Amplitude-phase-adjustable low-RCS curved surface conformal reconfigurable metasurface structure

Abstract

The utility model discloses an amplitude-phase adjustable low RCS curved surface conformal reconfigurable metasurface structure comprising a plurality of metasurface units, and each metasurface unit comprises a metal patch layer, a dielectric layer, a metal floor, an isolation dielectric layer and a metal feed layer which are distributed from top to bottom. A metalized via hole is fixed between the metal feed layer and the metal patch layer and penetrates through the dielectric layer, the metal floor and the isolation dielectric layer, and the problem that an existing curved surface conformal reconfigurable metasurface cannot achieve phase modulation and amplitude modulation at the same time is solved. The curved surface conformal reconfigurable metasurface device can achieve phase and amplitude modulation at the same time and can be attached to the curved surface of any object.

Description

Technical Field

[0001] The utility model belongs to the technical field of electromagnetic communication, and relates to a low-RCS curved conformal reconfigurable metasurface structure with adjustable amplitude and phase. Background Art

[0002] With the rapid development of information and communication technology, the demand for precise control and regulation of electromagnetic waves is increasing day by day. In traditional communication and radar systems, traditional devices such as antennas are often used to achieve the regulation of electromagnetic waves. However, these devices often have problems such as limited regulation range, large volume, and complex manufacturing. In order to overcome these limitations, researchers have gradually turned their attention to metasurface technology.

[0003] A metasurface is a surface with a microscopic structure that can precisely regulate the propagation and scattering of electromagnetic waves. Compared with traditional antennas, metasurfaces have the advantages of simple structure, small volume, wide regulation range, and wide operating frequency range. The microscopic structure of the metasurface can be precisely manufactured through processing technologies such as PCB technology and additive manufacturing, and its regulation performance is affected by the design and preparation process of the microscopic structure.

[0004] A conformal metasurface is an artificial micro-structure that can regulate the propagation and scattering of electromagnetic waves, and its characteristic is that it has a shape adapted to the surrounding environment. In terms of reducing RCS (radar cross section), conformal metasurfaces have important applications and functions.

[0005] Conformal metasurfaces can be used to design and manufacture stealth materials or stealth coatings. By precisely controlling the micro-structure of the conformal metasurface, the regulation of absorption, reflection, and scattering of electromagnetic waves can be achieved, thereby reducing the RCS of the target. This stealth technology can play an important role in military applications, helping military equipment such as fighter planes and ships reduce the probability of being detected by enemy radars.

[0006] However, the problem that the existing curved conformal reconfigurable metasurfaces cannot simultaneously achieve phase modulation and amplitude modulation limits the application of metasurfaces in reducing RCS of complex curved structures. Therefore, it is necessary to propose a low-RCS curved conformal reconfigurable metasurface structure with adjustable amplitude and phase to solve the above problems. Summary of the Utility Model

[0007] In view of the above problems, to overcome the defects of the prior art, the utility model proposes a low-RCS curved conformal reconfigurable metasurface structure with adjustable amplitude and phase. The purpose of the utility model is to solve the problem that the existing curved conformal reconfigurable metasurfaces cannot simultaneously achieve phase modulation and amplitude modulation, and to provide a curved conformal reconfigurable metasurface device that can simultaneously achieve phase and amplitude modulation and can be attached to the curved surface of any object.

[0008] To achieve the above object, the technical solution adopted by the present utility model is as follows: The present utility model includes a plurality of metasurface units. The metasurface unit includes a metal patch layer, a dielectric layer, a metal floor, an isolation dielectric layer, and a metal feed layer distributed from top to bottom. A metallized via is fixed between the metal feed layer and the metal patch layer, and the metallized via penetrates through the dielectric layer, the metal floor, and the isolation dielectric layer.

[0009] Preferably, the metal patch layer includes four rows of metal patch components. Each row of the metal patch components is provided with four groups of metal patch modules. Each group of the metal patch modules includes a diode, a first polarization patch and a second polarization patch connected by the diode and symmetric about the diode, and a first metal patch and a second metal patch respectively fixed on the side of the first polarization patch and the second polarization patch facing away from the diode.

[0010] Preferably, the center of the diode coincides with the center point of the upper surface of the metal patch module, and the side of the diode is parallel to the side of the metal patch module.

