Radome and antenna

Abstract

The present application provides a radome and an antenna, the radome comprising a substrate and a functional coating, the substrate comprising a first layer having a closed hole and a second layer having an open hole located on one side of the first layer, the open hole comprising a bottom wall and an opening arranged away from the first layer, the bottom wall being connected to the hole wall of at least one closed hole, and the functional coating being arranged at least in the open hole. The radome can prevent the functional coating from being rubbed off by arranging it in the opening, and the closed holes in the first layer can buffer part of the external force, reduce the damage to the functional coating by the external force, and thus can maintain good functional characteristics for a long time, and the closed holes in the first layer can also make the radome have a low electromagnetic wave penetration loss value and a low dielectric constant, which is conducive to electromagnetic wave transmission.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a radome and an antenna. Background Art

[0002] As one of the key devices in wireless transmission systems, the antenna is installed in an outdoor environment to radiate and receive electromagnetic waves from space. Its performance parameters directly affect indicators such as electromagnetic wave wireless transmission distance, coverage area, and system stability. The radome is one of the necessary components of the antenna. It is required to effectively protect the antenna's radiation unit from the outdoor environment and maximize the penetration of electromagnetic waves. It is generally made of plastic and other materials, but the wave transmission performance of plastic materials is not ideal. In the natural environment, water film, ice, and snow adhere to the surface of the radome, which affects the transmission of electromagnetic waves, manifesting as adverse effects such as decreased antenna gain, beam deflection, and changes in radiation distribution. This effect worsens with the increase of electromagnetic wave frequency. Currently, there are two solutions. One is to add a rain / snow shield above the antenna. The rain / snow shield in this solution is separated from the antenna, which increases material costs and occupies tower space. It also cannot solve the scenario where the wind blows rain and snow toward the antenna from the front. The other is to add a cover cloth with hydrophobic material to the outside of the antenna, or directly spray hydrophobic material on the antenna components to prevent rain, ice or snow. However, after a period of use, the hydrophobic material is easily rubbed off by rain, snow or gravel and loses its hydrophobic properties, so it needs to be replaced, cleaned and re-sprayed regularly, which makes the later cost too high and is not conducive to large-scale promotion. Summary of the invention

[0003] The present application provides a radome that can both extend the service life of a hydrophobic coating and ensure electromagnetic wave transmission.

[0004] In a first aspect, a radome is provided, comprising a substrate and a functional coating, wherein the substrate comprises a first layer and a second layer located on one side of the first layer, the first layer is provided with a plurality of closed holes, a surface of the second layer away from the first layer is provided with a plurality of open holes, the open holes comprising a bottom wall and an opening located away from the first layer, the bottom wall being connected to a hole wall of at least one closed hole, and the functional coating is at least arranged in the open hole.

[0005] Among them, the hole wall of the opening includes a bottom wall and a peripheral wall, one end of the peripheral wall is connected to the bottom wall, and the other end of the peripheral wall is an opening. When the functional coating is set in the opening, or the outer surface of the functional coating is concave compared to the outer surface of the second layer, the peripheral wall of the opening of the second layer can be used to protect the functional coating in the opening, prevent the functional coating from being rubbed off, and thus enable the antenna cover to maintain good functional characteristics for a long time when used in an outdoor environment, that is, the life of the functional coating can be extended. When the functional coating is a hydrophobic coating, the hydrophobic coating is prepared from a hydrophobic material, and waterproofing is achieved through the unique micro-nano structure of the hydrophobic material. The micro-nano structure is characterized by the formation of micron-scale protrusions on the surface of the hydrophobic coating, and there are nano-scale "burrs" on each micron-scale protrusion. When a water drop is on the surface of the hydrophobic coating, it will form a spherical shape due to surface tension, reaching a super-hydrophobic angle greater than 150°. Because the protrusions protrude outward and are extremely small micro-nano structures, they are easily damaged by external forces, resulting in a deterioration of the hydrophobic effect. For example: friction of various foreign objects caused by vibration during packaging and transportation, friction of various media caused by touch, bumps, etc. during installation and maintenance, and dust impact during long-term outdoor use, etc., will all directly act on the protrusions. The present application is to set the hydrophobic coating in the opening, and fill the depth of the hydrophobic coating in the opening. When there is external foreign friction, the surrounding wall of the opening can be used to protect the hydrophobic coating in the opening to prevent the protrusion from being rubbed off. In some embodiments, when the thickness of the functional coating is greater than the depth of the opening, or when the functional coating is still accumulated on the surface of the second layer, the functional coating on the surface of the second layer is not protected by the surrounding wall of the opening and will be rubbed off by foreign objects. However, since there is a functional coating inside the opening, even after the functional coating on the surface of the second layer is rubbed off, the functional coating inside the opening can still maintain its functional characteristics, which can also extend the service life of the functional coating.

[0006] In the present application, the bottom wall of the open hole is connected to the hole wall of the closed hole, that is, the open hole is connected to the closed hole, the closed hole is hollow, and its hole wall has elastic force. When foreign objects such as rain, snow or sand fall into the open hole and exert force on the functional coating, the elastic force of the closed hole connected to the bottom wall of the open hole can buffer part of the external force, thereby reducing the damage to the functional coating caused by the external force to protect the functional coating. Among them, the bottom walls of some open holes are connected to the hole wall of one closed hole, and the bottom walls of some open holes are connected to the hole walls of two or more closed holes.

[0007] In the present application, the closed cells of the first layer contain air, and the air has extremely low electromagnetic wave penetration loss and a relatively low dielectric constant, so that the antenna cover has a low electromagnetic wave penetration loss value and a low dielectric constant, thereby improving the transmission performance of electromagnetic waves.

[0008] On the one hand, the peripheral wall of the opening of the antenna cover of the present application can prevent the functional coating from being rubbed off and can maintain good functional characteristics for a long time. On the other hand, the open holes and the closed holes are connected, and the closed holes can buffer part of the external forces and reduce the damage to the functional coating caused by the external forces. On the other hand, the closed holes of the first layer can make the antenna cover have a low electromagnetic wave penetration loss value and a low dielectric constant, which is beneficial to electromagnetic wave transmission.

[0009] In a possible implementation, the substrate is a polymer microporous foaming substrate. Wherein, the polymer in the polymer microporous foaming substrate includes at least one of polypropylene, polystyrene, polyester foaming substrate, rigid polyvinyl chloride, rigid polyurethane and polymethacrylimide. In some embodiments, the substrate may also be a non-polymer substrate.

[0010] In some embodiments, the polymer microporous foaming matrix is ​​a polypropylene microporous foaming matrix. The polypropylene microporous foaming matrix has good mechanical properties, thermal stability and structural stability. In some embodiments, the polypropylene microporous foaming plate can be cut to obtain it. Before the polypropylene microporous foaming plate is not cut, there are no open holes on any surface of the polypropylene microporous foaming plate, and all are closed. The polypropylene microporous foaming plate is cut at the cut surface to obtain the polypropylene microporous foaming matrix. The cut surface is the surface of the second layer of the polypropylene microporous foaming matrix. Before the cut surface is not cut, the holes located on the cut surface are closed holes. After the cut surface is cut, the closed holes are cut into open holes, and the holes on the surface opposite to the cut surface in the polypropylene microporous foaming matrix are closed holes. In the present application, it is preferred to use the polypropylene microporous foam matrix obtained by cutting the polypropylene microporous foam sheet as the matrix, which has a simple process, does not require additional components, and saves costs. In addition, the polypropylene microporous foam matrix as a whole has a certain flexibility, and when impacted by external forces, it can play a certain buffering role, thereby protecting the feed source or reflective substrate inside the antenna cover. Similarly, for other polymer microporous foam sheets, the polymer microporous foam matrix can be obtained by cutting them.

[0011] When a polymer microporous foaming matrix is ​​used as the matrix, the closed cells in the polymer microporous foaming matrix are continuously distributed, and the closed cells are connected to each other through the cell walls. The open cells distributed in the second layer after being cut are also continuously distributed, and the open cells are connected to each other through the surrounding walls. The polymer microporous foaming sheet is obtained by foaming the original polymer sheet. Taking the polypropylene microporous foaming sheet as an example, the original polypropylene sheet is foamed by CO 2The supercritical foaming method is used to foam, and the foaming parameters such as the foaming agent, foaming time, foaming temperature and foaming pressure in the foaming process are controlled to obtain a polypropylene microporous foamed sheet with a specified foaming ratio. For example, the polypropylene original sheet is foamed to obtain a polypropylene microporous foamed sheet with a foaming ratio of 25 times. For original sheets of different polymers, the foaming method and foaming parameters can be adjusted adaptively. When the original density of the same original sheet is the same, the foaming ratio is controlled by parameters such as the foaming temperature, foaming pressure and foaming time, or the diameter distribution range of closed cells and open cells can be controlled by the foaming parameters.

