Self-adaptive thin film electromagnetic shielding screen

Abstract

An adaptive shielding device for a lens or window (1) of a piece of equipment provided with an electrically conductive housing (10) containing an optical or RF sensor (20) behind the lens or the window, the device comprising a shielding screen on at least one face of the lens or the window, the invention relates to a device for shielding a piece of equipment, said shielding screen comprising a switchable RF shielding mesh (2) having a micrometer pitch, said switchable RF shielding mesh being at least partially surrounded by an insulator-metal transition material (3) arranged between said mesh and an electrically conductive envelope (11) for shielding said piece of equipment, said device comprising a susceptor element (5), the susceptor element is arranged to face or contact the insulator-metal transition material and is adapted to convert incident electromagnetic energy (RFH) into activation heat for the insulator-metal transition material (3, 3a, 31), the susceptor element is dimensioned to transition the insulator-metal transition material (3, 3a, 31, 31a) into a conductive state under the action of the electromagnetic energy so as to electrically connect the mesh to the conductive envelope when the incident electromagnetic energy exceeds a given threshold.

Description

Technical Field

[0001] The present disclosure relates to the field of optically transparent electromagnetic shielding screens with adaptive conductive meshes for electromagnetic and / or optical sensor systems to protect them from the effects of intense electromagnetic radiation. In optically transparent shielding screens with adaptive conductive meshes, when an electromagnetic field exceeding a certain threshold critical for the optimal operation of at least one sensor is detected by the protection component, the mesh is grounded to the housing in which said sensor is incorporated. Background Art

[0002] The main goal of shielding screens against external electromagnetic (EM) interference is to protect on-board optoelectronic devices and their optical sensors, while ensuring high optical transparency in the ultraviolet (UV), visible and infrared (IR) ranges for optimal operation of said optoelectronic devices and associated optical sensors. Currently, these screens offer predefined and constant shielding effectiveness values ​​determined by the internal parameters of the RF shield formed by the metal mesh of the screen, with micrometric spacing, connected to the ground of the device.

[0003] Regarding switchable RF shields with conductive meshes, document WO2018 / 215243A1 in the name of the applicant proposes a shielding screen with a conductive mesh with micrometric spacing, which is directly printed on the inner face of the lens or window (made of silicon, germanium, sapphire, B-grade glass, etc.) of different optoelectronic device objects. The conductive mesh with micrometric spacing is defined by the following: the width of its conductive component band, usually about 10 microns; its mesh spacing, usually about 100 microns; and the thickness of the conductive material used, usually about 2 microns. The modulation of the shielding effectiveness (SE) is obtained by controlling the value of the contact impedance between this conductive mesh and the ground return of the shielding screen. This control is achieved by either: implanting local components such as PIN, MEMS, NEMS or other diodes between the conductive mesh and the ground return; or using a printed tape based on an insulator-metal transition material (usually VO2), whose two states (on (conductive) and off (electrically insulating)) largely change the value of the contact impedance of the screen to the ground in a completely reversible manner and thus change the SE value of the screen.

[0004] This first solution requires a command to activate the change in the contact impedance of the shield and a power supply preferably external to the device to be protected.

[0005] Furthermore, application FR21 02339 filed by the applicant on March 10, 2021 describes a technical solution consisting of capturing the energy of external EM disturbances via a rectifier antenna and using the resulting direct current to activate local components such as PINs, MEMS, NEMS or other diodes, or using a printed tape based on an insulator-metal transition material (typically VO2) to activate a micropump that injects a liquid into the channel between the RF shield and the ground, so as to dynamically adapt the SE value of the shielding screen and thus make the RF shield switchable. The entire system thus becomes a shielding screen with controlled shielding effectiveness (SE), whose SE value automatically increases in the presence of external electromagnetic (EM) disturbances, without the need for an operator to activate the system. This solution does not require a power supply, but is effective for receiving high EM energy, in particular in cases where the means for grounding the shield require high currents or voltages to achieve their activation. Summary of the invention

