Ceramic radome

Abstract

The present invention provides a ceramic radome, comprising at least one functional layer, the functional layer comprising a ceramic substrate and a conductive layer, the conductive layer comprising a plurality of non-connected cross-shaped conductive geometric structures; wherein the ceramic substrate and the conductive layer enable the ceramic radome to have such electromagnetic characteristics: when electromagnetic waves pass through the radome, the electromagnetic wave penetration rate is greater than 90% within the operating frequency range. The radome using the technical solution of the present invention adopts a ceramic-based material and can be used in a high-temperature environment, and adopts a conductive geometric structure in the functional layer to improve the wave transmittance, thereby having a high wave transmittance within a wider operating frequency range.

Description

Technical Field

[0001] The present invention relates to the field of electronic equipment, and in particular to a ceramic antenna cover. Background Art

[0002] Antennas are usually placed outdoors for operation. If they are directly affected by the external environment (sunlight, wind, rain, snow, etc.), the antenna life will be shortened, the electrical performance will be reduced, and the stability will be poor. Therefore, the radome is widely used as a component that carries the mission of protecting the normal operation of the antenna. The first electromagnetic property that the radome must have is high-performance wave transmission, because the antenna receives and transmits signals through the outer shell of the radome for transmission. In order to ensure high-performance wave transmission, conventional radomes are often made of composite resin materials with low dielectric constant and low loss.

[0003] However, for certain specific environmental requirements, such as the need to operate in a high temperature environment, it is difficult to meet the requirements using resin-based materials. Therefore, it is necessary to use a ceramic-based radome. However, the ceramic radome in the prior art has poor wave transmission effect, a very narrow frequency band, and poor scanning angle stability. If the ceramic-based radome is to truly be widely used, it is very important to break through the narrowband limitation. Summary of the invention

[0004] The present invention aims to provide a ceramic antenna cover, which mainly solves the problems of poor wave transmission effect, narrow frequency band adaptation and poor scanning angle stability of the ceramic-based antenna cover in the prior art.

[0005] In order to achieve the above object, the present invention provides a ceramic radome, comprising at least one functional layer.

[0006] The energy layer includes a ceramic substrate and a conductive layer, wherein the conductive layer includes a plurality of disconnected cross-shaped conductive geometric structures;

[0007] The ceramic substrate and the conductive layer enable the ceramic antenna cover to have such electromagnetic properties: when electromagnetic waves pass through the antenna cover, within the operating frequency range, the electromagnetic wave penetration rate is greater than 90%.

[0008] The antenna cover provided by the embodiment of the present invention adopts a ceramic-based material and can be used in a high-temperature environment. The conductive geometric structure is used in the functional layer to improve the wave transmittance, thereby having a good wave transmission effect in a wider frequency range. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0010] Figure 1A longitudinal sectional view of a ceramic radome according to a first embodiment of the present invention is shown;

[0011] Figure 2 A plan view showing a structural unit of a ceramic radome according to a first embodiment of the present invention;

[0012] Figure 3 A diagram showing simulation test results of a ceramic radome according to a first embodiment of the present invention;

[0013] Figure 4 A longitudinal sectional view of a ceramic radome according to a second embodiment of the present invention is shown;

[0014] Figure 5 A plan view showing a structural unit of a ceramic radome according to a second embodiment of the present invention;

[0015] Figure 6 A diagram showing simulation test results of a ceramic radome according to a second embodiment of the present invention;

[0016] Figure 7 A longitudinal sectional view of a ceramic radome according to a third embodiment of the present invention is shown;

[0017] Figure 8 A plan view showing a structural unit of a ceramic radome according to a third embodiment of the present invention; and

[0018] Fig. 9 The figure shows the simulation test results of the ceramic antenna cover according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] In order to make it easier for those skilled in the art to understand the present invention, the technical solution of the present invention is briefly introduced below.

[0021] The present invention designs a new type of ceramic antenna cover using metamaterial technology. Metamaterial is an artificial composite structure material with extraordinary physical properties that natural materials do not have. By orderly arranging conductive geometric structures, the relative dielectric constant and magnetic permeability of each point in space are changed. Metamaterial is a new type of material with special electromagnetic response that uses artificial conductive geometric structures as basic units and arranges them in space in a specific way. The characteristics of its electromagnetic response often do not depend on the intrinsic properties of its constituent materials, but are determined by the characteristics of its artificial conductive geometric structure. In addition, metamaterials can achieve dielectric constants, magnetic permeabilities, and wave-absorbing polarization properties that ordinary materials cannot have within a certain range, thereby effectively controlling the propagation characteristics of electromagnetic waves.

