A wearable device

Abstract

Embodiments of the present application provide a wearable device for improving the connection stability between the wearable device and a mobile terminal. The wearable device includes a first housing, a second housing, a connecting arm, a first circuit board, a feed source, a peripheral device, and a flexible circuit board. The connecting arm connects the first housing and the second housing, the first circuit board is disposed in the first housing, the feed source is disposed on the first circuit board, the peripheral device is disposed in the second housing, the flexible circuit board is disposed in the connecting arm, and the flexible circuit board is coupled between the peripheral device and the first circuit board. At least part of the flexible circuit board is coupled with the feed source. When a user wears the wearable device, the connecting arm is buckled on the side of the outer edge of the user's ear, and the communication performance of the wearable device can be improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of antennas, and in particular to a wearable device. BACKGROUND

[0002] The wearable device can carry an antenna, and communicate with a mobile terminal through the antenna, so as to perform the functions of playing music and calling in cooperation with the mobile terminal. However, in the working scenario of the communication connection between the wearable device and the mobile terminal, there are many factors that increase the transmission loss of electromagnetic waves, which leads to the decline of the connection stability between the wearable device and the mobile terminal, thereby causing the poor communication performance between the wearable device and the mobile terminal. SUMMARY

[0003] Embodiments of the present application provide a wearable device, which can improve the radiation efficiency of the antenna and the connection stability between the wearable device and the mobile terminal.

[0004] To achieve the above-mentioned purpose, embodiments of the present application adopt the following technical solutions:

[0005] The wearable device provided by embodiments of the present application includes a first housing, a second housing, a connecting arm, a first circuit board, a feed source, a peripheral device, and a flexible circuit board. The connecting arm connects the first housing and the second housing, the first circuit board is arranged in the first housing, the feed source is arranged on the first circuit board, the peripheral device is arranged in the second housing, and the flexible circuit board is arranged in the connecting arm. The flexible circuit board is coupled between the first circuit board and the peripheral device, and the flexible circuit board is at least partially coupled with the feed source.

[0006] The flexible circuit board is coupled between the first circuit board and the peripheral device, and can be used to transmit signals between the first circuit board and the peripheral device. The flexible circuit board is at least partially coupled with the feed source, and at least part of the flexible circuit board can serve as an antenna and be communicatively connected with the mobile terminal. When a user wears the wearable device provided by embodiments of the present application, the second housing is located in the concha cavity of the user, the first housing is located outside the ear of the user and away from one side of the second housing, and the connecting arm is buckled on one side of the outer edge of the ear of the user, extending from the concha cavity to the rear part of the ear. Compared with the first housing or the second housing, the position of the connecting arm is less shielded. The flexible circuit board is arranged in the connecting arm, which is conducive to improving the radiation efficiency of the antenna, thereby improving the connection stability between the wearable device and the mobile terminal and the communication performance between the wearable device and the mobile terminal.

[0007] In some embodiments, the flexible circuit board includes a first metal layer coupled between a first circuit board and a peripheral device, coupled to a feed source, and used to generate a first resonance to cover the operating frequency band of the wearable device. In this case, the first metal layer is coupled to the first circuit board, for example, to a ground plane (second metal layer) on the first circuit board, and can establish a common reference potential with the first circuit board. The first metal layer is coupled to the peripheral device, serving as a ground plane for the peripheral device and providing a reference potential. The coupling of the first metal layer between the first circuit board and the peripheral device, where the electronic components on the first circuit board and the peripheral device have the same reference potential, can make signal transmission more accurate. The coupling of the first metal layer to the feed source and generating the first resonance to cover the operating frequency band of the wearable device allows the first metal layer to function as an antenna. The first metal layer being part of the flexible circuit board, with at least a portion of the flexible circuit board serving as an antenna, provides the same advantages as described above.

[0008] In some embodiments, the flexible circuit board includes a first metal layer and a first metal trace, the first metal layer and the first metal trace having a first spacing, the first metal layer being coupled between a first circuit board and a peripheral device, and the first metal trace being coupled to a feed source. In this case, the first metal trace can be used to receive an excitation signal transmitted by the feed source, the first metal trace can be used to generate radiation, or the first metal trace can be used to couple a signal to the first metal layer through the first spacing; at least one of the first metal layer and the first metal trace can function as an antenna. The beneficial effects of the flexible circuit board at least partially functioning as an antenna, with the first metal layer or the first metal trace being part of the flexible circuit board, are as described above.

[0009] In one possible implementation, the width of the first gap is greater than or equal to 0.2 mm. In this case, the compact design of the wearable device can be maintained while ensuring the spacing between the first metal trace and the first metal layer.

[0010] In one possible implementation, a first metal trace is used to couple a signal to a first metal layer, causing the first metal layer to generate a first resonance, which covers the operating frequency band of the wearable device. In some examples, the width of the first gap includes 0.2mm-0.4mm to ensure the coupling strength between the first metal trace and the first metal layer.

[0011] In one possible implementation, the first metal trace can be used to generate a second resonance, which covers the operating frequency band of the wearable device. In some examples, the width of the first gap is greater than 0.4 mm to reduce interference from the first metal layer to the first metal trace.

[0012] In some embodiments, the connecting arm includes a resilient metal element spaced apart from the flexible circuit board, the resilient metal element serving to form a third resonance. In this case, the resilient metal element allows the connecting arm to maintain a preset shape, thereby allowing the wearable device to be clipped onto the user's ear. In one possible implementation, the third resonance may be generated by coupling a first metal trace. In another possible implementation, the third resonance may be generated by coupling a first metal layer. In some examples, the resonant frequency band of the third resonance at least partially overlaps with the resonant frequency band of the first resonance, thereby achieving a wideband effect. Compared to using multiple first metal traces to achieve multiple resonances, utilizing the existing structure in the wearable device to achieve multiple resonances is beneficial for the compact design of electronic devices.

[0013] In one possible implementation, the connecting arm further includes an insulating sleeve, with the elastic metal component and flexible circuit board all housed within the insulating sleeve. This is a structurally simple implementation.

[0014] In some embodiments, the wearable device includes a second tuning device coupled to one end of a flexible circuit board facing the first housing, the flexible circuit board being grounded through the second tuning device. In this case, the second tuning device can be used to adjust the electrical length of the first metal layer or the first metal trace, such that the resonant position of the first resonance generated by the first metal layer or the resonant position of the second resonance generated by the first metal trace meets design requirements.

[0015] In some embodiments, the wearable device further includes a second circuit board, and a third tuning device is coupled to one end of the flexible circuit board facing the second housing. The flexible circuit board is grounded through the third tuning device. In this case, the third tuning device can be used to adjust the electrical length of the first metal layer or the first metal trace, so that the resonant position of the first resonance generated by the first metal layer or the resonant position of the second resonance generated by the first metal trace meets the design requirements.

[0016] In some embodiments, the wearable device operates in a frequency band of 2.4 GHz to 2.485 GHz. The second tuning device includes an inductor with an inductance value of 27 nH to 82 nH. The third tuning device also includes an inductor with an inductance value of 27 nH to 82 nH. When the wearable device operates in a frequency band of 2.4 GHz to 2.485 GHz, the physical length of the radiator is approximately 12.5 cm, which is much larger than the size of the connecting arm. The inclusion of an inductor in the second or third tuning device can be used to increase the electrical length of the first metal layer or the first metal trace, thereby ensuring that the resonant position of the first resonance generated by the first metal layer or the resonant position of the second resonance generated by the first metal trace meets design requirements.

[0017] In some embodiments, the wearable device includes a second tuning device and a third tuning device. The second and third tuning devices, used in conjunction, allow for more flexible adjustment of the electrical length of the first metal layer or the first metal trace.

[0018] In some embodiments, the elastic metal element is electrically connected to a second or third tuning device. In this case, the second or third tuning device can be used to adjust the electrical length of the elastic metal element, thereby allowing the second or third tuning device to adjust the resonant position of the third resonance so that the resonant frequency of the third resonance meets the design requirements.

[0019] In some embodiments, the width of the first metal trace is greater than or equal to 0.2 mm. In this case, a wider first metal trace can enable the resonance (e.g., the first resonance or the second resonance) to have a wider bandwidth. Compared to setting multiple radiators to achieve a wider bandwidth, achieving a wider bandwidth through a single radiator (the first metal trace or the first metal layer) is beneficial for the compact design of wearable devices.

