Antenna assembly and mobile terminal

Abstract

The utility model discloses an antenna assembly and a mobile terminal.The antenna assembly comprises a flexible circuit board, a near field communication chip, a matching circuit, an antenna coil and a connector, the flexible circuit board comprises a first surface and a second surface which are opposite, and the near field communication chip is located on the second surface of the flexible circuit board; the matching circuit is arranged on the second surface of the flexible circuit board and is electrically connected with the near field communication chip; the antenna coil is located on the first surface of the flexible circuit board and electrically connected with the matching circuit; the connector is located on the second surface of the flexible circuit board and is electrically connected with the near field communication chip; the connector is used for being connected with a mainboard in the mobile terminal; wherein the flexible circuit board and the main board are mutually independent; the problem of high cost caused by large occupied space of the mainboard in the mobile terminal can be effectively relieved.

Description

Technical Field

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

[0002] The NFC (Near Field Communication) function is not standard in a mobile phone product, but is only supported in certain versions. However, conventional designs require the NFC chip and NFC matching circuit to be designed on the same mainboard PCB. Even if this version does not require NFC function, because multiple versions share the PCB, this results in wasted mainboard PCB area, increasing the space occupied by the mainboard PCB in the product, making the product cost high. Utility Model Content

[0003] The present application provides an antenna assembly and a mobile terminal, which can effectively alleviate the problem of high cost caused by the large space occupied by the mainboard in the mobile terminal.

[0004] The present application provides an antenna assembly, which is applied to a mobile terminal. The antenna assembly includes: a flexible circuit board, which includes a first surface and a second surface relative to each other; a near-field communication chip, which is located on the second surface of the flexible circuit board; a matching circuit, which is arranged on the second surface of the flexible circuit board and is electrically connected to the near-field communication chip; an antenna coil, which is located on the first surface of the flexible circuit board and is electrically connected to the matching circuit; a connector, which is located on the second surface of the flexible circuit board and is electrically connected to the near-field communication chip; the connector is used to connect to a mainboard in the mobile terminal; wherein the flexible circuit board and the mainboard are independent of each other.

[0005] In some embodiments of the antenna assembly, one side of the flexible circuit board has a protrusion, and the connector is close to the protrusion.

[0006] In some embodiments of the antenna assembly, the near-field communication chip and the matching circuit are located side by side in the middle portion of the flexible circuit board, and the direction in which the near-field communication chip and the matching circuit are located is the length direction of the flexible circuit board.

[0007] In some embodiments, the antenna assembly further includes a peripheral circuit, which is located on the second surface of the flexible circuit board and is located on opposite sides of the near-field communication chip with the matching circuit; the peripheral circuit is electrically connected to the near-field communication chip.

[0008] In some embodiments of the antenna assembly, the peripheral circuit and the connector are arranged side by side, and the direction in which the peripheral circuit and the connector are located is the width direction of the flexible circuit board.

[0009] In some embodiments of the antenna assembly, the matching circuit includes at least two matching devices, the antenna coil includes a main coil and a connecting coil, one end of the connecting coil is connected to one of the matching devices, one end of the main coil is connected to the other matching device, and the other end of the connecting coil is connected to the other end of the main coil; the main coil forms a surrounding trace along the edge of the flexible circuit board to surround the connector, near-field communication chip, matching circuit and peripheral circuit.

[0010] In some embodiments of the antenna assembly, the other end of the connecting coil extends to the edge of the flexible circuit board and is electrically connected to the other end of the main body coil, and the other end of the connecting coil and the other end of the main body coil are aligned along the width direction of the flexible circuit board.

[0011] In some embodiments of the antenna assembly, a first via is provided on the flexible circuit board at the other end of the connection coil, and a second via is provided on the flexible circuit board at the other end of the main coil; the first via and the second via are connected by a metal copper strip, and the metal copper strip is located on the second surface of the flexible circuit board.

[0012] In some embodiments of the antenna assembly, a copper layer is provided in the projection area of ​​the antenna coil on the second surface.

