A broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions

Abstract

The present invention relates to the field of electromagnetic wave control technology, and discloses a broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions, comprising a prismatic dielectric column consisting of an upper and lower rhombus-shaped bottom surface and four rectangular side surfaces, wherein two adjacent rectangular side surfaces are both first Huygens achromatic metasurfaces, and the remaining two adjacent rectangular side surfaces are both second Huygens achromatic metasurfaces; the present invention achieves broadband achromatic stealth under oblique incidence conditions by placing Huygens achromatic metasurfaces on the rectangular side surfaces of the prismatic dielectric column, while not significantly increasing the volume of the metadevice and saving resources.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic wave control technology, and in particular to a broadband linearly polarized achromatic stealth meta-device under oblique incidence conditions. Background Art

[0002] Controlling electromagnetic waves is a crucial area of ​​research in the electromagnetic field. Electromagnetic stealth technology, a key branch of this field, has significant practical applications in areas such as stealth skin design, camouflage protection, and electromagnetic compatibility. Stealth technology can be achieved by manipulating the electromagnetic wavefront in both reflection and transmission space. Compared to achieving stealth through electromagnetic wavefront manipulation in reflection space with the goal of achieving a low radar cross section (RCS), electromagnetic stealth in transmission space currently suffers from limitations such as poor stealth effectiveness, strong dispersion dependence, a narrow operating frequency band, and limited operating environments. The emergence of metasurfaces provides a new platform for electromagnetic wave wavefront manipulation. Their flexible control capabilities make broadband achromatic stealth devices technically feasible.

[0003] Existing achromatic metadevices are generally implemented in two ways. One is to use multiple resonances based on the Lorentz resonance model to achieve broadband and efficient dispersion control. This method is suitable for wavefront control in the reflection space. For wavefront control in the transmission space, the required metasurface cross-section is large, which is not conducive to integration. The other is to use the Huygens principle to construct multiple electric and magnetic resonances to achieve multi-resonance point control, thereby achieving flexible control of the dispersion characteristics of the incident wave over a broadband range. Specifically in the design of stealth devices, the key to electromagnetic cloaking of a specific object lies in manipulating the wavefront of the incident wave so that the wavefront of the electromagnetic wave after passing through the object can be restored to the wavefront state of the incident wave. The simplest example is the cloaking of a dielectric material of a specific shape. According to the generalized Snell's law, this situation is achieved by achieving a singular deflection of the incident electromagnetic wave from air to dielectric space, that is, the direction of the transmitted beam is consistent with the direction of the incident beam. This effect can be achieved by adding a metasurface to the surface of the dielectric material to provide the required phase gradient. Summary of the Invention

[0004] In response to the above-mentioned deficiencies in the prior art, the present invention provides a broadband linearly polarized achromatic stealth metastructure device under oblique incidence conditions, which can achieve electromagnetic stealth for prismatic dielectric columns with a dielectric constant of 3.55 in the range of 9.5 GHz-10.5 GHz under horizontally polarized electromagnetic wave irradiation conditions. The surface profile of the electromagnetic metastructure used is at the subwavelength level, which can effectively reduce the profile of the stealth skin and is conducive to the development of small stealth devices.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions comprises a prismatic dielectric column consisting of an upper and lower rhombus-shaped base surface and four rectangular side surfaces, wherein two adjacent rectangular side surfaces are first Huygens achromatic metasurfaces, and the remaining two adjacent rectangular side surfaces are second Huygens achromatic metasurfaces;

[0007] The first Huygens achromatic metasurface includes a first dielectric plate and a second dielectric plate that are tightly attached to each other, a first metal layer attached to the upper surface of the first dielectric plate, a second metal layer attached to the lower surface of the second dielectric plate, and a third metal layer attached to the lower surface of the first dielectric plate and the upper surface of the second dielectric plate.

[0008] The second Huygens achromatic metasurface includes a third dielectric plate and a fourth dielectric plate that are tightly attached to each other, a fourth metal layer attached to the upper surface of the third dielectric plate, a fifth metal layer attached to the lower surface of the second dielectric plate, and a sixth metal layer attached to the lower surface of the first dielectric plate and the upper surface of the second dielectric plate.