[0020] In some embodiments, the flexible circuit board further includes a second metal trace, the first metal trace and the second metal trace having a second spacing, the second metal trace being coupled between the first circuit board and a peripheral device, and the width of the first metal trace being greater than the width of the second metal trace. In this case, the second metal trace can be used to transmit signals between the first circuit board and the peripheral device. The advantage of the wider first metal trace being greater than the width of the second metal trace is as described above.

[0021] In some examples, the width of the first metal trace is greater than 0.2 mm, and the width of the second metal trace is greater than 0.05 mm. In some examples, the width of the first metal trace is greater than or equal to 0.4 mm, and the width of the second metal trace is greater than 0.05 mm. In some examples, the width of the first metal trace includes 0.4 mm.

[0022] In one possible implementation, the width of the second interval is greater than or equal to 0.2 mm. In this case, the compact design of the wearable device can be maintained while ensuring the spacing between the first and second metal traces.

[0023] In some embodiments, the first metal trace and the second metal trace are disposed on the same layer. This is a simple implementation method.

[0024] In some embodiments, the second metal trace includes at least one first trace and at least one second trace, which are stacked together, wherein the first metal trace and the at least one second trace are arranged on the same layer. In this case, compared to all the second metal traces being arranged side by side, the stacked arrangement of the first and second traces can result in a smaller connecting arm width and a more aesthetically pleasing wearable device.

[0025] In one possible implementation, the number of at least one first trace is greater than the number of at least one second trace. With the same wiring area and uniform wiring, the spacing between two adjacent first traces is smaller than the spacing between two adjacent second traces. Setting the first and second metal traces on the same layer allows for more efficient use of the wiring area of ​​the layer containing the second traces. Compared to setting the first and second metal traces side-by-side, this results in a narrower connecting arm and a more aesthetically pleasing wearable device. In another possible implementation, the second metal trace is located between two adjacent second traces.

[0026] In some embodiments, the first metal trace includes a first segment, a second segment, and a first tuning device. The first segment is coupled to the feed source, and the second segment is coupled to the first segment via the first tuning device. In this case, the first tuning device can be used to adjust the electrical length of the first metal trace, thereby adjusting the resonant position of the second resonance so that the resonant position of the second resonance meets the design requirements.

[0027] In some embodiments, the second resonance includes a first sub-resonance and a second sub-resonance, wherein the center frequencies of the first and second sub-resonances are not equal. A first metal trace is used to generate the first sub-resonance, and the first metal trace and a first tuning device are used together to generate the second sub-resonance. In this case, the first tuning device has a relatively small impact on the electrical length of the first metal trace under the first sub-resonance, but a relatively large impact on the electrical length of the first metal trace under the second sub-resonance. Therefore, the resonance position of the second sub-resonance can be adjusted with minimal impact on the resonance position of the first sub-resonance, so that the resonance frequencies of the first and second sub-resonances meet the design requirements.

[0028] In one possible implementation, the first sub-resonance may include the fundamental mode of the first metal trace, and the second sub-resonance may include the third-order mode of the first metal trace. In another possible implementation, the first tuning device under the first sub-resonance may include a current zero point. In yet another possible implementation, the physical length of the first segment is L1, the physical length of the second segment is L2, and L1 ≥ L2.

[0029] In some embodiments, the first tuning device includes a metal circuit that is bent between the first and second segments. In this case, the bent metal circuit between the first and second segments is equivalent to a series inductor between the first and second segments, and the metal circuit has less impact on the bending performance of the connecting arm compared to directly using an inductor. In one possible implementation, the first tuning device includes an inductor. In another possible implementation, the first tuning device includes both an inductor and a metal circuit. In yet another possible implementation, the metal circuit at least partially comprises an S-shape or a spiral shape.

[0030] In some embodiments, one end of the first metal trace is coupled to the feed source, and the other end of the first metal trace extends to the first housing, with the other end configured to be grounded. This is a structurally simple implementation.

[0031] In some embodiments, both ends of the first metal trace are coupled to a feed source, and the two ends of the first metal trace are used to feed in a pair of common-mode signals. This is a simple implementation.

[0032] In some embodiments, the first metal trace includes a first segment, a second segment, and a third segment, with the first segment and the second segment arranged parallel and spaced apart. One end of the first segment is coupled to a feed source, the other end of the first segment is coupled to one end of the third segment, the other end of the third segment is coupled to one end of the second segment, and the other end of the second segment is configured to be grounded. The first metal trace is used to generate a second resonance, which includes a first sub-resonance and a second sub-resonance, the center frequencies of which are not equal. The first segment and the second segment are used to generate the first sub-resonance, and the first, second, and third segments are used together to generate the second sub-resonance. In this case, adjusting the physical length of the third segment has a relatively small impact on the electrical length of the first metal trace under the first sub-resonance, while adjusting the physical length of the third segment has a relatively large impact on the electrical length of the first metal trace under the second sub-resonance. Therefore, the resonance position of the second sub-resonance can be adjusted with minimal impact on the resonance position of the first sub-resonance. The first metal trace can generate both the first and second sub-resonances, which is beneficial for the compact design of electronic devices compared to setting multiple first metal traces in wearable devices.

[0033] In one possible implementation, the vertical projection of the second metal trace on the flexible circuit board is located between the vertical projections of the first segment and the second segment on the flexible circuit board, thereby reducing the interference of the second metal trace on the first metal trace.

[0034] In one possible implementation, the first sub-resonator may include the fundamental mode of the first metal trace, and the second sub-resonator may include the second-order mode of the first metal trace. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a wearable device provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the structure of a connecting arm provided in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of another connecting arm provided in an embodiment of this application;

[0038] Figure 4 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of the structure of a circuit board and a circuit board support provided in an embodiment of this application;

[0041] Figure 7 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0042] Figure 8 This is a schematic diagram of the structure of a flexible circuit board provided in an embodiment of this application;

[0043] Figure 9 This is a schematic diagram of a working scenario for a wearable device provided in an embodiment of this application;

[0044] Figure 10 This is a schematic diagram of the working scenario of another wearable device provided in an embodiment of this application;

[0045] Figure 11 This is a schematic diagram of the working scenario of another wearable device provided in an embodiment of this application;

[0046] Figure 12 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0047] Figure 13 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0048] Figure 14 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0049] Figure 15 This is a schematic diagram of another flexible circuit board structure provided in an embodiment of this application;

[0050] Figure 16This is a schematic diagram of another flexible circuit board structure provided in an embodiment of this application;

[0051] Figure 17 This is a schematic diagram of another flexible circuit board structure provided in an embodiment of this application;

[0052] Figure 18 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0053] Figure 19 for Figure 18 Simulation diagram of the electrical performance of wearable devices in China;

[0054] Figure 20 for Figure 18 Current distribution diagram of wearable devices in China;

[0055] Figure 21 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0056] Figure 22 for Figure 21 Simulation diagram of the electrical performance of wearable devices in China;

[0057] Figure 23 for Figure 21 Current distribution diagram of wearable devices in China;

[0058] Figure 24 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0059] Figure 25 for Figure 24 A current distribution diagram of a wearable device;

[0060] Figure 26 for Figure 24 Another current distribution diagram for wearable devices;

[0061] Figure 27 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0062] Figure 28 for Figure 27 Simulation diagram of the electrical performance of wearable devices in China;

[0063] Figure 29 This is a schematic diagram of the structure of a radio frequency front-end circuit provided in an embodiment of this application;

[0064] Figure 30 This is a schematic diagram of the structure of another wearable device provided in an embodiment of this application;

[0065] Figure 31 for Figure 30A current distribution diagram of a wearable device;

[0066] Figure 32 for Figure 30 Another current distribution diagram for wearable devices.

