Metal elastic sheet antenna

Abstract

According to the metal elastic sheet antenna provided by the invention, the hole-shaped structure is loaded on the top radiating body, the surface current path of the top radiating body is reconstructed, partial current at the tail end of the top radiating body is counteracted, and the far-field electric field synthesis intensity is reduced, so that the gain is accurately controlled under the condition that the radiation efficiency is not influenced. The hole-shaped structure reduces the metal projection area of the top radiator and the grounding metal sheet, and reduces the equivalent value of parasitic capacitance, thereby meeting the condition of reducing the height of the antenna profile, and achieving the low-profile design. The feed metal sheet is of a metal strip-shaped structure and serves as a tuning unit, and antenna impedance matching is optimized while current distribution on the surface of the antenna radiator is optimized. The grounding point design ensures uniform surface current distribution of the top radiator and inhibits edge scattering; and the current is further stabilized by combining a hole-shaped structure, and directional diagram distortion is reduced.

Description

Technical Field

[0001] The present application relates to the field of microwave communication technology, and more specifically to a metal shrapnel antenna. Background Art

[0002] With the rapid development of mobile communication technology, micro base stations (MBs) are playing an increasingly important role in network coverage. Micro BTSs are compact, flexible, and adaptable to complex network scenarios, complementing mobile communication networks. To meet this flexibility, micro BTSs must be miniaturized, which poses a challenge to antenna design. Antenna performance directly impacts micro BTS coverage and communication quality, so the design of compact and high-performance antennas has become a research priority.

[0003] In micro base station design, metal shrapnel antennas are widely used due to their structural advantages. Their radiator is made of metal and achieves electromagnetic wave radiation through a specific structural design. Compared to PCB antennas, metal shrapnel antennas have lower dielectric loss. The radiator is suspended in air or supported by a plastic bracket, resulting in high radiation efficiency, typically exceeding 75%.

[0004] However, with the trend toward miniaturization of micro base stations, traditional metal shrapnel antennas cannot meet certain standards or application scenarios, where antenna gain must be below a specific value to meet limits on power flux density, SAR, or EMF. For example, stringent requirements for radiation safety in wireless communication equipment set clear upper limits for key RF performance indicators to protect public health and environmental safety. In such cases, the inherent high efficiency and high gain characteristics of metal shrapnel antennas may make it difficult to meet the upper limit requirements for gain indicators. Therefore, how to achieve low gain while maintaining or optimizing antenna performance is a pressing technical challenge in current metal shrapnel antenna design. Summary of the Invention

[0005] In order to solve the problem that the high efficiency and high gain characteristics inherent in the above-mentioned traditional metal shrapnel antenna are difficult to meet the upper limit requirement of the gain index.

[0006] The present application provides a metal shrapnel antenna, comprising: a top radiator and a grounded metal sheet;

[0007] The top radiator is arranged above the ground metal sheet, there is a distance between the top radiator and the ground metal sheet, and an equivalent LC resonant circuit is formed between the top radiator and the ground metal sheet;

[0008] Wherein, the top radiator is equivalent to an inductor;

[0009] The distance between the top radiator and the ground metal sheet is equivalent to a capacitor;

[0010] At least one hole-shaped structure is provided on the top radiator, and the hole-shaped structure is configured to reconstruct the surface current path of the top radiator to offset part of the radiation current.

[0011] In a feasible implementation, the top radiator has a projected area on the surface of the grounded metal sheet;

[0012] The hole structure passes through the upper and lower surfaces of the top radiator to reduce the projection area of ​​the top radiator on the ground metal sheet.

[0013] In a feasible implementation, there are multiple hole-like structures, and the shapes of the multiple hole-like structures are any one of rectangular, square, circular or polygonal.

[0014] In a feasible implementation, the grounding metal sheet includes at least one grounding point, and the grounding point is located in an edge area of ​​the grounding metal sheet.

[0015] In a feasible implementation, the grounding point includes a first grounding point and a second grounding point;

[0016] The first grounding point and the second grounding point are respectively located on two opposite edges of the grounding metal sheet.

[0017] In a feasible implementation, it further includes a feeding metal sheet;

[0018] The feed metal sheet is arranged between the top radiator and the ground metal sheet, one end of the feed metal sheet extends to the bottom of the top radiator, and a side wall of the feed metal sheet maintains a distance from a side wall of the ground metal sheet.