[0012] In a possible implementation, the thickness of the functional coating is less than or equal to the depth of the opening. The depth direction of the opening is perpendicular to the surface of the second layer of the radome. When the thickness of the functional coating is less than the depth of the opening, foreign matter will not touch the functional coating when rubbing the surface of the second layer, thereby effectively protecting the functional coating. In this embodiment, the thickness of the functional coating is 1 micron-5 microns, and the depth of the opening is 5 microns-100 microns. When the thickness of the functional coating is equal to the depth of the opening, when the foreign matter rubs the surface of the second layer, it can only damage the functional coating at the opening position at most, and the functional coating located inside the opening will not be worn away, and the functional characteristics of the functional coating can also be maintained. When the thickness of the functional coating is greater than the depth of the opening, that is, the functional coating will accumulate on the surface of the second layer, and when the foreign matter falls on the surface, the part of the functional coating that is higher than the depth of the opening will first be worn away, while the part of the functional coating that is lower than the opening can still maintain the functional characteristics. In this embodiment, in order to save the cost of the functional coating, the thickness of the functional coating can be set to be less than or equal to the depth of the opening.

[0013] It should be noted that in this embodiment, the thickness of the functional coating is less than or equal to the depth of the opening. Due to process limitations, it is allowed that the thickness of the functional coating in a small portion of the openings is greater than the depth of the openings, but the proportion of the small portion of the openings is within the preset error range. For example, when the functional coating is prepared by spraying the functional material by spraying, the thickness of the functional coating in a small portion of the openings is greater than the depth of the openings due to the precision limitation of the spraying process. The preset error can be controlled to 1% or 2% according to the process precision.

[0014] In one possible implementation, the diameter difference between the open cells and the closed cells is less than a preset value. When a polymer microporous foaming matrix is ​​used as a matrix, the polymer original sheet is formed into a polymer microporous foaming matrix having multiple closed cells through a foaming process. Since the open cells are obtained by cutting the closed cells, the diameter range distribution of the open cells and the closed cells is the same, and the diameter difference between the open cells and the closed cells is less than a preset value. For example, the preset value is 0. The diameter difference refers to the difference in the diameter range of the open cells and the closed cells, and does not refer to the diameter difference between a single open cell and a single closed cell. When the diameter difference between the open cells and the closed cells is less than the preset value, the polymer microporous foaming matrix is ​​better controlled during the foaming process and is easy to form.

[0015] In a possible implementation, the diameter of the opening is 5 microns to 100 microns. Wherein "5 microns to 100 microns" in this application represents a range value, and the range includes the endpoint values ​​at both ends. For example, the diameter of the opening is 5 microns to 100 microns, which means that the diameter of the opening is between 5 microns and 100 microns, and includes two endpoint values ​​of 5 microns and 100 microns. This statement in the following text is similar to the above. In this embodiment, the diameter of the opening is micron-level, which is relatively small. When larger foreign matter falls on the substrate, it will not fall into the opening, and most of the external foreign matter can be isolated, thereby protecting the functional coating in the opening; when smaller foreign matter falls into the opening, the extremely small size foreign matter is generally small in mass and low in impact force, and the functional coating itself can withstand it. In addition, the pore wall of the closed pore below the opening has a certain buffering effect, which maximizes the protection of the functional coating from being damaged by foreign matter to extend the service life of the functional coating. When the diameter of the opening is set to be greater than 100 microns, only foreign bodies with a diameter greater than 100 microns can be isolated, which will affect the isolation effect for foreign bodies with a diameter less than 100 microns. However, in some application environments, the diameter of the opening can also be set to be greater than 100 microns; and when it is set to be less than 5 microns, the process difficulty increases, and it is more difficult to control when using the foaming process, but with the advancement of the process, the diameter of the opening can also be less than 5 microns. In this embodiment, when it is set between 5 microns and 100 microns, it can ensure the isolation of small-sized foreign body protection functional coatings and reduce the process difficulty.

[0016] In this embodiment, the diameter of the closed cell is 5 microns to 100 microns. When the diameter of the closed cell is set within the above range, on the one hand, it is conducive to the penetration of electromagnetic waves and improves the electromagnetic wave transmission performance; on the other hand, at the same foaming ratio, when the diameter of the closed cell is set too large, the pore wall of the closed cell will become thicker, and the thickening of the pore wall will reduce the elasticity. For the closed cell connected to the open hole, its buffering ability against the impact of foreign objects will decrease, thereby damaging the functional coating. When the diameter of the closed cell is set too small, when a polymer microporous foaming matrix is ​​used as the matrix, it is difficult for the foaming process to control the diameter of the closed cell to be smaller, which increases the process difficulty. When the functional coating is set as a hydrophobic coating in this application, it is found through experiments that when the diameter of the closed cell is set within the above range, the hydrophobic properties of the antenna cover are better. In some application environments, the diameter of the closed cell 310 can also be set to be greater than 100 microns, or less than 5 microns.

[0017] When the substrate is a polymer microporous foaming substrate, since the open cells originate from the closed cells, the diameter range distribution of the closed cells and the open cells is the same. The shape of the open cells can be hemispherical, spherical at any angle, ellipsoidal, irregular curved surface, etc., and the shape of the closed cells can be spherical, ellipsoidal, square, or irregular curved surface, etc.

[0018] In one possible implementation, the ratio of the number of openings with a diameter of 5 microns to 50 microns in the second layer to the number of all openings is greater than a preset ratio. The smaller the diameter of the opening, the smaller the size of the isolated foreign matter. When the number of openings greater than the preset ratio is in the range of 5 microns to 50 microns in diameter, at least foreign matter with a diameter of more than 50 microns can be isolated. The preset ratio can be set as needed, for example, the preset ratio is 60%, 80% or 90%. In some embodiments, the area of ​​all openings with a diameter of 5 microns to 50 microns in the second layer accounts for a greater proportion of the area of ​​the surface of the second layer away from the first layer than the preset area ratio, and the isolation effect of isolating foreign matter is improved by setting the area ratio of openings with small diameters. For example, the preset area ratio is 50%, 70% or 90%.

[0019] Wherein, when the substrate is a polypropylene microporous foam substrate, and the open pores are derived from the closed pores after cutting, the substrate can be selected according to the section after cutting. For example, when the polypropylene microporous foam sheet is cut with a section surface to obtain a polypropylene microporous foam substrate, when it is found through detection that the number of open pores with a diameter of 5 microns to 50 microns in the second layer is less than 60%, the polypropylene microporous foam substrate can be cut with another section surface to obtain a new polypropylene microporous foam substrate. When it is found through detection that the number of open pores with a diameter of 5 microns to 50 microns in the second layer is greater than 60%, the polypropylene microporous foam substrate can be used as the substrate, and the substrate whose ratio of the number of open pores with a diameter of 5 microns to 50 microns in the second layer to the number of all open pores is greater than a preset ratio can be selected by this method. Similarly, for the case where the area ratio of the open pores with a diameter of 5 microns to 50 microns in the second layer to the surface of the second layer away from the first layer is greater than the preset area ratio, the above method can also be used to select. Wherein the method for detecting the diameter of the closed pores includes using a microscopic electron microscope for observation and detection. In some embodiments, the number or area proportion of the openings with smaller diameters can be reversely determined by counting the openings with larger diameters in the second layer.

[0020] When the substrate is a non-polymer substrate, the openings on the substrate can be obtained by laser laser, chemical etching or deposition, and the process parameters can be adjusted to obtain a ratio of the number of openings with a diameter of 5 microns to 50 microns in the second layer to the total number of openings greater than a preset ratio, or to obtain a ratio of the area of ​​the second layer away from the first layer occupied by the openings with a diameter of 5 microns to 50 microns greater than a preset area ratio.

[0021] In a possible implementation, the pore wall thickness of the open hole is 0.1 micron-2 microns, and the pore wall thickness of the closed hole is 0.1 micron-2 microns. Wherein, the pore wall of the open hole includes a bottom wall and a peripheral wall, and the thickness of the bottom wall and the peripheral wall is 0.1 micron-2 microns. When the substrate is a polypropylene microporous foaming substrate, and the open hole comes from the closed hole after cutting, the distribution range of the pore wall thickness of the open hole and the pore wall thickness of the closed hole are the same. Under the same foaming ratio, if the wall thickness is too large, the closed hole will also become larger, and the diameter of the open hole formed after cutting will become larger, which will affect the isolation effect of foreign matter. The smaller the wall thickness, the greater the process difficulty, and it is difficult to control that most of the wall thickness is less than 0.1 micron. The pore wall thickness of the open hole and the closed hole is set within the above range, and the pore wall of the closed hole and the bottom wall of the open hole can also have better elastic force, thereby buffering the loss of foreign matter to the functional coating in the open hole. In some embodiments, the pore wall thickness of the open hole can also be set to be greater than 2 microns, or less than 0.1 microns. For example, when the substrate is a non-polymer substrate, the thickness of the pore wall of the opening can be achieved by laser, chemical etching or deposition.