[0067] Figure label:

[0068] 100-Wearable device; 200-Mobile terminal; 1-First housing; 11-First part; 12-Second part; 2-Second housing; 21-Third part; 22-Fourth part; 3-Connecting arm; 30-Insulating sleeve; 31-Support member; 32-Flexible circuit board; 32A-First connector; 32B-Second connector; 5-Peripheral device; 51-Battery; 52-Processing chip; 53-Electrical connector; 54-Speaker; 55-Microphone; 56-Bone sensor; 57-RF front-end circuit; 571-First switch; 572-Second switch; 573-Filter; 61-First circuit board; 62-Sub-board; 71-Circuit board support; 81-Second metal trace; 811-First trace; 812-Second trace; 82-First metal trace; 821 - First segment; 822 - Second segment; 823 - Third segment; 83 - First metal layer; 91 - First tuning device; 92 - Second tuning device; 93 - Third tuning device; 01 - First metal line; 02 - Second metal line; 03 - Third metal line; 04 - Fourth metal line; H1 - First gap; H2 - Second gap. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0070] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0071] The limitations mentioned in this application, such as collinearity, symmetry (e.g., axial symmetry, or central symmetry), parallelism, perpendicularity, orthogonality, and similarity (e.g., same length, same width, etc.), are all relative to the current technological level and not absolute, strict mathematical definitions. Collinearity of three elements can be understood as the line connecting two elements, or its extension, intersecting with another element, or the closest distance to another element being approximately 2mm. A predetermined angular deviation may exist between two parallel or perpendicular components. In one embodiment, the predetermined threshold may be less than or equal to a threshold of 1mm, for example, 0.5mm or 0.1mm. In one embodiment, the predetermined angle may be within the range of ±10°, for example, a predetermined angular deviation of ±5°.

[0072] In this application, unless otherwise expressly specified and limited, the term "connection" shall be interpreted broadly. For example, "connection" may be a fixed mechanical connection, a detachable mechanical connection, or an integral part; or, "connection" may be a direct connection or an indirect connection through an intermediate medium.

[0073] Furthermore, unless otherwise explicitly specified and limited, the term "coupling" should be interpreted broadly. For example, "coupling" can refer to a direct electrical connection, such as physical contact and electrical conduction between two components. It can also be understood as the electrical connection between different components in a circuit structure through physical lines that can transmit electrical signals, such as copper foil or wires on a printed circuit board (PCB), to transmit electrical signals. Alternatively, "coupling" can refer to an indirect electrical connection between two components through an intermediate medium. Or, "coupling" can refer to an electrical connection between two components in a non-contact manner, such as an electrical connection between two components using capacitive coupling to transmit electrical signals.

[0074] Furthermore, in the embodiments of this application, "connection" refers to the transmission of signals / energy between two or more components through the above-mentioned "coupling" or "indirect coupling" methods.

[0075] In the embodiments of this application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0076] The electronic devices in this application embodiment can be mobile phones, tablets, laptops, smart home devices, wearable devices, virtual reality (VR) electronic devices, augmented reality (AR) electronic devices, etc. Electronic devices can also be handheld devices with wireless communication capabilities, computing devices, other processing devices connected to a wireless modem, in-vehicle devices, electronic devices in 5G networks, or electronic devices in future evolved public land mobile networks (PLMNs), etc., and this application embodiment is not limited to these categories. For ease of explanation, a wearable device is used as an example for illustration.

[0077] This application does not limit the type of wearable device. Wearable devices can be watches, bracelets, earphones, ear hooks, ear clips, smart glasses, smart helmets, etc. For ease of explanation, the following example uses wireless earphones as an example. This application does not limit the form of wireless earphones; wireless earphones can be in-ear earphones, ear hook earphones, ear clip earphones, etc. For ease of explanation, the following example uses wireless earphones as an example. Figure 1 The wearable device 100 shown is an example of an ear clip-on headphone.

[0078] like Figure 1 As shown, the wearable device 100 includes: a first housing 1, a second housing 2, and a connecting arm 3, which connects the first housing 1 and the second housing 2. For ease of description, the geometric center of the first housing 1, the geometric center of the second housing 2, and the geometric center of the connecting arm 3 define a unique plane. The direction perpendicular to this plane is defined as the Z-axis, the direction from the end of the connecting arm 3 that connects to the second housing 2 towards the center of the second housing 2 is defined as the X-axis, and the direction perpendicular to both the X-axis and the Z-axis is defined as the Y-axis.

[0079] In order to secure the ear hook to the user's ear, in some embodiments, such as Figure 1 As shown, the connecting arm 3 is generally U-shaped and connects the first housing 1 and the second housing 2. For example, along the length of the connecting arm 3, the connecting arm 3 has a first end and a second end disposed opposite to each other, the first end being connected to the first housing 1 and the second end being connected to the second housing 2.

[0080] To improve user comfort, in some embodiments, the connecting arm 3 can be deformable. The connecting arm 3 can be used to adjust the distance between the first housing 1 and the second housing 2, changing the distance from an initial distance to an adjustable distance. The initial distance refers to the distance between the first housing 1 and the second housing 2 when the ear clip is not worn on the user's ear. The adjustable distance refers to the distance after the initial distance has increased or decreased. It should be noted that both the initial distance and the adjustable distance refer to the straight-line distance between the first housing 1 and the second housing 2, for example, the straight-line distance between the surfaces of the first housing 1 and the second housing 2 facing each other.

[0081] In order to make the connecting arm 3 have a predetermined shape, in some embodiments, such as Figure 2 As shown, the connecting arm 3 may include a support member 31. When the connecting arm 3 has deformability, to ensure that the first end and the second end are always kept within a certain distance range, and to reduce the risk that the support member 31 cannot recover its preset shape after repeated stretching, one possible implementation is that the support member 31 includes a deformable material, such as an elastic metal material or other materials. For example, the support member 31 may include an elastic metal component. For example, the support member 31 may be a metal column or metal sheet made of shape memory alloy.

[0082] To facilitate the connection of the connecting arm 3 to the first housing 1 or the second housing 2, in some embodiments, such as Figure 2 As shown, the connecting arm 3 may include a first connecting member 41 and a second connecting member 42, with the first connecting member 41 disposed at a first end and the second connecting member 42 disposed at a second end. In one possible implementation, the connecting arm 3 includes an insulating sleeve 30, with a support member 31 at least partially disposed within the insulating sleeve 30, the first connecting member 41 at least partially disposed within the insulating sleeve 30, and the second connecting member 42 at least partially disposed within the insulating sleeve 30. In some examples, such as... Figure 2 As shown, the support member 31 passes through the insulating sleeve 30. One end 31A of the support member 31 is fixedly connected to the first connector 41, and the other end 31B of the support member 31 is fixedly connected to the second connector 42.

[0083] To achieve electrical connection between electronic components within the first housing 1 and electronic components within the second housing 2, for example, to achieve signal transmission between electronic components within the first housing 1 and electronic components within the second housing 2, in some embodiments, such as... Figure 3 As shown, the connecting arm 3 may include a flexible circuit board 32. In one possible embodiment, there is a gap between the flexible circuit board 32 and the insulating sleeve 30. When the connecting arm 3 is bent, the degree of deformation of the flexible circuit board 32 can be less than the degree of deformation of the insulating sleeve 30, thereby improving the bending life of the flexible circuit board 32.

[0084] Based on this, one possible implementation is as follows: Figure 4 As shown, the connecting arm 3 may include a support member 31 and a flexible circuit board 32. Both the support member 31 (e.g., an elastic metal member) and the flexible circuit board 32 are disposed within the insulating sleeve 30. This embodiment does not limit the relative positional relationship between the support member 31 and the flexible circuit board 32 within the insulating sleeve 30. For ease of explanation, the following description assumes that the support member 31 is positioned on the side of the flexible circuit board 32 facing the auricle when worn.

[0085] The above describes the structure of connecting arm 3. In some embodiments, such as... Figure 5 As shown, the wearable device 100 may include a first circuit board 61, which is disposed within the first housing 1. This application embodiment does not limit the form of the first circuit board 61; it may include a flexible circuit board, a rigid circuit board, or a rigid-flex circuit board. For example, the first circuit board 61 may be implemented as a rigid printed circuit board or a flexible printed circuit board.

[0086] The first circuit board 61 can be disposed within the first housing 1 in various ways. For example, such as... Figure 5 As shown, the first housing 1 may include a first portion 11 and a second portion 12, and a first circuit board 61 is disposed within the cavity enclosed by the first portion 11 and the second portion 12. In some examples, the wearable device 100 may include a battery 51, which is disposed within the first housing 1. In some examples, the wearable device 100 may include a circuit board support 71, which is disposed within the first housing 1. In some examples, such as... Figure 6 As shown, the wearable device 100 may include a processing chip 52, which may be disposed on a first circuit board 61. The processing chip 52 may, for example, include a system-on-chip (SoC) or a baseband integrated circuit (BBIC). In some examples, the wearable device 100 may include a radio frequency integrated circuit (RFIC), which may be disposed on the first circuit board 61 and electrically connected to the processing chip 52. In some examples, the wearable device 100 may include a radio frequency front-end (RFFE) circuit, which may be disposed on the first circuit board 61 and coupled between the RFIC and the radiator. In some scenarios, the RFIC or RF front-end circuit may be referred to as a feed source. In one possible implementation, the RF front-end circuit is at least partially integrated into the RF front-end chip. In some examples, such as... Figure 6As shown, the wearable device 100 also includes an electrical connector 53, which may include, for example, a board-to-board (BTB) connector, and the electrical connector 53 may be electrically connected to the flexible circuit board 32.