[0013] An embodiment of the present application further provides a mobile terminal, which includes a mainboard, a battery, and an antenna assembly located between the mainboard and the battery.

[0014] The antenna assembly and mobile terminal provided in this application include a near-field communication chip, matching circuit, and antenna coil separately disposed on a flexible circuit board, rather than being integrated onto the mainboard of the mobile terminal. When the mobile terminal requires near-field communication functionality, the antenna assembly can be directly connected to the mainboard via a connector during assembly. When the mobile terminal does not require near-field communication functionality, the antenna assembly is not assembled, thereby preventing the near-field communication chip, matching circuit, and antenna coil from occupying space on the mainboard, thereby reducing the mainboard area and, in turn, lowering costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0016] Figure 1 A schematic diagram of the structure between the mainboard, battery and antenna assembly in the mobile terminal provided in an embodiment of the present application.

[0017] Figure 2 This is a diagram of the overall structure of the antenna assembly provided in an embodiment of the present application.

[0018] Figure 3This is a schematic diagram of the second surface structure of the flexible circuit board in the antenna assembly provided in an embodiment of the present application.

[0019] Figure 4 A schematic structural diagram of the raised portion in the antenna assembly provided in an embodiment of the present application.

[0020] Figure 5 This is a schematic diagram of the first surface structure of the flexible circuit board in the antenna assembly provided in an embodiment of the present application.

[0021] Figure 6 A schematic diagram of the electrical connections between the matching circuit, connector, near-field communication chip, and antenna coil in the antenna assembly provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features indicated. The features specified as "first" and "second" may explicitly or implicitly include one or more features. In the description of this utility model, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0024] See also Figure 1 、 Figure 2 、 Figure 3 and Figure 4 This embodiment provides a mobile terminal, which includes a mainboard 10, a battery 20 and an antenna assembly 30. It is usually designed that there is a certain gap between the mainboard 10 and the battery 20, and the antenna assembly 30 is arranged in the gap between the battery 20 and the mainboard 10.

[0025] Specifically, the antenna assembly 30 includes a flexible circuit board 31, a near-field communication chip 32, a matching circuit 33, an antenna coil 34 and a connector 35. The flexible circuit board 31 includes a first surface and a second surface relative to each other. The near-field communication chip 32 is located on the second surface of the flexible circuit board 31. The matching circuit 33 is arranged on the second surface of the flexible circuit board 31 and is electrically connected to the near-field communication chip 32; the antenna coil 34 is located on the first surface of the flexible circuit board 31 and is electrically connected to the matching circuit 33; the connector 35 is located on the second surface of the flexible circuit board 31 and is electrically connected to the near-field communication chip 32; the connector 35 is used to connect to the mainboard 10 in the mobile terminal; wherein, the flexible circuit board 31 and the mainboard 10 are independent of each other.

[0026] In this embodiment, the NFC chip 32, matching circuit 33, and antenna coil 34 are separately mounted on the flexible printed circuit board 31, rather than being integrated onto the mainboard 10. When the mobile terminal requires NFC functionality, the antenna assembly 30 can be directly connected to the mainboard 10 via connector 35 during assembly. When the mobile terminal does not require NFC functionality, the antenna assembly 30 is omitted. This prevents the NFC chip 32, matching circuit 33, and antenna coil 34 from occupying space on the mainboard 10, thereby reducing the mainboard 10's footprint and ultimately lowering costs.

[0027] In some embodiments, one side of the flexible circuit board 31 has a raised portion 311, and the connector 35 is located near the raised portion 311. In this embodiment, the raised portion 311 is provided on the flexible circuit board 31, so that the entire flexible circuit board 31 forms a structure similar to a raised U-shaped structure. In this embodiment, the connector 35 is located near the raised portion 311 to facilitate connection with the mainboard 10.

[0028] Among them, the main body part of the flexible circuit board 31 connected to the protrusion 311 is narrow and long. In this embodiment, the main body part is set to be narrow and long to adapt to the gap between the battery 20 and the main board 10, as well as the recessed area of ​​the front protection plate of the battery 20.