[0006] The present disclosure aims to more easily implement an adaptive electromagnetic shielding device for protecting a piece of equipment containing a photoelectric sensor, and proposes an optically transparent adaptive electromagnetic shielding device for a lens or window of a piece of equipment, the piece of equipment having a conductive cover, the conductive cover containing at least one optical or RF sensor behind the lens or the window, the device comprising a shielding screen on at least one face of the lens or the window, the shielding screen comprising a switchable RF shielding mesh, the switchable RF shielding mesh being at least partially surrounded by a boundary of an insulator-metal transition material arranged between the mesh and the conductive envelope for shielding the piece of equipment, the device comprising a susceptor element, the susceptor element being arranged to face or contact the insulator-metal transition material and being suitable for converting incident electromagnetic energy into activation heat for the insulator-metal transition material, the susceptor element being dimensioned to cause the insulator-metal transition material to transform into a conductive state under the action of the electromagnetic energy so as to electrically connect the mesh to the conductive envelope at low impedance when the incident electromagnetic energy exceeds a given threshold.

[0007] This makes it possible for the adaptive shield to automatically transform from a configuration that allows electromagnetic waves to pass through to a shielding configuration that blocks said waves in excess of a given incident electromagnetic energy.

[0008] The spacing of the RF shielding mesh is preferably micrometric in order to provide active shielding at frequencies from a few GHz to tens of GHz.

[0009] The features set out in the following paragraphs may be implemented optionally, independently of one another or in combination with one another:

[0010] According to a first embodiment, a switchable RF shielding mesh and an insulator-metal transition material are arranged on one face of the lens or the window inside the piece of equipment, while a susceptor element is implemented on an outer face of the lens or the window and comprises a layer of conductive material facing a surface of the insulator-metal transition material.

[0011] The insulator-metal transition material may form a first frame around the mesh, and the susceptor element may be shaped as a second frame facing the first frame.

[0012] In this case, the surface area of ​​the second frame may be greater than or equal to the surface area of ​​the first frame.

[0013] The susceptor element may comprise a layer of translucent conductive material covering the outer face of the lens or window.

[0014] According to a second embodiment, a switchable RF shielding mesh and an insulator-metal transition material are placed on the outer face of the lens or the window, and the sensor element includes a conductive material layer facing the surface of the insulator-metal transition material and placed on an electrically insulating layer covering the insulator-metal transition material.

[0015] According to a third embodiment, a switchable RF shielding mesh, an insulator-metal transition material and a sensor element are arranged on one face of the lens or the window, inside or outside the piece of equipment, the sensor element being implemented in the form of a frame surrounding the insulator-metal transition material, the insulator-metal transition material surrounding the switchable RF shielding mesh.

[0016] According to a fourth embodiment, a switchable RF shielding mesh and a frame made of an insulator-metal transition material are placed on the outer face of the lens or the window, and a susceptor element comprises a layer of conductive material, which faces the surface of the insulator-metal transition material and is placed on an electrically insulating layer, which in turn covers the insulator-metal transition material. The switchable RF shielding mesh can be specifically implemented with an insulator-metal transition material placed on the outer face of the lens or the window and covering the outer face, and the susceptor element comprises a layer of conductive material placed on and covering an insulating layer, which itself covers the insulator-metal transition material.

[0017] In this case, the layer of conductive material and / or the layer of insulating material may comprise an optically transparent mesh covering the switchable RF shielding mesh, in particular in the region of the lens or window facing the sensor of the system to be protected.

[0018] For all solutions, the switchable RF shielding mesh can be a mesh made of conductive material with micrometric spacing, the configuration of the mesh being periodic or aperiodic (Voronoi type).

[0019] The mesh with micrometric spacing may be made of a material selected from titanium / silver double layer insulator-metal transition material or gold.

[0020] The insulator-metal transition material may be a VO2 type material having a thickness between 1000 nm and 2000 nm.

[0021] The susceptor element may be a gold film having a thickness of 2 to 10 nanometers.