[0087] The above describes the first housing 1 and its internal electronic components. In some embodiments, such as... Figure 7 As shown, the wearable device 100 may further include a peripheral device 5 disposed within the second housing 2. For example, the second housing 2 may include a third portion 21 and a fourth portion 22, with the peripheral device 5 disposed within a cavity enclosed by the third portion 21 and the fourth portion 22.

[0088] The embodiments of this application do not limit the type and number of peripheral devices 5. In some examples, peripheral device 5 may include at least one of an input device, an output device, or a storage device. For example, peripheral device 5 may include at least one of a sensor, an acoustic device, or a transducer. It should be understood that acoustic devices or transducers mainly realize the mutual conversion between electrical signals and acoustic signals. In some examples, such as... Figure 7 As shown, peripheral device 5 may include, for example, one or more of a speaker (SPK) 54, a microphone (MIC) 55, and a vibrate pickup sensor (VPU) 56. In some examples, such as... Figure 7 As shown, the wearable device 100 may also include a sub-board 62, with peripheral devices 5 connected to the sub-board 62. The sub-board 62 may include a carrier board, a flexible printed circuit board, or a rigid printed circuit board.

[0089] To implement peripheral device 5 (see Figure 7 ) and the first circuit board 61 (see Figure 5 Electrical connections, such as Figure 4 As shown, the flexible circuit board 32 may include a first connector 32A and a second connector 32B. The first connector 32A can be used for coupling with the first circuit board 61, and the second connector 32B is used for coupling with the peripheral device 5. In some examples, the first connector 32A can be used for coupling with the electrical connector 53 (see...). Figure 6 Coupling. In some examples, to accommodate the spatial layout within the first housing 1, the second housing 2, and the connecting arm 3, such as... Figure 4 As shown, the flexible circuit board 32 can adopt an irregular contour design. This application embodiment does not limit the shape / contour of the flexible circuit board 32; for ease of explanation, the flexible circuit board 32 will be described as rectangular below.

[0090] To achieve signal transmission between the first connector 32A and the second connector 32B, in some examples, such as Figure 8As shown, the flexible circuit board 32 may include a second metal trace 81. The second metal trace 81 may include one or more traces. For example, the second metal trace 81 may include a first metal line 01 for transmitting a power signal. For example, the second metal trace 81 may include a second metal line 02 for connecting a speaker 54; there may be multiple second metal lines 02, such as two. For example, the second metal trace 81 may include a third metal line 03 for connecting a microphone 55; there may be multiple third metal lines 03, such as two. For example, the second metal trace 81 may include a fourth metal line 04 for connecting a bone sensor 56; there may be multiple fourth metal lines 04, such as two.

[0091] To facilitate the grounding of peripheral device 5, in some embodiments, the following continues... Figure 8 As shown, the flexible circuit board 32 may further include a first metal layer 83, which can serve as a ground plane. In some examples, the first metal layer 83 is coupled between the first circuit board 61 and the peripheral device 5. The coupling of the first metal layer 83 to the first circuit board 61 allows the first metal layer to establish a common reference potential with the first circuit board. Since the electronic components on the first circuit board and the peripheral device 5 have the same reference potential, signal transmission can be more accurate.

[0092] In some examples, the first circuit board 61 may also include a second metal layer, with the first metal layer 83 and the second metal layer coupled together. The first metal layer 83 or the second metal layer may be referred to as a ground plane, or a grounding plane. For example, the first metal layer 83 may be formed by etching metal onto the surface of any layer of the dielectric substrate of the flexible circuit board 32, and the second metal layer may be formed by etching metal onto the surface of any layer of the dielectric substrate of the first circuit board 61.

[0093] This application embodiment does not limit the type and number of second metal traces in the flexible circuit board 32. The type and number of second metal traces can be adjusted according to design requirements. For example, the type of second metal traces can be adjusted according to the type of peripheral device 5. For instance, peripheral device 5 may include a capacitive sensor, and the second metal traces may include a sixth metal line used to connect to the capacitive sensor. For example, the number of second metal traces can be adjusted according to design specifications such as sound quality.

[0094] This application embodiment does not restrict the arrangement order of the second metal traces in the flexible circuit board 32. Figure 8This is only one possible implementation. To match the appearance design of the wearable device 100, in some embodiments, the second metal trace includes a first trace and a second trace, which are stacked. Compared to the first trace and the second trace being arranged side by side, the stacked arrangement of the first trace and the second trace can make the width of the connecting arm 3 smaller, and the appearance of the wearable device 100 more aesthetically pleasing.

[0095] The shape of the flexible circuit board 32 is not limited in this embodiment. Figure 8 This is only one possible implementation. To facilitate the placement of the flexible circuit board 32 within the insulating sleeve 30, the portion of the flexible circuit board 32 within the insulating sleeve 30 is approximately strip-shaped. To facilitate the electrical connection between the flexible circuit board 32 and the first circuit board 61 or the peripheral device 5, the extension direction of the portion of the flexible circuit board 32 outside the insulating sleeve 30 may be approximately different from the extension direction of the portion of the flexible circuit board 32 within the insulating sleeve 30.

[0096] This application does not restrict the electrical connection method between the flexible circuit board 32 and the first circuit board 61 or peripheral device 5. The flexible circuit board 32 can be electrically connected to the first circuit board 61 or peripheral device 5 by means of soldering, BTB fastening, spring contact, etc. For ease of explanation, the following description takes the electrical connection between the flexible circuit board 32 and the first circuit board 61 or peripheral device 5 via BTB as an example.

[0097] The above description is based on the example of the first circuit board 61 being disposed in the first housing 1 and the peripheral device 5 being disposed in the second housing 2. In some examples, the first circuit board 61 may be disposed in the second housing 2 and the peripheral device 5 may be disposed in the first housing 1. This application does not impose any restrictions on this.

[0098] To enable communication between the wearable device 100 and the mobile terminal 200, the wearable device 100 may also include an antenna. For example... Figure 9As shown, the mobile terminal 200 is, for example, a mobile phone or a computer. The antenna of the wearable device 100 can be connected to the mobile terminal 200 and receive data signals sent by the mobile terminal 200. This application embodiment does not limit the communication technology used by the antenna. The antenna or the wearable device containing the antenna can use one or more of the following communication technologies: Bluetooth (BT), Global Positioning System (GPS), Global System for Mobile Communication (GSM), Wireless Fidelity (WiFi), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), 5G, and other future communication technologies. For ease of explanation, the following embodiments use Bluetooth or StarFlash communication for the antenna structure or the electronic device containing the antenna.

[0099] Therefore, the wearable device 100 has various use cases. In some embodiments, such as Figure 10 As shown, a common use case for wearable device 100 is that it is worn on the user's head, while the mobile terminal 200 communicating with wearable device 100 is in the user's pocket or hand. Wearable device 100 is, for example, an earphone, and mobile terminal 200 is, for example, a mobile phone. The signal propagation path between wearable device 100 and mobile terminal 200 is affected by the medium, resulting in signal loss. Furthermore, when the user is in a complex environment (e.g., a train station, a shopping mall, etc.), if there are interference signals on the same frequency band as the wearable device, the connection between wearable device 100 and mobile terminal 200 is easily affected by the interference signals. For example, if the wearable device operates on a frequency band including the Bluetooth band (2.4GHz-2.485GHz), then hotspot signals, WiFi signals, or Bluetooth signals from other devices are all interference signals. These interference signals also reduce the signal-to-noise ratio, resulting in poor communication quality, stuttering or even disconnection of wearable device 100, affecting the user experience.

[0100] To improve the connection stability between wearable devices and mobile terminals, this application provides a wearable device 100, in which the antenna is disposed within a connecting arm 3. For example, the flexible circuit board 32 of the wearable device 100 is at least partially coupled to a feed source, and at least a portion of the flexible circuit board 32 can serve as a radiator for the antenna.