[0029] Specifically, as an embodiment, the width of the main body of the flexible circuit board 31 is 10 mm-11 mm, and the length of the main body of the flexible circuit board 31 is 50 mm.

[0030] As an embodiment, the connector 35 in this embodiment is a BTB connector 35 (board-to-board connector 35), which has multiple pins and can be snapped together with another connector 35. The other connector 35 is soldered to the mainboard 10PCB of the mobile terminal. When the mobile terminal requires the antenna assembly 30, the antenna assembly 30 is assembled inside the mobile terminal. The two BTB connectors 35 are snapped together to connect the circuit on the mainboard 10PCB of the mobile terminal to the near-field communication chip 32 in the antenna assembly 30, thereby enabling the near-field communication chip 32 of the antenna assembly 30 to operate.

[0031] In some embodiments, the NFC chip 32 and matching circuit 33 are positioned side by side in the middle of the flexible circuit board 31, with the NFC chip 32 and matching circuit 33 aligned along the length of the flexible circuit board 31. The NFC chip 32 can be sized at 2.3 mm by 4 mm and positioned horizontally on the flexible circuit board 31, meaning the length of the NFC chip 32 is aligned with the length of the flexible circuit board 31. In this embodiment, the centers of the NFC chip 32 and matching circuit 33 are roughly aligned, and this line aligns with the length of the flexible circuit board 31, facilitating the narrow and long design of the main body of the flexible circuit board 31.

[0032] In some embodiments, the antenna assembly 30 further includes a peripheral circuit 36. The peripheral circuit 36 ​​is located on the second surface of the flexible printed circuit board 31 and is located on opposite sides of the near-field communication chip 32 along with the matching circuit 33. The peripheral circuit 36 ​​is electrically connected to the near-field communication chip 32. In this embodiment, the centers of the peripheral circuit 36, the near-field communication chip 32, and the matching circuit 33 are approximately aligned on the same straight line, that is, arranged side by side along the length of the flexible printed circuit board 31, thereby facilitating the narrow and long design of the flexible printed circuit board 31. The peripheral circuit 36 ​​comprises components such as capacitors and resistors between the near-field communication chip 32 and the connector 35. The components containing these capacitors and resistors do not exceed the width of the near-field communication chip 32. This maintains the width of the entire antenna assembly 30. Furthermore, because this area is located between the connector 35 and the near-field communication chip 32, wiring is facilitated.

[0033] In some embodiments, the peripheral circuit 36 ​​and connector 35 are arranged side by side, and the direction of the peripheral circuit 36 ​​and connector 35 is the width direction of the flexible circuit board 31. The centers of the near-field communication chip 32 and the matching circuit 33 are generally aligned, while the connector 35 and the antenna coil 34 are aligned, with the connector 35 close to the near-field communication chip 32. This layout minimizes the area of ​​the flexible circuit board 31, and the entire antenna assembly 30 occupies a smaller space, making it more suitable for mobile terminals.

[0034] See also Figure 5 In some embodiments, the matching circuit 33 includes at least two matching components. The antenna coil 34 includes a main coil 341 and a connecting coil 342. One end C of the connecting coil 342 is connected to one of the matching components, one end A of the main coil 341 is connected to the other matching component, and the other end D of the connecting coil 342 is connected to the other end B of the main coil 341. The main coil 341 forms a loop along the edge of the flexible printed circuit board 31 to surround the connector 35, the near-field communication chip 32, the matching circuit 33, and the peripheral circuit 36. In this embodiment, the main coil 341 is positioned close to the edge of the near-field communication chip 32, and the width of the loop on one side is approximately 3.5 mm.