[0022] In one possible implementation, the functional coating includes at least one of a hydrophobic coating, a self-cleaning coating, a high temperature resistant coating, or an antibacterial and mildew proof coating. The hydrophobic coating is used to block rain and ice and snow on the surface of the radome, the self-cleaning coating can be used to block dust on the surface of the radome, the high temperature resistant coating can be used for heat insulation, and the antibacterial and mildew proof coating can be used for antibacterial and mildew proofing of the surface of the radome. The specific type of functional coating can be selected according to the application environment of the radome. In some embodiments, the hydrophobic coating is a super-hydrophobic nano coating, which has a good hydrophobic and anti-ice and snow effect, and can make the second layer surface contact angle greater than 150°. In other embodiments, the hydrophobic coating can also be an organic hydrophobic coating. In some embodiments, the high temperature resistant coating is a PTFE modified fluororesin coating. In some embodiments, the antibacterial and mildew proof coating is a fluorocarbon mildew proof coating. In some embodiments, the functional coating includes two or more of the above coatings. For example, some functional coatings include both hydrophobic and self-cleaning functions. For example, a hydrophobic coating and an antibacterial and mildew proof coating can be respectively provided in different areas on the substrate as needed. In other embodiments, the functional coating may also be other functional coatings, preferably functional coatings that do not affect electromagnetic wave transmission.

[0023] In a possible implementation, a plurality of convex portions are provided on the surface of the second layer away from the first layer. The convex portions are spherical, conical, or cylindrical, etc., and the convex portions can further protect the functional coating from being rubbed off, such as friction caused by various foreign objects caused by vibration during packaging and transportation, and friction caused by various media caused by touching and bumping during installation and maintenance. In some embodiments, the convex portions are evenly distributed on the second layer. The size and number of the convex portions can be set according to the size of the antenna cover, and are not limited in this application.

[0024] In a possible implementation, the surface of the second layer away from the first layer is a plane or a curved surface. When the surface of the second layer away from the first layer is a curved surface, during the handling process, the contact point between the second layer having the curved surface and the handling tool is not the entire surface of the second layer, which can reduce the contact area between the handling tool and the antenna cover during the handling process, thereby reducing the friction damage of the handling tool to the antenna cover. When the second layer is a curved surface, the openings of the openings are distributed on the curved surface. The curved surface shown in the figure is wavy. In some embodiments, the curved surface can also be arc-shaped. For example, when the antenna cover is applied to the antenna in the figure, the antenna cover can be adapted to the shape of the reflective substrate and is a pot-shaped arc surface.

[0025] In a possible implementation, the surface of the second layer away from the first layer is a curved surface, the curved surface includes a plurality of interlaced concave sub-surfaces and convex sub-surfaces, the curvature center of the concave sub-surface is located on the side of the second layer away from the first layer, the curvature center of the convex sub-surface is located on the side of the second layer adjacent to the first layer, and the width of the concave sub-surface is greater than the width of the convex sub-surface. The curvature and width of the concave sub-surface can be set according to product requirements. Setting the curvature and width of the concave sub-surface to be larger is conducive to the sliding of snow and rainwater, and setting the width and curvature of the convex sub-surface to be smaller reduces the contact area between the convex sub-surface and foreign objects, so as to protect the functional coating in the concave sub-surface and prevent it from being rubbed off during transportation.

[0026] In a possible implementation, the substrate includes a plurality of substrate sublayers stacked, and a plurality of openings are provided on at least one surface of the substrate sublayer, and the openings are enclosed with the adjacent substrate sublayer surface to form closed holes. The plurality of substrate sublayers include two or more substrate sublayers. In this embodiment, the openings in the substrate sublayer can be prepared by laser laser, chemical etching or deposition. In this embodiment, the substrate includes three substrate sublayers, namely, the first substrate sublayer, the second substrate sublayer and the third substrate sublayer, and the openings are first formed on the upper and lower surfaces of the first substrate sublayer, and then the first substrate layer is bonded to the second substrate sublayer, and the openings on one surface of the first substrate sublayer become closed holes, and the openings on the other surface of the first substrate sublayer are the openings in the second layer. In some embodiments, a plurality of openings corresponding to each other may be provided on the two substrate sublayers, and then the surfaces of the two substrate sublayers with openings are matched, and the openings become closed holes, such as the closed holes in the second substrate sublayer and the third substrate sublayer in the figure. In actual radome products, the number of substrate sublayers in the substrate is not limited to three, but may be two or other numbers, which may be set according to actual needs. When there are two substrate sublayers, openings may be formed on the upper and lower surfaces of one of the substrate sublayers, and an opening may be formed on one surface of the other substrate sublayer, and then the two substrate sublayers are overlapped, wherein the openings on the outer surface are the openings of the second layer, and the openings enclosed by the two substrate sublayers become closed holes.

[0027] In some embodiments, other functional layers, such as a heat-resistant layer, may be provided between the multiple stacked substrate sub-layers. One or more functional layers may be added without affecting the transmission of electromagnetic waves.

[0028] In a possible implementation, the side of the substrate away from the functional coating may also have other functional layers, such as a heat-resistant layer. One or more functional layers may be added without affecting the transmission of electromagnetic waves.

[0029] In one possible implementation, the thickness of the radome is 8mm-60mm. When a polymer microporous foam matrix is ​​used as the matrix, the hardness of the radome is related to the foaming ratio and thickness of the polymer microporous foam matrix. The higher the foaming ratio, the thinner the thickness, the lower the hardness, and the higher the flexibility. The thickness and structural strength of the radome of the present application can be set according to the actual product needs. When the radome is applied to the antenna, the radome needs to have a certain structural strength and a certain flexibility, so that a strong structural support can be achieved. At the same time, when the radome is subjected to external force, the toughness of the polymer microporous foam matrix material itself can buffer the hard friction damage on the surface of the radome. When the radome is applied to the antenna, since the radome is directly laid on the reflective substrate, the structural strength requirement is not high, and the thickness of the radome can be set to be smaller. Among them, the specific thickness of the radome is not limited to the above-mentioned thickness range, and its specific thickness and size can be set according to the actual size of the antenna.

[0030] In a second aspect, an antenna is provided, the antenna comprising a feed source, a reflective substrate, and the above-mentioned radome, the feed source and the radome being fixed on the reflective substrate, and the feed source being located between the incident surface of the reflective substrate and the radome. The above-mentioned radome can protect the feed source and the reflective substrate without affecting the electromagnetic wave transmission performance of the antenna.

[0031] In a third aspect, an antenna is provided, the antenna comprising a feed source, a reflective substrate, and the above-mentioned radome, the radome being arranged on the incident surface of the reflective substrate, and the feed source being arranged on a side of the radome away from the reflective substrate. The above-mentioned radome can protect the reflective substrate without affecting the electromagnetic wave transmission performance of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0033] Figure 1 is a schematic diagram of the structure of an antenna provided in one embodiment of the present application;

[0034] Figure 2 It is a schematic diagram of the structure of an antenna transmitting a signal provided in an embodiment of the present application;

[0035] Figure 3 It is a schematic diagram of the structure of an antenna receiving a signal provided in an embodiment of the present application;

[0036] Figure 4 is a schematic diagram of the structure of an antenna provided in one embodiment of the present application;

[0037] Figure 5 is a schematic structural diagram of a radome provided in one embodiment of the present application;

[0038] Figure 6a yes Figure 5 A partial enlarged view of the N part;

[0039] Figure 6b is a scanning electron microscope image of a surface having an opening of a substrate of a radome provided in one embodiment of the present application;

[0040] Figure 7 It is a schematic structural diagram of a radome in the prior art provided by an embodiment of the present application being rubbed by a foreign object;

[0041] Figure 8 is a schematic structural diagram of a radome being rubbed by a foreign object provided by an embodiment of the present application;

[0042] Fig. 9 This is a schematic diagram of the structure of a polypropylene microporous foam sheet provided in one embodiment of the present application before it is cut;

[0043] Fig.10 This is a schematic diagram of the structure of a polypropylene microporous foamed sheet after being cut open, provided in one embodiment of the present application;

[0044] Fig.11 This is a schematic diagram of the structure of a polypropylene microporous foam sheet provided in one embodiment of the present application before it is cut;

[0045] Fig.12 This is a schematic diagram of the structure of a polypropylene microporous foamed sheet after being cut open, provided in one embodiment of the present application;

[0046] Fig.13 is a schematic structural diagram of a radome provided in one embodiment of the present application;

[0047] Fig.14 is a schematic structural diagram of a radome provided in one embodiment of the present application;

[0048] Fig.15 is a schematic structural diagram of a radome provided in one embodiment of the present application;

[0049] Fig.16 is a schematic diagram of preparing a substrate of a radome provided in one embodiment of the present application;

[0050] Fig.17 It is a structural schematic diagram of a base of a radome provided in one embodiment of the present application;

[0051] Fig.18 It is a structural schematic diagram of a base of a radome provided in one embodiment of the present application;

[0052] Fig.19 It is a structural schematic diagram of a base of a radome provided in one embodiment of the present application;

[0053] Fig. 20 It is a schematic diagram of the waterproof effect of the antenna cover provided in one embodiment of the present application;

[0054] Fig.21 It is a schematic diagram of the waterproof effect of the antenna cover provided by a comparative embodiment of the present application;

[0055] Fig. 22 It is a schematic diagram of the snow-proof effect of the antenna cover provided in one embodiment of the present application;

[0056] Fig.23 This is a schematic diagram of the snow-proof effect of the antenna cover provided in a comparative embodiment of the present application;

[0057] Fig.24 It is a schematic diagram of the structure of the electromagnetic wave transmission signal of the antenna cover provided in a comparative embodiment of the present application;

[0058] Fig.25 This is a test effect diagram of the antenna cover provided in one embodiment of the present application. DETAILED DESCRIPTION

[0059] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0060] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application are explained and described below.

