Electronic device based on flexible antenna

Abstract

The utility model relates to an electronic device based on a flexible antenna. The electronic device comprises the flexible antenna (1) and a mainboard (2), wherein the flexible antenna (1) comprises a covering film (11) and a copper-clad layer (12), the copper-clad layer (12) is laid on the covering film (11), the covering film (11) is provided with a positioning hole (13), the copper-clad layer (12) comprises a copper wire which is bent and extends, and at least one bent part surrounds the positioning hole (13); the flexible antenna (1) is electrically connected with the mainboard (2), and the flexible antenna (1) can be bent and turned over to the mainboard (2). The electronic device solves the problem that the antenna performance is limited by the space size of the electronic mainboard, and improves the overall performance of the antenna.

Description

Technical Field

[0001] The present application relates to the field of flexible antennas, and in particular to an electronic device based on a flexible antenna. Background Art

[0002] 2.45GHz Bluetooth antennas are important RF connection components in consumer electronic products. If the traditional monopole antenna is directly integrated with the rigid PCB, it will greatly challenge the use area of ​​the PCB. If a separate antenna design is used, the antenna needs to be connected to the motherboard. Whether it is an integrated or separate connection solution, it will have a certain impact on the performance of the antenna to varying degrees.

[0003] As consumer electronics products develop towards miniaturization and lightness, the demand for miniaturization and lightness of 2.45GHz Bluetooth antennas is becoming increasingly prominent. The design length of the microstrip monopole antenna on the PCB is usually 1 / 4 wavelength. Considering the electromagnetic wave propagation in the PCB dielectric material and free space in actual applications, the length of the microstrip monopole antenna should be 16.6-30.5mm, which makes it difficult to achieve good antenna performance on a PCB with limited area.

[0004] Currently, no effective solution has been proposed for the problem in related technologies that antenna performance is restricted by the size of the electronic motherboard space. Utility Model Content

[0005] The embodiment of the present application provides an electronic device based on a flexible antenna, so as to at least solve the problem in the related art that the antenna performance is restricted by the size of the electronic motherboard space. In this embodiment, the electronic device includes: a flexible antenna and a motherboard; wherein:

[0006] The flexible antenna at least comprises a covering film and a copper-clad layer, wherein the copper-clad layer is laid on the covering film, the covering film is provided with a positioning hole, and the copper-clad layer comprises a copper wire extending in a curved manner, and at least one curved portion surrounds the positioning hole;

[0007] The flexible antenna is electrically connected to the main board, and the flexible antenna can be bent and flipped onto the main board.

[0008] In some of the embodiments, some segments of the copper wire are routed along the edge of the cover film.

[0009] In some embodiments, the copper wire starts from a preset starting point on the covering film and extends along the edge of the covering film. When the positioning hole appears near the extended position, the copper wire bypasses the positioning hole and then returns to the edge of the covering film to continue extending until it reaches a preset end point on the covering film.

[0010] In some embodiments, the area of ​​the copper cladding layer does not exceed 50% of the surface area of ​​the covering film.

[0011] In some embodiments, the line width of the copper wire is not less than 0.1 mm; or, the thickness of the copper wire is not less than 50 um; or, the total thickness of the flexible antenna is not less than 167 um.

[0012] In some embodiments, the portion of the covering film where the copper cladding layer is not laid is hollow.

[0013] In some embodiments, the projection area of ​​the hollow portion of the covering film on the mainboard at least partially covers the electronic component distribution area on the mainboard.

[0014] In some embodiments, the material of the covering film includes polyimide or polyester film.

[0015] In some embodiments, the mainboard includes a ground terminal, and the copper clad layer is connected to the ground terminal.

[0016] In some of the embodiments, the invention further comprises: a shell, wherein the covering film and the main board are installed in the shell, and the shell is provided with a mounting structure, and the mounting structure is matched and connected with the positioning hole.

[0017] Compared with the related art, the electronic device based on the flexible antenna provided by the embodiment of the present application increases the length of the copper wire by bending it without increasing the area of ​​the cover film, and extending the length of the antenna can improve the return loss and gain. Moreover, the copper wire is routed around the positioning hole, and the antenna can be extended as much as possible without filling the positioning hole, thereby improving the overall performance of the antenna and solving the problem that the antenna performance is restricted by the size of the electronic motherboard space.

