Transmission / reflection / wave-absorbing multimode integrated reconfigurable metasurface

Abstract

The invention discloses a transmission / reflection / wave-absorbing multimode integrated reconfigurable metasurface, which relates to the technical field of reconfigurable metasurfaces, and comprises a first dielectric substrate and a second dielectric substrate which are arranged in a spaced and overlapped manner, and a plurality of metasurface units which are arranged on one surface of the first dielectric substrate and one surface of the second dielectric substrate and are periodically arranged, the metasurface unit of the first dielectric substrate is provided with a first PIN diode, the metasurface unit of the second dielectric substrate is provided with a second PIN diode, and the connection and disconnection of the first PIN diode and the second PIN diode are controlled by adopting an external voltage bias method, so that the flexible switching of two basic working modes of transmission and reflection can be realized, and the transmission and reflection effects are improved. The electromagnetic wave absorption function can be further activated, transmission type polarization, reflection type polarization and wave absorption of the metasurface are achieved, and the transmission / reflection / wave absorption three-in-one multi-mode regulation and control capacity is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reconfigurable metasurfaces, in particular to a reconfigurable metasurface with transmission / reflection / absorption multi-mode integration. BACKGROUND

[0002] With the rapid development of electromagnetic technology and the continuous expansion of application fields, modern electromagnetic environment is becoming increasingly complex and diverse. Traditional transmission-type, reflection-type and transmission / reflection-type metasurfaces have obvious limitations in dealing with complex electromagnetic scenarios due to the lack of wave absorption function. To break this bottleneck, research has focused on multi-mode reconfigurable metasurfaces with transmission, reflection and absorption functions. Among them, the transmission mode is mainly used to ensure the effective transmission and reception of signals such as communication and radar, the reflection mode is used to create deceptive jamming, and the absorption mode is used to reduce the radar cross section (RCS) of the target to improve the stealth performance.

[0003] In addition, most of the current metasurfaces can only produce electromagnetic responses to electromagnetic waves incident in one direction, which has significant polarization dependence, which may cause additional losses due to polarization mismatch, and even cause problems such as failure to normally receive electromagnetic signals. In view of this challenge, it is of great significance to study polarization-insensitive metasurfaces, which can produce consistent electromagnetic responses to any linearly polarized incident waves, thereby effectively overcoming the performance degradation problem caused by polarization mismatch.

[0004] Chinese Patent No. 119852727A, entitled "Reconfigurable metasurface for realizing absorption, transmission and reflection polarization conversion", the metasurface unit includes a polygonal phase change material, a polygonal phase change material ring, a first phase change material strip and a metal strip. By changing the state of the phase change material, the function conversion of transmission, reflection and absorption is realized. However, in this invention, the phase change material is used to realize the conversion between the functions of the metasurface, and the state of the phase change material needs to be changed by adjusting the external temperature, so there are disadvantages such as slow response speed of metasurface function conversion and high control environment requirement.

[0005] In summary, the existing technology mainly relies on phase change materials for regulation and control, which has poor response speed and narrow bandwidth. SUMMARY

[0006] The purpose of the present application is to provide a reconfigurable metasurface with transmission / reflection / absorption multi-mode integration, which can realize transmission / reflection / absorption functions by dynamically adjusting the working state of the PIN diode, and has the advantages of fast response speed, simple control method and wider relative bandwidth. It effectively solves the technical problems of single working mode, slow response speed of metasurface mode conversion and narrow working bandwidth of existing metasurfaces.

[0007] To achieve the above purpose, the present application provides the following technical solutions: A transmissive / reflective / absorptive multi-mode integrated reconfigurable metasurface, comprising a first dielectric substrate and a second dielectric substrate arranged in a spaced and overlapped manner, and a plurality of metasurface units arranged in a periodic manner on a surface of the first dielectric substrate and the second dielectric substrate, wherein the metasurface units of the first dielectric substrate are provided with first PIN diodes, and the metasurface units of the second dielectric substrate are provided with second PIN diodes, and the on-off of the first PIN diodes and the second PIN diodes is controlled by an external voltage biasing method, so as to not only realize flexible switching of two basic working modes of transmission and reflection, but also further activate an electromagnetic wave absorption function, and realize the functions of metasurface transmission type polarization maintenance, reflection type polarization maintenance and wave absorption.