[0022] The present invention designs a ceramic antenna cover based on metamaterial technology, which is composed of a large number of functional layers with conductive geometric structures. Each structural unit includes a ceramic substrate and a conductive layer compounded on the ceramic substrate, and the conductive layer includes a plurality of unconnected cross-shaped conductive geometric structures, and the cross conductive geometric structure is composed of two mutually perpendicular straight lines or curves. The ceramic substrate and the conductive layer make the ceramic antenna cover have such electromagnetic characteristics: when the electromagnetic wave passes through the antenna cover, the electromagnetic wave penetration rate is greater than 90% within the working frequency range. That is to say, the metal layer is compounded in the ceramic to provide a wave-transmitting channel for the electromagnetic wave.

[0023] Through the above material in this embodiment, the conductive geometric structure is arranged in the ceramic substrate, thereby improving the electromagnetic wave transmission effect. Based on the material obtained in the above manner, the material can be designed to meet more application scenarios according to the needs of use, and the weight of the material can be reduced.

[0024] Preferably, the composite ceramic layer and conductive layer may be a ceramic layer sandwiched with a conductive layer, or may be a composite of multiple conductive layers and multiple ceramic layers.

[0025] Preferably, the conductive layer is a metal layer, for example, a metal with high electrical conductivity such as copper or silver.

[0026] There are many ways to arrange the conductive geometric structures on the ceramic substrate, which can be periodic or non-periodic.

[0027] Different conductive geometric structures will bring different wave-transmitting effects, thus greatly expanding the application prospects of the present invention for electromagnetic waves of different frequencies. Three embodiments are given below as examples.

[0028] The longitudinal cross-sectional structure of the antenna cover of the first embodiment of the present invention is shown in FIG. Figure 1 The functional layer is a sandwich structure, with the ceramic substrate (quartz reinforced silicon dioxide or silicon nitride and other ceramic materials) located on both sides of the conductive layer. Figure 1 The case where the ceramic substrates on the left and right sides have an asymmetric structure is shown. Figure 1 The ceramic layer 20 on the middle right side is 11.4 mm thick; from the outside to the center are the coupling agent 11 with a thickness of about 0.2 mm, and the cast sheet 12 with a thickness of about 0.15 mm. The center is the conductive layer 13, and the thickness of the conductive layer 13 is 0.018 mm.

[0029] Preferably, the functional layer may further include a protective layer. Figure 1 The figure shows that the leftmost layer of the functional layer is the protective layer 30, which is coated with quartz fiber and is used to protect the ceramic antenna cover. The thickness is about 0.5 mm. The quartz fiber layer can also be glass fiber, quartz glass fiber, high silica glass fiber and other fiber materials that can withstand high temperatures.

[0030] In a specific implementation process, only one side of the conductive layer has a cast sheet located between the conductive layer and the ceramic substrate; or the conductive layer and the ceramic substrate are bonded by heating without using a binder.

[0031] If the functional layer is divided into multiple structural units, the plane structure of each structural unit is as follows Figure 2 As shown, the structural unit is square with a side length of 10.58 mm, including a ceramic substrate 40 and a conductive layer. The conductive layer includes a cross-shaped conductive geometric structure. The material of the cross-shaped conductive geometric structure can be a high-conductivity metal such as copper or silver. The length of the cross is approximately the same as the length of the structural unit, and the line width of the cross is 0.24 mm.

[0032] The CST software simulation results of the first embodiment of the present invention are as follows: Figure 3 As shown, the horizontal axis is the electromagnetic wave frequency (unit: GHz, gigahertz), and the vertical axis is the transmittance index (unit: dB, signal attenuation value / decibel). It can be seen from the figure that the transmittance of the ceramic antenna cover is above 90% (-1dB) in the range of 2-9GHz.