[0061] DH: Damp Heat, damp heat test.

[0062] UV: ultraviolet, ultraviolet light.

[0063] ISO:International Organization for Standardization.

[0064] CO 2 :carbon dioxide.

[0065] PTFE: Poly tetra fluoroethylene.

[0066] In the present application, "-" indicates a range value, and the range includes the endpoint values ​​at both ends. For example, a diameter of 5 microns-100 microns means that the diameter is between 5 microns and 100 microns, and includes the two endpoint values ​​of 5 microns and 100 microns.

[0067] The present application provides a radome and an antenna, the radome comprising a substrate and a functional coating, the substrate comprising a first layer and a second layer located on one side of the first layer, the first layer being provided with a plurality of closed holes, the second layer being provided with a plurality of open holes on a surface away from the first layer, the open holes comprising a bottom wall and an opening arranged away from the first layer, the bottom wall being connected to the hole wall of at least one closed hole, and the functional coating being arranged at least in the open hole. The radome can prevent the functional coating from being rubbed off by arranging it in the opening, and the closed holes in the first layer can buffer part of the external force, reduce the damage to the functional coating by the external force, and thus can maintain good functional characteristics for a long time, and the closed holes in the first layer can also make the radome have a low electromagnetic wave penetration loss value and a low dielectric constant, which is conducive to electromagnetic wave transmission.

[0068] See also Figure 1 In one embodiment of the present application, an antenna 1 is provided, comprising a feed source 10, a reflective substrate 20 and a radome 30. The feed source 10 and the radome 30 are fixed on the reflective substrate 20, and the feed source 10 is located between the incident surface 21 of the reflective substrate 20 and the radome 30. In this embodiment, the reflective substrate 20 is a pot-shaped reflective substrate, the center of the reflective substrate 20 has a mounting position, and is mounted on the support 40 through the mounting position. The feed source 10 is fixed on the support 40 through a feed tube 50 and is located at the center of the reflective substrate 20. The radome 30 is fixedly connected to the edge of the reflective surface 20. The radome 30 and the reflective surface 20 enclose a receiving space 60, and the feed source 10 is located in the receiving space 60. In other embodiments, the shape of the reflective substrate 20 can also be a horn shape, a parabola shape, a rectangle or other curved surface shapes. The feed source 10 is used to transmit and receive signals, the reflective substrate 20 is used to reflect signals, the feed tube 50 is used to support the feed source 10 and to transmit the received signal of the feed source 10 and the transmitted signal of the feed source 10, and the antenna cover 30 is used to protect the antenna 1 from being damaged by rain, snow or sand. Figure 2 and Figure 3 , Figure 2 It is a schematic diagram of the structure of antenna 1 transmitting signals. Figure 3 It is a structural diagram of antenna 1 receiving signals. The specific working process of antenna 1 is: when transmitting a signal, after the signal is transmitted to the feed source 10 through the feed tube 50, the feed source 10 radiates electromagnetic waves M outward, which are reflected by the incident surface 21 of the reflective substrate 20 and penetrate the antenna cover 30 to radiate into space; in the receiving direction, the electromagnetic wave M in the space penetrates the antenna cover 30 to enter the interior of the antenna 1, and is reflected by the reflective substrate 20 and converges to the feed source 10. For example, the electromagnetic wave M can be a signal wave in any frequency band of 700MHz-110GHz. The antenna 1 in this embodiment can be a microwave antenna. It should be noted that Figure 1 The structure of the antenna 1 shown does not constitute a limitation on the antenna 1 , and may include more or fewer components, or combine certain components, or separate certain components, or arrange the components differently.

[0069] The second layer of the antenna cover 30 of the present application is arranged away from the feed source 10 compared to the first layer, that is, the side with the opening and the functional coating faces the external environment. When the functional coating is a hydrophobic coating, the antenna cover 30 can not only ensure the signal transmission performance of the electromagnetic wave signal, but also extend the service life of the hydrophobic coating, and avoid being damaged by friction from rain, snow and sand and gravel, resulting in adverse effects such as decreased gain of the antenna 1, beam deflection, and changes in radiation distribution.

[0070] See also Figure 4 In one embodiment of the present application, an antenna 2 is provided, comprising a feed source 10, a reflective substrate 20 and a radome 30. The radome 30 is arranged on the incident surface 21 of the reflective substrate 20. The feed source 10 is arranged on the side of the radome 30 away from the reflective substrate 20. Specifically, it can be installed on the reflective substrate 20 through a feed tube 50. Among them, the second layer of the radome 30 is arranged farther away from the reflective substrate 20 than the first layer. The specific working process of the antenna 2 is as follows: when transmitting a signal, the feed source 10 radiates electromagnetic waves outward, which are incident on the incident surface 21 of the reflective substrate 20 through the radome 30 and reflected into the external space; in the receiving direction, the electromagnetic waves in the external space penetrate the radome 30, enter the reflective substrate 20 and are reflected and converged to the feed source 10. In this embodiment, the radome 30 only covers the reflective substrate 20 but not the feed source 10, and is directly laid on the reflective substrate 20. For example, the antenna 2 in this embodiment can be a satellite antenna. In this embodiment, the reflective substrate 20 is parabolic. In other embodiments, the reflective substrate 20 may also be in a trumpet shape, a rectangle, or other curved shapes. Figure 4 The structure of the antenna 2 shown does not constitute a limitation on the antenna 2, and may include more or fewer components, or combine certain components, or separate some components, or arrange the components differently.

[0071] See also Figure 5 and Figure 6a In one embodiment of the present application, a radome 30 is provided. The radome 30 includes a substrate 100 and a functional coating 200. The substrate 100 includes a first layer 110 and a second layer 120 located on one side of the first layer 110. The first layer 110 is provided with a plurality of closed holes 310. The surface of the second layer 120 away from the first layer 110 is concavely provided with a plurality of open holes 320. The open holes 320 include a bottom wall 321 and an opening 322 (such as a bottom wall 322) located away from the first layer 110. Figure 6a As shown), the bottom wall 321 is connected to the hole wall 311 of at least one closed hole 310, and the functional coating 200 is at least arranged in the open hole 320.

[0072] The hole wall of the opening 320 includes a bottom wall 321 and a peripheral wall 323, one end of the peripheral wall 323 is connected to the bottom wall 321, and the other end of the peripheral wall 323 is an opening 322. When the functional coating 200 is set in the opening 320, or the outer surface of the functional coating 200 is concave compared to the outer surface of the second layer 120, the peripheral wall 323 of the opening 320 of the second layer 120 can be used to protect the functional coating 200 in the opening 320 and prevent the functional coating 200 from being rubbed off, so that the radome 30 can maintain good functional characteristics for a long time when used in an outdoor environment, that is, the life of the functional coating 200 can be extended. Please refer to Figure 7 When the functional coating 200 is a hydrophobic coating 210, the hydrophobic coating 210 is made of a hydrophobic material and is waterproof through the unique micro-nano structure of the hydrophobic material. The characteristic of the micro-nano structure is that micron-sized protrusions 211 are formed on the surface of the hydrophobic coating 210, and there are nano-sized "burrs" on each micron-sized protrusion 211. When water droplets are on the surface of the hydrophobic coating 210, they will form a spherical shape due to surface tension, reaching a super-hydrophobic angle greater than 150°. Since the protrusions 211 protrude outward and are extremely small micro-nano structures, they are easily damaged by external forces, resulting in deterioration of the hydrophobic effect. For example: friction caused by various foreign objects 400 caused by vibration during packaging and transportation, friction caused by various media caused by touch and bumps during installation and maintenance, and dust impact during long-term outdoor use, will all directly act on the protrusions 211. Please refer to Figure 8 In the present application, the hydrophobic coating 210 is disposed in the opening 320, and the hydrophobic coating 210 is deeply filled in the opening 320. When there is friction with external foreign matter 400, the peripheral wall 323 of the opening 320 can be used to protect the hydrophobic coating 210 in the opening and prevent the protrusion 211 from being rubbed off. In some embodiments, when the thickness of the functional coating 200 is greater than the depth of the opening 320, or when the functional coating 200 is still accumulated on the surface of the second layer 120, the functional coating 200 on the surface of the second layer 120 is not protected by the peripheral wall 323 of the opening 320, and will be rubbed off by the foreign matter 400. However, since there is a functional coating 200 inside the opening 320, even if the functional coating 200 on the surface of the second layer 120 is rubbed off, the functional coating 200 inside the opening 320 can still maintain its functional characteristics, and the service life of the functional coating 200 can also be extended.