[0011] Preferably, the dielectric layer is closely attached to the lower side of the metal patch layer, and the dielectric layer is a cuboid.

[0012] Preferably, the metal floor is attached to the lower side of the dielectric layer. A circular through hole is formed on the metal floor, and the metallized via passes through the through hole and does not contact the through hole.

[0013] Preferably, the metal feed layer includes a third metal patch and a fourth metal patch. The third metal patch includes a first fan-shaped branch, a first ring, and a line metal. The first fan-shaped branch and the line metal are fixed to the first ring. The fourth metal patch includes a second fan-shaped branch and a second ring. The second fan-shaped branch is fixed to the second ring. A plurality of the metallized vias are respectively fixed on the first ring and the second ring.

[0014] Preferably, the metal patch layer, the metal floor, and the metal feed layer have the same thickness and are made of a metal with a high conductivity.

[0015] Compared with the prior art, the present utility model has the following beneficial effects:

[0016] 1. The present utility model designs a conformal reconfigurable metasurface unit with adjustable amplitude and phase. By adjusting the state of the diode, the modulation of the amplitude and phase of the incident electromagnetic wave can be realized, the RCS reduction of the overall structure can be achieved, and the stealth effect in a complex electromagnetic environment can be realized.

[0017] 2. By designing a conformal topological structure, the present utility model can be fitted to the surface of a complex three-dimensional curved structure. Compared with a planar metasurface, the present utility model can be applied to working environments with high requirements for the external shape, such as aircraft and ships. Description of the Drawings

[0018] Figure 1 Exploded view of a low RCS curved conformal reconfigurable metasurface structure with adjustable amplitude and phase according to an embodiment of the present invention;

[0019] Figure 2 Planar schematic diagram of the metal patch layer of the unit of the present invention;

[0020] Figure 3 Planar schematic diagram of the metal feed layer of the unit of the present invention;

[0021] Figure 4 S11 amplitude curve diagram of the unit of the present invention in the frequency range of 7.5 GHz to 11.5 GHz;

[0022] Figure 5 S11 phase curve diagram of the unit of the present invention in the frequency range of 7.5 GHz to 11.5 GHz;

[0023] Figure 6 Comparison diagram of the RCS of the E-plane of the embodiment of the present invention and a metal plate of the same size;

[0024] Figure 7 Comparison diagram of the RCS of the H-plane of the embodiment of the present invention and a metal plate of the same size;

[0025] Figure 8 Variation diagram of the monostatic RCS of the embodiment of the present invention and a metal plate of the same size with frequency.

[0026] Reference numerals: 1 - metal patch layer, 2 - dielectric layer, 3 - metal floor, 4 - isolation dielectric layer, 5 - metal feed layer, 6 - metallized via, 7 - diode, 8 - first polarization patch, 9 - second polarization patch, 10 - first metal patch, 11 - second metal patch, 12 - through hole, 13 - third metal patch, 14 - fourth metal patch. Detailed Description of the Invention

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] Next, a more detailed description will be given of the specific implementation manners of the present invention in conjunction with the attached Figure 1-8 drawings.

[0029] Refer to Figure 1, the structure of the low RCS surface conformal reconfigurable metasurface with adjustable amplitude and phase from top to bottom is the metal patch layer 1, dielectric layer 2, metal floor 3, isolation dielectric layer 4, metal feeding layer 5, and metallized vias 6 passing through the unit. The overall structure consists of 4×4 conformal metasurfaces arranged periodically on the surface of a cylinder with a radius of 100 mm. Figure 1-3 Shown is one of the conformal metasurfaces;

[0030] Metal patch layer 1: As Figure 1 and Figure 2 shown, the metal patch layer 1 includes a pin diode 7 of model SMP1320, a first polarization patch 8, a second polarization patch 9, a first metal patch 10, and a second metal patch 11. The first polarization patch 8 is connected to the second polarization patch 9 through the attached diode 7. The first metal patch 10 and the second metal patch 11 are respectively close to the first polarization patch 8 and the second polarization patch 9. The diode 7 has conduction, cutoff, and loss states;

[0031] Figure 2 The parameters in

[0032] are: d1 = 0.3 mm, d2 = 5.75 mm, w1 = 5.5 mm, s = 0.3 mm, dt = 0.5 mm, wt = 1 mm, dp1 = 1.5 mm, dp2 = 0.5 mm, dp3 = 0.5 mm, wp1 = 2 mm, wp2 = 2 mm, wp3 = 2 mm, wp4 = 1.25 mm, wp5 = 1.5 mm;