[0009] The first metal layer and the second metal layer both have the first metal surface pattern, the fourth metal layer and the fifth metal layer both have the second metal surface pattern, the third metal layer has the third metal surface pattern, and the sixth metal layer has the fourth metal surface pattern;

[0010] The first metal surface pattern includes a plurality of first units, and each first unit has four identical ∟-shaped metal patterns in the diagonal direction;

[0011] The second metal surface pattern includes a plurality of second units and a plurality of third units. The diagonal direction of each second unit is four identical ∟-shaped metal patterns. Each third unit is provided with a rectangular patch, and the center of the rectangular patch coincides with the center of the third unit.

[0012] The third metal surface pattern includes a plurality of fourth units, each of which is surrounded by four identical metal lines;

[0013] The fourth metal surface pattern includes a plurality of fifth units and a plurality of sixth units, each fifth unit is surrounded by four identical metal lines, and each sixth unit is provided with a rectangular patch, the center of the rectangular patch coincides with the center of the sixth unit;

[0014] The two right-angled sides of the ∟-shaped metal pattern are respectively parallel to the rhombus sides of the prismatic dielectric column and the upper and lower rhombus bottom surfaces of the prismatic dielectric column, and the right angle formed by the two right-angled sides of the ∟-shaped metal pattern is located in the diagonal direction of the first unit and the second unit, and the opening direction of the right angle is toward the center of the first unit and the second unit;

[0015] The metal wires are parallel to the fourth unit and the fifth unit respectively, and the center of each metal wire is located on the line connecting the center of the fourth unit and the fifth unit and the center of the side length of the fourth unit and the fifth unit corresponding to the metal wire.

[0016] Furthermore, the four rectangular side surfaces are congruent rectangles, and the four rectangular side surfaces are perpendicular to the upper and lower rhombus bases of the prismatic dielectric column. The width of the rectangular side surface is equal to the length of the side edge of the prismatic dielectric column, and the length of the rectangular side surface is equal to the length of the rhombus side of the upper and lower rhombus bases of the prismatic dielectric column. The cross-section formed by each rectangular side surface and two side edges that are not adjacent to the prismatic dielectric column is a rectangle.

[0017] Furthermore, the interior angles formed by the upper and lower rhombus bases are 60°, 120°, 60°, and 120°, respectively.

[0018] Furthermore, both the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are rectangles that are completely identical to the rectangular side surfaces.

[0019] Furthermore, the lengths of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 248.4 mm, the widths of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 207 mm, and the thicknesses of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 4.3 mm.

[0020] Furthermore, the thickness of the first metal layer and the fourth metal layer is 0.1 mm, the thickness of the second metal layer and the fifth metal layer is 0.1 mm, and the thickness of the third metal layer and the sixth metal layer is 0.1 mm.

[0021] Furthermore, the first units in the first metal surface pattern are evenly arranged along the rhombus edges of the upper and lower rhombus bottom surfaces of the prismatic dielectric column to form a matrix, and the size of the first units is 10.35 mm.

[0022] Furthermore, the second units in the second metal surface pattern are evenly arranged along the rhombus edges of the upper and lower rhombus bottom surfaces of the prismatic dielectric column to form a matrix, and a plurality of third units are arranged in a matrix between the plurality of second units. The sizes of the second and third units are both 10.35 mm.

[0023] Furthermore, the fourth units in the third metal surface pattern are evenly arranged along the side edges of the prismatic dielectric column to form a matrix, and the size of the third unit is 10.35 mm.

[0024] Furthermore, the fifth units in the fourth metal surface pattern are evenly arranged along the side edges of the prismatic dielectric column to form a matrix, and a plurality of sixth units are arranged in a matrix between the plurality of fifth units. The sizes of the fifth unit and the sixth unit are both 10.35 mm.

[0025] The present invention has the following beneficial effects:

[0026] 1. The present invention proposes a broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions. This device achieves broadband achromatic stealth under oblique incidence conditions by placing a Huygens achromatic metasurface on the rectangular side surface of a prismatic dielectric column.