[0073] In the present application, the bottom wall 321 of the open hole 320 is connected to the hole wall 311 of the closed hole 310 (eg Figure 6aAs shown in FIG. 1 , that is, the open hole 320 is connected to the closed hole 310, the closed hole 310 is in a hollow state, and its hole wall 311 has elastic force. When foreign matter such as rain, snow or sand falls into the open hole 320 and exerts force on the functional coating 200, the elastic force of the closed hole 310 connected to the bottom wall 321 of the open hole 320 can buffer part of the external force, thereby reducing the damage to the functional coating 200 caused by the external force, so as to protect the functional coating 200. Among them, the bottom wall 321 of some open holes 320 is connected to the hole wall 311 of one closed hole 310, and the bottom wall 321 of some open holes 320 is connected to the hole wall 311 of two or more closed holes 310.

[0074] In the present application, the closed cells 310 of the first layer 110 contain air, and the air has extremely low electromagnetic wave penetration loss and a relatively low dielectric constant, so that the antenna cover 30 has a low electromagnetic wave penetration loss value and a low dielectric constant, thereby improving the transmission performance of electromagnetic waves.

[0075] On the one hand, the surrounding wall 323 of the opening 320 of the antenna cover 30 of the present application can prevent the functional coating 200 from being rubbed off and can maintain good functional characteristics for a long time. On the other hand, the opening 320 is connected to the closed hole 310, and the closed hole 310 can buffer part of the external force and reduce the damage to the functional coating 200 caused by the external force. On the other hand, the closed hole 310 of the first layer 110 can make the antenna cover 30 have a low electromagnetic wave penetration loss value and a low dielectric constant, which is beneficial to electromagnetic wave transmission.

[0076] In a possible implementation, the substrate 100 is a polymer microporous foaming substrate. The polymer in the polymer microporous foaming substrate includes at least one of polypropylene, polystyrene, polyester foaming substrate, rigid polyvinyl chloride, rigid polyurethane and polymethacrylimide. In some embodiments, the substrate 100 may also be a non-polymer substrate.

[0077] In some embodiments, the polymer microporous foaming matrix is ​​a polypropylene microporous foaming matrix 101. The polypropylene microporous foaming matrix 101 has good mechanical properties, thermal stability and structural stability. In some embodiments, the polypropylene microporous foaming plate 3 can be cut open, and before the cutting, there are no openings 320 on any surface of the polypropylene microporous foaming plate 3, and all are closed. Please refer to Fig. 9 and Fig.10 , Fig. 9 This is a schematic diagram of the structure of the polypropylene microporous foam sheet 3 before it is cut open. Fig.10It is a structural schematic diagram after the polypropylene microporous foam plate 3 is cut at the cutting plane L. The polypropylene microporous foam plate 3 is cut at the cutting plane L to obtain the polypropylene microporous foam matrix 101. The cut cutting plane is the surface of the second layer 120 of the polypropylene microporous foam matrix 101. Before cutting, the holes located at the cutting plane L are closed holes 310. After cutting at the cutting plane L, the closed holes 310 are cut into open holes 320. The holes on the surface of the polypropylene microporous foam matrix 101 opposite to the cutting plane L are closed holes 310. In the present application, it is preferred to use the polypropylene microporous foam matrix 101 obtained by cutting the polypropylene microporous foam plate 3 as the matrix 100. The process is simple, no additional components are required, and the cost is saved. In addition, the polypropylene microporous foam matrix 101 has a certain flexibility as a whole. When impacted by external force, it can play a certain buffering role, thereby protecting the feed source 10 or the reflective substrate 20 inside the antenna cover 300. Similarly, other polymer microporous foamed boards can be cut open to obtain the polymer microporous foamed matrix.

[0078] When a polymer microporous foam matrix is ​​used as the matrix 100, the closed cells 310 in the polymer microporous foam matrix are continuously distributed, and the closed cells 310 are connected to each other through the cell walls 311. The open cells 320 distributed in the second layer 120 after being cut are also continuously distributed, and the open cells 320 are connected to each other through the peripheral walls 323. Figure 6b As shown, Figure 6b is a scanning electron microscope image of the surface of the polypropylene microporous foamed substrate 101 having the openings 320, Figure 6b The irregular circle in the figure is the opening 320, and the white periphery of the circle is the peripheral wall 323 of the opening 320. Figure 6b It can be seen that the openings 320 are connected to each other through the peripheral wall 323. The polymer microporous foamed sheet 3 is obtained by a foaming process of a polymer original sheet. Taking the polypropylene microporous foamed sheet 3 as an example, the polypropylene original sheet is CO 2 The supercritical foaming method is used for foaming. By controlling the foaming parameters such as the foaming agent, foaming time, foaming temperature and foaming pressure in the foaming process, a polypropylene microporous foamed sheet 3 with a specified foaming ratio is obtained. For example, the polypropylene original sheet is foamed to obtain a polypropylene microporous foamed sheet 3 with a foaming ratio of 25 times. For original sheets of different polymers, the foaming method and foaming parameters can be adjusted adaptively. When the original density of the same original sheet is the same, the foaming ratio is controlled by parameters such as the foaming temperature, foaming pressure and foaming time, or the diameter distribution range of the closed cells 310 and the open cells 320 can be controlled by the foaming parameters.

[0079] In a possible implementation, the thickness of the functional coating 200 is less than or equal to the depth of the opening 320. The depth direction of the opening 320 is perpendicular to the surface of the second layer 120 of the radome 30. When the thickness of the functional coating 200 is less than the depth of the opening 320, the foreign matter 400 will not touch the functional coating 200 when rubbing the surface of the second layer 320, thereby effectively protecting the functional coating 200. In this embodiment, the thickness of the functional coating 200 is 1 micron-5 microns, and the depth of the opening 320 is 5 microns-100 microns. When the thickness of the functional coating 200 is equal to the depth of the opening 320, when the foreign matter 400 rubs the surface of the second layer 320, it can only damage the functional coating 200 at the position of the opening 322 at most, and the functional coating 200 located inside the opening 320 will not be worn away, and the functional characteristics of the functional coating 20 can also be maintained. When the thickness of the functional coating 200 is greater than the depth of the opening 320, that is, the functional coating 200 will accumulate on the surface of the second layer 120, when the foreign matter 400 falls on the surface 320, the portion of the functional coating 200 above the depth of the opening 320 will be worn away first, while the portion of the functional coating 200 below the opening 322 can still maintain the functional characteristics. In this embodiment, in order to save the cost of the functional coating 200, the thickness of the functional coating 200 can be set to be less than or equal to the depth of the opening 320.

[0080] It should be noted that in this embodiment, the thickness of the functional coating 200 is less than or equal to the depth of the opening 320. Due to process limitations, it is allowed that the thickness of the functional coating 200 in a small portion of the openings 320 is greater than the depth of the openings 320, but the proportion of the small portion of the openings 320 is within the preset error range. For example, when the functional coating 200 is prepared by spraying the functional material by spraying, the thickness of the functional coating 200 in a small portion of the openings 320 is greater than the depth of the openings 320 due to the precision limitation of the spraying process. The preset error can be controlled to 1% or 2% according to the process precision.

[0081] In a possible implementation, the diameter difference between the open pores 320 and the closed pores 310 is less than a preset value. When a polymer microporous foaming matrix is ​​used as the matrix 100, the polymer original sheet is formed into a polymer microporous foaming matrix having a plurality of closed pores 310 through a foaming process. Since the open pores 320 are obtained by cutting the closed pores 310, the diameter range distribution of the open pores 320 and the closed pores 310 is the same, and the diameter difference between the open pores 320 and the closed pores 310 is less than a preset value. For example, the preset value is 0. The diameter difference refers to the difference in the diameter range of the open pores 320 and the closed pores 310, and does not refer to the diameter difference between a single open pore 320 and a single closed pore 310. When the diameter difference between the open pores 320 and the closed pores 310 is less than the preset value, the polymer microporous foaming matrix is ​​better controlled during the foaming process and is easy to form.