[0032] The dielectric layer 2 is closely attached to the lower side of the metal patch layer 1 and is a cuboid with length, width, and height of p = 16 mm, p = 16 mm, and h1 respectively. The relative permittivity of the material is ε1 = 2.8, and the loss tangent angle is tan δ1 = 0.017;

[0033] The metal floor 3 is attached to the lower side of the dielectric layer 2 and has length and width both of p = 16 mm, p = 16 mm, and has a circular through-hole 12 with a radius of rh = 0.5 mm;

[0034] The isolation dielectric layer 4 is located between the metal floor 3 and the metal feeding layer 5 and is a cuboid with length, width, and height of p = 16 mm, p = 16 mm, and h2 respectively. The relative permittivity of the material is ε2 = 2.8, and the loss tangent angle is tan δ2 = 0.017;

[0035] Referring to Figure 3 , the metal feeding layer 5 includes a third metal patch 13 and a fourth metal patch 14. The third metal patch 13 includes a fan-shaped branch, a ring, and a linear metal. The fourth metal patch 14 includes a fan-shaped branch and a ring. Figure 3The parameters therein are: p = 16 mm, vr1 = 1 mm, vr2 = 3.5 mm, lv = 4 mm, vt = 2.5 mm, vw = 0.25 mm;

[0036] The metallized vias 6 are two cylinders with a radius r1 = 0.5 mm, and lv satisfies 2rh < lv < p - 4rh, hh = 3htp + h1 + h2, and the height hh = 3htp + h1 + h2 = 2.265 mm;

[0037] The metal patch layer 1, the metal floor 3, and the metal feeding layer 5 have the same thickness and are made of metals with high conductivity such as silver, copper, and aluminum;

[0038] Refer to Figure 4 As shown, the graph of the reflection amplitude parameter of the amplitude - phase adjustable low - RCS curved - surface conformal reconfigurable metasurface unit when the diode 7 is in the on, off, and loss states. Figure 4 In it, Frequency is the frequency with the unit of GHz, S - parameter is the scattering parameter with the unit of dB, the working frequency band of the unit is 7.5 GHz - 11.5 GHz. At the center frequency of 8.1 GHz, the reflection coefficient |S 11 | = - 2.29 dB in the on - state of the conformal unit, the reflection coefficient |S 11 | = - 1.19 dB in the off - state of the conformal unit, and the reflection coefficient |S 11 | = - 15.85 dB in the loss state of the conformal unit;

[0039] Refer to Figure 5 As shown is the graph of the reflection phase parameter of the amplitude - phase adjustable low - RCS curved - surface conformal reconfigurable metasurface unit. Figure 5 In it, Frequency is the frequency with the unit of GHz, Phase is the reflection phase of the unit with the unit of deg. At the center frequency of 8.1 GHz, the phase difference between the on - state and the off - state of the conformal unit is 176°;

[0040] Refer to Figure 6 This is the comparison graph of the RCS of the E - plane of the embodiment of the present utility model and an equal - sized metal plate. Figure 6 In it, for the conformal metasurface array and its equal - sized metal plate at the center frequency of 8.1 GHz, all the units are in the wave - absorbing state. When the plane wave is incident perpendicularly, the selected plane is parallel to the electromagnetic wave polarization direction. The abscissa Theta is the angle in the spherical coordinate system, and the ordinate is the RCS reduction. It can be seen that the RCS of the array surface is lower than that of the metal plate, achieving a good wave - absorbing effect;

[0041] Refer to Figure 7 This is the comparison graph of the RCS of the H - plane of the embodiment of the present utility model and an equal - sized metal plate. Figure 7At the center frequency of 8.1 GHz, all the elements of the conformal metasurface array and its equal-sized metal plate are in the wave-absorbing state. When a plane wave is incident perpendicularly, the selected plane is perpendicular to the polarization direction of the electromagnetic wave. The abscissa Theta is the angle in the spherical coordinate system, and the ordinate is the RCS reduction. It can be seen that the array surface reduces the RCS compared to the metal plate, achieving a good wave-absorbing effect;