[0027] 2. The Huygens achromatic metasurface can provide the compensation phase required to achieve broadband achromatic stealth electromagnetic wave control. It can guide horizontal linearly polarized electromagnetic waves incident at a certain angle within a set frequency band into the prismatic dielectric column and ensure that the electromagnetic waves propagate in the same direction within the dielectric column as in air. This allows the Huygens achromatic metasurface to achieve broadband dispersion-free stealth in horizontal two-dimensional space when illuminated by horizontal linearly polarized waves.

[0028] 3. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions will not significantly increase the volume of the metadevice, saving resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions proposed by the present invention;

[0030] Figure 2 Schematic diagram of the structure of the first metal layer and the second metal layer of the first Huygens achromatic metasurface in the embodiment;

[0031] Figure 3 Schematic diagram of the structure of the third metal layer of the first Huygens achromatic metasurface in the embodiment;

[0032] Figure 4 Schematic diagram of the structure of the fourth metal layer and the fifth metal layer of the second Huygens achromatic metasurface in the embodiment;

[0033] Figure 5 Schematic diagram of the structure of the sixth metal layer of the second Huygens achromatic metasurface in the embodiment;

[0034] Figure 6 Schematic diagram of the real distribution of the horizontally polarized electric field on the xoz plane of the broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions in the embodiment when operating at 9.6 GHz;

[0035] Figure 7Schematic diagram of the real distribution of the horizontally polarized electric field on the xoz plane of the broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions in the embodiment when operating at 10 GHz;

[0036] Figure 8 Schematic diagram of the real distribution of the horizontally polarized electric field on the xoz plane of the broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions in the embodiment when operating at 10.7 GHz. DETAILED DESCRIPTION

[0037] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0038] like Figure 1As shown, a broadband linear polarization achromatic stealth metastructure device under oblique incidence conditions includes a prismatic dielectric column consisting of an upper and lower rhombus bottom surface and four rectangular side surfaces, wherein two adjacent rectangular side surfaces are first Huygens achromatic metastructure surfaces, and the remaining two adjacent rectangular side surfaces are second Huygens achromatic metastructure surfaces; the first Huygens achromatic metastructure surface includes a first dielectric plate and a second dielectric plate that are tightly attached, a first metal layer attached to the upper surface of the first dielectric plate, a second metal layer attached to the lower surface of the second dielectric plate, and a second metal layer attached to the lower surface of the first dielectric plate and the upper surface of the second dielectric plate. The third metal layer; the second Huygens achromatic metasurface includes a third dielectric plate and a fourth dielectric plate that are tightly fitted together, a fourth metal layer attached to the upper surface of the third dielectric plate, a fifth metal layer attached to the lower surface of the second dielectric plate, and a sixth metal layer attached to the lower surface of the first dielectric plate and the upper surface of the second dielectric plate; the first metal layer and the second metal layer are both first metal surface patterns, the fourth metal layer and the fifth metal layer are both second metal surface patterns, the third metal layer is the third metal surface pattern, and the sixth metal layer is the fourth metal surface pattern; the first metal surface pattern includes a plurality of first units, each first unit The diagonal direction of the second metal surface pattern is four identical ∟-shaped metal patterns; the second metal surface pattern includes a plurality of second units and a plurality of third units, the diagonal direction of each second unit is four identical ∟-shaped metal patterns, each third unit is provided with a rectangular patch, and the center of the rectangular patch coincides with the center of the third unit; the third metal surface pattern includes a plurality of fourth units, and each fourth unit is surrounded by four identical metal wires; the fourth metal surface pattern includes a plurality of fifth units and a plurality of sixth units, and each fifth unit is surrounded by four identical metal wires, and each sixth unit is surrounded by A rectangular patch is provided in each unit, and the center of the rectangular patch coincides with the center of the sixth unit; the two right-angled sides of the ∟-shaped metal pattern are parallel to the rhombus sides of the prismatic dielectric column and the upper and lower rhombus bottom surfaces of the prismatic dielectric column, respectively, and the right angle formed by the two right-angled sides of the ∟-shaped metal pattern is located in the diagonal direction of the first unit and the second unit, and the opening direction of the right angle is toward the center of the first unit and the second unit; the metal wires are parallel to the fourth unit and the fifth unit, respectively, and the center of each metal wire is located on the line connecting the center of the fourth unit and the fifth unit and the center of the side length of the fourth unit and the fifth unit corresponding to the metal wire.