[0082] In a possible implementation, the diameter of the opening 320 is 5 microns to 100 microns. In the present application, "5 microns to 100 microns" represents a range value, and the range includes the endpoint values ​​at both ends. For example, the diameter of the opening 320 is 5 microns to 100 microns, which means that the diameter of the opening 320 is between 5 microns and 100 microns, and includes the two endpoint values ​​of 5 microns and 100 microns. This expression in the following text is similar to the above. In this embodiment, the diameter of the opening 320 is in the micron level, which is relatively small. When a larger foreign object 400 falls on the substrate 100, it will not fall into the opening 320, and most of the external foreign objects can be isolated, thereby protecting the functional coating 200 in the opening 320; when a smaller foreign object 400 falls into the opening 320, the extremely small foreign object is generally of small mass and low impact force, which the functional coating 200 itself can withstand. In addition, the hole wall 311 of the closed hole 310 below the opening 320 has a certain buffering effect, thereby maximizing the protection of the functional coating 200 from being damaged by foreign objects, thereby extending the service life of the functional coating 200. When the diameter of the opening 320 is set to be greater than 100 microns, only foreign bodies with a diameter greater than 100 microns can be isolated, which will affect the isolation effect of foreign bodies 400 with a diameter less than 100 microns. However, in some application environments, the diameter of the opening 320 can also be set to be greater than 100 microns; and when it is set to be less than 5 microns, the process difficulty increases, and it is more difficult to control when using the foaming process, but with the advancement of the process, the diameter of the opening 320 can also be less than 5 microns. In this embodiment, when it is set between 5 microns and 100 microns, it can ensure the isolation of small-sized foreign body protection functional coating 200 and reduce the process difficulty.

[0083] In this embodiment, the diameter of the closed hole 310 is 5 microns to 100 microns. When the diameter of the closed hole 310 is set within the above range, it is beneficial to the penetration of electromagnetic waves and improves the electromagnetic wave transmission performance. On the other hand, at the same foaming ratio, when the diameter of the closed hole 310 is set too large, the hole wall 311 of the closed hole 310 will become thicker, and the thickening of the hole wall 311 will reduce the elasticity. For the closed hole 310 connected to the open hole 320, its buffering ability against the impact of foreign objects will decrease, thereby damaging the functional coating 200. When the diameter of the closed hole 310 is set too small, when a polymer microporous foaming matrix is ​​used as the matrix 100, it is difficult to control the diameter of the closed hole 310 in the foaming process, which increases the process difficulty. When the functional coating 200 is set as a hydrophobic coating 210 in this application, it is found through experiments that when the diameter of the closed hole 310 is set within the above range, the hydrophobic properties of the antenna cover 30 are better. In some application environments, the diameter of the closed hole 310 can also be set to be greater than 100 microns, or less than 5 microns.

[0084] When the substrate 100 is a polymer microporous foam substrate, since the open cells 320 originate from the closed cells 310, the diameter range distribution of the closed cells 310 and the open cells 320 is the same. The shape of the open cells 320 can be a hemisphere, a sphere at any angle, an ellipsoid, an irregular curved surface, etc., and the shape of the closed cells 310 can be a sphere, an ellipsoid, a square, or an irregular curved surface, etc.

[0085] In a possible implementation, the ratio of the number of openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 to the number of all openings 320 is greater than a preset ratio. The smaller the diameter of the opening 320, the smaller the size of the isolated foreign matter 400. When the diameter range of the openings 320 greater than the preset ratio is 5 microns to 50 microns, at least foreign matter with a diameter of more than 50 microns can be isolated. The preset ratio can be set as needed, for example, the preset ratio is 60%, 80% or 90%. In some embodiments, the area ratio of all openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 to the area ratio of the surface of the second layer 120 away from the first layer 110 is greater than the preset area ratio, and the isolation effect of isolating foreign matter 400 is improved by setting the area ratio of the openings 320 with small diameters. For example, the preset area ratio is 50%, 70% or 90%.

[0086] When the substrate 100 is a polypropylene microporous foam substrate, and the open pores 320 are derived from the closed pores 310 after cutting, the selection can be made based on the cross-sectional conditions after cutting. Figures 9 to 12 ,in Fig. 9 and Fig.10 It is a schematic diagram of the structure of the polypropylene microporous foam plate 3 before and after it is cut at the section plane L. Fig.11 and Fig.12It is a structural schematic diagram after the polypropylene microporous foam plate 3 is cut at the cutting plane L1. When the polypropylene microporous foam plate 3 is cut at the cutting plane L, a polypropylene microporous foam matrix 101 is obtained. When it is found through detection that the number of openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 is less than 60%, the polypropylene microporous foam matrix 101 can be cut at the cutting plane L1 to obtain a new polypropylene microporous foam matrix 102. When it is found through detection that the number of openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 is greater than 60%, the polypropylene microporous foam matrix 102 can be used as the matrix 100. This method is used to select a matrix 100 in which the ratio of the number of openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 to the number of all openings 320 is greater than a preset ratio. Similarly, in the case where the area ratio of the surface of the second layer 120 away from the first layer 110 occupied by the openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 is greater than the preset area ratio, the above method can also be used for selection. The method for detecting the diameter of the closed pores 320 includes using a microscopic electron microscope for observation and detection. In some embodiments, the number or area ratio of the openings 320 with smaller diameters can be reversely determined by counting the openings 320 with larger diameters in the second layer 120.

[0087] When the substrate 100 is a non-polymer substrate, the openings 320 on the substrate 100 can be obtained by laser lithography, chemical etching or deposition, and the process parameters can be adjusted to obtain a ratio of the number of openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 to the number of all openings 320 that is greater than a preset ratio, or an area ratio of the openings 320 with a diameter of 5 microns to 50 microns in the second layer 120 on the surface of the second layer 120 away from the first layer 110 that is greater than a preset area ratio.

[0088] In a possible implementation, the pore wall thickness of the open pore 320 is 0.1 micron to 2 microns, and the pore wall thickness of the closed pore 310 is 0.1 micron to 2 microns. Among them, the pore wall of the open pore 320 includes a bottom wall 321 and a peripheral wall 323, and the thickness of the bottom wall 321 and the peripheral wall 323 is 0.1 micron to 2 microns. When the substrate 100 is a polypropylene microporous foam substrate, and the open pore 320 originates from the closed pore 310 after cutting, the distribution range of the pore wall thickness of the open pore 320 and the pore wall thickness of the closed pore 310 are the same. Under the same foaming ratio, if the wall thickness is too large, the closed pore 310 will also become larger, and the diameter of the open pore 320 formed after cutting will become larger, which affects the isolation effect of the foreign matter 400. The smaller the wall thickness, the greater the process difficulty, and it is difficult to control that most of the wall thickness is less than 0.1 micron. The pore wall thickness of the open pore 320 and the closed pore 310 is set within the above range, and the pore wall 11 of the closed pore 310 and the bottom wall 321 of the open pore 320 can also have better elastic force, thereby buffering the loss of the functional coating 200 in the open pore 320 by the foreign matter 400. In some embodiments, the pore wall thickness of the open pore 320 can also be set to be greater than 2 microns, or less than 0.1 microns. For example, when the substrate 100 is a non-polymer substrate, the pore wall thickness of the open pore 320 can be achieved by laser laser, chemical etching or deposition.

[0089] In a possible implementation, the functional coating 200 includes at least one of a hydrophobic coating 210, a self-cleaning coating, a high temperature resistant coating, or an antibacterial and mildew proof coating. The hydrophobic coating 210 is used to block rain and ice and snow on the surface of the antenna cover 30, the self-cleaning coating can be used to block dust on the surface of the antenna cover 30, the high temperature resistant coating can be used for heat insulation, and the antibacterial and mildew proof coating can be used for antibacterial and mildew proofing of the surface of the antenna cover 30. The specific type of functional coating 200 can be selected according to the application environment of the antenna cover 30. In some embodiments, the hydrophobic coating 210 is a super-hydrophobic nano-coating, which has a good hydrophobic and anti-ice and snow effect, and can make the surface contact angle of the second layer 120 greater than 150°. In other embodiments, the hydrophobic coating 210 can also be an organic hydrophobic coating. In some embodiments, the high temperature resistant coating is a PTFE modified fluororesin coating. In some embodiments, the antibacterial and mildew proof coating is a fluorocarbon mildew proof coating. In some embodiments, the functional coating 200 includes two or more of the above coatings. For example, some functional coatings 200 include both hydrophobic and self-cleaning functions. For another example, a hydrophobic coating 210 and an antibacterial and antifungal coating may be provided in different areas of the substrate 100 as required. In other embodiments, the functional coating 200 may also be other functional coatings, preferably a functional coating 200 that does not affect electromagnetic wave transmission.