[0019] In a feasible implementation, a feeding point is provided at the end of the feeding metal sheet;

[0020] The feeding point is located at an end of the feeding metal sheet away from the top radiator, and the feeding point is connected to an external signal source through a probe feeding or a microstrip feeding method.

[0021] In a feasible implementation, it further includes a plastic bracket;

[0022] The plastic bracket is located above the grounding metal sheet, and the bottom of the plastic bracket is fixedly connected to the top surface of the grounding metal sheet;

[0023] The top radiator is fixed on the top of the plastic bracket, and the top radiator is isolated from the ground metal sheet by the plastic bracket.

[0024] In a feasible implementation, the plastic bracket is made of insulating material;

[0025] The top surface of the plastic bracket is completely in contact with the bottom surface of the top radiator, and the bottom surface of the plastic bracket is spaced apart from the upper surface of the grounding metal sheet.

[0026] In a feasible implementation, the top radiator has the hole-shaped structure and forms a strip-shaped metal structure away from the edge of the ground metal sheet.

[0027] From the above content, it can be seen that the present application provides a metal shrapnel antenna, which reconstructs the current path on the surface of the top radiator by loading a hole structure on the top radiator, realizes partial current cancellation at the tail end of the top radiator, reduces the synthetic intensity of the far-field electric field, and thus accurately controls the gain without affecting the radiation efficiency. The hole structure reduces the metal projection area between the top radiator and the grounded metal sheet, reduces the equivalent value of the parasitic capacitance, thereby meeting the conditions for reducing the antenna profile height and realizing a low-profile design. The feed metal sheet is a metal strip structure, which serves as a tuning unit, optimizing the current distribution on the surface of the antenna radiator while optimizing the antenna impedance matching. The grounding point design ensures uniform current distribution on the surface of the top radiator and suppresses edge scattering; combined with the hole structure, it further stabilizes the current and reduces the distortion of the pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are incorporated into and constitute a part of this specification, illustrate embodiments consistent with the implementation of the present invention, and together with the description, serve to explain the principles of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the implementation of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0029] Figure 1 Schematic diagram of the structure of the metal shrapnel antenna shown in an embodiment of the present application;

[0030] Figure 2 yes Figure 1 Rear view;

[0031] Figure 3 yes Figure 1 A top view of

[0032] Figure 4 Schematic diagram of the three-dimensional structure of the metal shrapnel antenna shown in an embodiment of the present application;

[0033] Figure 5 Schematic diagram of the shape of the pore structure shown in the embodiment of the present application;

[0034] Figure 6 is a reflection coefficient simulation curve of the metal shrapnel antenna shown in an embodiment of the present application;

[0035] Figure 7 is a gain simulation curve of the metal shrapnel antenna shown in an embodiment of the present application;

[0036] Figure 8 This is an efficiency simulation curve of the metal shrapnel antenna shown in the embodiment of the present application.

[0037] Figure annotation:

[0038] 1-top radiator; 2-plastic bracket; 3-feeding metal sheet; 4-hole structure; 5-feeding point; 6-first grounding point; 7-second grounding point; 8-grounding metal sheet; 9-strip metal structure. DETAILED DESCRIPTION

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of the implementation of the example embodiments of the present invention.

[0040] In micro base station design, metal shrapnel antennas are widely used due to their structural advantages. Their radiator is made of metal, and electromagnetic wave radiation is achieved through a specific structural design. Compared to PCB antennas, metal shrapnel antennas have lower dielectric loss. The radiator is suspended in air or supported by a plastic bracket, resulting in high radiation efficiency, typically exceeding 75%. However, with the trend toward miniaturization in micro base stations, traditional metal shrapnel antennas cannot meet certain standards or application scenarios where antenna gain must be below a specific value to meet power flux density, SAR, or EMF limits. For example, strict requirements for radiation safety in wireless communication equipment set clear upper limits for key RF performance indicators to protect public health and environmental safety. In such cases, the inherent high efficiency and high gain characteristics of metal shrapnel antennas may make it difficult to meet the upper limit requirements for gain indicators.