[0101] With the first circuit board 61 located inside the second housing 2 and the peripheral device 5 located inside the first housing 1, in order to facilitate the user's hearing of sound, such as Figure 11 As shown, when a user wears the wearable device 100 provided in this embodiment, the second housing 2, which is equipped with the peripheral device 5, is located inside the user's concha, the first housing 1 is located outside the user's ear and on the side opposite to the second housing 2, and the connecting arm 3 is fastened to the outer edge of the user's ear, extending from the concha to the back of the ear. Compared to the first housing 1 or the second housing 2, the position of the connecting arm 3 has less obstruction, which can improve the radiation efficiency of the antenna, thereby improving the connection stability between the wearable device 100 and the mobile terminal 200, and improving the communication performance between the wearable device 100 and the mobile terminal 200.

[0102] An antenna is a device used to receive / transmit electromagnetic wave radiation. An antenna may include a radiator. The radiator can convert guided wave energy from a transmitter into radio waves, or convert radio waves into guided wave energy, for radiating or receiving radio waves. For example, modulated high-frequency current energy (or guided wave energy) generated by the transmitter is transmitted to the radiator via a feed line, where the radiator can convert this energy into electromagnetic wave energy of a certain polarization and radiate it in the desired direction. For example, the radiator can further convert electromagnetic wave energy of a certain polarization from a specific direction in space into modulated high-frequency current energy, which is then transmitted to the receiver input via a feed line.

[0103] In this embodiment, the antenna can be implemented as a radiator specifically designed for transmitting or receiving electromagnetic waves, or it can be implemented as feeding an existing structure in the wearable device 100 in a suitable manner so that the structure can transmit or receive electromagnetic waves.

[0104] Therefore, there can be various ways to implement the antenna placement within the connecting arm 3. In some embodiments, such as... Figure 12 As shown, the flexible circuit board 32 includes a second metal trace 81, a first metal layer 83, and a first metal trace 82. The second metal trace 81 and the first metal trace 82 are spaced apart, and the first metal layer 83 and the first metal trace 82 are spaced apart. The second metal trace 81 is coupled between the first circuit board 61 and the peripheral device 5, the first metal layer 83 is coupled between the first circuit board 61 and the peripheral device 5, and the first metal trace 82 is coupled to a feed source disposed on the first circuit board 61.

[0105] To maintain a compact layout for the wearable device 100, in some embodiments, such as Figure 12As shown, a second gap H2 is provided between the second metal trace 81 and the first metal trace 82, and the width of the second gap H2 is greater than or equal to 0.2 mm. In some embodiments, a first gap H1 is provided between the first metal layer 83 and the first metal trace 82, and the width of the first gap H1 is greater than or equal to 0.2 mm.

[0106] In this case, at least one of the first metal trace 82 and the first metal layer 83 can serve as a radiator, that is, at least one of the first metal trace 82 and the first metal layer 83 can be used to generate resonance.

[0107] In one possible implementation, the first metal layer 83 is coupled to the feed source, and the first metal layer 83 is used to generate a first resonance, which is used to cover the operating frequency band of the wearable device.

[0108] In one possible implementation, the first metal trace 82 is coupled to the feed source. The first metal trace 82 can be used to receive the excitation signal transmitted by the feed source and can also be used to generate a second resonance to cover the operating frequency band of the wearable device. In this case, the first metal trace 82 can be considered as a radiator set up to transmit or receive electromagnetic waves. In some examples, to reduce the interference of the second metal trace 81 on the first metal trace 82, the width of the first gap H1 is greater than 0.4 mm, and the width of the second gap H2 is greater than 0.4 mm.

[0109] In one possible implementation, the first metal trace 82 is used to couple a signal to the first metal layer 83, causing the first metal layer 83 to generate a first resonance, which covers the operating frequency band of the wearable device. In this case, the first metal trace 82 can be considered as a feeding structure for transmitting energy to a radiator, and the first metal layer 83 can be considered as a radiator. In this case, the antenna can be implemented to feed an existing structure in the wearable device 100 in a suitable manner, enabling the structure to transmit or receive electromagnetic waves. In some examples, to ensure the coupling strength between the first metal trace 82 and the first metal layer 83, the width of the first gap H1 includes 0.2 mm to 0.4 mm.

[0110] The first interval H1 can be implemented in various ways. For example, if the first metal trace 82 and the first metal layer 83 are disposed on different layers of the flexible circuit board 32, the first interval H1 can include the distance between the first metal trace 82 and the first metal layer 83 along the thickness direction. Alternatively, if the first metal trace 82 and the first metal layer 83 are disposed on the same layer of the flexible circuit board 32, the first interval H1 can include the distance along the arrangement direction of the first metal trace 82 and the first metal layer 83.

[0111] In one possible implementation, the first metal trace 82 is used to couple a signal to the second metal trace 81 and the first metal layer 83, so that the second metal trace 81 and the first metal layer 83 generate a first resonance.

[0112] In one possible implementation, the first metal trace 82 is used to generate a second resonance, and the first metal trace 82 is used to couple a signal to the first metal layer 83 so that the first metal layer 83 generates a second resonance.

[0113] One possible implementation is, such as Figure 13 As shown, the connecting arm 3 also includes a support member 31, which may be, for example, an elastic metal member. The support member 31 is spaced apart from the flexible circuit board 32 and is used to form a third resonance. In some examples, the third resonance may be generated by coupling a signal from the first metal trace 82 to the support member 31. In some examples, the third resonance may be generated by coupling a signal from the first metal layer 83 to the support member 31.

[0114] The design and dimensions of wearable devices must serve ergonomics. In this example, the connecting arm of the wearable device needs to be clipped to the user's ear during use. Therefore, the design and dimensions of the connecting arm must primarily consider the stability of the clip and the user's wearing comfort. Thus, whether a new structure is incorporated into the connecting arm as a radiator (e.g., a first metal trace), or an existing structure in the connecting arm is appropriately fed to reuse as a radiator (e.g., a second metal trace or support), there are relatively strict limitations on the shape and physical length of the radiator. For example, as shown... Figure 13 As shown, in order to facilitate connection with the first circuit board 61, the flexible circuit board 32 may include two parts with different extension directions, and the first metal trace 82 disposed on the flexible circuit board 32 may also include two parts with different extension directions.

[0115] The above explanation uses shape as an example. The physical length affects the electric length of the radiator, thus affecting its resonant position. To ensure that the resonant position of the first or second resonance meets design requirements, in some embodiments, such as... Figure 14 As shown, the wearable device 100 includes a second tuning device 92, which is coupled to one end of the flexible circuit board 32 facing the first housing 1. The flexible circuit board 32 is grounded through the second tuning device 92. For example, a second metal layer serves as a ground plane, and the flexible circuit board 32 is electrically connected to the second metal layer through the second tuning device 92.

[0116] In the embodiments of this application, "end" or "one end" should not be narrowly interpreted as necessarily an endpoint or end that is physically disconnected from other radiators. It can also be considered as a point or segment on a continuous radiator. In some embodiments, "one end" may include a coupling region on the radiator that couples to other conductive structures. For example, in the case where the first metal trace is used to generate the second resonance, the region where the first metal trace and the second metal trace face each other.

[0117] The above description uses the flexible circuit board 32 grounded through the second tuning device 92. In some embodiments, such as... Figure 14 As shown, the wearable device 100 includes a third tuning device 93, which is coupled to one end of the flexible circuit board 32 facing the second housing 2. The flexible circuit board 32 is grounded through the third tuning device 93. As an example, the sub-board includes a third metal layer serving as a ground plane, and the flexible circuit board 32 is electrically connected to the third metal layer through the third tuning device 93. As an example, a first metal layer 83 serves as a ground plane, and the flexible circuit board 32 is electrically connected to the first metal layer 83 through the third tuning device 93.

[0118] The above description uses the flexible circuit board 32 grounded via the second tuning device 92 or the third tuning device 93. In some embodiments, such as Figure 14 As shown, the wearable device 100 may include a second tuning device 92 and a third tuning device 93. The second tuning device 92 or the third tuning device 93 can be used to adjust the electrical length of the first metal trace 82 or the first metal layer 83, so that the resonant position of the second resonance generated by the first metal trace 82 is similar to the resonant position of the first resonance generated by the first metal layer 83, or meets design requirements. The combined use of the second tuning device 92 and the third tuning device 93 allows for more flexible adjustment of the electrical length of the first metal trace 82 or the second metal trace 81.