[0033] The longitudinal cross-sectional structure of the antenna cover of the second embodiment of the present invention is shown in FIG. Figure 4 As shown. The thickness of the conductive geometric structure is 0.018mm, and the substrate used is ceramic (quartz reinforced silicon dioxide or silicon nitride and other ceramic materials). The functional layer is a sandwich structure, and the ceramic substrate is located on both sides of the conductive layer. The ceramics on both sides of the conductive layer are asymmetric structures. The second ceramic layer on the left side of the figure is 2mm thick, and the first ceramic layer 20 on the right side is 8mm thick; from the outside to the center, there are the coupling agent 11 and the cast sheet 12, and the center is the conductive layer 13, such as copper or silver and other high conductivity metals. The thickness of the coupling agent 11 is about 0.2mm, and the thickness of the cast sheet 12 is about 0.15mm.

[0034] If the functional layer is divided into multiple structural units, the plane structure of each structural unit is as follows Figure 5 As shown, the structural unit is square with a side length of 6 mm, including a ceramic substrate 40 and a conductive layer, the conductive layer includes a cross-shaped conductive geometric structure, and at least one conductive sheet electrically isolated from the cross-shaped conductive geometric structure, and the conductive sheet is located in the four quadrants formed by the cross-shaped conductive geometric structure. The shape of the conductive sheet can be at least one of a triangle, a quadrilateral, a pentagon, a hexagon, a circle, and an ellipse. Figure 5 The figure shows the case where the conductive sheet is four quadrilateral conductive sheets. The cross-shaped conductive geometric structure is located in the center, and the four quadrilateral conductive sheets are located at the four corners of the structural unit. The metal material can be copper or silver, the distance between the two conductive sheets is 3.6 mm, the side length of the conductive sheet is about 1.2 mm, and the length of the cross is approximately the same as the length of the structural unit.

[0035] The CST software simulation results of the second embodiment of the present invention are as follows: Figure 6 As shown, the horizontal axis is the electromagnetic wave frequency (unit: GHz), and the vertical axis is the transmittance index (unit: dB). It can be seen from the figure that in the range of 10-17GHz, the transmittance of the ceramic antenna cover is above 90% (-1dB).

[0036] The longitudinal cross-sectional structure of the antenna cover of the third embodiment of the present invention is shown in FIG. Figure 7 The thickness of the conductive geometric structure is 0.018 mm, and the substrate used is ceramic (ceramic materials such as quartz reinforced silicon dioxide or silicon nitride). The overall structure is as follows Figure 7 As shown, the functional layer is a sandwich structure, the ceramic substrate is located on both sides of the conductive layer, and the conductive layer is symmetrically structured. From both sides to the center, there are ceramic material 20, bonding agent 11, and cast sheet 12. The center is the conductive layer 13, and the thickness of the ceramic layers on both sides is 4.5 mm.

[0037] If the functional layer is divided into multiple structural units, the plane structure of each structural unit is as follows Figure 8 As shown, the structural unit is square with a side length of 6mm, including a ceramic substrate and a conductive layer, the conductive layer includes four adjacent cross-shaped conductive geometric junctions, and at least one conductive sheet, at least one conductive sheet is located in the open ring formed by the four adjacent cross-shaped conductive geometric structures. The conductive layer can be made of copper or silver. The line width of the cross-shaped conductive geometric structure is 0.2mm, the length is 4.2mm, the distance between two adjacent cross-shaped conductive geometric structures is 4.2mm, and the side length of the conductive sheet is 2.6mm.

[0038] The CST software simulation results of the third embodiment of the present invention are as follows: Fig. 9 As shown, the horizontal axis is the electromagnetic wave frequency (unit: GHz), and the vertical axis is the wave transmittance index (unit: dB). It can be seen from the figure that the wave transmittance of the ceramic antenna cover is above 90% (-1dB) in the range of 7-13GHz.

[0039] Some embodiments are shown above. Depending on the specific circumstances during implementation, the thickness of the conductive geometric structure can be 1 to 50 microns. Preferably, the thickness of the conductive geometric structure is 10 to 30 microns. More preferably, the thickness of the conductive geometric structure can be 16 to 20 microns. The thickness of the conductive geometric structure is 16 to 20 microns. The width of the conductive geometric structure is 2 to 6 millimeters. The line widths of the conductive geometric structures between different functional layers are different, such as the line width of the conductive geometric structure is 20 to 1000 microns. Preferably, the line width of the conductive geometric structure is 50 to 500 microns. More preferably, the line width of the conductive geometric structure is 100 to 200 microns. The line widths of the conductive geometric structures of different conductive geometric structure layers are different, and the ratio of the line widths of the conductive geometric structures of different conductive geometric structure layers can range from 0 to 0.2. Preferably, the ratio of the line widths of the conductive geometric structures of different conductive geometric structure layers ranges from 0.05 to 0.1.