[0018] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0020] Figure 1 is a schematic structural diagram of an electronic device in one embodiment;

[0021] Figure 2 is a schematic diagram of flipping of a flexible antenna in one embodiment;

[0022] Figure 3is a schematic structural diagram of an electronic device in another embodiment;

[0023] Figure 4 is a schematic structural diagram of an electronic device in another embodiment;

[0024] Figure 5 is a schematic diagram of simulation settings for a flexible antenna in another embodiment;

[0025] Figure 6 It is a schematic diagram of the three-dimensional gain direction of the flexible antenna in one embodiment;

[0026] Figure 7 FIG. 4 is a schematic diagram of antenna return loss for a flexible antenna in an embodiment.

[0027] Figure numerals: 1, flexible antenna; 2, main board; 11, covering film; 12, copper cladding layer; 13, positioning hole; 14, hollow part; 21, grounding terminal; 22, wire. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0029] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0030] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0031] This embodiment provides an electronic device (hereinafter referred to as electronic device) based on a flexible antenna 1 . Figure 1 is a schematic diagram of the structure of the electronic device of this embodiment, such as Figure 1 As shown, the electronic device includes: a flexible antenna 1 and a main board 2; wherein the flexible antenna 1 at least includes a covering film 11 and a copper clad layer 12, the copper clad layer 12 is laid on the covering film 11, the covering film 11 is provided with a positioning hole 13, the copper clad layer 12 includes a bent and extended copper wire, and at least one bent portion surrounds the positioning hole 13; the flexible antenna 1 is electrically connected to the main board 2, and the flexible antenna 1 can be bent and flipped onto the main board 2.

[0032] Among them, the positioning hole 13 is used to match and connect with the columnar structure of the external shell to fix the flexible antenna 1, and the positioning hole 13 can be a geometric shape such as a circle, an ellipse, a polygon, etc. The material used by the covering film 11 can include polyimide or polyester film, as a flexible substrate, which can protect the copper clad layer 12. The mainboard 2 may include a grounding terminal 21, and the copper clad layer 12 is connected to the grounding terminal 21 through a wire 22. Optionally, the electronic device also includes a shell, the covering film 11 and the mainboard 2 are installed in the shell, and the shell is provided with a mounting structure, which is matched and connected with the positioning hole 13 for fixing the flexible antenna 1. Among them, the mounting structure can be a columnar or other structure. The flexible antenna 1 can set the frequency according to the communication method adopted by the electronic device. For example, when Bluetooth communication is adopted, the frequency of the flexible antenna 1 can be 2.4GHz; when ZigBee communication is adopted, the frequency of the flexible antenna 1 can be 2.4G Hz or 900MHz; when 4G network communication is adopted, the frequency of the flexible antenna 1 can be set according to the frequency band divided by each communication operator.

[0033] In this embodiment, the flexible antenna 1 and the mainboard 2 are integrally formed, which reduces the cost of separately manufacturing a detachable antenna and reduces the impact of different connection methods on the antenna performance.

[0034] like Figure 2 As shown, the connection between the flexible antenna 1 and the main board 2 can be bent 180 degrees up and down. This large bending angle allows the flexible antenna 1 to be used in limited spaces, especially in wearable devices, such as smart wearable watches, dynamic blood glucose monitoring systems, etc.

[0035] The flexible antenna 1 is composed of only a covering film 11 and a copper cladding layer 12, and the substrate and solder resist layer of the conventional microstrip monopole antenna are removed, thereby reducing the overall thickness and mass of the antenna.

[0036] The copper clad layer 12 is composed of a section of copper wire. Without increasing the area of ​​the covering film 11, the copper wire is bent to increase its length, and extending the length of the antenna can improve the return loss and gain. In addition, the copper wire is routed around the positioning hole 13, and the antenna can be extended as much as possible without filling the positioning hole 13. Therefore, the bandwidth of the antenna at -10dB is widened, the antenna gain is improved, the anti-interference ability is enhanced, the return loss S11 value at the center frequency is reduced, and the overall performance of the antenna is improved.

