Design method of smart ring and antenna

Abstract

This application discloses a design method for a smart ring and an antenna. The smart ring includes a ring-shaped housing, a battery assembly, and a circuit board assembly. The ring-shaped housing includes a ring-shaped metal outer shell. The battery assembly is disposed inside the ring-shaped metal outer shell. The circuit board assembly is disposed inside the ring-shaped metal outer shell and includes an antenna FPC and a rigid-flex board. The antenna FPC is connected to a first end of the rigid-flex board, and a second end of the rigid-flex board is connected to a first end of the battery assembly. The antenna FPC is electromagnetically coupled to the ring-shaped metal outer shell, and the resonant frequency of the antenna FPC matches the self-resonant frequency of the ring-shaped metal outer shell, so that the ring-shaped metal outer shell acts as an auxiliary radiator for the antenna. The smart ring provided by this application can ensure the antenna's radiation effect while using a metal outer shell, thus improving product performance.

Description

Technical Field

[0001] This application belongs to the field of smart wearable device technology, specifically relating to a design method for a smart ring and antenna. Background Technology

[0002] Smart rings, as miniaturized wearable devices, have the advantage of being easy to use, but their form factor limits the space available for use, and their shells are mostly made of cylindrical metal, which can easily create electromagnetic shielding effects, resulting in poor antenna radiation performance. Summary of the Invention

[0003] This application aims to provide a design method for a smart ring and antenna, which at least solves one of the problems in the background art.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows: According to a first aspect of this application, a smart ring is provided, comprising: An annular housing, the annular housing comprising an annular metal outer shell; A battery assembly disposed inside the annular metal casing; A circuit board assembly is disposed inside the annular metal housing and includes an antenna FPC and a rigid-flex board. The antenna FPC is connected to a first end of the rigid-flex board, and a second end of the rigid-flex board is connected to a first end of the battery assembly. The antenna FPC is electromagnetically coupled to the annular metal shell, and the resonant frequency of the antenna FPC matches the self-resonant frequency of the annular metal shell, so that the annular metal shell serves as an auxiliary radiator for the antenna.

[0005] Optionally, the antenna FPC includes an FPC insulating layer and a metal layer disposed on or inside the FPC insulating layer; the metal layer is attached to the inner ring surface of the annular metal shell to form a conformal coupling region, the metal layer is insulated from the annular metal shell, and the FPC insulating layer and the metal layer are connected to the first end of the rigid-flex plate.

[0006] Optionally, the rigid-flex board includes an antenna matching circuit, a feed source, a high-frequency isolation circuit, and a GND network; The metal layer is connected to the antenna matching circuit, the antenna matching circuit is connected to the feed source, and the high-frequency isolation circuit is connected to the GND network and connected to the annular metal shell through a conductive connector.

[0007] Optionally, the metal layer is recessed inward relative to the FPC insulating layer, and the edges of the metal layer and the insulating layer are rounded.

[0008] Optionally, the conformal coupling region is attached to the inner surface of the annular metal casing using double-sided adhesive, and an insulating support structure is filled between the second end of the battery assembly and the antenna FPC; and / or, The distance between the conformal coupling region and the inner surface of the annular metal shell is constant.

[0009] Optionally, the battery assembly is configured as an arc shape, the circuit board assembly is configured as a multi-angled state, and at least a portion of the antenna FPC extends between the second end of the battery assembly and the annular metal casing, so that the battery assembly and the circuit board assembly together form an annular structure.

[0010] Optionally, the annular housing further includes a potting inner shell, which is disposed inside the annular metal outer shell and covers the battery assembly and the circuit board assembly; and / or, The annular housing is configured as an open ring.

[0011] According to a second aspect of this application, an antenna design method is provided, applied to the smart ring described in the first aspect, the design method comprising: The self-resonant frequency of the annular metal casing is determined based on the size parameters and relative positions of the annular metal casing, the battery assembly, and the rigid-flex plate. By adjusting the size parameters of the antenna FPC, the resonant frequency of the antenna FPC is matched with one of the self-resonant frequencies of the annular metal shell.

[0012] Optionally, one of the self-resonant frequencies of the annular metal casing can be set to the self-resonant frequency closest to the target frequency band.

[0013] Optionally, the antenna FPC has a conformal coupling region, and adjusting the dimensional parameters of the antenna FPC includes: Adjust the length and / or width of the conformal coupling region.

[0014] Optionally, the dimensional parameters of the annular metal shell include one or more of the following: the annular width of the annular metal shell, the outer diameter of the annular metal shell, and the radial thickness of the annular metal shell; And / or, the dimensional parameters of the rigid-flex plate include the length of the rigid-flex plate and / or the minimum radial distance between the rigid-flex plate and the annular metal shell; And / or, the dimensional parameters of the battery assembly include the radial thickness of the battery assembly and / or the radial distance of the battery assembly to the inner surface of the annular metal casing.

