams.

In order to achieve the purpose, the invention adopts the technical scheme that:

a checkerboard type graphene super-surface for generating non-coplanar separation beams comprises M x N graphene super-surface units which are periodically arranged, wherein the distance between every two adjacent graphene super-surface units is less than one fourth of the working wavelength of incident waves; the graphene super-surface unit comprises a first dielectric plate 1 and a second dielectric plate 2 which are square and stacked up and down, a first rectangular graphene patch 3 is printed on one diagonal line of the upper surface of the first dielectric plate 1, a second rectangular graphene patch 4 is printed on the upper surface of the second dielectric plate 2, a rectangular slot is etched on a connecting line of midpoints of two long sides of the second rectangular graphene patch 4, the connecting line of midpoints of two short sides of the rectangular slot is perpendicular to the normal direction of an incident wave plane, and a metal floor 5 is printed on the lower surface of the second dielectric plate 2; when a zero Fermi level is applied to a first rectangular graphene patch 3 on H super-surface units contained in the super-surface and a non-zero Fermi level is applied to a second rectangular graphene patch 4, the H graphene super-surface units are in a same-polarization electromagnetic response state 0 and are used for generating coplanar abnormal reflected beams which are the same as incident wave polarization; when a non-zero Fermi level is applied to the first rectangular graphene patch 3 on the rest M x N-H graphene super-surface units contained in the graphene super-surface, and a zero Fermi level is applied to the second rectangular graphene patch 4, the M x N-H graphene super-surface units are in a cross polarization electromagnetic response state 1 and are used for generating an abnormal reflection wave beam with different surfaces and the same polarization as an incident wave, the graphene super-surface units corresponding to the H co-polarization electromagnetic response states 0 and the graphene super-surface units corresponding to the M x N-H cross polarization electromagnetic response states 1 are distributed randomly or in a cross mode to form a chessboard structure, wherein M is more than or equal to 2, and N is more than or equal to 2.

In the checkerboard type graphene super-surface for generating non-coplanar separated beams, a connecting line of midpoints of two short sides of the rectangular graphene patch 3 coincides with a diagonal line of the upper surface of the first dielectric plate 1.

In the rectangular slot, the connecting line of the midpoints of the two short sides of the rectangular slot coincides with the connecting line of midpoints of a group of opposite sides of the upper surface of the second dielectric plate 2.

The first dielectric plate 1 is much thinner than the second dielectric plate 2.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, H graphene super-surface units corresponding to the same-polarization electromagnetic response state 0 and M x N-H graphene super-surface units corresponding to the cross-polarization electromagnetic response state 1 which are randomly or crossly distributed form a checkerboard structure, and through a rectangular gap etched on a connecting line of the middle points of two long sides of the second rectangular graphene patch, the coupling between the graphene super-surface units can be reduced, so that the units can generate two independent electromagnetic responses, and the non-coplanar characteristic of separated beams is realized.

2. According to the invention, as different Fermi energy levels are applied to the two rectangular graphene patches on the graphene super-surface unit, part of the graphene super-surface unit presents a same-polarization electromagnetic response state, and the other part of the graphene super-surface unit presents a cross-polarization electromagnetic response state, a polarization matching effect can be generated, so that coplanar and non-coplanar separation beams have higher polarization purity characteristics.

3. According to the invention, the strength reconfigurable characteristic of the separated wave beam can be realized by adjusting the proportion of the graphene super-surface unit in the homopolarization electromagnetic response state to the graphene super-surface unit in the cross-polarization electromagnetic response state.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural diagram of a graphene super-surface unit according to the present invention.

FIG. 3 is a diagram showing simulation results of unequal amplitude separation of electromagnetic beams in the xy plane and the yz plane according to the present invention.

FIG. 4 is a diagram showing the simulation results of the present invention in which the xy-plane and yz-plane electromagnetic beams are separated in equal amplitude.

Detailed Description

The invention is further described below with reference to the following figures and specific examples.

Referring to fig. 1, the graphene super-surface unit comprises mxn graphene super-surface units which are periodically arranged, and the distance between adjacent graphene super-surface units is less than a quarter of the operating wavelength of incident waves, so as to ensure low grating lobe of separated beams, where M is greater than or equal to 2 and N is greater than or equal to 2.

Referring to fig. 2, the graphene super-surface unit includes a first dielectric plate 1 and a second dielectric plate 2 which are square and stacked up and down. A first rectangular graphene patch 3 is printed on one diagonal line of the upper surface of the first dielectric slab 1, and a connecting line of midpoints of two short sides of the first rectangular graphene patch is superposed with a diagonal line of the upper surface of the first dielectric slab 1, so that the phase is modulated while orthogonal conversion of electric field polarization is realized. And a second rectangular graphene patch 4 is printed on the upper surface of the second dielectric plate 2 and used for modulating the phase while ensuring that the electric field polarization is unchanged. Rectangular gaps are etched on connecting lines of middle points of two long sides of the second rectangular graphene patch 4 and used for enhancing the local effect of the field, and the connecting lines of the middle points of the two short sides of the rectangular gaps are perpendicular to the normal direction of an incident wave plane so as to guarantee the effect of homopolarity resonance. And a metal floor 5 is printed on the lower surface of the second dielectric plate 2 and used for reflection in real site.