[0090] See also Fig.13In a possible implementation, a plurality of convex portions 130 are provided on the surface of the second layer 120 away from the first layer 110. The convex portion 130 is spherical, conical, or cylindrical, etc. The convex portion 130 can further protect the functional coating 200 from being rubbed off, such as friction caused by various foreign objects caused by vibration during packaging and transportation, and friction caused by various media caused by touch, bumps, etc. during installation and maintenance. In some embodiments, the convex portions 130 are evenly distributed on the second layer 120. The size and number of the convex portions 130 can be set according to the size of the antenna cover 30, and are not limited in this application.

[0091] See also Figure 5 and Fig.14 In a possible implementation, the surface of the second layer 120 away from the first layer 110 is a plane or a curved surface 140. When the surface of the second layer 120 away from the first layer 110 is a curved surface 140 (such as Fig.14 As shown in FIG. 1 , during the handling process, the contact point between the second layer 120 having the curved surface 140 and the handling tool is not the entire surface of the second layer 120, which can reduce the contact area between the handling tool and the radome 30 during the handling process, thereby reducing the friction damage of the handling tool to the radome 30. When the second layer 120 is a curved surface 140, the openings 322 of the opening 320 are distributed on the curved surface 140. Fig.14 The curved surface 140 shown in FIG. 1 is wavy. In some embodiments, the curved surface 140 may also be arc-shaped, for example, when the radome 30 is applied to Figure 1 When the antenna 1 is in the shape of the reflective substrate 20, the antenna cover 30 can be adapted to the shape of the reflective substrate 20 and is a pot-shaped curved surface.

[0092] See also Fig.15 In a possible implementation, the surface of the second layer 120 away from the first layer 110 is a curved surface 140, and the curved surface 140 includes a plurality of interlaced concave sub-surfaces 141 and convex sub-surfaces 142, the curvature center of the concave sub-surface 141 is located on the side of the second layer 120 away from the first layer 110, and the curvature center of the convex sub-surface 142 is located on the side of the second layer 120 adjacent to the first layer 110, and the width of the concave sub-surface 141 is greater than the width of the convex sub-surface 142. The curvature and width of the concave sub-surface 141 can be set according to product requirements. The curvature and width of the concave sub-surface 141 are set larger, which is conducive to the sliding of snow and rainwater. The width and curvature of the convex sub-surface 142 are set smaller, which reduces the contact area between the convex sub-surface 142 and foreign objects, so as to protect the functional coating 200 in the concave sub-surface 141 and prevent it from being rubbed off during transportation.

[0093] See also Fig.16 and Fig.17In a possible implementation, the substrate 100 includes a plurality of stacked substrate sublayers 150, and a plurality of openings 320 are provided on at least one surface of the substrate sublayer 150. The openings 320 and the adjacent surfaces of the substrate sublayer 150 are combined to form closed holes 310. The plurality of substrate sublayers 150 include two or more substrate sublayers 150. In this embodiment, the openings 320 in the substrate sublayer 150 can be prepared by laser lithography, chemical etching, or deposition. Fig.16 As shown, in this embodiment, the substrate 100 includes three substrate sublayers 150, namely a first substrate sublayer 151, a second substrate sublayer 152 and a third substrate sublayer 153. Open holes 320 are first formed on the upper and lower surfaces of the first substrate sublayer 151, and then the first substrate layer 151 and the second substrate sublayer 152 are attached to each other, and the open holes 320 on one surface of the first substrate sublayer 151 are converted into closed holes 310 (such as Fig.17 As shown in FIG. 1 , the opening 320 on the other surface of the first substrate sublayer 151 is the opening 320 in the second layer 120. In some embodiments, a plurality of openings 320 corresponding to each other may be provided on two substrate sublayers 150, and then the surfaces of the two substrate sublayers 150 with the openings 320 are aligned, and the openings 320 become closed holes 310, as shown in FIG. Fig.16 The closed holes 310 in the second substrate sublayer 152 and the third substrate sublayer 153. In the actual radome 30 product, the substrate sublayers 152 in the substrate 100 are not limited to only three, but can also be two or other numbers, which can be set according to actual needs. When there are two substrate sublayers 150, openings 320 can be formed on the upper and lower surfaces of one of the substrate sublayers 150, and openings 320 can be formed on one surface of the other substrate sublayer 150, and then the two substrate sublayers 150 are overlapped, wherein the openings 320 located on the outer surface are the openings 320 of the second layer 120, and the openings 320 enclosed by the two substrate sublayers 150 become closed holes 310.

[0094] See also Fig.18 In some embodiments, other functional layers, such as a heat-resistant layer 160, may be provided between the multiple stacked substrate sub-layers 150. One or more functional layers may be added without affecting the transmission of electromagnetic waves.

[0095] See also Fig.19 In a possible implementation, the side of the substrate 100 away from the functional coating 200 may also have other functional layers, such as a heat-resistant layer 160 , and one or more functional layers may be added without affecting the transmission of electromagnetic waves.

[0096] In a possible implementation, the thickness of the radome 30 is 8mm-60mm. When a polymer microporous foaming matrix is ​​used as the matrix 100, the hardness of the radome 30 is related to the foaming ratio and thickness of the polymer microporous foaming matrix. The higher the foaming ratio, the thinner the thickness, the lower the hardness, and the higher the flexibility. The thickness and structural strength of the radome 30 of the present application can be set according to the actual product needs. When the radome 30 is applied to the antenna 1, the radome 30 needs to have a certain structural strength and a certain flexibility, that is, to achieve a strong structural support. At the same time, when the radome 30 is subjected to external force, the toughness of the polymer microporous foaming matrix material itself can buffer the hard friction damage on the surface of the radome 30. When the radome 30 is applied to the antenna 2, since the radome 30 is directly laid on the reflective substrate 20, the structural strength requirement is not high, and the thickness of the radome 30 can be set to be smaller. Among them, the specific thickness of the radome 30 is not limited to the above thickness range, and its specific thickness and size can be set according to the actual size of the antenna 1.

[0097] In order to illustrate the beneficial effects of the antenna cover 30 in the present application, the present application also provides the following specific implementation methods, comparative implementation methods and test results for illustration.

[0098] Implementation Method 1

[0099] This embodiment 1 provides an antenna 1 (such as Figure 1 As shown), the antenna 1 includes a feed source 10, a reflective substrate 20 and a radome 30 (as shown Figure 5 As shown in the figure, the feed source 10 and the radome 30 are fixed on the reflective substrate 20, and the feed source 10 is located between the incident surface 21 of the reflective substrate 20 and the radome 30. The reflective substrate 20 is a pot-shaped reflective substrate, the center of the reflective substrate 20 has a mounting position, and is mounted on the support 40 through the mounting position. The feed source 10 is fixed on the support 40 through the feed tube 50 and is located at the center of the reflective substrate 20. The radome 30 is fixedly connected to the edge of the reflective surface 20. The radome 30 and the reflective surface 20 enclose a receiving space 60, and the feed source 10 is located in the receiving space 60.

[0100] The radome 30 includes a substrate 100 and a functional coating 200. The substrate 100 is a polypropylene microporous foam substrate 101. The polypropylene microporous foam substrate 101 includes a first layer 110 and a second layer 120 located on one side of the first layer 110. The first layer 110 is provided with a plurality of closed cells 310. The surface of the second layer 120 away from the first layer 110 is concavely provided with a plurality of openings 320. The openings 320 include a bottom wall 321 and an opening 322 arranged away from the first layer 110. The bottom wall 321 is connected to a hole wall 311 of at least one closed cell 310. The functional coating 200 is arranged in the openings 320. The surface of the second layer 120 away from the first layer 110 is a plane, and the second layer 120 is arranged away from the feed source 10 compared to the first layer 110, that is, the side with the functional coating 200 faces the outside, and the surface of the first layer 110 away from the second layer 120 is closed. The functional coating 200 is a hydrophobic coating 210, specifically a super hydrophobic nano coating, the thickness of the hydrophobic coating 210 ranges from 1 micron to 5 microns, the depth of the opening 320 ranges from 5 microns to 100 microns, and the thickness of the hydrophobic coating 210 is less than the depth of the opening 320. The opening 320 is formed by cutting the closed pores 310 of the cross-section of the polypropylene microporous foaming substrate 101. The diameter distribution range of the opening 320 is 5 microns to 100 microns, and the diameter distribution range of the closed pores 310 is 5 microns to 100 microns. The pore wall thickness distribution range of the opening 320 is 0.1 microns to 2 microns, and the pore wall thickness distribution range of the closed pores 310 is 0.1 microns to 2 microns.

[0101] Comparative Implementation Methods

[0102] In this comparative embodiment, different from the above-mentioned embodiment 1, no hydrophobic coating 210 is provided in the opening 320 of the polypropylene microporous foamed substrate 101 , and the rest is the same as the embodiment 1.

[0103] The waterproof and ice-proof effects of the antenna 1 in the above embodiment 1 and the comparative embodiment were measured. Figure 20 to Figure 23 shown.