[0015] Optionally, the antenna design method further includes: By adjusting the resonant frequency point formed by the antenna FPC through impedance matching, the resonant frequency point formed by the antenna FPC is within the target frequency band when the smart ring is worn.

[0016] In this application, by electromagnetically coupling the antenna FPC with the annular metal shell and matching the resonant frequency, the metal shell, which originally formed a shield, is transformed into an auxiliary radiating component for the antenna. This effectively solves the shielding problem of the metal shell on the antenna and improves the antenna radiation effect of the smart ring within a limited space.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the internal structure of a smart ring provided in this application; Figure 2 This is a schematic diagram of the unfolded structure of the circuit board assembly provided in this application; Figure 3 This is one of the electrical connection diagrams of the antenna FPC provided in this application; Figure 4 This is the second schematic diagram of the electrical connection of the antenna FPC provided in this application; Figure 5 This is a simulation diagram of the antenna radiation effect of the smart ring provided in this application; Figure 6 This is a schematic diagram of an antenna design method provided in this application.

[0019] Figure label: 1. Metal casing; 2. Battery assembly; 3. Antenna FPC; 31. FPC insulation layer; 32. Metal layer; 4. Flexible-rigid bonding board; 41. Flexible board; 42. Rigid board; 5. Conductive connector. Detailed Implementation

[0020] Embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application are within the scope of protection of this application.

[0021] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] The following is combined Figures 1-6 This application describes a design method for a smart ring and an antenna according to embodiments thereof.

[0025] like Figures 1 to 4 As shown, according to some embodiments of this application, a smart ring is provided, including an annular shell, a battery assembly 2, and a circuit board assembly; the annular shell includes an annular metal outer shell 1; the battery assembly 2 is disposed inside the annular metal outer shell 1; the circuit board assembly is disposed inside the annular metal outer shell 1 and includes an antenna FPC3 and a rigid-flex board 4, the antenna FPC3 is connected to a first end of the rigid-flex board 4, and the second end of the rigid-flex board 4 is connected to the first end of the battery assembly 2; wherein, the antenna FPC3 is electromagnetically coupled to the annular metal outer shell 1, and the resonant frequency point formed by the antenna FPC3 matches the self-resonant frequency point of the annular metal outer shell 1, so that the annular metal outer shell 1 serves as an auxiliary radiator of the antenna.

[0026] Specifically, in this embodiment, the smart ring adopts a ring-shaped shell as its basic structure, with the core being a ring-shaped metal shell 1. The battery assembly 2 and the circuit board assembly are both built into the inner side of the metal shell 1, achieving a compact layout design for a miniaturized wearable device. The circuit board assembly integrates an antenna FPC 3 and a rigid-flex board 4, which are terminated. The other end of the rigid-flex board 4 is connected to the battery assembly 2, allowing the internal circuitry to form a coherent assembly structure. The antenna FPC 3, as a core radio frequency component, has no direct electrical connection to the ring-shaped metal shell 1; it is coupled only through spatial arrangement. The overall structure takes into account the wearing form requirements of the smart ring while reserving reasonable coupling space for antenna radiation, adapting to the space utilization characteristics of wearable devices.

[0027] In the above structure, the smart ring provided in this application breaks through the limitations of traditional metal shell 1 in shielding the antenna. It utilizes the self-resonance characteristics and electromagnetic coupling principle of the annular metal shell 1 to achieve antenna radiation. Specifically, the annular metal shell 1 possesses an inherent self-resonant frequency due to its structure. By forming electromagnetic coupling between the antenna FPC and the metal shell 1 and precisely matching their resonant frequencies, radio frequency energy can be transferred from the antenna FPC 3 to the metal shell 1 through near-field coupling. This excites the metal shell 1, which originally served a shielding function, making it an auxiliary radiator of the antenna. Working in conjunction with the antenna FPC, it completes the radiation of electromagnetic waves. This fundamentally resolves the technical contradiction between the metal shell 1 and antenna radiation, adapting to the structural characteristics of the annular metal shell 1. The final antenna radiation effect is described in [reference needed]. Figure 5 .

[0028] Among them, the self-resonant frequency of the annular metal shell 1 is the inherent resonant frequency formed by the inherent parasitic parameters of its own annular cylindrical metal structure. This frequency is determined by the size parameters such as the annular width and outer diameter of the metal shell 1. There are usually multiple self-resonant frequencies. It is the key frequency characteristic that the metal shell 1 can generate radiation by being excited by radio frequency energy. The antenna FPC3 is a flexible radio frequency component integrated into the smart ring circuit board assembly. It is connected to one end of the rigid-flex board 4 and is the core structure for realizing radio frequency energy transfer and coupling.