[0022] Advantageously, the switchable RF shielding mesh is dimensioned to provide a shielding effectiveness of 10 dB to 40 dB in a frequency band of 0.1 GHz to 40 GHz when it is electrically connected at low impedance to the conductive envelope through the insulator-metal transition material exhibiting electrical conductivity.

[0023] The optical transparency of the shielding screen is at least 50% in the visible light range, regardless of whether the shielding is active or inactive. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, details and advantages will become apparent upon reading the following detailed description and upon examining the accompanying drawings, in which:

[0025] [ Figure 1A ] shows a top view of a first embodiment of an adaptive shield according to the present disclosure;

[0026] [ Figure 1B ] shows a bottom view of a first embodiment of an adaptive shield according to the present disclosure;

[0027] [ Figure 1C ]exhibit Figure 1A A top view of a variant of ;

[0028] [ Figure 2 ] shows a schematic diagram of a sensor device behind a window including a self-adaptive shield under low electromagnetic stress;

[0029] [ Figure 3 ] demonstrates the performance of the disclosed Figure 2 A schematic diagram of a device;

[0030] [ Figure 4A ] is a top view of a second embodiment of an adaptive shield according to the present disclosure;

[0031] [ Figure 4B ]for Figure 4A A bottom view of an exemplary embodiment of an adaptive shield;

[0032] [ Figure 4C ]for Figure 4A A top view of a variant of an adaptive shield;

[0033] [ Figure 5A ] is a top view of a third embodiment of an adaptive shield according to the present disclosure;

[0034] [ Figure 5B ]for Figure 5A A bottom view of an exemplary embodiment of an adaptive shield;

[0035] [ Fig. 6A ] is a side view of a fourth embodiment of an adaptive shield according to the present disclosure;

[0036] [ Figure 6B ]for Fig. 6A Side view of a variant of the adaptive shield. DETAILED DESCRIPTION

[0037] The object of the present disclosure is to implement an optically transparent adaptive electromagnetic shielding screen, which means that the adaptive electromagnetic shielding screen automatically changes from a state allowing electromagnetic radiation to pass to a state blocking this radiation as soon as a given incident electromagnetic energy threshold is exceeded, and returns to an optically transparent state when the electromagnetic energy drops back below the threshold. To achieve this, the present disclosure proposes a device, such as Figure 1B As shown in FIG. 1 , the device comprises a shielding screen implemented in a light-transparent lens or window by means of a conductive micrometer grid 2, which is surrounded by a frame 3, which is implemented by, for example, VO2, V2O3, BaVS3, PrNiO3, NdNiO3, Fe3O4, NiS, LaCoO3, SmNiO3, NbO2, La 5 / 3 Sr 1 / 3 A border made of an insulator-metal transition material (pure or doped material or solid solution material, but this list is not exhaustive) such as NiO4, Ti2O3, GeTe, Ge2Sb2Te5, etc., the framework comprising the following means: in the presence of external electromagnetic interference, increasing the temperature of the strip made of the insulator-metal transition material forming the border constituting the framework until the strip becomes conductive to electromagnetic energy above a given threshold.

[0038] According to this disclosure:

[0039] a. When the boundary of the insulator-metal transition material is in an electrically insulating state (off state), for example, a temperature θ of less than 67°C for the material VO2 VO2 , a conductive mesh with a center-to-center micrometric spacing has a high contact impedance between the perimeter of the screen and the bulk of the system to be protected. Therefore, the shielding effectiveness is minimal;

[0040] b. When the boundary of the insulator-metal transition material is in a conductive state (on state), that is, when the temperature θ VO2Above 67° C., a conductive mesh with a center-to-center micrometric spacing has a low contact impedance between the periphery of the screen and the bulk of the system to be protected. Subsequently, the shielding effectiveness is maximum.

[0041] Thus, the mesh is a switchable RF shielding mesh with micrometric spacing connected to the ground of a piece of equipment with low or no contact impedance, depending on the temperature of the strip of insulator-metal transition material forming the border of the frame.