[0104] in Fig. 20 This is a schematic diagram of the waterproof effect of implementation mode 1. Fig.21 Schematic diagram of waterproof effect of comparative implementation mode, from Fig. 20 It can be seen that the water on the surface of the antenna cover 30 in the first embodiment is in the form of water droplets and does not infiltrate the surface of the antenna cover 30, indicating that the hydrophobic effect is good; Fig.21 It can be seen that the water on the surface of the antenna cover 30 in the comparative embodiment is in the form of a water film, which is completely immersed on the surface of the antenna cover 30, which will seriously affect the signal transmission of the electromagnetic wave, mainly manifested in the reflection, refraction and scattering of the electromagnetic wave, such as Fig.24As shown, when a water film 410 accumulates on the surface of the antenna cover 30 away from the feed source 10, the electromagnetic wave M will be reflected, refracted or scattered, which will manifest as adverse effects such as decreased antenna gain, beam deflection, and changes in radiation distribution, and this effect will worsen as the frequency of the electromagnetic wave increases. Implementation 1 can completely avoid the impact of water on the antenna cover 30 during rainfall on the antenna 1.

[0105] in Fig. 22 This is a schematic diagram of the anti-ice and snow effect of implementation mode 1. Fig.23 This is a schematic diagram of the anti-ice and snow effect of the comparative implementation method. Fig. 22 It can be seen that there is no ice or snow on the surface of the radome 30 in Embodiment 1, and ice is only attached to the top of the radome 30, which has little effect on the transmission of electromagnetic waves, indicating that the surface of the radome 30 has a good effect of blocking ice and snow. Fig.23 It can be seen that a lot of ice and snow are accumulated on the surface of the antenna cover 30 in the comparative embodiment, and the ice and snow completely cover the surface of the antenna cover 30, which will seriously affect the signal transmission of electromagnetic waves, mainly manifested as reflection, refraction and scattering of electromagnetic waves, and then manifested as adverse effects such as antenna gain reduction, beam deflection, and radiation distribution changes, and this effect worsens with the increase of the frequency of the electromagnetic wave. It can be seen that under the same ice and snow conditions, the antenna cover 30 in embodiment 1 can reduce the amount of ice / snow attached, improve the anti-ice / snow ability of antenna 1 and the availability index of antenna 1.

[0106] In order to further illustrate the beneficial effects of the antenna cover 30 of the present application, the antenna cover 30 in embodiment 1 is also subjected to outdoor environmental tests, including initial water contact angle, friction resistance test, reliability test, salt spray resistance test and falling sand test.

[0107] See Table 1 for details. In Test 1, the antenna cover 30 was not treated in any way, and the initial water contact angle was directly tested. The initial water contact angle is an important criterion for measuring the hydrophobic effect. A contact angle greater than 90° is hydrophobic, and a contact angle greater than 150° is super hydrophobic. The friction resistance test refers to simulating various types of medium friction that may be generated during the installation, use, and maintenance of the equipment, including rubbing the wire gloves (Test 2), steel wool (Test 3), and sandpaper (Test 4) 1000 times respectively, wherein the steel wool uses the steel wool model 0000#, 0000# indicates a model of steel wool thickness, and the sandpaper uses the sandpaper model P240, P240 indicates 240 mesh, which refers to the thickness of the sandpaper and the amount of abrasive per square inch. The higher the mesh number, the finer the abrasive and the greater the amount. Reliability testing refers to the accelerated aging process test that simulates high temperature, high humidity and strong ultraviolet environment, including damp heat test (test 5) and ultraviolet light test (test 6). The temperature of the damp heat test is 85°C, the humidity is 85%, and the holding time is 2000h; the ultraviolet light power during the ultraviolet light test is 12W / m 2, the temperature is 60℃, and the holding time is 2000h. The salt spray resistance test refers to the accelerated aging process test simulating the coastal environment, the salt water concentration is 5% (test 7), and the holding time is 30 days. The falling sand test refers to the accelerated aging process test simulating the wind and sand environment, using the GB / T 23988 method and using 67kg Chinese ISO standard sand (test 8). After the surface of the antenna cover 30 is treated by the above method, its hydrophobic effect is tested. The test structure is shown in Table 1 and Fig.25 shown.

[0108] Table 1

[0109]

[0110] It can be seen from Table 1 above that the initial contact angle of the surface of the antenna cover 30 in Implementation 1 is 158.475°, which is greater than 150° and has super hydrophobic properties. The contact angles in Tests 2 to 7 decreased slightly, but were all maintained above 154°, also having super hydrophobic properties. Although the contact angle decreased in Test 8 to 138.194°, it also had hydrophobic properties.

[0111] The present application also tests the electromagnetic wave transmission performance of the antenna 1 in Implementation 1, wherein the relative dielectric constant of the antenna cover 30 is 1.1. The lower the relative dielectric constant, the more conducive to electromagnetic wave transmission. Antenna 1 supports signal wave transmission in the frequency band of 700MHz-110GHz. The electromagnetic wave radiation pattern emitted by antenna 1 is undistorted. The electromagnetic wave radiation pattern refers to the distribution of electromagnetic wave radiation intensity, which is a conventional indicator of antenna 1, indicating the radiation intensity distribution of antenna 1 in each direction. The undistorted electromagnetic wave radiation pattern indicates that the antenna cover 30 does not affect the electromagnetic wave transmission of antenna 1. Through testing, when antenna 1 transmits electromagnetic waves of 700MHz-110GHz, the electromagnetic wave penetration loss of the antenna cover 30 is close to 0dB, indicating that the antenna cover 30 has extremely low electromagnetic wave penetration loss.

[0112] The above is a detailed introduction to the antenna cover and antenna provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and embodiments of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the ideas of the present application, there will be changes in the specific embodiments and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A radome, It is characterized in that The antenna cover includes a substrate and a functional coating, wherein the substrate is a polymer microporous foam substrate, the polymer microporous foam substrate has a plurality of closed cells, the polymer microporous foam substrate includes a first layer and a second layer connected as an integral structure, the second layer is located on one side of the first layer, the first layer is provided with a plurality of the closed cells, a surface of the second layer away from the first layer is concavely provided with a plurality of openings, the openings include a bottom wall and an opening arranged away from the first layer, the bottom wall is connected to a pore wall of at least one of the closed cells, the functional coating is at least arranged in the openings, and the openings are formed by some of the closed cells in the polymer microporous foam substrate.

2. The radome according to claim 1, It is characterized in that The thickness of the functional coating is less than or equal to the depth of the opening.

3. The radome according to claim 1, It is characterized in that The diameter difference between the open hole and the closed hole is smaller than a preset value.

4. The radome according to any one of claims 1 to 3, It is characterized in that The diameter of the opening is 5 micrometers to 100 micrometers.

5. The radome according to claim 4, It is characterized in that The ratio of the number of openings with a diameter of 5 micrometers to 50 micrometers in the second layer to the number of all openings is greater than a preset ratio.

6. The radome according to any one of claims 1 to 3, It is characterized in that The thickness of the pore wall of the open pores is 0.1 micrometer to 2 micrometers, and the thickness of the pore wall of the closed pores is 0.1 micrometer to 2 micrometers.

7. The radome according to any one of claims 1 to 3, It is characterized in that The depth of the opening is 5 micrometers to 100 micrometers.

8. The radome according to any one of claims 1 to 3, It is characterized in that The functional coating includes at least one of a hydrophobic coating, a self-cleaning coating, a high temperature resistant coating or an antibacterial and mildew proof coating.

9. The radome according to any one of claims 1 to 3, It is characterized in that A plurality of protrusions are disposed on a surface of the second layer away from the first layer.

10. The radome according to any one of claims 1 to 3, It is characterized in that A surface of the second layer away from the first layer is a flat surface or a curved surface.

11. The radome according to claim 10, It is characterized in that The surface of the second layer away from the first layer is a curved surface, and the curved surface includes a plurality of interlaced concave sub-surfaces and convex sub-surfaces, the center of curvature of the concave sub-surface is located on the side of the second layer away from the first layer, the center of curvature of the convex sub-surface is located on the side of the second layer adjacent to the first layer, and the width of the concave sub-surface is greater than the width of the convex sub-surface.

12. The radome according to any one of claims 1 to 3, It is characterized in that The substrate comprises a plurality of stacked substrate sub-layers, at least one surface of the substrate sub-layers is provided with a plurality of openings, and the openings and adjacent surfaces of the substrate sub-layers are enclosed to form the closed pores.

13. An antenna, It is characterized in that The antenna comprises a feed source, a reflective substrate and a radome as described in any one of claims 1 to 12, wherein the feed source and the radome are fixed on the reflective substrate, and the feed source is located between the incident surface of the reflective substrate and the radome.

14. An antenna, It is characterized in that The antenna comprises a feed source, a reflective substrate and an antenna cover as described in any one of claims 1 to 12, wherein the antenna cover is arranged on the incident surface of the reflective substrate, and the feed source is arranged on a side of the antenna cover away from the reflective substrate.

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