[0008] In some embodiments, the metasurface units of the first dielectric substrate include a strip-shaped metal band arranged on the four edges of the first dielectric substrate, the inner side of the strip-shaped metal band is sequentially provided with a second rectangular ring band, a first rectangular ring band and a rectangular metal structure, the four edges of the rectangular metal structure are provided with a connecting metal structure, the connecting metal structure connects the rectangular metal structure with the first rectangular ring band in the horizontal direction and the vertical direction, and connects the first rectangular ring band with the second rectangular ring band, and the second rectangular ring band is connected with the strip-shaped metal band through the first PIN diode.

[0009] In some embodiments, the center points of the first rectangular ring band, the second rectangular ring band and the rectangular metal structure coincide with the center point of the surface of the first dielectric substrate.

[0010] In some embodiments, the first rectangular ring band, the connecting metal structure, the strip-shaped metal band and the second rectangular ring band are all composed of strip-shaped metal patches, and the width of the strip-shaped metal patch of the first rectangular ring band is greater than the width of the strip-shaped metal patch of the connecting metal structure, the strip-shaped metal band and the second rectangular ring band.

[0011] In some embodiments, the metasurface units of the second dielectric substrate include a third rectangular ring band arranged on the edge of the second dielectric substrate, the inner side of the third rectangular ring band is provided with a fourth rectangular ring band, the fourth rectangular ring band is connected with the third rectangular ring band through the second PIN diode, and the center position of the fourth rectangular ring band is provided with a cavity. The hollow structure is conducive to the dissipation of the energy of the electromagnetic wave itself in the metasurface unit structure, and effectively increases the wave absorption capacity.

[0012] In some embodiments, the center points of the third rectangular ring band, the fourth rectangular ring band and the cavity coincide with the center point of the surface of the second dielectric substrate.

[0013] In some embodiments, the third rectangular ring band and the fourth rectangular ring band are both composed of strip-shaped metal patches, and the width of the strip-shaped metal patch of the third rectangular ring band is greater than the width of the strip-shaped metal patch of the fourth rectangular ring band.

[0014] In some embodiments, the surface area of the cavity is less than the surface area of the rectangular metal structure.

[0015] Compared with the prior art, the present application has the following beneficial effects: The present application can not only realize flexible switching of the two basic working modes of transmission and reflection by dynamically adjusting the working state of the PIN diode in the metasurface unit, but also further activate the electromagnetic wave absorption function, forming a multi-mode regulation and control capability of transmission / reflection / absorption trinity.

[0016] The metasurface of the present application exhibits excellent comprehensive performance in the 1.86-3.20 GHz frequency band (relative bandwidth 53.0%): in this frequency band, the transmission type polarization maintaining function with an insertion loss of less than 2dB or the reflection type polarization maintaining function with an insertion loss of less than 0.3dB can be stably realized, and at the same time, an electromagnetic wave absorption efficiency of more than 80% can also be achieved; especially crucially, in the core interval of 2.27-2.88 GHz (relative bandwidth 23.7%), the absorption efficiency can be further improved to more than 90%, significantly optimizing the energy absorption effect in a specific frequency band.

[0017] The present application effectively solves the problems of single working mode, slow response speed of metasurface mode conversion, and narrow working bandwidth commonly existing in existing metasurfaces, and provides an innovative solution for practical application scenarios such as signal transmission regulation and control of wireless communication systems and electromagnetic scattering suppression of radar stealth systems. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the overall structure of the present application (single metasurface unit); Figure 2 is a schematic diagram of the metasurface unit structure on the first dielectric substrate of the present application (wherein, unit: mm); Figure 3 is a schematic diagram of the metasurface unit structure on the second dielectric substrate of the present application (wherein, unit: mm); Figure 4 is a schematic diagram of the transmission coefficient of the transmission mode of the present application; Figure 5 is a schematic diagram of the transmission coefficient of the reflection mode of the present application; Figure 6 is a schematic diagram of the transmission coefficient of the absorption mode of the present application; Figure 7 is a schematic diagram of the absorption efficiency of the absorption mode of the present application The figures shown in the drawings: 1, first dielectric substrate, 2, second dielectric substrate, 3, first rectangular ring band, 4, connecting metal structure, 5, strip-shaped metal band, 6, second rectangular ring band, 7, third rectangular ring band, 8, fourth rectangular ring band, 9, cavity, 10, first PIN diode, 11, second PIN diode, 12, rectangular metal structure. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0020] Please refer to Figures 1-3 A transmissive / reflective / absorptive multi-mode integrated reconfigurable metasurface includes a first dielectric substrate 1 and a second dielectric substrate 2, both of which are rectangular in shape. The first dielectric substrate 1 and the second dielectric substrate 2 are the same in size and material, both of which use FR-4 material with a dielectric constant of 4.3 and a loss tangent of 0.025 as the substrate, with a side length of 40 mm and a thickness of 0.7 mm. The first dielectric substrate 1 and the second dielectric substrate 2 are arranged in front of and behind each other with a spacing distance of 10 mm. The first dielectric substrate 1 is arranged in front, and the second dielectric substrate 2 is arranged behind. The first dielectric substrate 1 and the second dielectric substrate 2 each have one surface arranged with a periodic array of metasurface units. By controlling the on-off of the first PIN diode 10 and the second PIN diode 11 in the metasurface unit, the functions of metasurface transmissive polarization maintenance, reflective polarization maintenance and wave absorption are realized.