[0035] In this embodiment, the near-field communication chip 32, matching circuit 33, and peripheral circuit 36 ​​in the antenna assembly 30 occupy a relatively small area but are relatively thick. The antenna coil 34, on the other hand, occupies a larger area but is thinner. Therefore, in this embodiment, the matching circuit 33, near-field communication chip 32, and peripheral circuit 36 ​​are all located in the center of the flexible circuit board 31, while the antenna coil 34 is located on the periphery. The entire antenna assembly 30 is implemented using the flexible circuit board 31, which helps reduce the overall thickness of the antenna assembly 30. The antenna coil 34 is narrow and long, and the routing around the near-field communication chip 32 closely aligns with the chip 32, helping to minimize the size of the antenna assembly 30, allowing it to fit into the gap between the battery 20 and the motherboard 10.

[0036] As an example, the other end D of the connecting coil 342 extends to the edge of the flexible printed circuit board 31 and is electrically connected to the other end B of the main coil 341. The other end D of the connecting coil 342 and the other end B of the main coil 341 are aligned along the width of the flexible printed circuit board 31. In this embodiment, the connecting coil 342 of the antenna coil 34 extends from the matching circuit 33 to the edge of the flexible printed circuit board 31 and connects to the main coil 341. This maximizes the overall length of the antenna coil 34, thereby ensuring the number of turns of the antenna coil 34. This avoids the problem of direct connection to the main coil 341 at the location of the matching circuit 33, which would result in a small number of local coil turns and poor antenna radiation performance.

[0037] In some embodiments, a first via is provided on the flexible circuit board 31 at the other end D of the connection coil 342, and a second via is provided on the other end B of the flexible circuit board 31 at the other end of the main coil 341. The first and second vias are connected by a metal copper strip 37, and the metal copper strip 37 is located on the second surface of the flexible circuit board 31. In this embodiment, to prevent the antenna coil 34 from being connected across the same surface of the flexible circuit board 31, the coil 342 and the main coil 341 are connected by providing a via and a metal copper strip 37 in the flexible circuit board 31.

[0038] In some embodiments, a copper layer is provided in the projection area of ​​the antenna coil 34 on the second surface. The copper layer is provided to enhance signal reflection, thereby enhancing antenna performance.

[0039] See also Figure 6 In the antenna assembly 30, the connector 35 is electrically connected to the near-field communication chip 32, and the near-field communication chip 32 is connected to the antenna coil 34 through the matching circuit 33; wherein the near-field communication chip 32 is a chip that processes near-field communication signals and drives the antenna coil 34 to transmit and receive signals; the matching circuit 33 is used to adjust the characteristic parameters of the antenna coil 34 so that the antenna coil 34 can better adapt to the near-field communication chip 32, so that the signal transmission and reception loss of the near-field communication chip 32 is small and the communication capability is strong. In this application, the connector 35, the near-field communication chip 32, the matching circuit 33, the antenna coil 34 and the peripheral circuit 36 ​​are separately arranged on the flexible circuit board 31, and then connected to the mainboard 10 through the connector 35. When the mobile terminal requires the near-field communication function, this antenna assembly 30 is assembled into the mobile terminal. If the antenna assembly 30 does not need to add the near-field communication function, the antenna assembly 30 does not need to be assembled. This is equivalent to reserving only a position on the mainboard 10 for another connector 35 connected to the connector 35 in the antenna assembly 30, and there is no need to set positions for the near-field communication chip 32 and the matching circuit 33, thereby reducing the space occupied by the mainboard 10, thereby reducing the area of ​​the mainboard 10 and reducing costs.

[0040] As an embodiment, the antenna coil 34 in the antenna assembly 30 can also be set separately. The antenna coil 34 can be connected to the flexible circuit board 31 by welding or spring contact. This can further reduce the flexible circuit board 31 on which the near-field communication chip 32 is set, so that the gap between the flexible circuit board 31 and the battery 20 and the main board 10 is more adaptable; at the same time, it can also increase the placement flexibility of the antenna coil 34, and the antenna coil 34 can be placed in a suitable position where there is space inside the mobile terminal, for example, the antenna coil 34 can be set above the battery 20 or above the main board 10, etc.