[0041] In order to solve the above problems, the present invention provides a metal shrapnel antenna. Figure 1-Figure 4 As shown, the metal shrapnel antenna mainly includes a top radiator 1 and a grounding metal sheet 8 .

[0042] Top radiator 1 is positioned above grounded metal sheet 8, with a certain distance between them, forming an equivalent LC resonant circuit. Top radiator 1 acts as an inductor, while the distance between them acts as a capacitor. Furthermore, top radiator 1 is provided with at least one hole-like structure 4, which serves to reshape the surface current path of top radiator 1, thereby offsetting some of the radiated current.

[0043] The top radiator 1, the primary radiating element of the antenna, converts electrical energy into electromagnetic waves and radiates them. The grounded metal plate 8 provides a stable ground reference plane for the antenna and forms an equivalent LC resonant circuit with the top radiator 1, affecting the antenna's resonant frequency and bandwidth. The hole structure 4 alters the surface current distribution of the top radiator 1, reconstructing the surface current path. This achieves partial current cancellation at the radiator's tail end and reduces the far-field electric field strength, thereby precisely controlling gain without affecting radiation efficiency.

[0044] Specifically, when current enters the top radiator 1 through the feed structure, it generates a current distribution on its surface. The presence of the hole-shaped structure 4 forces the current to take a detour, thereby changing the current distribution pattern. This reconfiguration effect can offset some of the redundant radiation current, optimize radiation directivity, and reduce back radiation. Furthermore, the distance between the top radiator 1 and the grounded metal plate 8 forms a capacitor, which, together with the equivalent inductance of the top radiator 1, forms an LC resonant circuit, which determines the antenna's resonant frequency and bandwidth. Therefore, based on the principle of the LC resonant circuit, the antenna's resonant frequency and bandwidth can be further optimized by adjusting the distance and shape between the top radiator 1 and the grounded metal plate 8.

[0045] In this embodiment, the surface current distribution of the top radiator 1 is altered by introducing a hole-like structure 4, thereby reconfiguring the surface current path. This reconfiguration offsets some redundant radiation current, optimizing radiation directivity and reducing backscatter, thereby precisely controlling gain without compromising radiation efficiency. This feature enables the antenna to meet specific safety limits while simultaneously meeting miniaturization requirements.

[0046] Secondly, by adjusting the spacing and shape between the top radiator 1 and the grounded metal plate 8, the antenna's resonant frequency and bandwidth can be further optimized. Leveraging the principle of an LC resonant circuit, the antenna can be flexibly adjusted to meet specific frequency band and bandwidth requirements based on specific application scenarios and performance requirements. This antenna boasts a simple structure, stable performance, and ease of integration. It is suitable for use in wireless communication devices such as micro base stations, and meets the upper limit requirements for antenna gain.

[0047] In some embodiments of the present application, the top radiator 1 has a projected area on the surface of the grounded metal sheet 8. The hole-like structure 4 penetrates the upper and lower surfaces of the top radiator 1, effectively reducing the projected area of ​​the top radiator 1 on the grounded metal sheet 8. In other words, the presence of the hole-like structure 4 on the top radiator 1 reduces the metal projected area between the top radiator 1 and the grounded metal sheet 8, thereby reducing the parasitic capacitance between the two, allowing the antenna to maintain matching at a lower height, thereby reducing the antenna's cross-sectional height.

[0048] Specifically, the hole structure 4 reduces the projected area of ​​the top radiator 1 on the grounded metal sheet 8, altering the antenna structure's electromagnetic field distribution, thereby affecting the antenna's radiation performance and impedance matching. When current enters the top radiator 1 through the feed structure, the hole structure 4 penetrates the top radiator 1, reducing the projected area of ​​the top radiator 1 on the grounded metal sheet 8. This reduces the equivalent value of the parasitic capacitance, thereby meeting the requirement for a lower antenna profile height and achieving a low-profile design. This meets the requirements for optimizing compliance, performance, and miniaturization for micro base station antennas.

[0049] In some embodiments of the present application, the number of the porous structures 4 is multiple, refer to Figure 5 As shown, the shapes of the plurality of hole-like structures 4 can be any one of rectangular, square, circular or polygonal.

