Multifunctional integrated electromagnetic protection metasurface structure

Abstract

The invention discloses a multifunctional integrated electromagnetic protection metasurface structure which comprises an electromagnetic induction structure, a dielectric substrate and a field nonlinear device. The electromagnetic induction structure is composed of a plurality of metal meshes which are electrically connected through the field nonlinear device; the electromagnetic induction structure is arranged on the dielectric substrate. The problem that existing in-band electromagnetic protection and microwave infrared transmission cannot be considered at the same time can be effectively solved, optical radio frequency structure integrated protection is achieved, and great significance is achieved for electromagnetic protection research in the field of precise optical radar composite detection.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic wave transmission, and in particular relates to a multifunctional integrated electromagnetic protection super surface structure. Background Art

[0002] In the fifth dimension of electromagnetic space, high-energy strong electromagnetic attacks pose a major threat to electronic systems. With the full integration of optical components and microwave transmission in aerospace, composite detection, communication equipment and medical facilities, protective surfaces with high-quality optical and microwave dual-band signal transmission and strong electromagnetic shielding compatibility have attracted much attention.

[0003] At present, the energy selective surface based on field-induced nonlinear devices and electromagnetic induction structures can simultaneously achieve fast time domain response to electromagnetic attacks as well as energy domain and frequency domain selection functions. It is an adaptive electromagnetic protection device that takes into account the weak points of protection within the band and has the advantages of high power tolerance and fast adaptive response speed. It is widely used in the field of electromagnetic protection of electronic systems, and realizes electromagnetic shielding, anti-interference and out-of-band suppression functions without affecting the transmission function of working signals. However, its composition structure of semiconductor devices, artificial electromagnetic metal structures and dielectric substrates makes it not transparent. Therefore, it is urgent to study and design the integration of light transmission, wave transmission and electromagnetic protection of energy selective surfaces, and realize the attenuation and shielding of strong electromagnetic pulses under the premise of ensuring the normal transmission of useful signals. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0005] A multifunctional integrated electromagnetic protection metasurface structure, comprising: an electromagnetic induction structure, a dielectric substrate and a field-induced nonlinear device;

[0006] The electromagnetic induction structure is composed of a plurality of metal grids and is electrically connected through the field-induced nonlinear device;

[0007] The electromagnetic induction structure is arranged on the dielectric substrate.

[0008] Preferably, the metal grid is in the shape of a square or an orthogonal circle;

[0009] A metal frame is used at the edge of the metal grid to ensure the electrical connection characteristics of the structure;

[0010] The periodic size of the metal grid is set to be much larger than the wavelength of infrared light and much smaller than the wavelength of microwaves. The electromagnetic shielding function in the low frequency band is achieved based on the metal conductive network connection that is much smaller than the wavelength of microwaves. At the same time, high light transmittance characteristics in the visible and infrared bands are achieved based on the extremely small metal line width and large duty cycle.

[0011] Preferably, the electromagnetic induction structure is set to a sub-wavelength size of a transmission band microwave, and the electromagnetic induction structure will generate electromagnetic resonance with an incident wave of a corresponding frequency point, thereby forming transmission and reflection of the incident wave;

[0012] The electromagnetic induction structure can also sense the electric field energy in space and trigger the field-controlled switch device by the concentration of electric field strength; when the field-controlled switch device is not turned on, the electromagnetic induction structure has a wave-transmitting effect in the radar working band and a microwave attenuation effect outside the radar working band; when the field-controlled switch device is turned on, the electromagnetic induction structure has a shielding effect in the radar working band.

[0013] Preferably, the dielectric substrate is made of transparent quartz glass and polymethyl methacrylate; the transparent dielectric substrate makes the metasurface light-transmissive;

[0014] The dielectric substrate also provides support for the impedance matching design of the metasurface, and impedance matching is achieved by adjusting the relative dielectric constant of the medium to achieve microwave transmission and shielding performance.

[0015] Preferably, the field-induced nonlinear device adopts a Schottky diode, and the field-induced nonlinear device changes its switching state according to the strength of the spatial radiation field, thereby inducing an adaptive transformation of the metasurface impedance, thereby realizing the conversion of the metasurface working mode from a transmission state to a shielding state.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention proposes a multifunctional integrated electromagnetic protection metasurface structure, which is realized by combining an electromagnetic induction structure composed of a nano-scale metal grid, a semiconductor material, and a transparent substrate. The cross-shaped electromagnetic induction structure realizes the low-loss transmission function of the signal within the radar band and the signal attenuation outside the band; the switching characteristics of the field-induced nonlinear semiconductor material realize the conversion of signal transmission and shielding within the radar band; and the nano-scale metal grid setting of the transparent medium substrate and the electromagnetic induction structure realizes the high transmittance of visible light and infrared of the new microscopic array metasurface. The present invention can effectively solve the problem that the existing in-band electromagnetic protection and microwave infrared transmission cannot be taken into account at the same time, realize the integrated protection of optical radio frequency structure, and has very important significance for the research on electromagnetic protection in the field of precision optical radar composite detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 Schematic diagram of the super surface structure of an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a grid-like super-surface structure according to an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of a microwave transmission curve of a metasurface according to an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of a microwave transmission curve of a grid-like metasurface according to an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of the field intensity distribution of a metasurface according to an embodiment of the present invention;