[0029] When the two work together, the antenna FPC and the annular metal shell 1 form electromagnetic coupling, and the resonant frequency of the antenna FPC precisely matches the self-resonant frequency of the metal shell 1. This means that the resonant frequency of the antenna FPC 3 coincides with or is close to one of the self-resonant frequencies of the annular metal shell 1, allowing radio frequency energy to be transferred from the antenna FPC 3 to the metal shell 1 through near-field coupling. This excites the metal shell 1 to resonate, transforming it from an electromagnetic shielding structure into an antenna auxiliary radiator, thus cooperating with the antenna FPC to complete electromagnetic wave radiation. (See [link to relevant documentation]). Figure 5 .

[0030] The smart ring provided in this application effectively solves the electromagnetic shielding problem of the annular metal shell 1, transforming the shielding structure into a radiating structure, significantly improving the antenna radiation effect of the smart ring in a limited space. Furthermore, it eliminates the need for additional independent radiating components, directly reusing the metal shell 1 as an auxiliary radiator, maximizing the use of the internal space of the wearable device and meeting the miniaturization design requirements of the smart ring. In addition, the overall structure is compact, with the integrated assembly of the antenna FPC 3, the rigid-flex board 4, and the battery component 2, balancing the structural stability and radio frequency performance of the device while retaining the original advantages of the metal shell 1 in terms of mechanical strength and appearance. The annular shell or the annular metal shell 1 can be either a closed cylindrical shape or a non-closed arc shape; there are no restrictions on this.

[0031] Optionally, such as Figures 2 to 4 As shown, the antenna FPC3 includes an FPC insulating layer 31 and a metal layer 32 (e.g., a copper layer) disposed on or inside the FPC insulating layer 31; the metal layer 32 is attached to the inner ring surface of the annular metal shell 1 to form a conformal coupling region, the metal layer 32 is insulated from the annular metal shell 1, and the FPC insulating layer 31 and the metal layer 32 are connected to the first end of the rigid-flex plate 4.

[0032] Specifically, in this embodiment, by setting the antenna FPC3 as a composite structure of FPC insulating layer 31 and metal layer 32, with the metal layer 32 attached to the inner ring surface of the annular metal shell 1 to form a conformal coupling region, and the metal layer 32 being insulated from the shell, the radiation effect of the antenna is further improved. The conformal attachment allows the coupling region to fully contact the shell, significantly improving electromagnetic coupling efficiency and ensuring stable RF energy transmission; the insulation design avoids signal short-circuit losses caused by electrical contact between the two, ensuring accurate resonant frequency matching. Simultaneously, the FPC insulating layer 31 and metal layer 32 are directly connected to the rigid-flex board 4, simplifying the assembly structure of the antenna and circuit board, adapting to the confined space of the smart ring, further optimizing the auxiliary radiation effect of the metal shell 1, making the overall antenna radiation performance more stable, and balancing structural compactness and RF transmission reliability.

[0033] Optionally, such as Figures 2 to 4 As shown, the rigid-flex board 4 includes an antenna matching circuit, a feed source, a high-frequency isolation circuit, and a GND network; the metal layer 32 on the antenna FPC is connected to the antenna matching circuit, the antenna matching circuit is connected to the feed source, and the high-frequency isolation circuit and GND network are connected and connected to the annular metal shell 1 through the conductive connector 5.

[0034] Specifically, in some embodiments, the rigid-flex board 4 may include an antenna matching circuit and a feed source. The annular metal housing 1 is physically isolated from the antenna FPC3, but coupled conformally. The conformal coupling regions of the antenna FPC3 portion are physically connected together via antenna connection regions (FPC insulating layer 31 and metal layer 32). The antenna connection regions are connected to the surface antenna matching circuit through at least one via in the rigid-flex board 4. The antenna matching circuit is connected to the feed source (RF chip) via a feed line.

[0035] In other embodiments, by integrating the antenna matching circuit, feed source, high-frequency isolation circuit, and GND network on the rigid-flex board 4, and establishing a connection architecture between each module and the antenna FPC3 and the annular metal shell 1, dual optimization of RF performance and electrostatic discharge (ESD) protection performance is achieved. The antenna matching circuit connects the metal layer 32 and the feed source, precisely controlling the RF signal transmission characteristics to ensure accurate matching of the resonant frequency points of the antenna FPC3 and the metal shell 1, thus improving energy transfer efficiency. The feed source provides stable RF excitation for the antenna, solidifying the radiation foundation. The conductive connector 5 can be made of conductive foam, conductive tape, metal springs, etc., to achieve connectivity. The high-frequency isolation circuit can typically be implemented using series inductors. These components, while forming an ESD path, isolate high-frequency signals, ensuring that high-frequency signals can pass through the antenna radiator (annular metal shell) normally.