[0039] In this embodiment, the first, second, third, and fourth dielectric plates are all made of F4BTME350. Each of the first, second, third, and fourth dielectric plates is 2 mm thick, 248.4 mm long, and 207 mm wide. Furthermore, the prismatic dielectric columns are made of PTFE, which has a dielectric constant of 2.2.

[0040] also, Figure 1 The schematic diagram of the structure of the broadband linear polarization achromatic stealth metadevice under oblique incidence conditions is given, specifically: Figure 1 In the figure, 100 represents a broadband linear polarization achromatic stealth meta-device, 130 represents a prismatic dielectric column, and a three-dimensional coordinate is established with the center of the lower rhombus bottom surface of the prismatic dielectric column as the origin. The long axis of the lower rhombus bottom surface, the side edge length of the prismatic dielectric column (the height of the prismatic dielectric column), and the short axis of the lower rhombus bottom surface are used as the x-axis, y-axis, and z-axis to specifically describe the setting positions of the first Huygens achromatic meta-surface and the second Huygens achromatic meta-surface, wherein the Huygens achromatic meta-surfaces located on both sides of the rectangular side surface of the prismatic dielectric column are about Figure 1 The yoz planes in the figure are mirror-symmetric, that is, 110 and 120 represent two different types of Huygens achromatic metasurfaces, namely the first Huygens achromatic metasurface and the second Huygens achromatic metasurface, located on both sides of the two 60° internal angles of the upper and lower rhombus bases of the prismatic dielectric column; 111 and 113 both represent the first Huygens achromatic metasurface, and the two metasurfaces are symmetrically placed along the z-axis; 121 and 122 both represent the second Huygens achromatic metasurface, and the two metasurfaces are symmetrically placed along the z-axis; and the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are tightly attached to the four rectangular side surfaces of the prismatic dielectric column, and the upper and lower rhombus bases of the prismatic dielectric column are in contact with the air. In this embodiment, the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both used to form a specific phase gradient within a broadband range (the working bandwidth is 9.6 GHz-10.7 GHz) to guide the incident horizontal linear polarization plane wave along the original direction into the prismatic dielectric column in a specific frequency band; therefore, the first Huygens achromatic metasurface and the second Huygens achromatic metasurface can ensure that the wrapped prismatic dielectric column achieves broadband achromatic stealth in the horizontal two-dimensional space under the irradiation of the horizontal linear polarization plane wave, and will not significantly increase the volume of the metasurface device, thus saving resources.

[0041] At the same time, both the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are sandwich structures of metal layer-dielectric plate-metal layer-dielectric plate-metal layer, and their overall cross-section is sub-wavelength, which can effectively reduce the cross-section of the stealth skin, and therefore has reference significance for the miniaturization of stealth devices. And the specific structure of the metal layer is as follows Figure 2-Figure 5 As shown:

[0042] The metal surface patterns of the first metal layer and the second metal layer in the first Huygens achromatic metasurface are the same and the first metal surface pattern is as follows: Figure 2 As shown, Figure 2The first metal surface pattern shown includes several first units, each of which has a diagonal direction that is a ∟-shaped metal pattern from four different samples. The two right-angled sides of the ∟-shaped metal pattern are respectively parallel to the rhombus sides of the prismatic dielectric column and the upper and lower rhombus-shaped base surfaces of the prismatic dielectric column. The right angle formed by the two right-angled sides of the ∟-shaped metal pattern is located in the diagonal direction of the first unit, with the opening of the right angle facing the center of the first unit. This arrangement ensures that the main difference between the different first units along the rhombus side direction lies in the length and width of the right-angled side of the ∟-shaped metal pattern, thereby adjusting the length and width of the right-angled side according to the phase gradient required to achieve wavefront control.