[0042] To activate the transition of the insulator-metal material, the device uses a susceptor element 5, which is placed facing the insulator-metal transition material or even in contact with this material and is suitable for converting incident electromagnetic energy into heat that activates the insulator-metal transition material. The susceptor element is sized and positioned to cause the insulator-metal transition material to transition to a conductive state under the action of electromagnetic energy above a given threshold, so as to electrically connect the mesh to the conductive envelope at low impedance when the incident electromagnetic energy exceeds this given threshold.

[0043] Throughout this application, the term "facing" means that the susceptor material is aligned with the insulator-metal transition material along a direction perpendicular to the plane of the window.

[0044] In the schematic representation of the preferred solution Figure 1A and 1B In the case of a switchable RF shielding mesh 2 and an insulator-metal transition material 3 are arranged on one face of the lens or the window, inside the piece of equipment, while a susceptor element 5 is arranged on an external face of the lens or the window 1 and comprises a layer of conductive material forming a frame, the frame facing the surface of the frame formed by the insulator-metal transition material 3. The heat generated by the susceptor element in the presence of electromagnetic energy is transferred through the lens 1, such as a sapphire window, and heats the frame made of the insulator-metal transition material, which in the presence of sufficient heat transforms into a conductive state.

[0045] As an example, tests were conducted with a window consisting of a sapphire substrate 0.5 mm thick and measuring 50 mm by 50 mm, on which were placed:

[0046] a.- On the front side: a frame hollowed out at its center, made of an ultra-thin gold layer 5 nanometers thick and forming a 7 mm wide border to form the susceptor material 5 around the transparent area of ​​the window;

[0047] b.- On the back side: a frame 3 made of a thin VO2 layer 1.5 microns thick, forming a border 3 mm wide. The VO2 frame is in contact at its outer edge with a conductive frame 4 consisting of a titanium / silver (Ti / Ag) bilayer 2.5 mm wide and connecting the frame 3 to the conductive envelope of the piece of equipment. The VO2 frame is connected at its inner edge to a square mesh with micrometric spacing, consisting of a titanium / silver (Ti / Ag) bilayer with a strip width equal to 10 microns, a spacing equal to 200 microns and a thickness of 5 nanometers / 2 microns and a side length equal to 40 mm, forming a switchable RF shielding mesh 2.

[0048] When the frame made of VO2 material is in an electrically insulating state (off state at a temperature below 67°C), the shielding effectiveness is equal to approximately 15dB in the 2GHz-18GHz band. When the frame made of VO2 material is in a conductive state (on state at a temperature above 67°C), the shielding effectiveness is equal to approximately 25dB in the 2GHz-18GHz band. The optical transparency of the screen in the visible light range (from 400nm to 800nm) remains greater than 77%, regardless of the off or on state of the frame made of VO2 material.

[0049] According to this example, the frame made of VO2 material has a thickness of about 1000 to 2000 nanometers, and preferably about 1400 to 1600 nanometers, although it is possible to choose a different thickness if another insulator-metal transition material is chosen.

[0050] Reverberation chamber tests according to the method described in the document CL Holloway, DA Hill, J. Ladbury, G. Koepke and R. Garzia, "Shielding effectiveness measurements of materials using nested reverberation chambers", IEEE Trans. Electromagn. Compat., Vol. 45, No. 2, pp. 350-356, May 2003, doi: 10.1109 / TEMC.2003.809117, allowed to experimentally demonstrate that an ultra-thin gold layer (5 to 10 nm thick) subjected to electromagnetic stress in the frequency band from 2.7 GHz to 3.2 GHz and at an electric power of 55 W at the amplifier output made it possible to increase the temperature of the sapphire substrate from a value of 22°C to a value greater than 110°C.

[0051] Figure 2 and 3 A device is schematically shown, which includes a conductive housing, in this case a metal housing 10, which contains an optical or RF sensor 20 facing a lens or window 1, which supports a shielding device as described in Figures 1 and 2, and in which the insulator-metal transition material is, for example, material VO2.