[0041] An embodiment of the present application also provides an antenna assembly, which includes a flexible circuit board, a near-field communication chip, a matching circuit, an antenna coil and a connector. The flexible circuit board includes a first surface and a second surface relative to each other. The near-field communication chip is located on the second surface of the flexible circuit board. The matching circuit is arranged on the second surface of the flexible circuit board and is electrically connected to the near-field communication chip; the antenna coil is located on the first surface of the flexible circuit board and is electrically connected to the matching circuit; the connector is located on the second surface of the flexible circuit board and is electrically connected to the near-field communication chip; the connector is used to connect to a mainboard in a mobile terminal; wherein the flexible circuit board and the mainboard are independent of each other.

[0042] In this embodiment, the NFC chip, matching circuit, and antenna coil are separately mounted on the flexible printed circuit board, rather than integrated on the mainboard. When NFC functionality is required in the mobile terminal, the antenna assembly can be directly connected to the mainboard via a connector. When NFC functionality is not required, the antenna assembly is not installed. This eliminates the need for the NFC chip, matching circuit, and antenna coil to occupy space on the mainboard, thereby reducing the mainboard footprint and ultimately lowering costs. Since the antenna assembly is described in detail above, it will not be further detailed here.

[0043] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0044] The above is a detailed introduction to the antenna assembly provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An antenna assembly, characterized in that: The antenna assembly is applied to a mobile terminal, and the antenna assembly includes: A flexible circuit board, the flexible circuit board comprising a first surface and a second surface opposite to each other; A near field communication chip, wherein the near field communication chip is located on the second surface of the flexible circuit board; A matching circuit, the matching circuit being disposed on the second surface of the flexible circuit board and electrically connected to the near field communication chip; an antenna coil, the antenna coil being located on the first surface of the flexible circuit board and being electrically connected to the matching circuit; A connector, the connector is located on the second surface of the flexible circuit board and is electrically connected to the near field communication chip; the connector is used to connect to a main board in the mobile terminal; wherein the flexible circuit board and the main board are independent of each other.

2. The antenna assembly according to claim 1, characterized in that: One side of the flexible circuit board has a protrusion, and the connector is close to the protrusion.

3. The antenna assembly according to claim 1, characterized in that: The near field communication chip and the matching circuit are arranged side by side in the middle part of the flexible circuit board, and the direction where the near field communication chip and the matching circuit are located is the length direction of the flexible circuit board.

4. The antenna assembly according to claim 3, characterized in that: The antenna assembly further includes a peripheral circuit, which is located on the second surface of the flexible circuit board and is located on opposite sides of the near field communication chip with the matching circuit; the peripheral circuit is electrically connected to the near field communication chip.

5. The antenna assembly according to claim 4, characterized in that: The peripheral circuit and the connector are arranged side by side, and the direction in which the peripheral circuit and the connector are located is the width direction of the flexible circuit board.

6. The antenna assembly according to claim 4, characterized in that: The matching circuit includes at least two matching devices, the antenna coil includes a main body coil and a connecting coil, one end of the connecting coil is connected to one of the matching devices, one end of the main body coil is connected to the other matching device, and the other end of the connecting coil is connected to the other end of the main body coil; The main body coil forms a surrounding trace along the edge of the flexible circuit board to surround the connector, the near field communication chip, the matching circuit and the peripheral circuit.

7. The antenna assembly according to claim 6, characterized in that: The other end of the connecting coil extends to the edge of the flexible circuit board and is electrically connected to the other end of the main body coil, and the other end of the connecting coil and the other end of the main body coil are aligned along the width direction of the flexible circuit board.

8. The antenna assembly according to claim 6, characterized in that: A first via is provided on the flexible circuit board at the other end of the connecting coil, and a second via is provided on the flexible circuit board at the other end of the main coil; the first via and the second via are connected by a metal copper strip, and the metal copper strip is located on the second surface of the flexible circuit board.

9. The antenna assembly according to claim 6, characterized in that: A copper layer is provided in the projection area of ​​the antenna coil located on the second surface.

10. A mobile terminal, characterized in that: The invention comprises a main board, a battery and an antenna component located between the main board and the battery.

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