[0021] The metasurface unit is printed on one surface of the first dielectric substrate 1 and the second dielectric substrate 2 by using a strip-shaped metal patch, or the metal sheet is etched on the surface of the dielectric substrate by using an etching method. The strip-shaped metal patch or the metal sheet is made of copper material.

[0022] In some embodiments, the metasurface unit of the first dielectric substrate 1 comprises a strip-shaped metal band 5 arranged at the four edges of the first dielectric substrate 1, the strip-shaped metal band 5 comprises four separate strip-shaped metal patches, each of which has a length smaller than the length or width of the dielectric substrate. Inside the strip-shaped metal band 5, a second rectangular ring band 6, a first rectangular ring band 3 and a rectangular metal structure 12 are arranged in sequence with a certain distance. The rectangular metal structure 12 is provided with connecting metal structures 4 along the horizontal and vertical directions at its four edges. The connecting metal structures 4 are arranged at the gaps between the rectangular metal structure 12 and the first rectangular ring band 3, and between the first rectangular ring band 3 and the second rectangular ring band 6, and connect the rectangular metal structure 12 and the first rectangular ring band 3, and the first rectangular ring band 3 and the second rectangular ring band 6 in the horizontal and vertical directions. The four edges of the second rectangular ring band 6 are connected to the four separate strip-shaped metal patches of the strip-shaped metal band 5 through the first PIN diode 10. For incident electromagnetic waves, the metal patches of different structures can not only increase the resonance of electromagnetic waves with metal patches to increase the bandwidth, but also increase the metal structure coverage area of the metasurface unit structure to enhance the reflection effect.

[0023] The connecting metal structure 4 is composed of 8 strip-shaped metal patches in the vertical and horizontal directions, which are all connected to the four edges of the first rectangular ring band 3, the second rectangular ring band 6 and the rectangular metal structure 12.

[0024] The strip-shaped metal band 5, the second rectangular ring band 6, the first rectangular ring band 3 and the rectangular metal structure 12 are all spaced apart by a certain distance. The anode of the first PIN diode 10 on the right side of the second rectangular ring band 6 is connected to the second rectangular ring band 6, and the cathode is connected to the strip-shaped metal band 5. The anode of the first PIN diode 10 on the upper side of the second rectangular ring band 6 is connected to the second rectangular ring band 6, and the cathode is connected to the strip-shaped metal band 5. The cathode of the first PIN diode 10 on the left side of the second rectangular ring band 6 is connected to the second rectangular ring band 6, and the anode is connected to the strip-shaped metal band 5. The cathode of the first PIN diode 10 on the lower side of the second rectangular ring band 6 is connected to the second rectangular ring band 6, and the anode is connected to the strip-shaped metal band 5.

[0025] The first rectangular ring band 3 and the second rectangular ring band 6 are both surrounded by strip-shaped metal patches to form a rectangular shape. The center points of the first rectangular ring band 3, the second rectangular ring band 6 and the rectangular metal structure 12 coincide with the center point of the surface of the first dielectric substrate 1. The first rectangular ring band 3, the connecting metal structure 4, the strip-shaped metal band 5 and the second rectangular ring band 6 are all composed of strip-shaped metal patches. The width of the strip-shaped metal patch of the first rectangular ring band 3 is greater than the width of the strip-shaped metal patch of the connecting metal structure 4, the strip-shaped metal band 5 and the second rectangular ring band 6.