[0040] From the above description, it can be seen that the present invention achieves the following technical effects:

[0041] 1. The metamaterial ceramic antenna cover of the present invention adopts ceramic-based materials and can be used in high-temperature environments.

[0042] 2. The present invention adopts a conductive geometric structure in the structural unit, so that it has a very good wave transmission effect in a very wide frequency range. The wave transmittance of the ceramic antenna cover is above 90% (-1dB) within the designed frequency range.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A ceramic radome, characterized in that: The invention comprises at least one functional layer, wherein the functional layer is divided into a plurality of structural units, each structural unit of the functional layer comprises a ceramic substrate and a conductive layer, wherein the conductive layer comprises a cross-shaped conductive geometric structure and four quadrilateral conductive sheets electrically isolated from the cross-shaped conductive geometric structure; the cross-shaped conductive geometric structure is located at the center of the structural unit, and the four quadrilateral conductive sheets are respectively completely located in four corners of the structural unit; The ceramic substrate and the conductive layer enable the ceramic antenna cover to have such electromagnetic properties that when electromagnetic waves pass through the ceramic antenna cover, the electromagnetic wave penetration rate is greater than 90% within the operating frequency range of 10-17 GHz.

2. The ceramic radome according to claim 1, characterized in that: The cross-shaped conductive geometric structures are arranged periodically.

3. The ceramic radome according to claim 1, characterized in that: The cross-shaped conductive geometric structure is arranged non-periodically.

4. The ceramic radome according to claim 1, characterized in that: At least one of the conductive sheets is located in an open ring formed by four adjacent cross-shaped conductive geometric structures.

5. The ceramic radome according to claim 1, characterized in that: At least one of the conductive sheets is located within the four quadrants formed by the cross-shaped conductive geometric structure.

6. The ceramic radome according to claim 1, characterized in that: The cross-shaped conductive geometric structure is composed of two straight lines or curves that are perpendicular to each other.

7. The ceramic radome according to claim 1, characterized in that: The functional layer is a sandwich structure, and the ceramic substrate is located on both sides of the conductive layer.

8. The ceramic radome according to claim 1 or 7, characterized in that: At least one side of the conductive layer further includes a casting sheet located between the conductive layer and the ceramic substrate.

9. The ceramic radome according to claim 8, characterized in that: At least one side of the conductive layer further includes a bonding agent between the ceramic substrate and the casting sheet.

10. The ceramic radome according to claim 1 or 7, characterized in that: The functional layer further comprises a protective layer located outside the ceramic substrate.

11. The ceramic radome according to claim 10, characterized in that: The material of the protective layer is quartz fiber and / or glass fiber and / or quartz glass fiber and / or high-silica glass fiber.

12. The ceramic radome according to claim 1, characterized in that: The conductive geometric structure has a thickness of 1 to 50 micrometers.

13. The ceramic radome according to claim 12, characterized in that: The conductive geometric structure has a thickness of 10 to 30 microns.

14. The ceramic radome according to claim 13, characterized in that: The conductive geometric structure has a thickness of 16 to 20 microns.

15. The ceramic radome according to claim 1, characterized in that: The conductive geometric structure has a width of 2 to 6 millimeters.

16. The ceramic radome according to claim 15, characterized in that: The conductive geometric structures have a line width of 20 to 1000 microns.

17. The ceramic radome according to claim 16, characterized in that: The conductive geometric structures have a line width of 50 to 500 microns.

18. The ceramic radome according to claim 17, characterized in that: The line width of the conductive geometric structure is 100 to 200 microns.

19. The ceramic radome according to claim 1, characterized in that: The line widths of the conductive geometric structures in different conductive layers are different.

20. The ceramic radome according to claim 19, characterized in that: The ratio of the line widths of the conductive geometric structures of different conductive layers ranges from 0 to 0.

2.

21. The ceramic radome according to claim 20, characterized in that: The ratio of the line widths of the conductive geometric structures of different conductive layers ranges from 0.05 to 0.1.

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