[0042] Refer to Figure 8 This is the graph of the monostatic RCS of the embodiment of the present invention and the equal-sized metal plate changing with frequency, Figure 8 The abscissa Frequency is the working bandwidth, with the unit of GHz, and the ordinate is the reduction value of the monostatic RCS when a plane wave is incident perpendicularly, with the unit of dB. At the center frequency of 8.1 GHz, the maximum reduction of the RCS of the conformal metasurface compared to the equal-sized metal plate is 18 dB;

[0043] The above simulation example analysis shows that the amplitude-phase adjustable low-RCS curved surface conformal reconfigurable metasurface device can reduce the RCS of the array within the working frequency range and can be attached to complex curved surfaces;

[0044] The working principle of this application is:

[0045] Generally, in electromagnetics, the RCS (radar cross section) is usually expressed by the radar cross section σ per unit area, and the general calculation formula is as follows:

[0046]

[0047] Among them, E s and E i are the far-field scattering and incident electric field intensities respectively, and r is the distance from the target to the measuring device. However, in practical applications, it is very difficult to directly measure E s and E i , so RCS can be expressed in another way:

[0048]

[0049] Among them, S s and S i are the power densities of the incident electromagnetic wave and the scattered electromagnetic wave measured at the target respectively. It can be concluded from this that the radar cross section is closely related to the power density S i of the scattered electromagnetic wave. Therefore, for the two methods of RCS reduction by the metasurface, the first is to reduce the amplitude of the scattered electromagnetic wave, that is, to absorb the incident electromagnetic wave to reduce the RCS. The second method is for the metasurface to conform to the generalized Snell's law:

[0050]

[0051] The incident angle is θi , the reflection angle is θ r , the refraction angle is θ t , the refractive index of the medium where the incident wave is located is n i , the refractive index of the transmitted medium is n t , φ is the dynamic phase in the propagation path of the electromagnetic wave, and λ0 is the wavelength in free space. By changing the phase gradient of the metasurface, the scattering direction of the electromagnetic wave can be modulated, and RCS reduction can be achieved.

[0052] Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A low RCS curved surface conformal reconfigurable metasurface structure with adjustable amplitude and phase, characterized by: The invention comprises a plurality of metasurface units, wherein the metasurface units include a metal patch layer, a dielectric layer, a metal floor, an isolation dielectric layer and a metal feed layer distributed from top to bottom, a metallized via is fixed between the metal feed layer and the metal patch layer, and the metallized via penetrates the dielectric layer, the metal floor and the isolation dielectric layer; The metal patch layer includes four rows of metal patch components, each row of the metal patch components is provided with four groups of metal patch modules, each group of the metal patch modules includes a diode, a first polarization patch and a second polarization patch connected by the diode and symmetrical about the diode, and a first metal patch and a second metal patch respectively fixed on the side of the first polarization patch and the second polarization patch facing away from the diode.

2. The low RCS curved surface conformal reconfigurable metasurface structure with adjustable amplitude and phase according to claim 1, characterized in that: The center of the diode coincides with the center point of the upper surface of the metal patch module, and the side of the diode is parallel to the side of the metal patch module.

3. The low RCS curved surface conformal reconfigurable metasurface structure with adjustable amplitude and phase according to claim 1, characterized in that: The dielectric layer is closely attached to the lower side of the metal patch layer, and the dielectric layer is a rectangular parallelepiped.

4. The low RCS curved surface conformal reconfigurable metasurface structure with adjustable amplitude and phase according to claim 1, characterized in that: The metal floor is attached below the dielectric layer. A circular through hole is provided on the metal floor. The metalized via passes through the through hole and does not contact the through hole.

5. The low RCS curved surface conformal reconfigurable metasurface structure with adjustable amplitude and phase according to claim 1, characterized in that: The metal feed layer includes a third metal patch and a fourth metal patch, the third metal patch includes a first fan-shaped branch, a first ring and a line metal, the first fan-shaped branch and the line metal are fixed to the first ring, the fourth metal patch includes a second fan-shaped branch and a second ring, the second fan-shaped branch is fixed to the second ring, and the plurality of metallized vias are respectively fixed on the first ring and the second ring.

6. The low RCS curved surface conformal reconfigurable metasurface structure with adjustable amplitude and phase according to claim 1, characterized in that: The metal patch layer, metal floor and metal feed layer have the same thickness and are made of metal.

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