[0043] The third metal layer in the first Huygens achromatic metasurface is a third metal surface pattern as follows: Figure 3 As shown, Figure 3 The third metal surface pattern shown includes several fourth units, each surrounded by four metal wires of varying sizes. The metal wires are parallel to the fourth units, with the center of each wire located on the line connecting the center of the fourth unit and the center of the side of the corresponding fourth unit. This arrangement ensures that the primary difference between fourth units along different diamond sides lies in the length of the metal wires, allowing the length of the metal wires to be adjusted based on the phase gradient required to achieve wavefront control.

[0044] The metal surface patterns of the fourth metal layer and the fifth metal layer in the second Huygens achromatic metasurface are the same and are the second metal surface pattern. Figure 4 As shown, the second metal surface pattern includes a plurality of second units and a plurality of third units, wherein Figure 4 In the middle, 1 is a number of third units, and the rest are a number of second units. The diagonal direction of each second unit is a ∟-shaped metal pattern of four different samples. A rectangular patch is provided in each third unit, and the center of the rectangular patch coincides with the center of the third unit; and the two right-angled sides of the ∟-shaped metal pattern are respectively parallel to the rhombus sides of the prismatic dielectric column and the upper and lower rhombus bottom surfaces of the prismatic dielectric column, and the right angle formed by the two right-angled sides of the ∟-shaped metal pattern is located in the diagonal direction of the second unit, and the opening direction of the right angle is toward the center of the second unit; the purpose of such a setting is to make the main difference between the second units along the rhombus side direction lie in the length of the right-angled side of the ∟-shaped metal pattern and the width of the right-angled side, so as to adjust the length of the right-angled side and the width of the right-angled side according to the phase gradient required to achieve wavefront control; at the same time, the main difference between the third units along the rhombus side direction lies in the size of the rectangular patch, so as to adjust the size of the rectangular patch according to the phase gradient required to achieve wavefront control;

[0045] The sixth metal layer in the second Huygens achromatic metasurface is the fourth metal surface pattern. Figure 5As shown, the fourth metal surface pattern includes a plurality of fifth units and a plurality of sixth units, wherein Figure 5 2 represents several sixth units. Each fifth unit is surrounded by four metal wires of different specifications. Each sixth unit is equipped with a rectangular patch, the center of which coincides with the center of the sixth unit. The metal wires are parallel to the fifth units, and the center of each metal wire is located on the line connecting the center of the fifth unit and the center of the side length of the fifth unit to which the metal wire corresponds. The purpose of this arrangement is to ensure that the main difference between the fifth units along the different directions of the diamond side is the length of the metal wire, and the length of the metal wire is adjusted according to the phase gradient required to achieve wavefront control. At the same time, the main difference between the sixth units along the different directions of the diamond side is the size of the rectangular patch, and the size of the rectangular patch is adjusted according to the phase gradient required to achieve wavefront control.

[0046] In summary, the metal layers in the first Huygens achromatic metasurface and the second Huygens achromatic metasurface can appropriately reduce the ∟-shaped metal patterns, the number of metal wires, and the rectangular patches according to the actual phase requirements that need to be met, thereby not significantly increasing the volume of the metasurface.

[0047] Specifically, the four rectangular side surfaces are congruent rectangles, and the four rectangular side surfaces are perpendicular to the upper and lower rhombus bases of the prismatic dielectric column. The width of the rectangular side surface is equal to the length of the side edges of the prismatic dielectric column. The length of the rectangular side surface is equal to the length of the rhombus sides of the upper and lower rhombus bases of the prismatic dielectric column. The cross-section formed by each rectangular side surface and the two side edges that are not adjacent to the prismatic dielectric column is a rectangle.

[0048] Specifically, the interior angles formed by the upper and lower rhombus bases are 60°, 120°, 60°, and 120°, respectively.

[0049] Specifically, the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both rectangles that are completely identical to the rectangular side surfaces.