[0050] Specifically, the shape and number of the pore structure 4 can be adjusted based on actual needs. For example, a multi-pore array can be used in high-frequency bands to balance bandwidth and efficiency. A multi-pore array can form multi-path radiation and support multi-band coverage. A single large pore design can be used in low-frequency bands to offset redundant radiation current, reduce back radiation, and lower costs.

[0051] It is understandable that the shapes of the plurality of hole-like structures 4 may be the same or different, and the number and shape of the hole-like structures 4 may be more flexibly selected to adapt to different scenarios.

[0052] In some embodiments of the present application, the grounding metal sheet 8 includes at least one grounding point located at an edge of the grounding metal sheet 8. Furthermore, in this embodiment, the grounding point includes a first grounding point 6 and a second grounding point 7, which are located at opposite edges of the grounding metal sheet 8, respectively.

[0053] Specifically, the grounding point is connected to the grounding metal sheet 8 via a conductive material to ensure stable current transmission. The grounding metal sheet 8 provides a stable ground reference plane for the antenna and forms an equivalent LC resonant circuit with the top radiator 1. The grounding point helps stabilize the current on the surface of the antenna's top radiator 1.

[0054] When current flows through the feed structure and into the top radiator 1, it generates a current distribution on its surface. Some of this current flows back to the signal source through the grounding metal plate 8, forming a loop. The grounding points ensure a more even distribution of current across the grounding metal plate 8, reducing current concentration and reflection. In particular, the first and second grounding points 6 and 7, located on opposite sides of the grounding metal plate 8, help disperse the current, creating a balanced current distribution, suppressing cross-polarization, and improving the antenna's radiation efficiency and stability.

[0055] In practical applications, metal shrapnel antennas can be optimized for performance by adjusting the location and number of grounding points. For example, a single grounding point offers a simpler structure, lower costs, and is suitable for single-band applications. Using multiple grounding points, on the other hand, creates multiple current return paths, improves stability, and supports multi-band resonance. By properly adjusting the location and number of grounding points, metal shrapnel antennas can significantly optimize performance indicators such as resonant frequency, bandwidth, radiation efficiency, and directivity, meeting the needs of diverse application scenarios.

[0056] In some embodiments of the present application, a feed metal sheet 3 is further included. The feed metal sheet 3 is located between the top radiator 1 and the ground metal sheet 8, one end of which extends to the bottom of the top radiator 1, and the side wall maintains a certain distance from the side wall of the ground metal sheet 8 to prevent short circuit.

[0057] In some embodiments, a feeding point 5 is provided at the end of the feeding metal sheet 3 . The feeding point 5 is located at the end of the feeding metal sheet 3 away from the top radiator 1 and is connected to an external signal source through probe feeding or microstrip feeding.

[0058] Specifically, the feed metal plate 3 connects the antenna to an external signal source and transmits power to the top radiator 1. This design helps optimize the antenna's impedance matching and improve transmission efficiency. The feed point 5 serves as the interface between the antenna and the external signal source, enabling power transmission via probe or microstrip feeding.

[0059] When an external signal source transmits electrical energy to the feed metal plate 3 through the feed point 5, the energy is then transferred along the feed metal plate 3 to the top radiator 1. The design of the feed metal plate 3 helps optimize the energy transmission path and reduce energy loss. Furthermore, by adjusting the geometry and dimensions of the feed metal plate 3, the antenna's impedance matching performance can be optimized, improving transmission efficiency.

[0060] This embodiment, through the feed metal plate 3 and feed point 5, addresses the low power transmission efficiency and poor impedance matching performance of traditional metal spring antennas. The design of the feed metal plate 3 helps optimize the power transmission path and reduce energy loss. Furthermore, by adjusting the geometry and size of the feed metal plate 3, the antenna's impedance matching performance can be optimized, improving transmission efficiency. The design of the feed point 5 provides a flexible feeding method to meet the needs of different application scenarios.

[0061] In some embodiments of the present application, a plastic bracket 2 is further included. The plastic bracket 2 is located above the grounded metal sheet 8, and the bottom of the plastic bracket 2 is fixedly connected to the top surface of the grounded metal sheet 8. The top radiator 1 is fixed to the top of the plastic bracket 2, and the top radiator 1 is isolated from the grounded metal sheet 8 by the plastic bracket 2.