[0024] Figure 6 Schematic diagram of the grid-based metasurface field intensity distribution according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Embodiment 1

[0028] In this embodiment, a multifunctional integrated electromagnetic protection metasurface structure includes: an electromagnetic induction structure, a dielectric substrate and a field-induced nonlinear device.

[0029] The electromagnetic induction structure is composed of a plurality of metal grids and is electrically connected through a field-induced nonlinear device; the electromagnetic induction structure is arranged on a dielectric substrate.

[0030] The metal grid is in square or orthogonal circular shape; a metal frame is used at the edge of the metal grid to ensure the electrical connection characteristics of the structure; the period size of the metal grid is set to be much larger than the wavelength of infrared light and much smaller than the wavelength of microwaves, and the electromagnetic shielding function in the low frequency band is achieved based on the metal conductive network connection that is much smaller than the wavelength of microwaves. At the same time, high light transmittance characteristics in the visible and infrared bands are achieved based on the extremely small metal line width and large duty cycle.

[0031] The electromagnetic induction structure is set to a subwavelength size of microwaves in the transmission band. The electromagnetic induction structure will produce electromagnetic resonance with the incident wave of the corresponding frequency point, thereby forming transmission and reflection of the incident wave; the electromagnetic induction structure can also sense the electric field energy in space, and trigger the field-controlled switching device through the concentration of electric field strength; when the field-controlled switching device is not turned on, the electromagnetic induction structure has a wave-transmitting effect in the radar working band and a microwave attenuation effect outside the radar working band; when the field-controlled switching device is turned on, the electromagnetic induction structure has a shielding effect in the radar working band.

[0032] The dielectric substrate is made of transparent quartz glass and polymethyl methacrylate materials; the setting of the transparent dielectric substrate makes the metasurface light-transmissive; the dielectric substrate also provides support for the impedance matching design of the metasurface, and realizes impedance matching by adjusting the relative dielectric constant of the medium, thereby realizing the transmission and shielding performance of microwaves.

[0033] The field-induced nonlinear device uses a Schottky diode. The field-induced nonlinear device changes its switching state according to the strength of the space radiation field, causing an adaptive transformation of the metasurface impedance, thereby realizing the conversion of the metasurface working mode from a transmission state to a shielding state.

[0034] Embodiment 2

[0035] In this embodiment, if Figure 1 , Figure 2 As shown, a multifunctional integrated electromagnetic protection supersurface structure is a new cross-shaped light-transmitting, microwave-transmitting, electromagnetic protection integrated microscopic array supersurface structure based on the combination of nano-scale metal grids, semiconductor materials and transparent substrates, including metal grids, electromagnetic induction structures, dielectric substrates, and field-induced nonlinear devices.

[0036] The metal grid is set to a periodic size that is much larger than the infrared light wavelength and much smaller than the microwave wavelength. Here, the grid periodic size is set to 20μm. The electromagnetic shielding function is achieved through an interconnected metal conductive network. At the same time, high light transmittance in the visible and infrared bands is achieved through extremely small line width and large duty cycle. The transmittance in the visible and infrared bands meets the working requirements of precision optical instruments.

[0037] The metal electromagnetic induction structure is composed of several metal grids, and the square and orthogonal circular metal grids are used to form an artificial electromagnetic structure of the energy selection surface. Here, the square grid is taken as an example. Figure 2As shown in the figure, a metal frame is used at the edge of the metal grid to ensure the electrical connection characteristics of the structure. In order to ensure the perfect fit between the grid structure and the overall structure, the periodic size of the grid structure should be proportional to the corresponding selectable structure width. The size of the metal electromagnetic induction structure is set to a sub-wavelength size. The periodic size of the unit surface is set to 2mm. It can produce electromagnetic resonance with the incident wave at the corresponding frequency point, forming different electromagnetic responses such as transmission and reflection, and plays a decisive role in the angle stability, polarization characteristics, impedance matching, etc. of the ESS; secondly, the electromagnetic induction structure can sense the energy of the electric field in space and trigger the field-controlled switch device. When the switch device is not turned on, the surface has a wave-transmitting effect in the radar working band and a microwave attenuation effect outside the radar working band.