[0050] In this embodiment, the lengths of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both equal to the lengths of the rhombus sides of the upper and lower base surfaces of the prismatic dielectric column, and the widths of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both equal to the widths of the four rectangular side surfaces, that is, the lengths of the side edges of the prismatic dielectric column.

[0051] Specifically, the lengths of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 248.4 mm, the widths of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 207 mm, and the thicknesses of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 4.3 mm.

[0052] Specifically, the thickness of the first metal layer and the fourth metal layer is 0.1 mm, the thickness of the second metal layer and the fifth metal layer is 0.1 mm, and the thickness of the third metal layer and the sixth metal layer is 0.1 mm.

[0053] Specifically, the first units in the first metal surface pattern are evenly arranged along the rhombus edges of the upper and lower rhombus bottom surfaces of the prismatic dielectric column to form a matrix, and the size of the first units is 10.35 mm.

[0054] Specifically, the second units in the second metal surface pattern are evenly arranged along the rhombus edges of the upper and lower rhombus bottom surfaces of the prismatic dielectric column to form a matrix, and a plurality of third units are arranged in a matrix between the plurality of second units. The sizes of the second and third units are both 10.35 mm.

[0055] Specifically, the fourth units in the third metal surface pattern are evenly arranged along the side edges of the prismatic dielectric column to form a matrix, and the size of the third units is 10.35 mm.

[0056] Specifically, the fifth units in the fourth metal surface pattern are evenly arranged along the side edges of the prismatic dielectric column to form a matrix, and a plurality of sixth units are arranged in a matrix between the plurality of fifth units. The sizes of the fifth unit and the sixth unit are both 10.35 mm.

[0057] like Figure 6-Figure 8 As shown, Figure 6-Figure 8 Schematic diagram of the real part distribution of the horizontally polarized electric field obtained by simulation of the xoz plane of the broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions at the lower operating frequency of 9.6 GHz, the central operating frequency of 10 GHz, and the higher operating frequency of 10.7 GHz; Figure 6-Figure 8 It can be seen that when the achromatic stealth metadevice operates at 9.6 GHz, 10 GHz, and 10.7 GHz, the dominant polarization on the xoz plane is horizontal. The electromagnetic wavefront is relatively flat in both air and dielectric media, and the propagation direction is consistent, both along the negative z-axis. Furthermore, this embodiment only provides two different metal layer structures. In other embodiments, the metal layers can be configured in other shapes. As long as the metal layers are arranged in an equiperiodic manner and can form the required phase gradient, broadband dispersion-free stealth can be achieved under transmission conditions.

[0058] In summary, the broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions proposed by the present invention achieves wavefront control of electromagnetic waves incident at 30° obliquely from air into a medium and from the medium into air by closely contacting the Huygens achromatic metasurface on the four rectangular side surfaces of a prismatic dielectric column. Specifically, it achieves broadband dispersionless stealth under transmission conditions, ensuring that the wavefront of the electromagnetic wave passing through the prismatic dielectric column, whose four rectangular side surfaces are wrapped by the Huygens achromatic metasurface, maintains the same flatness as the wavefront of the incident wave. Furthermore, the broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions proposed by the present invention is not limited to prismatic dielectric columns but can also be extended to dielectric objects of other geometric shapes.

[0059] Specific embodiments are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