[0037] In one embodiment, Figure 3 A structural schematic diagram of an electronic device is provided, such as Figure 3As shown, the electronic device includes: a flexible antenna 1 and a mainboard 2; wherein the flexible antenna 1 includes a covering film 11 and a copper clad layer 12, the copper clad layer 12 is laid on the covering film 11, the covering film 11 is provided with a positioning hole 13, the copper clad layer 12 includes a bent and extended copper wire, part of the copper wire is wired along the edge of the covering film 11, and at least one bent portion surrounds the positioning hole 13; the flexible antenna 1 is electrically connected to the mainboard 2, and the flexible antenna 1 can be bent and flipped onto the mainboard 2. With such a configuration, the area of ​​the covering film 11 can be fully utilized and the antenna length can be extended as much as possible.

[0038] Further, the copper wire starts from a preset starting point on the cover film 11 and extends along the edge of the cover film 11. When a positioning hole 13 appears near the extended position, the copper wire bypasses the positioning hole 13 and then returns to the edge of the cover film 11 to continue extending until it reaches the preset end point on the cover film 11. In this way, the cover film 11 can form as many bends as possible, and the bends are wired around the positioning holes 13 without blocking the positioning holes 13. Preferably, the cover film 11 is provided with a plurality of positioning holes 13. Further, a copper wire is surrounded by each positioning hole 13.

[0039] In one embodiment, the area of ​​the copper clad layer 12 does not exceed 50% of the surface area of ​​the cover film 11. Optionally, the diameter of the flexible antenna 1 can be 18 mm, wherein the copper clad layer 12 occupies no more than 12 mm of the area of ​​the cover film 11. The line width of the copper wire is not less than 0.1 mm, the thickness of the copper wire is not less than 50 um, and the total thickness of the flexible antenna 1 is not less than 167 um.

[0040] In one embodiment, Figure 4 A structural schematic diagram of an electronic device is provided, such as Figure 4 As shown, the electronic device includes: a flexible antenna 1 and a mainboard 2; wherein the flexible antenna 1 includes a covering film 11 and a copper clad layer 12, the copper clad layer 12 is laid on the covering film 11, the covering film 11 is provided with a positioning hole 13, the copper clad layer 12 includes a bent and extended copper wire, some segments of the copper wire are wired along the edge of the covering film 11, the copper wire starts from a preset starting point on the covering film 11, extends along the edge of the covering film 11, and when a positioning hole 13 appears near the extended position, the copper wire bypasses the positioning hole 13 and then returns to the edge of the covering film 11 to continue extending until it reaches a preset end point on the covering film 11; the flexible antenna 1 is electrically connected to the mainboard 2, and the flexible antenna 1 can be bent and flipped onto the mainboard 2.

[0041] Furthermore, the preset starting point and the preset end point on the cover film 11 may be set at the edge of the cover film 11 , so as to fully utilize the area of ​​the cover film 11 to layout the flexible antenna 1 .

[0042] In actual applications, when the flexible antenna 1 covers the surface of the mainboard 2, the flexible antenna 1 will touch the electronic components on the mainboard 2. In order to solve this problem, the portion of the covering film 11 where the copper cladding layer 12 is not laid is hollowed out, and the hollowed-out portion of the covering film 11 is temporarily defined as a hollow portion 14. The projection area of ​​the hollow portion 14 on the mainboard 2 at least partially covers the distribution area of ​​the electronic components on the mainboard 2, so that the flexible antenna 1 does not affect at least part of the electronic components on the mainboard 2, and at the same time makes the flexible antenna 1 and the mainboard 2 fit more closely. Optionally, the projection area of ​​the hollow portion 14 on the mainboard 2 completely covers the distribution area of ​​the electronic components on the mainboard 2, or the projection area of ​​the hollow portion 14 on the mainboard 2 is larger than the distribution area of ​​the electronic components on the mainboard 2.

[0043] In one embodiment, for Figure 4 The electronic device shown is simulated to obtain the return loss and three-dimensional gain direction of the flexible antenna 1. Figure 5 A schematic diagram of the simulation setup is given. Figure 6 A schematic diagram of the antenna's three-dimensional gain direction is given. Figure 7 A schematic diagram of antenna return loss is given.