[0026] The super surface unit of the second dielectric substrate 2 comprises a third rectangular ring band 7 arranged at the edge of the second dielectric substrate 2, a fourth rectangular ring band 8 is arranged at the inner side of the third rectangular ring band 7 at a distance, the fourth rectangular ring band 8 is connected with the third rectangular ring band 7 through a second PIN diode 11, and a rectangular cavity 9 is arranged at the center position of the fourth rectangular ring band 8. The hollow structure is beneficial to the dissipation of the energy of the electromagnetic wave itself in the super surface unit structure, and effectively increases the wave absorption capacity.

[0027] The anode of the second PIN diode 11 arranged at the right side of the fourth rectangular ring band 8 is connected with the fourth rectangular ring band 8, and the cathode is connected with the third rectangular ring band 7; the anode of the second PIN diode 11 arranged at the lower side of the fourth rectangular ring band 8 is connected with the fourth rectangular ring band 8, and the cathode is connected with the third rectangular ring band 7; the cathode of the second PIN diode 11 arranged at the left side of the fourth rectangular ring band 8 is connected with the fourth rectangular ring band 8, and the anode is connected with the third rectangular ring band 7; the cathode of the second PIN diode 11 arranged at the upper side of the fourth rectangular ring band 8 is connected with the fourth rectangular ring band 8, and the anode is connected with the third rectangular ring band 7.

[0028] The third rectangular ring band 7 and the fourth rectangular ring band 8 are both surrounded by strip-shaped metal patches to form a rectangular shape, the width of the strip-shaped metal patch of the third rectangular ring band 7 is greater than the width of the strip-shaped metal patch of the fourth rectangular ring band 8. The center point of the third rectangular ring band 7, the fourth rectangular ring band 8 and the cavity 9 coincides with the center point of the surface of the second dielectric substrate 2. The width of the strip-shaped metal patch of the third rectangular ring band 7 is greater than the width of the strip-shaped metal patch of the fourth rectangular ring band 8.

[0029] The working principle of the application is as follows: The medium substrate with different shaped metal patches and PIN diodes are used together to realize the transmission / reflection / absorption function of linearly polarized wave incidence. The first layer of dielectric substrate 1 mainly realizes the transmission and reflection function under the action of different PIN diode states, and the second layer of dielectric substrate 2 mainly realizes the wave absorption function under the action of different PIN diode states.

[0030] The super surface unit of the application is highly symmetrical, so x The electromagnetic response of the polarized wave or y The polarized incident wave is the same. Taking x The polarized incident wave as an example, the super surface works in the wave absorption state, and the wave absorption efficiency mainly depends on the reflectivity and transmissivity: ; Among them, ; ; In the formula, is the frequency, 、 、 are the frequencies are the corresponding transmittance, reflectance, and absorptance.

[0031] The technical effects of the present application are described below in connection with simulation experiments: 1. Simulation conditions and content: In the simulation software CST used, the boundary conditions of the unit structure were set to simulate an infinite array, and the linearly polarized wave was incident vertically from the +z direction to simulate the multi-mode of the super surface.

[0032] Simulation 1: When the first layer of front PIN diode is turned off and the second layer of front PIN diode is turned off, the different transmissive polarization characteristics of the present application are simulated, and the results are shown in Figure 4 .

[0033] Simulation 2: When the first layer of front PIN diode is turned off and the second layer of front PIN diode is turned on, the different reflective polarization characteristics of the present application are simulated, and the results are shown in Figure 5 .

[0034] Simulation 3: When the first layer of front PIN diode is turned on and the second layer of front PIN diode is turned on, the different absorptive characteristics of the present application are simulated, and the results are shown in Figure 6 .

[0035] 2. Analysis of simulation results: Referring to Figure 4 , after the linearly polarized wave is incident vertically from the +z direction to the unit structure of the super surface, it will maintain its original polarization characteristics and be transmitted from the -z direction within 1.86-3.20 GHz (relative bandwidth of 53.0%) with an insertion loss of less than 2 dB.

[0036] Referring to Figure 5 , after the linearly polarized wave is incident vertically from the +z direction to the unit structure of the super surface, it will maintain its original polarization characteristics and be reflected from the +z direction within 1.50-4.00 GHz (relative bandwidth of 90.9%).