[0052] The metal housing 10 is provided with a metal envelope 11 for the sapphire window 1 and is electrically connected to a conductive frame 4 surrounding a frame 3 made of VO2 material. This frame surrounds a switchable RF shielding mesh 2 which itself is provided here with a border 2b for electrical connection to the VO2 frame on the inner face of the window.

[0053] exist Figure 2 configuration, low energy radiated RF L The outer face of the irradiation window and the frame 5 forming the susceptor element. In this configuration, the temperature of the insulator-metal transition material remains low and the material remains an electrical insulator.

[0054] The RF signal and the ultraviolet, visible, and infrared light signals VI are transmitted through the window and received by the sensor 20 .

[0055] exist Figure 3 Medium and high energy RF signals H The susceptor element is irradiated and its temperature rises. The generated heat C is transmitted through the window to the insulator-metal transition material and, if the energy of the electromagnetic radiation is sufficient, the temperature of the material increases until it reaches the transition temperature. Once the transition temperature is reached, the insulator-metal transition material becomes conductive, which allows low-impedance electrical contact between the mesh 2 and the housing 10 and blocks RF signals, while ultraviolet, visible and infrared light signals VI can still reach the sensor 20.

[0056] Figure 1C Corresponds to Figure 1A A variant in which the outer face of the sapphire substrate forming the window 1 is completely covered with an ultra-thin susceptor material layer 5a, for example a 2 nm to 10 nm thick and preferably a 4 nm to 6 nm thick gold layer for thin windows, as described above, while the inner face of the window remains in contact with Figure 1B This embodiment increases the electromagnetic energy captured by the screen when it is subject to external electromagnetic interference and therefore reduces the electromagnetic energy required to obtain a temperature increase sufficient to cause the conductive transition of the insulator-metal material. However, this embodiment reduces the optical transparency of the shield, with the maximum optical transparency of a thin 5 nm thick gold layer on sapphire approaching 50% in the visible range.

[0057] In cases where the insulator-metal transition material is a material other than VO2, or depending on the energy of the RF signal we wish to trigger the transition, it may be possible to increase or decrease the surface area covered by the susceptor element.

[0058] Figure 4A , Figure 4B and Figure 4C Another variant is a conductive mesh 32a with a micrometric pitch made entirely of an insulator-metal transition material on the back side of the sapphire substrate 1, which is surrounded by a frame 31a for connection to the Figure 2 The conductive envelope 11 of the frame itself is made of an insulator-metal transition material, such as VO2 or some other insulator-metal transition material, as stated above. When the VO2 material is in a conductive state, a relatively low shielding effectiveness is obtained, approximately 10 dB in the 2 GHz-18 GHz band, because of its conductivity (σ = approximately 3×10 5 S / m) is less than the conductivity of silver (σ=6.1×10 7 S / m). However, the absence of a mesh Ti / Ag double layer with micrometric spacing simplifies the manufacturing process. For the external surface, Figure 4A The frame 51a formed of an ultra-thin gold layer having a thickness of 4 to 6 nanometers and the inner portion of the frame formed of an ultra-thin mesh gold layer 52a are shown. In the case of a window 1 with a small surface area, the ultra-thin mesh gold layer 52a can be eliminated, and the frame 51a is sufficient to provide the heat required for the insulator-metal transition of the mesh 32a and the frame 31a made of VO2 material. Figure 4C It is shown that the entire outer face of the window 1 is covered with a continuous ultra-thin gold layer 52b, which ensures a better increase in the temperature of the window 1, but at the expense of optical transparency.

[0059] Figure 5A and Figure 5B The exemplary embodiment of replaces the mesh made of Ti / Ag double layer with an ultra-thin mesh 52 made of gold with micrometric spacing, approximately 5 nanometers thick. The conductive frame of the frame 3 surrounding the VO2 material is replaced by a gold frame to produce a susceptor material in direct electrical contact with the VO2 frame. This simplifies the manufacture of the screen and leaves the outer face of the window 1 bare. However, the shielding effectiveness of such an ultra-thin gold layer (approximately 30 dB in the 2 GHz-18 GHz band) is less than the shielding effectiveness of a mesh Ti / Ag layer with micrometric spacing having a thickness of 5 nm / 2 μm (which is approximately 30 dB to 40 dB in the 2 GHz-18 GHz band).