[0060] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions, characterized by: A prismatic dielectric column comprising an upper and lower rhombus-shaped base and four rectangular side surfaces, wherein two adjacent rectangular side surfaces are first Huygens achromatic metasurfaces, and the remaining two adjacent rectangular side surfaces are second Huygens achromatic metasurfaces; The first Huygens achromatic metasurface includes a first dielectric plate and a second dielectric plate that are tightly attached to each other, a first metal layer attached to the upper surface of the first dielectric plate, a second metal layer attached to the lower surface of the second dielectric plate, and a third metal layer attached to the lower surface of the first dielectric plate and the upper surface of the second dielectric plate. The second Huygens achromatic metasurface includes a third dielectric plate and a fourth dielectric plate that are tightly attached to each other, a fourth metal layer attached to the upper surface of the third dielectric plate, a fifth metal layer attached to the lower surface of the second dielectric plate, and a sixth metal layer attached to the lower surface of the first dielectric plate and the upper surface of the second dielectric plate. The first metal layer and the second metal layer both have the first metal surface pattern, the fourth metal layer and the fifth metal layer both have the second metal surface pattern, the third metal layer has the third metal surface pattern, and the sixth metal layer has the fourth metal surface pattern; The first metal surface pattern includes a plurality of first units, and each first unit has four identical ∟-shaped metal patterns in the diagonal direction; The second metal surface pattern includes a plurality of second units and a plurality of third units. The diagonal direction of each second unit is four identical ∟-shaped metal patterns. Each third unit is provided with a rectangular patch, and the center of the rectangular patch coincides with the center of the third unit. The third metal surface pattern includes a plurality of fourth units, each of which is surrounded by four identical metal lines; The fourth metal surface pattern includes a plurality of fifth units and a plurality of sixth units, each fifth unit is surrounded by four identical metal lines, and each sixth unit is provided with a rectangular patch, the center of the rectangular patch coincides with the center of the sixth unit; The two right-angled sides of the ∟-shaped metal pattern are respectively parallel to the rhombus sides of the prismatic dielectric column and the upper and lower rhombus bottom surfaces of the prismatic dielectric column, and the right angle formed by the two right-angled sides of the ∟-shaped metal pattern is located in the diagonal direction of the first unit and the second unit, and the opening direction of the right angle is toward the center of the first unit and the second unit; The metal wires are parallel to the fourth unit and the fifth unit respectively, and the center of each metal wire is located on the line connecting the center of the fourth unit and the fifth unit and the center of the side length of the fourth unit and the fifth unit corresponding to the metal wire.

2. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 1, characterized in that: The four rectangular side surfaces are congruent rectangles, and the four rectangular side surfaces are perpendicular to the upper and lower rhombus bases of the prismatic dielectric column. The width of the rectangular side surface is equal to the length of the side edge of the prismatic dielectric column, and the length of the rectangular side surface is equal to the length of the rhombus side of the upper and lower rhombus bases of the prismatic dielectric column. The cross-section formed by each rectangular side surface and two non-adjacent side edges of the prismatic dielectric column is a rectangle.

3. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 2, characterized in that: The interior angles formed by the upper and lower rhombus bases are 60°, 120°, 60°, and 120° respectively.

4. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 3, characterized in that: The first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both rectangles that are completely identical to the rectangular side surfaces.

5. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 4, characterized in that: The length of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 248.4 mm, the width of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 207 mm, and the thickness of the first Huygens achromatic metasurface and the second Huygens achromatic metasurface are both 4.3 mm.

6. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 5, characterized in that: The thickness of the first metal layer and the fourth metal layer is 0.1 mm, the thickness of the second metal layer and the fifth metal layer is 0.1 mm, and the thickness of the third metal layer and the sixth metal layer is 0.1 mm.

7. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 6, characterized in that: The first units in the first metal surface pattern are evenly arranged along the rhombus edges of the upper and lower rhombus bottom surfaces of the prismatic dielectric column to form a matrix, and the size of the first unit is 10.35 mm.

8. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 7, characterized in that: The second units in the second metal surface pattern are evenly arranged along the rhombus edges of the upper and lower rhombus bottom surfaces of the prismatic dielectric column to form a matrix. Several third units are arranged in a matrix between several second units. The sizes of the second and third units are both 10.35 mm.

9. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 8, characterized in that: The fourth unit in the third metal surface pattern is evenly arranged along the side edge direction of the prismatic dielectric column to form a matrix, and the size of the third unit is 10.35 mm.

10. The broadband linearly polarized achromatic stealth metadevice under oblique incidence conditions according to claim 9, characterized in that: The fifth units in the fourth metal surface pattern are evenly arranged along the side edges of the prismatic dielectric column to form a matrix. Several sixth units are arranged in a matrix between several fifth units. The sizes of the fifth unit and the sixth unit are both 10.35 mm.

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