[0037] Referring to Figure 6 , after the linearly polarized wave is incident vertically from the +z direction to the unit structure of the super surface, the reflected and transmitted wave components are weak within 1.84-3.33 GHz (relative bandwidth of 57.6%).

[0038] Referring to Figure 7When linearly polarized waves are vertically incident on the super surface unit structure from the +z direction, the absorptivity can achieve wave absorption function in 1.84-3.33GHz (the relative bandwidth is 57.6%), wherein the absorption efficiency is greater than 80%, and especially, the absorption efficiency is greater than 90% in 2.27-2.88GHz (the relative bandwidth is 23.7%).

[0039] In the transmission mode, when any linearly polarized wave is incident, the linearly polarized wave can maintain its original polarization state when transmitting through the super surface; in the reflection mode, when any linearly polarized wave is incident, the super surface can maintain the same polarization state to reflect; in the wave absorption mode, when any linearly polarized wave is incident, the super surface can absorb the energy of the electromagnetic wave, and no other reflected wave or transmitted wave is generated.

[0040] In summary, by controlling the bias voltage of the electrically controlled active device PIN diode loaded in the super surface unit structure to switch the transmission mode / reflection mode / absorption mode, the interaction between the linearly polarized incident wave and the super surface unit structure is realized, and the reconfigurable function is realized.

[0041] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the present application, and any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application are within the scope of the present application.

Claims

1. A reconfigurable metasurface integrating transmission / reflection / absorption multimode, characterized in that, The device includes a first dielectric substrate (1) and a second dielectric substrate (2) arranged at intervals and overlapping each other, and a plurality of metasurface units arranged periodically on one surface of the first dielectric substrate (1) and the second dielectric substrate (2). The metasurface units of the first dielectric substrate (1) are provided with a first PIN diode (10), and the metasurface units of the second dielectric substrate (2) are provided with a second PIN diode (11). By controlling the on and off of the first PIN diode (10) and the second PIN diode (11), the functions of maintaining transmissive polarization, maintaining reflective polarization and absorbing waves of the metasurface are realized.

2. The reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 1, characterized in that, The metasurface unit of the first dielectric substrate (1) includes a strip metal strip (5) disposed around the periphery of the first dielectric substrate (1). The inner side of the strip metal strip (5) is provided with a second rectangular ring strip (6), a first rectangular ring strip (3) and a rectangular metal structure (12) in sequence. The rectangular metal structure (12) is provided with a connecting metal structure (4) around its periphery. The connecting metal structure (4) connects the rectangular metal structure (12) and the first rectangular ring strip (3) in the horizontal direction and the first rectangular ring strip (3) and the second rectangular ring strip (6) in the vertical direction. The second rectangular ring strip (6) and the strip metal strip (5) are connected through the first PIN diode (10).

3. The reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 2, characterized in that, The center point of the first rectangular ring (3), the second rectangular ring (6), and the rectangular metal structure (12) coincides with the center point of the surface of the first dielectric substrate (1).

4. The reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 2, characterized in that, The first rectangular ring (3), the connecting metal structure (4), the strip metal strip (5), and the second rectangular ring (6) are all composed of strip metal patches. The width of the strip metal patch of the first rectangular ring (3) is greater than the width of the strip metal patch of the connecting metal structure (4), the strip metal strip (5), and the second rectangular ring (6).

5. The reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 1, characterized in that, The metasurface unit of the second dielectric substrate (2) includes a third rectangular ring (7) disposed on the edge of the second dielectric substrate (2), and a fourth rectangular ring (8) is provided on the inner side of the third rectangular ring (7). The fourth rectangular ring (8) is connected to the third rectangular ring (7) through a second PIN diode (11), and a cavity (9) is provided at the center of the fourth rectangular ring (8).

6. The reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 5, characterized in that, The center points of the third rectangular ring (7), the fourth rectangular ring (8), and the cavity (9) coincide with the center point of the surface of the second dielectric substrate (2).

7. The reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 5, characterized in that, The third rectangular ring (7) and the fourth rectangular ring (8) are both made of strip-shaped metal patches. The width of the strip-shaped metal patch of the third rectangular ring (7) is greater than the width of the strip-shaped metal patch of the fourth rectangular ring (8).

8. A reconfigurable metasurface integrating transmission / reflection / absorption multimode as described in claim 5, characterized in that, The surface area of ​​the cavity (9) is smaller than the surface area of ​​the rectangular metal structure (12).

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