[0060] Fig. 6A and Figure 6Bare variants in which only the outer face of the window 1 is structured. These embodiments are based on a frame stack on the outer face of the window, the frame stack being: a first frame comprising susceptor material 5c, 5d; a frame of insulating electrical material 6a, 6b one hundred nanometers thick, the insulating electrical material being for example TiO2 or Al2O3; and a frame of insulator-metal transition material 3a, 31 surrounding the conductive mesh 2a, or a frame of insulator-metal transition material 32. In the embodiment in which the mesh is the Ti / Ag mesh of FIG. 1 Fig. 6A In this case, the properties regarding shielding effectiveness and optical transparency of the screen are retained, but an improvement in the switching speed between the on-state and the off-state is added, since the heat generated by the sensor material layer during external EM disturbances only has to be transferred through the thin TiO2 or Al2O3 layer and no longer through the much thicker window.

[0061] However, the manufacture of these variants is more complicated due to the need to use a new dielectric buffer layer 6a, 6b with high thermal conductivity, for example made of a TiO2 or Al2O3 material with a thickness of, for example, about 100 nanometers. This TiO2 or Al2O3 buffer dielectric layer must be inserted between the ultra-thin gold layer and the VO2 layer. When the ultra-thin gold layer converts the energy of the electromagnetic wave into heat, this heat is transferred to the thin VO2 layer through the buffer layer and causes an insulator-metal transition of the VO2 material. However, this gold layer must remain electrically insulated from the VO2 layer so that it retains all its receptor capabilities.

[0062] exist Figure 6B In this case, the Ti / Ag mesh is replaced by a VO2 mesh 32 connected to a VO2 frame 31, and the insulating layer and the gold layer themselves are provided with corresponding meshes 6c and 5e.

[0063] The present disclosure is not limited to the examples described above by way of example, but covers all variants that are conceivable to a person skilled in the art within the context of the protection sought. In particular, the various solutions described can be combined, for example Figure 5A and 5B The solution is that the gold network can be made from Figure 1B Similarly, the thicknesses and lateral dimensions described above are indicative only and may vary depending on the energy level of electromagnetic radiation to which the shield needs to be adapted and the size of the window.

[0064] Based on the disclosed conductive mesh with micrometric spacing, the frequency range of protection sought against external EM interference covers the 0.1 GHz to 40 GHz band. Mesh spacings of millimeters or even centimeters in size are also conceivable, but at the expense of high frequencies of protection of the shielding screen.

[0065] The invention is not limited to the examples described above, and in particular, for the placement of the materials, other combinations are possible, as long as the susceptor material is positioned so as to allow it to heat the insulator-metal transition material in the presence of a given electromagnetic energy, which insulator-metal transition material itself is positioned so as to allow the switchable RF shield to be connected to the conductive envelope of the lens or window. In the context of the present disclosure, it is also possible to replace the thin film or ultra-thin gold layer used as susceptor with a layer of graphite, stainless steel, molybdenum or silicon carbide or even aluminum (this list is not exhaustive). In the context of the present disclosure, it is also possible to replace the metal mesh with a continuous or mesh-like thin layer of a material belonging to the family of transparent conductive oxides (TCO), such as pure or doped In2O3 (ITO, FTO, etc.), pure or doped ZnO (AZO, etc.), without this list being exhaustive.