[0062] In this embodiment, the plastic bracket 2 provides solid physical support for the top radiator 1, allowing it to be stably suspended in the air. This design prevents the top radiator 1 from directly transmitting RF energy through the dielectric medium, significantly reducing dielectric loss and improving the antenna's radiation efficiency. The plastic bracket 2 helps maintain the overall stability of the antenna unit structure. During operation, regardless of external factors such as mechanical vibration and temperature fluctuations, the plastic bracket 2 ensures that the antenna maintains its original shape and performance, thus ensuring stable operation.

[0063] In some embodiments of the present application, the plastic bracket 2 is made of insulating material; the top surface of the plastic bracket 2 is completely in contact with the bottom surface of the top radiator 1, and the bottom surface of the plastic bracket 2 is spaced apart from the upper surface of the grounding metal sheet 8.

[0064] Maintaining a certain distance between the plastic bracket 2 and other components, such as the top radiator 1 and the grounding metal plate 8, effectively prevents electromagnetic interference and mechanical wear caused by direct contact between components. This spacing ensures electromagnetic compatibility and mechanical stability between the antenna components. Proper spacing can optimize the antenna's electromagnetic performance. For example, adjusting the distance between the plastic bracket 2 and the top radiator 1 can influence key parameters such as the antenna's resonant frequency, bandwidth, and radiation pattern.

[0065] In this embodiment, since the plastic bracket 2 does not carry radio frequency energy, dielectric loss is reduced, helping to improve the antenna's radiation efficiency. This makes the antenna more efficient when transmitting and receiving electromagnetic waves. When antenna gain needs to be controlled, low-gain characteristics can be achieved by adjusting the spacing between the plastic bracket 2 and the top radiator 1, combined with the design of the hole structure 4 on the top radiator 1. This helps meet radiation safety standards and avoid electromagnetic interference issues. Furthermore, the spacing of the plastic bracket 2, combined with the hole structure 4 on the top radiator 1, can meet the miniaturization requirements of micro base station antennas.

[0066] In practical applications, in addition to plastics, other non-metallic materials, such as ceramics and fiberglass, can also be considered for the bracket. These materials may have better mechanical or electromagnetic properties, meeting the requirements of specific applications. For example, ceramics have excellent high-temperature resistance and chemical stability, making them suitable for high-temperature or corrosive environments. Furthermore, in certain extreme miniaturization or specialized applications, it is possible to completely eliminate the bracket structure and secure the top radiator 1 in the desired position using other means, such as adhesives or suspension devices.

[0067] In some embodiments of the present application, the top radiator 1 has a hole structure 4 and a strip metal structure 9 is formed at the edge away from the ground metal sheet 8. The metal strip structure 9 can further optimize the antenna matching performance.

[0068] In combination with the above embodiments, this application provides a specific metal spring antenna design case, which is applied to micro base stations. Figure 1-Figure 4 shown.

[0069] The antenna consists of a top radiator 1, a plastic bracket 2, a ground metal sheet 8, and a feed metal sheet 3. The top radiator includes two hole structures 4. The number of hole structures 4 can be one, two, or more; Figure 5 As shown, the hole structure 4 includes, but is not limited to, rectangular, square, circular, or any polygonal shape. The grounding metal sheet 8 includes a first grounding point 6 and a second grounding point 7. It should be noted that the number of grounding points includes, but is not limited to, two, and may be one or more. The feed metal sheet 3 includes a feed point 5, and the feed method can be probe feed or microstrip feed.

[0070] Energy enters through feed point 5. At this point, the top radiator 1 acts as an inductor L, which forms a capacitor C with the bottom ground plane, forming an equivalent LC resonant circuit. The ground point stabilizes the current flow on the antenna radiator's surface, while the metal strip structure 9 optimizes antenna matching performance. The presence of two hole-like structures 4 on the top radiator 1 partially cancels out the current flowing on its surface, reducing the total electric field in the far field and ultimately lowering antenna gain.

[0071] The simulated reflection coefficient of the metal shrapnel antenna provided in this case Figure 6 As shown, its -15dB matching bandwidth can cover 3.5GHz-4GHz. Figure 7 This is the gain simulation result of the metal shrapnel antenna. The gain is less than 5dBi within the working bandwidth. Figure 8 This is the efficiency simulation result of the metal shrapnel antenna. The efficiency is greater than 90% within the working bandwidth.