[0119] In some embodiments, the wearable device 100 operates in a frequency band of 2.4 GHz to 2.485 GHz. The second tuning device 92 includes an inductor with an inductance value of 27 nH to 82 nH. The third tuning device 93 includes an inductor with an inductance value of 27 nH to 82 nH. For example, the inductance value of the second tuning device 92 or the third tuning device 93 may include, for example, 33 nH, 39 nH, 47 nH, 56 nH, 68 nH, or 82 nH.

[0120] When the wearable device 100 operates in the frequency band of 2.4GHz-2.485GHz, the physical length of the radiator is approximately 12.5cm, which is much larger than the size of the connecting arm. The second tuning device 92 or the third tuning device 93 includes an inductor, which can be used to increase the electrical length of the first metal layer 83 or the first metal trace 82, thereby ensuring that the resonant position of the first resonance generated by the first metal layer 83 or the resonant position of the second resonance generated by the first metal trace 82 meets the design requirements.

[0121] Electrical length can be defined as the ratio of physical length (i.e., mechanical or geometric length) multiplied by the transmission time of an electrical or electromagnetic signal in a medium, to the time required for that signal to travel a distance in free space equal to the physical length of the medium. The following formula can be satisfied:

[0122] ;

[0123] Where L is the physical length. denoted as , where b is the transmission time of the electrical or electromagnetic signal in the medium, and is the transmission time in free space.

[0124] Alternatively, electrical length can also refer to the ratio of physical length (i.e., mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave. The following formula can be satisfied:

[0125] ;

[0126] Where L is the physical length. The wavelength of the electromagnetic wave.

[0127] In some embodiments of this application, the physical length of the radiator can be understood as within ±20%, ±10%, or ±5% of the electrical length of the radiator.

[0128] In order to make the first or second resonance have a wider frequency band, in some embodiments, such as Figure 15 As shown, the width D2 of the first metal trace 82 is greater than the width D1 of the second metal trace 81. In one possible implementation, D1 ≥ 0.05 mm, D2 ≥ 0.2 mm. In some examples, D1 ≥ 0.05 mm, D2 ≥ 0.4 mm. In one possible implementation, D1 = 0.4 mm. In some examples, the second metal line 02 can be set as a metal sheet or metal layer, and the width of the first metal trace 82 is less than the width of the second metal line 02.

[0129] The above describes the method of resonance generation. The arrangement of the second metal trace 81 and the first metal trace 82 can be varied. In some embodiments, such as...Figure 15 As shown, the first metal trace 82 and the second metal trace 81 are arranged on the same layer. The arrangement of the first metal trace 82 and the second metal trace 81 on the same layer requires widening the width of the flexible circuit board 32, which in turn requires widening the width of the connecting arm 3, affecting the shape design of the wearable device 100.

[0130] To minimize the impact on the shape design of the wearable device 100, in some embodiments, such as Figure 16 As shown, the second metal trace 81 includes a first trace 811 and a second trace 812, which are stacked together. In some examples, continuing as... Figure 16 As shown, both the first trace 811 and the second trace 812 include multiple instances, with the number of first traces 811 being greater than the number of second traces 812. For example... Figure 16 The first trace 811 comprises five, and the second trace 812 comprises three. The first metal trace 82 is installed on the same layer as the second trace 812.

[0131] Since the number of first traces 811 is greater than the number of second traces 812, under the condition of the same wiring area and uniform wiring, the interval between two adjacent first traces 811 is smaller than the interval between two adjacent second traces 812. In this case, the first metal traces 82 and the second traces 812 are set on the same layer, which can make more reasonable use of the wiring area of ​​the layer where the second traces 812 are located.

[0132] This application embodiment does not limit the arrangement of the first metal trace 82 and the second trace 812. One possible implementation is as follows: Figure 16 As shown, the first metal trace 82 is located on one side of the second trace 812. In one possible implementation, as... Figure 17 As shown, the first metal trace 82 is located between two adjacent second traces 812.

[0133] The aforementioned features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. For example, the first metal trace 82 is used to couple a signal to the first metal layer 83, causing the first metal layer 83 to generate a first resonance. One possible implementation is as follows... Figure 18 As shown, the wearable device 100 includes a support member 31 and a flexible circuit board 32. The flexible circuit board 32 includes a first metal trace 82 and a first metal layer 83. The width of the first metal trace 82 is 0.4 mm, the physical length of the first metal trace 82 is 17 mm, and the first spacing H1 = 0.2 mm. The electrical performance of the wearable device 100 is simulated, such as... Figure 19 As shown, Figure 19 The horizontal axis represents frequency, and the vertical axis represents decibel (dB) value.

[0134] Figure 19 Curve ① in the figure represents the return loss curve of the wearable device. It can be seen that the wearable device generates a resonance at point 1 (f1=2.28GHz, S11=-23.22dB) and another resonance at point 2 (f2=2.80GHz, S11=-17.49dB). The resonances at point 1 and point 2 at least partially overlap, forming a relatively wide bandwidth, namely the frequency range between points 3 (f3=2.13GHz, S11=-6dB) and 4 (f4=3.01GHz, S11=-6dB), which constitutes the operating frequency band of the wearable device.

[0135] In this context, resonance refers to an antenna reaching an optimized electromagnetic energy conversion state at a specific frequency, at which point the radiator can transmit or receive electromagnetic waves with maximum efficiency. The resonant frequency is also called the resonant frequency. The resonant frequency can have a frequency range, called the bandwidth (or "operating frequency") of the radiator. The point of strongest resonance is called the resonant point, such as point 1 or point 2. The frequency corresponding to the resonant point is called the center frequency. In this embodiment, S11 represents return loss, and the frequency range with return loss less than -6dB is used as the resonant frequency range.

[0136] Bandwidth refers to the frequency range through which an antenna can effectively operate, i.e., the width of the operating frequency band. In the embodiments of this application, bandwidth refers to absolute bandwidth, which is the difference between the highest and lowest frequencies of the operating frequency band. Bandwidth covers a relatively wide range, thus exhibiting wideband characteristics.

[0137] The current distribution of wearable devices at f1=2.28GHz is as follows: Figure 20 As shown in (A), the current distribution on the first metal layer 83 is relatively large, while the current distribution on the support member 31 is relatively small. Therefore, it can be determined that the resonance at point 1 is the resonance generated by the first metal layer 83, which is the aforementioned first resonance. The current distribution of the wearable device at f2 = 2.80 GHz is as follows... Figure 20 As shown in (B), the current distribution on the first metal layer 83 is relatively small, while the current distribution on the support member 31 is relatively large. Therefore, it can be determined that the resonance at point 2 is the resonance generated by the support member 31 (elastic metal member), which is the aforementioned third resonance. The resonant frequency band of the third resonance at least partially overlaps with the resonant frequency band of the first resonance, thus achieving a wideband effect.

[0138] Figure 19 Curve ② in the figure represents the overall efficiency curve of wearable devices. Figure 19Curve ③ in the figure represents the radiative efficiency curve of the wearable device. Within the operating frequency band (2.13GHz~3.01GHz), the radiative efficiency and overall efficiency of the wearable device are relatively close. Specifically, at point 5, f5=2.4GHz, the overall efficiency is -8.09dB. At point 6, f6=2.44GHz, the overall efficiency is -8.24dB. At point 7, f7=2.48GHz, the overall efficiency is -8.48dB.

[0139] Radiation efficiency refers to the ratio of a radiator's gain to its directivity, or the ratio of its radiated power to its received power. Total efficiency, also known as system efficiency, is the ratio of the antenna's radiated power to its input signal power. Both of these efficiencies are used to measure a radiator's radiation capability and are generally expressed as a percentage. There is a conversion relationship between percentage and dB; the closer the efficiency is to 0 dB, the better the performance of the radiator.

[0140] The above description assumes that the first metal trace 82 is located on one side of the first metal layer 83. The first metal trace 82 can be located on the same layer as the second metal trace 81. One possible implementation is as follows: Figure 21 As shown, the width of the first metal trace 82 is 0.4 mm, the physical length of the first metal trace 82 is 17 mm, and the first spacing H1 = 0.2 mm. The second metal trace 81 (see...) Figure 16 This includes the first routing line 811 (see...) Figure 16 The first trace 811 and the second trace 812 are stacked, with the first metal trace 82 located between two adjacent second traces 812. In one possible implementation, the first metal trace 82 can be implemented by hollowing out a hole in the first metal layer 83. The electrical performance of the wearable device 100 is simulated, such as... Figure 22 As shown, Figure 22 The horizontal axis represents frequency, and the vertical axis represents decibel value.