When a zero fermi level is applied to the first rectangular graphene patch 3 on the super-surface unit, the first rectangular graphene patch 3 is in a transparent state to electromagnetic waves, and when a non-zero fermi level is applied to the second rectangular graphene patch 4, the second rectangular graphene patch 4 and the metal floor 5 form a resonance system, which presents a co-polarization electromagnetic response state 0 and is used for generating coplanar abnormal reflection beams which are the same as incident wave polarization. When a zero fermi level is applied to the second rectangular graphene patch 4 on the super-surface unit, the second rectangular graphene patch 4 is in a transparent state to electromagnetic waves, and when a non-zero fermi level is applied to the first rectangular graphene patch 3, the first rectangular graphene patch 4 is in a transparent stateThe rectangular graphene patch 3 and the metal floor 5 form a resonance system, and a cross-polarization electromagnetic response state 1 is presented for generating an out-of-plane abnormal reflection beam orthogonal to incident wave polarization. For the super-surface units, the graphene super-surface units corresponding to H co-polarization electromagnetic response states 0 and the graphene super-surface units corresponding to M x N-H cross-polarization electromagnetic response states 1 are distributed randomly or in a cross mode to form a checkerboard structure, the resonance modes of the graphene super-surface units in the two states are independent, and the intensities of the generated coplanar abnormal reflection beams and the generated heteroplanar abnormal reflection beams are related to the number of the graphene super-surface units corresponding to the electromagnetic response states 0 and 1. The phase shift phi distribution realized by the graphene super-surface unit in the two electromagnetic response states follows phi ═ k_r·r-k_iR, where r is the position of the center of the graphene unit, k_rAnd k is_iThe incident wave and the reflected wave vector at the central point position of the graphene unit are shown.

The thickness of the first dielectric plate 1 is far smaller than that of the second dielectric plate 2, and the first dielectric plate 1 is used for ensuring the independent resonance effect of the electromagnetic response state 0 and the electromagnetic response state 1.

The metamaterial unit period size of the invention is 12 μm. The length of the long side of the first rectangular graphene patch 3 is 8 μm, and the length of the short side is 5 μm. The second rectangular graphene patch 3 has a long side length a of 13 μm, a short side length b of 8 μm, and a slit width w of 1 μm. The first dielectric plate 1 has a thickness of 1 μm and the second dielectric plate 2 has a thickness of 6.5 μm.

The technical effects of the present invention will be further explained in conjunction with simulation experiments.

1. Simulation conditions and contents:

the CST Studio software is adopted to simulate the non-coplanar separation beam effect generated on the chessboard type graphene super-surface, the simulation verification of realizing the unequal amplitude separation of the xy-plane electromagnetic beam and the yz-plane electromagnetic beam is shown in figure 3, and the simulation verification of realizing the equal amplitude separation of the xy-plane electromagnetic beam and the yz-plane electromagnetic beam is shown in figure 4.

2. And (3) simulation result analysis:

fig. 3 is a diagram of simulation results of the unequal amplitude separation simulation of electromagnetic beams on an xz plane and a yz plane according to the present invention, in which the abscissa is an angle, the ordinate is intensity, the solid line is a separation beam intensity distribution on the xz plane, and the dotted line is a separation beam intensity distribution on the yz plane. According to the simulation, the number of the two graphene metamaterial units in the electromagnetic response state 0 and the electromagnetic response state 1 is 200, the beam separation of an xz plane and a yz plane is realized for 15-degree incident wave energy, and the beam pointing regulation is realized at the same time. Specifically, it has a beam pointing at 25 degrees in the xz plane, and a beam pointing at 30 degrees in the yz plane, and the two-beam intensity ratio is 0.62: 1, realizing the beam unequal amplitude separation of horizontally polarized oblique incident waves, wherein the polarization of the separated beams is horizontal polarization, and the polarization purity is more than 0.99.

Fig. 4 is a diagram of simulation results of the equal-amplitude separation simulation of electromagnetic beams on an xz plane and a yz plane, in which the abscissa is an angle, the ordinate is intensity, the solid line is a separation beam intensity distribution on the xz plane, and the dotted line is a separation beam intensity distribution on the yz plane. The number of two graphene metamaterial units in an electromagnetic response state 0 and an electromagnetic response state 1 is respectively set to be 250 and 150 in the simulation, beam separation of an xz plane and a yz plane is realized for incident wave energy of 15 degrees, and beam pointing regulation is realized at the same time. Specifically, it has a beam pointing at 25 degrees in the xz plane, and a beam pointing at 30 degrees in the yz plane, and the two-beam intensity ratio is 1: 1, the beam equal-amplitude separation of the horizontally polarized oblique incident wave is realized, and the intensity of the separated beam is reconstructed by controlling the number of 0-state and 1-state graphene metamaterial units.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, for example, the reflection unit may be embodied in various forms, and those skilled in the art can make various changes and modifications without departing from the innovative concept of the present invention, but these changes are all within the scope of the present invention.