Claims

1. An optically transparent adaptive electromagnetic shielding device for a lens or window (1) of a piece of equipment, the piece of equipment having a conductive housing (10), the conductive housing containing an optical or RF sensor (20) behind the lens or the window, the device comprising a shielding screen on at least one side of the lens or the window, the shielding screen comprising a switchable RF shielding mesh (2, 2a, 32, 32a, 52, 52a), the switchable RF shielding mesh being at least partially surrounded by a boundary of an insulator-metal transition material (3, 3a, 31, 31a) arranged between the mesh and the conductive housing (11) for shielding the piece of equipment, characterized in that It comprises a susceptor element (5, 5a, 5b, 5c, 5d, 5e, 51a, 52b) arranged to face or contact the insulator-metal transition material and adapted to convert incident electromagnetic energy (RF H ) is converted into activation heat for the insulator-metal transition material (3, 3a, 31, 31a), and the susceptor element is sized to cause the insulator-metal transition material (3, 3a, 31, 31a, 32, 32a) to transform into a conductive state under the action of the electromagnetic energy, so as to electrically connect the mesh to the conductive envelope at low impedance when the incident electromagnetic energy exceeds a given threshold.

2. The adaptive shielding device according to claim 1, characterized in that: The switchable RF shielding mesh (2) and the insulator-metal transition material (3) are arranged on one face of the lens or the window inside the piece of equipment, while the sensor element (5, 5a) is implemented on the outer face of the lens or the window (1) and comprises a layer of conductive material facing the surface of the insulator-metal transition material.

3. The adaptive shielding device according to claim 2, characterized in that: The insulator-metal transition material forms a first frame (3) around the mesh, and the susceptor element is shaped as a second frame (5) facing the first frame.

4. The adaptive shielding device according to claim 3, characterized in that: The surface area of ​​the second frame (5) is greater than or equal to the surface area of ​​the first frame.

5. The adaptive shielding device according to claim 2, characterized in that: The receptor element comprises a layer (5a) of translucent conductive material covering the outer face of the lens or window (1).

6. The adaptive shielding device according to claim 1, characterized in that: The switchable RF shielding mesh (2a) and the insulator-metal transition material (3a) are placed on the outer surface of the lens or the window, and the sensor element includes a conductive material layer (5c) facing the surface of the insulator-metal transition material and placed on the electrical insulation layer (6a) covering the insulator-metal transition material.

7. The shielding device according to claim 1, characterized in that: The switchable RF shielding mesh (52), the insulator-metal transition material (3) and the sensor element (5b) are arranged on one surface of the lens or the window, inside or outside the device, and the sensor element (5b) is implemented in the form of a frame surrounding the insulator-metal transition material, and the insulator-metal transition material surrounds the switchable RF shielding mesh.

8. The adaptive shielding device according to claim 6, characterized in that: The switchable RF shielding mesh (32) is implemented with the insulator-metal transition material placed on the outer surface of the lens or the window and covering the outer surface, and the sensor element includes a layer of conductive material (5e) placed on an insulating layer (6b, 6c), which itself covers the insulator-metal transition material.

9. The adaptive shielding device according to claim 8, characterized in that: The layer of conductive material and / or the layer of insulating material comprises an optically transparent mesh covering the switchable RF shielding mesh.

10. An adaptive shielding device according to any one of the preceding claims, characterized in that The switchable RF shielding mesh is a mesh made of conductive material with micrometric spacing.

11. An adaptive shielding device according to any one of the preceding claims, characterized in that The switchable RF shielding mesh is a mesh made of a material selected from a titanium / silver bilayer, an insulator-metal transition material or gold.

12. An adaptive shielding device according to any one of the preceding claims, characterized in that The insulator-metal transition material is a VO2 type material having a thickness between 1000 nm and 2000 nm.

13. An adaptive shielding device according to any one of the preceding claims, characterized in that The susceptor element is a gold film having a thickness of 2 to 10 nanometers.

14. An adaptive shielding device according to any one of the preceding claims, characterized in that The switchable RF shielding mesh (2, 2a, 32, 32a, 52, 52a) is dimensioned to provide a shielding effectiveness of 10dB to 40dB in a frequency band of 0.1 GHz to 40 GHz when it is connected to the conductive envelope (11) at low impedance through the insulator-metal transition material exhibiting electrical conductivity.

15. An adaptive shielding device according to any one of the preceding claims, characterized in that The optical transparency of the shielding screen is at least 50% in the visible light range.

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