[0072] In summary, the present application provides a metal shrapnel antenna, which reconstructs the current path on the surface of the top radiator by loading a hole structure on the top radiator, realizes partial current cancellation at the tail end of the top radiator, reduces the synthetic intensity of the far-field electric field, and thus accurately controls the gain without affecting the radiation efficiency. The hole structure reduces the metal projection area between the top radiator and the grounded metal sheet, reduces the equivalent value of the parasitic capacitance, thereby meeting the conditions for reducing the antenna profile height and realizing a low-profile design. The feed metal sheet is a metal strip structure, which serves as a tuning unit, optimizing the current distribution on the surface of the antenna radiator while optimizing the antenna impedance matching. The grounding point design ensures uniform current distribution on the surface of the top radiator and suppresses edge scattering; combined with the hole structure, it further stabilizes the current and reduces the distortion of the pattern.

[0073] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

Claims

1. A metal shrapnel antenna, characterized in that: include: A top radiator (1) and a ground metal sheet (8); The top radiator (1) is arranged above the grounding metal sheet (8), a distance is provided between the top radiator (1) and the grounding metal sheet (8), and an equivalent LC resonant circuit is formed between the top radiator (1) and the grounding metal sheet (8); Wherein, the top radiator (1) is equivalent to an inductor; The distance between the top radiator (1) and the grounding metal sheet (8) is equivalent to a capacitor; At least one hole-shaped structure (4) is provided on the top radiator (1), and the hole-shaped structure (4) is configured to reconstruct the surface current path of the top radiator (1) to offset part of the radiation current.

2. The metal shrapnel antenna according to claim 1, wherein: The top radiator (1) has a projected area on the surface of the grounding metal sheet (8); The hole-shaped structure (4) penetrates the upper and lower surfaces of the top radiator (1) to reduce the projection area of ​​the top radiator (1) on the grounding metal sheet (8).

3. The metal shrapnel antenna according to claim 1 or 2, characterized in that: The number of the porous structures (4) is multiple, and the shapes of the multiple porous structures (4) are any one of rectangular, square, circular or polygonal.

4. The metal shrapnel antenna according to claim 1 or 2, characterized in that: The grounding metal sheet (8) includes at least one grounding point, and the grounding point is located in an edge area of ​​the grounding metal sheet (8).

5. The metal shrapnel antenna according to claim 1 or 2, characterized in that: The grounding points include a first grounding point (6) and a second grounding point (7); The first grounding point (6) and the second grounding point (7) are respectively located at two opposite edges of the grounding metal sheet (8).

6. The metal shrapnel antenna according to claim 1 or 2, characterized in that: Also includes a feed metal sheet (3); The feed metal sheet (3) is arranged between the top radiator (1) and the ground metal sheet (8), one end of the feed metal sheet (3) extends to the bottom of the top radiator (1), and the side wall of the feed metal sheet (3) maintains a distance from the side wall of the ground metal sheet (8).

7. The metal shrapnel antenna according to claim 6, wherein: A feeding point (5) is provided at the end of the feeding metal sheet (3); The feeding point (5) is located at one end of the feeding metal sheet (3) away from the top radiator (1), and the feeding point (5) is connected to an external signal source through a probe feeding or a microstrip feeding method.

8. The metal shrapnel antenna according to claim 1 or 2, characterized in that: Also included is a plastic bracket (2); The plastic bracket (2) is located above the grounding metal sheet (8), and the bottom of the plastic bracket (2) is fixedly connected to the top surface of the grounding metal sheet (8); The top radiator (1) is fixed to the top of the plastic bracket (2), and the top radiator (1) and the grounding metal sheet (8) are isolated by the plastic bracket (2).

9. The metal shrapnel antenna according to claim 8, characterized in that: The plastic bracket (2) is made of insulating material; The top surface of the plastic bracket (2) is completely in contact with the bottom surface of the top radiator (1), and the bottom surface of the plastic bracket (2) is spaced apart from the upper surface of the grounding metal sheet (8).

10. The metal shrapnel antenna according to claim 6, wherein: The top radiator (1) has the hole-shaped structure (4) and forms a strip-shaped metal structure (9) at an edge away from the grounding metal sheet (8).

Images