[0141] Figure 22 Curve ① in the figure represents the return loss curve of the wearable device. It can be seen that the wearable device generates a resonance at point 1 (f1=2.42GHz, S11=-26.80dB) and another resonance at point 2 (f2=2.89GHz, S11=-16.01dB). The resonances at point 1 and point 2 at least partially overlap, forming a relatively wide bandwidth, namely the frequency range between points 3 (f3=2.25GHz, S11=-6dB) and 4 (f4=3.16GHz, S11=-6dB), which constitutes the operating frequency band of the wearable device.

[0142] Figure 22 Curve ② in the figure represents the overall efficiency curve of wearable devices. Figure 22Curve ③ in the figure represents the radiative efficiency curve of wearable devices. Within the operating frequency band (2.25GHz~3.16GHz), the radiative efficiency and overall efficiency of wearable devices are relatively close. Specifically, at point 5, f5=2.4GHz, the overall efficiency is -9.30dB. At point 6, f6=2.44GHz, the overall efficiency is -8.95dB. At point 7, f7=2.48GHz, the overall efficiency is -8.93dB.

[0143] Current distribution in wearable devices, such as Figure 23 As shown, the first metal trace 82 couples a signal to the first metal layer 83, causing the first metal layer 83 to resonate at point 1, which is the aforementioned first resonance. The first metal layer 83 couples a signal to the support member 31 (elastic metal member), causing the support member 31 to resonate at point 2, which is the aforementioned third resonance. The resonant frequency band of the third resonance at least partially overlaps with the resonant frequency band of the first resonance, thereby achieving a wideband effect.

[0144] The above two implementations are illustrated using the example of the first metal trace 82 coupling a signal to the first metal layer 83 to cause the first metal layer 83 to generate a first resonance. As an example, the following explanation uses the first metal trace 82 to generate a second resonance. One possible implementation is as follows... Figure 24 As shown, the width of the first metal trace 82 is 0.4 mm, the physical length of the first metal trace 82 is 17 mm, and the first spacing H1 is greater than 0.2 mm. The first metal trace 82 is used to generate a second resonance, which is used to cover the operating frequency band of the wearable device.

[0145] To ensure that the resonant position of the second resonance meets the design requirements, continue as follows: Figure 24 As shown, the wearable device 100 may further include a first tuning device 91 coupled between the second segment 822 and the first segment 821. In this case, the first tuning device 91 can be used to adjust the electrical length of the first metal trace 82, thereby adjusting the resonant position of the second resonance so that the resonant position of the second resonance meets the design requirements.

[0146] In some examples, the first metal trace 82 may have multiple modes, each generating a resonance. For example, the second resonance includes a first sub-resonance and a second sub-resonance, the center frequencies of which are different. The first sub-resonance is, for example, the fundamental mode of the first metal trace 82, and the second sub-resonance is, for example, the third mode of the first metal trace 82.

[0147] The fundamental mode (first-order mode), second-order mode, and third-order mode are all characteristic modes of a radiator. Characteristic modes are used to identify all the basic electromagnetic modes of a radiator, describe the distribution of the electromagnetic field within the radiator, and how the radiator responds to specific frequencies. For example, the first-order mode, also known as the fundamental mode, refers to the most basic resonant mode of the radiator. The first-order mode corresponds to the lowest frequency at which the radiator can effectively radiate or receive radiation, also called the fundamental frequency. The first-order mode usually corresponds to the natural radiation mode of the radiator. For example, the second-order mode means that the resonant frequency of the radiator is twice the fundamental frequency. For example, the third-order mode means that the resonant frequency of the radiator is three times the fundamental frequency.

[0148] The current distribution of the wearable device under the first sub-resonance (fundamental mode) was simulated, and the current vector diagram is shown below. Figure 25 As shown in (A), the current amplitude diagram is as follows: Figure 25 As shown in (B), the first metal trace 82 can be divided into a first segment 821 and a second segment 822 based on the current distribution. The first segment 821 is coupled to the feed source, and the second segment 822 is located on the side of the first segment 821 away from the first circuit board 61. The physical length of the first segment is L1, and the physical length of the second segment is L2, where L1 ≥ L2. Since the first segment 821 consists of two parts with different extension directions, L1 can be the sum of L11 and L12. It can be seen that the current amplitude of the second segment 822 is smaller than that of the first segment 821. The second segment 822 may include a current weak point or a current zero point. The first metal trace 82 (the first segment 821 and the second segment 822) is used to generate the first sub-resonance.

[0149] The current distribution of the wearable device under the second sub-resonance (third mode) was simulated, and the current vector diagram is shown below. Figure 26 As shown in (A), the current amplitude diagram is as follows: Figure 26 As shown in (B), the current distribution on the first segment 821 and the second segment 822 is relatively uniform, and the second segment 822 may include a current-strong point. The first metal trace 82 (the first segment 821 and the second segment 822) and the first tuning device 91 are used together to generate the second sub-resonance.

[0150] In this context, "strong current point" and "weak current point" are relative concepts. A strong current point is the location on the radiator where the current amplitude is relatively large, while a weak current point is the location on the radiator where the current amplitude is relatively small. Using excitation signals of different amplitudes, the amplitudes of the strong and weak current points may differ, but the amplitude of the strong current point remains the location on the antenna where the current amplitude is relatively large, and the weak current point remains the location on the antenna where the current intensity is relatively small. Similarly, "strong electric field point" and "weak electric field point" are relative concepts. A strong electric field point is the location on the radiator where the electric field amplitude is relatively large, and a weak electric field point is the location on the radiator where the electric field amplitude is relatively small. In some scenarios, a weak current point can also be referred to as a zero current point.

[0151] Based on this, the first tuning device 91 can be set in Figure 25 The current weakness is shown at the first tuning device 91 under the first sub-resonance, and the current strength is shown at the first tuning device 91 under the second sub-resonance. In this case, the first tuning device 91 has a small impact on the electrical length of the first metal trace 82 under the first sub-resonance, but a large impact on the electrical length of the first metal trace 82 under the second sub-resonance. Therefore, the resonance position of the second sub-resonance can be adjusted with minimal impact on the resonance position of the first sub-resonance, so that the resonance frequencies of the first and second sub-resonances meet the design requirements.

[0152] In some application scenarios, the operating frequency band of wearable devices may include 2.4GHz-2.4835GHz. Within this operating frequency band, the physical length of the radiator may include 12.5cm. The connecting arm of the wearable device is typically less than 12.5cm in size. To adjust the electrical length of the first metal trace 82, in one possible implementation, the first tuning device 91 may include an inductor.

[0153] The inductor in the embodiments of this application can be understood as lumped inductance and / or distributed inductance. Lumped inductance refers to an inductive component, such as an inductor element. Distributed inductance (or distributed inductance) refers to the equivalent inductance formed by a conductive element through its own structure.

[0154] To reduce the impact of inductive devices on the bending performance of the connecting arm, one possible implementation is as follows: Figure 27 As shown, the first tuning device 91 includes a metal circuit that is bent between the first segment 821 and the second segment 822. The bending of the metal circuit between the first segment 821 and the second segment 822 is equivalent to connecting an inductor in series between the two segments. Compared to directly using an inductor, the metal circuit has less impact on the bending performance of the connecting arm. In one possible implementation, the metal circuit at least partially includes an S-shape or a spiral shape. An S-shape is, for example, when the metal circuit bends in a plane, and a spiral shape is, for example, when the metal circuit bends in space. In another possible implementation, the first tuning device 91 may include an inductor and a metal circuit.

[0155] Based on this, the electrical performance of wearable devices is simulated, such as... Figure 28 As shown, Figure 28 The horizontal axis represents frequency, and the vertical axis represents decibel value. Figure 28Curve ① in the figure represents the return loss curve of the wearable device when the inductance value L of the first tuning device 91 is 1nH, and curve ② represents the return loss curve of the wearable device when the inductance value L of the first tuning device 91 is 2.4nH. It can be seen that as the inductance value of the first tuning device 91 increases, the center frequency of the resonance near 2.4GHz (i.e., the first sub-resonance) remains basically unchanged, while the center frequency of the resonance near 6GHz (i.e., the second sub-resonance) decreases significantly.