[0044] like Figure 5 and Figure 6 As shown, this embodiment uses HFSS simulation software, and its post-processing part can draw a three-dimensional directional diagram. Figure 5 First, define the radiation surface based on the spherical coordinate system, where the xz plane is the plane with φ=0° in the spherical coordinate system; the xy plane is the plane with θ=90° in the spherical coordinate system, and the three-dimensional spherical surface is represented by 0≤θ≤180°, 0≤φ≤360° in the spherical coordinate system, and the step size is set to 1°. Figure 6 , using color warmth to represent the gain size. The warmer the color, the greater the gain, and the colder the color, the smaller the gain. Max represents the maximum gain, and Min represents the minimum gain. Among them, dB (Gain Total) represents the total gain, and Phi (deg) represents Figure 5 Theta(deg) represents the size of φ in the spherical coordinate system defined in Figure 5 The size of θ in the spherical coordinate system defined in .

[0045] Then, interpolating is used to calculate the S parameters and field solutions in the entire frequency band. The maximum number of interpolation points (Max solutions) is set to 250, and the minimum interpolation error convergence standard (Error Tolerance) is 0.5%. These two are the stopping criteria for judging the interpolation sweep. If any of them is reached, the interpolation will stop. Figure 7The return loss result obtained by simulating the flexible antenna 1 is shown in Figure 1. The horizontal axis represents the frequency and the vertical axis represents the return loss. Among them, M1 represents the center frequency, and its S11 (return loss) reaches -38.51dB. The return losses of M2 and M3 both reach -10dB. It can be found that the bandwidth at -10dB can basically reach 130MHz.

[0046] Those skilled in the art should understand that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An electronic device based on a flexible antenna, characterized in that: include: A flexible antenna (1) and a main board (2); wherein: The flexible antenna (1) comprises at least a covering film (11) and a copper-clad layer (12), wherein the copper-clad layer (12) is laid on the covering film (11), the covering film (11) is provided with a positioning hole (13), and the copper-clad layer (12) comprises a bent and extended copper wire, and at least one bent portion surrounds the positioning hole (13); The flexible antenna (1) is electrically connected to the main board (2), and the flexible antenna (1) can be bent and flipped onto the main board (2).

2. The electronic device based on the flexible antenna according to claim 1, characterized in that: Part of the copper wire is routed along the edge of the cover film (11).

3. The electronic device based on the flexible antenna according to claim 2, characterized in that: The copper wire starts from a preset starting point on the covering film (11) and extends along the edge of the covering film (11); when the positioning hole (13) appears near the extended position, the copper wire bypasses the positioning hole (13) and then returns to the edge of the covering film (11) to continue extending until it reaches a preset end point on the covering film (11).

4. The electronic device based on the flexible antenna according to claim 1, characterized in that: The area of ​​the copper cladding layer (12) does not exceed 50% of the surface area of ​​the covering film (11).

5. The electronic device based on the flexible antenna according to claim 1, characterized in that: The line width of the copper wire is not less than 0.1 mm; or, the thickness of the copper wire is not less than 50 um; or, the total thickness of the flexible antenna (1) is not less than 167 um.

6. The electronic device based on the flexible antenna according to claim 1, characterized in that: The portion of the covering film (11) where the copper cladding layer (12) is not laid is in a hollow shape.

7. The electronic device based on the flexible antenna according to claim 6, characterized in that: The projection area of ​​the hollow portion (14) of the covering film (11) on the main board (2) at least partially covers the electronic component distribution area on the main board (2).

8. The electronic device based on the flexible antenna according to claim 1, characterized in that: The material used for the covering film (11) includes polyimide or polyester film.

9. The electronic device based on the flexible antenna according to claim 1, characterized in that: The mainboard (2) comprises a grounding terminal (21), and the copper cladding layer (12) is connected to the grounding terminal (21).

10. The electronic device based on the flexible antenna according to claim 1, characterized in that: Also includes: A shell, the covering film (11) and the main board (2) are installed in the shell, the shell is provided with a mounting structure, and the mounting structure is matched and connected with the positioning hole (13).

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