[0038] The dielectric substrate is made of transparent quartz glass and polymethyl methacrylate or other infrared materials that transmit light. Here, a sapphire substrate is used as the dielectric substrate with a dielectric constant of 9.3. The dielectric substrate serves as a carrier of the metasurface, and the metasurface can be made into different forms according to needs. Secondly, it provides support for the impedance matching design of the metasurface, and achieves impedance matching by adjusting the relative dielectric constant of the medium, thereby achieving microwave transmission and shielding performance. Finally, the setting of the transparent dielectric substrate can achieve the transmittance of the metasurface.

[0039] The field-induced nonlinear device uses a Schottky diode, and its equivalent capacitance C in the cut-off state of the diode is off =0.15pF, equivalent inductance L in the on state on =0.45nH, equivalent resistance R on =2Ω, and its main function is to change its own switching state according to the strength of the space radiation field, triggering the adaptive transformation of the metasurface impedance, and realizing the conversion of the metasurface working mode from the transmission state to the shielding state.

[0040] Figure 3 , Figure 4 The figure shows the signal insertion loss of the cross-shaped energy selective surface and the shielding effectiveness of the grid cross-shaped energy selective surface in the transmission working state and the protection working state respectively. It can be seen from the figure that the multifunctional integrated electromagnetic protection metasurface structure proposed by the present invention is basically consistent with the original energy selective surface in microwave transmission and strong electromagnetic protection performance. Figure 5 , Figure 6 The electric field intensity distribution diagrams of the cross-shaped energy selective surface and the grid-shaped cross-shaped energy selective surface respectively show that the electric field coupling distribution of the metasurface under strong electromagnetic radiation remains basically unchanged after grid-shaped treatment. From this, it can be inferred that grid-shaped treatment has little effect on the switching function of the field-induced nonlinear device on the energy selective surface. Figure 1 , Figure 2It can be seen that the multifunctional integrated electromagnetic protection metasurface structure proposed in the present invention has high-performance light transmission characteristics. Therefore, the present invention can effectively solve the problem that the existing in-band electromagnetic protection and microwave infrared transmission cannot be taken into account at the same time, and realize the integrated protection of optical radio frequency structure, which is of great significance to the electromagnetic protection research in the field of precision optical radar composite detection.

[0041] The above embodiments are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A multifunctional integrated electromagnetic protection metasurface structure, characterized in that: include: Electromagnetic induction structures, dielectric substrates and field-induced nonlinear devices; The electromagnetic induction structure is composed of a plurality of metal grids and is electrically connected through the field-induced nonlinear device; The electromagnetic induction structure is arranged on the dielectric substrate.

2. According to claim 1, a multifunctional integrated electromagnetic protection metasurface structure is characterized in that: The metal grid is in the form of a square or an orthogonal circle; A metal frame is used at the edge of the metal grid to ensure the electrical connection characteristics of the structure; The periodic size of the metal grid is set to be much larger than the wavelength of infrared light and much smaller than the wavelength of microwaves. The electromagnetic shielding function in the low frequency band is achieved based on the metal conductive network connection that is much smaller than the wavelength of microwaves. At the same time, high light transmittance characteristics in the visible and infrared bands are achieved based on the extremely small metal line width and large duty cycle.

3. According to claim 1, a multifunctional integrated electromagnetic protection metasurface structure is characterized in that: The electromagnetic induction structure is set to a sub-wavelength size of the transmission frequency band microwave, and the electromagnetic induction structure will generate electromagnetic resonance with the incident wave of the corresponding frequency point, thereby forming transmission and reflection of the incident wave; The electromagnetic induction structure can also sense the electric field energy in space and trigger the field-controlled switch device by the concentration of electric field strength; when the field-controlled switch device is not turned on, the electromagnetic induction structure has a wave-transmitting effect in the radar working band and a microwave attenuation effect outside the radar working band; when the field-controlled switch device is turned on, the electromagnetic induction structure has a shielding effect in the radar working band.

4. According to claim 1, a multifunctional integrated electromagnetic protection metasurface structure is characterized in that: The dielectric substrate is made of transparent quartz glass and polymethyl methacrylate materials; the transparent dielectric substrate is provided to make the metasurface light-transmissive; The dielectric substrate also provides support for the impedance matching design of the metasurface, and realizes impedance matching by adjusting the relative dielectric constant of the medium, thereby achieving microwave transmission and shielding performance.

5. The multifunctional integrated electromagnetic protection metasurface structure according to claim 1, characterized in that: The field-induced nonlinear device adopts a Schottky diode. The field-induced nonlinear device changes its switching state according to the strength of the space radiation field, triggering an adaptive transformation of the metasurface impedance, thereby realizing the transformation of the metasurface working mode from a transmission state to a shielding state.

Images