[0156] Figure 28 Curves ③ and ⑤ in the figure represent the overall efficiency and radiation efficiency curves of the wearable device when the inductance value L of the first tuning device 91 is 1nH, respectively. Curves ④ and ⑥ represent the overall efficiency and radiation efficiency curves of the wearable device when the inductance value L of the first tuning device 91 is 2.4nH, respectively. The radiation efficiency and overall efficiency of the wearable device are relatively close within the operating frequency band.

[0157] With L=2.4nH, wearable devices can operate in both the 2.4GHz and 5GHz frequency bands, and can employ Starlink communication technology. Compared to wearable devices operating only in the 2.4GHz band, those operating in both bands offer more communication options. Furthermore, the 5GHz spectrum has lower noise and higher bandwidth, resulting in less lag and higher signal quality during operation.

[0158] To accommodate wearable devices that can operate in both 2.4GHz and 5GHz frequency bands, this application embodiment also provides a radio frequency front-end circuit 57, such as... Figure 29 As shown, the RF front-end circuit 57 is coupled between the processing chip 52 and the first metal trace 82. This RF front-end circuit may include a power amplifier (PA), a low-noise amplifier (LNA), and a filter 573. This RF front-end circuit can be used to process 2.4 GHz or 5 GHz RF signals. A first switch 571 is used to selectively connect the first metal trace 82 to the PA or LNA, and a second switch 572 is used to selectively connect the PA or LNA to the filter 573, so as to cooperate with the first metal trace 82 to realize the function of transmitting or receiving signals.

[0159] The above explanation uses the first metal trace 82, including the first segment 821 and the second segment 822, as an example. One possible implementation is as follows: Figure 30 As shown, one end 82A of the first metal trace 82 is coupled to the feed source, and the other end 82B of the first metal trace 82 extends to the first housing 1. Figure 30(Not shown in the image), the other end 82B of the first metal trace 82 is configured to be grounded. For example, the first metal trace 82 includes a first segment 821, a second segment 822, and a third segment 823, with the first segment 821 and the second segment 822 arranged parallel and spaced apart. One end 82A of the first segment 821 is coupled to the feed source, the other end of the first segment 821 is coupled to one end of the third segment 823, the other end of the third segment 823 is coupled to one end of the second segment 822, and the other end 82B of the second segment 822 is configured to be grounded.

[0160] In some examples, the first metal trace 82 may have multiple modes, each generating a resonance. For example, the second resonance includes a first sub-resonance and a second sub-resonance, the center frequencies of which are different. The first sub-resonance is, for example, the fundamental mode of the first metal trace 82, and the second sub-resonance is, for example, the second-order mode of the first metal trace 82.

[0161] The current distribution of the wearable device under the first sub-resonance (fundamental mode) is simulated. The current pattern is shown below. Figure 31 As shown in (A), the current amplitude diagram is as follows: Figure 31 As shown in (B), the first segment 821 and the second segment 822 both include strong current points, and the third segment 823 includes weak current points or zero current points. The first and second segments are used to generate the first sub-resonance.

[0162] The current distribution of the wearable device under the second sub-resonance (secondary mode) is simulated. The current pattern is shown below. Figure 32 As shown in (A), the current amplitude diagram is as follows: Figure 32 As shown in (B), the first segment 821 and the second segment 822 both include a weak current point or a zero current point, and the third segment 823 includes a strong current point. The first, second, and third segments are used together to generate the second sub-resonance. In some examples, one end 82A of the first segment 821 may include a strong current point, and the other end 82B of the second segment 822 may also include a strong current point.

[0163] Based on this, adjusting the physical length of the third segment 823 has little effect on the electrical length of the first metal trace 82 under the first sub-resonance, while adjusting the physical length of the third segment 823 has a greater effect on the electrical length of the first metal trace 82 under the second sub-resonance. Thus, the resonance position of the second sub-resonance can be adjusted with little impact on the resonance position of the first sub-resonance.

[0164] To reduce interference from the second metal trace 81 to the first metal trace 82, one possible implementation is as follows: Figure 30 As shown, the vertical projection of the second metal trace 81 on the flexible circuit board is located between the vertical projection of the first segment 821 on the flexible circuit board and the vertical projection of the second segment 822 on the flexible circuit board.

[0165] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0166] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A wearable device, comprising: The wearable device comprises: a first housing, a second housing, and a connecting arm connecting the first housing and the second housing; a first circuit board disposed in the first housing; a feed disposed on the first circuit board; a peripheral device disposed in the second housing; a flexible circuit board disposed in the connecting arm, the flexible circuit board being coupled between the first circuit board and the peripheral device, at least a portion of the flexible circuit board being coupled with the feed such that the at least a portion of the flexible circuit board functions as an antenna.

2. The wearable device of claim 1, wherein, The flexible circuit board comprises a first metal layer coupled between the first circuit board and the peripheral device, the first metal layer being coupled with the feed, the first metal layer being configured to generate a first resonance configured to cover an operating frequency band of the wearable device.

3. The wearable device of claim 1, wherein, The flexible circuit board comprises a first metal layer and a first metal trace having a first interval, the first metal layer being coupled between the first circuit board and the peripheral device, the first metal trace being coupled with the feed.

4. The wearable device of claim 3, wherein, The first interval has a width greater than or equal to 0.2 mm.

5. The wearable device of claim 3 or 4, wherein, The first metal trace is configured to generate a second resonance configured to cover the operating frequency band of the wearable device.

6. The wearable device of claim 3 or 4, wherein, The first metal trace is configured to couple a signal to the first metal layer such that the first metal layer generates the first resonance configured to cover the operating frequency band of the wearable device.

7. The wearable device of claim 3 or 4, wherein, The first metal trace has a width greater than or equal to 0.2 mm.

8. The wearable device of claim 3 or 4, wherein, The flexible circuit board further comprises a second metal trace having a second interval, the second metal trace being coupled between the first circuit board and the peripheral device; the first metal trace has a width greater than a width of the second metal trace.

9. The wearable device of claim 8, wherein, The second metal trace comprises at least one first trace and at least one second trace, the at least one first trace and the at least one second trace being disposed in a stack, wherein the first metal trace is disposed in a same layer as the at least one second trace.

10. The wearable device of claim 9, wherein, A number of the at least one first trace is greater than a number of the at least one second trace.

11. The wearable device of claim 8, wherein, The first metal trace is disposed in a same layer as the second metal trace.

12. The wearable device of claim 5, wherein, The first metal trace comprises a first segment, a second segment, and a first tuning device, the first segment being coupled with the feed, the second segment being coupled with the first segment via the first tuning device.

13. The wearable device of claim 12, wherein, The second resonance comprises a first sub-resonance and a second sub-resonance, a center frequency of the first sub-resonance and a center frequency of the second sub-resonance being different; The first metal trace is configured to generate the first sub-resonance, the first metal trace and the first tuning device being collectively configured to generate the second sub-resonance.

14. The wearable device of claim 13, wherein, The first tuning device comprises a metal line, the metal line being disposed in a bend between the first segment and the second segment.

15. The wearable device of claim 5, wherein, One end of the first metal trace is coupled with the feed source, and the other end of the first metal trace extends to the first housing and is configured to be grounded.

16. The wearable device of any one of claims 1-4, wherein, The connecting arm includes an elastic metal piece which is arranged apart from the flexible circuit board and is used to form a third resonance.

17. The wearable device of any one of claims 2-4, wherein, The wearable device includes a second tuning device which is coupled with one end of the flexible circuit board towards the first housing and the flexible circuit board is grounded through the second tuning device. 18.The wearable device of claim 17, wherein, a working frequency band of the wearable device includes 2.4 GHz-2.485 GHz; the second tuning device includes an inductive device, and an inductance of the second tuning device includes 27 nH-82 nH.

19. The wearable device of any one of claims 2-4, wherein, The wearable device includes a third tuning device which is coupled with one end of the flexible circuit board towards the second housing and the flexible circuit board is grounded through the third tuning device. 20.The wearable device of claim 19, wherein, a working frequency band of the wearable device includes 2.4 GHz-2.485 GHz; the third tuning device includes an inductive device, and an inductance of the third tuning device includes 27 nH-82 nH.

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