[0036] Furthermore, the high-frequency isolation circuit, through the conductive connector 5, links the annular metal shell 1 with the GND network, effectively blocking high-frequency signals and ensuring the antenna operates normally in the high-frequency target band. Simultaneously, it optimizes grounding performance and improves electrostatic discharge (ESD) protection. Each circuit module is integrated on the rigid-flex board 4, eliminating the need for additional components and maximizing the use of the limited internal space of the smart ring, thus adapting to miniaturized wearable designs. The overall circuit architecture significantly enhances the stability and reliability of the auxiliary radiation from the metal shell 1, further optimizing the antenna's overall radiation performance and ESD protection capabilities.

[0037] Optionally, such as Figure 2 As shown, the metal layer 32 is recessed inward relative to the FPC insulating layer 31, and the edges of the metal layer 32 and the insulating layer 31 have rounded corners.

[0038] Specifically, in this embodiment, the metal layer 32 of the antenna FPC3 is contracted inward relative to the FPC insulating layer 31, and the edges of the metal layer 32 are rounded to achieve dual optimization of structural adaptation and radio frequency performance. The inward contraction of the metal layer 32 reserves a safe area at the edge of the FPC insulating layer 31, preventing scratches and short circuits caused by exposed edges during FPC processing and mounting, thus meeting the assembly precision requirements of the confined space of the smart ring. The rounded corner treatment eliminates the sharp corner effect of the metal layer 32's edges, reducing radio frequency signal reflection and loss at the edges, ensuring stable energy transfer during electromagnetic coupling, avoiding stray signal generation, and optimizing the consistency of antenna radiation.

[0039] Meanwhile, the above design meets the process requirements for FPC mass production, which can improve the processing yield and structural reliability of antenna FPC3, make the coupling between the conformal coupling area and the annular metal shell 1 more stable, and further ensure the overall RF performance of the antenna.

[0040] Optionally, such as Figures 1 to 2 As shown, the conformal coupling region is attached to the inner surface of the annular metal shell 1 with double-sided adhesive, and an insulating support structure is filled between the second end of the battery assembly 2 and the antenna FPC3; and / or, the distance between the conformal coupling region and the inner surface of the annular metal shell 1 is constant.

[0041] Specifically, in this embodiment, by attaching the conformal coupling area with double-sided adhesive, filling the insulating support structure, and ensuring a constant distance between the coupling area and the metal casing 1, both structural fixation and radio frequency performance are guaranteed. The double-sided adhesive ensures the conformal coupling area adheres tightly to the inner surface of the metal casing 1, guaranteeing electromagnetic coupling stability and simplifying the assembly process; the insulating support structure forms a clearance area between the battery assembly 2 and the antenna FPC3, improving the overall electromagnetic radiation efficiency of the antenna.

[0042] Furthermore, the conformal coupling region maintains a constant distance from the annular metal shell 1, ensuring consistent RF energy transfer efficiency and preventing resonant frequency shifts caused by spacing variations, thus making the antenna radiation performance more stable. The overall design is adapted to the confined space of the smart ring, improving the reliability of structural assembly and the consistency of RF performance.

[0043] Optionally, such as Figure 1 As shown, the battery assembly 2 is configured as an arc shape, the circuit board assembly is configured as a multi-angle shape, and at least part of the antenna FPC3 extends between the second end of the battery assembly 2 and the annular metal shell 1, so that the battery assembly 2 and the circuit board assembly together form an annular structure.

[0044] Specifically, in this embodiment, the battery assembly 2 is designed to be arc-shaped, and the circuit board assembly is designed to be in a multi-angle configuration, allowing part of the antenna FPC3 to extend between the second end of the battery assembly 2 and the metal casing 1, so that the two together form a ring structure, which fits the ring shape of the smart ring, maximizes the use of the narrow space inside the casing, and improves space utilization. The ring assembly structure allows for a higher degree of fit between the internal components and the ring-shaped metal casing 1, ensuring the effective arrangement of the conformal coupling area of ​​the antenna FPC3 and optimizing the spatial conditions for electromagnetic coupling.

[0045] Meanwhile, the integrated ring structure improves the assembly stability of internal components, avoids component displacement during wear that affects the coupling effect, makes the resonant coupling between antenna FPC3 and metal shell 1 more stable, further ensures the consistency of antenna radiation performance, and balances structural compactness and radio frequency stability.

[0046] Optionally, the annular housing further includes a potting inner shell, which is disposed inside the annular metal outer shell 1 and covers the battery assembly 2 and the circuit board assembly; and / or, the annular metal outer shell 1 is configured as an open ring.

[0047] Specifically, in this embodiment, a potting inner shell is added inside the annular metal outer shell 1 to cover the battery and circuit board assembly, achieving the dual effects of structural protection and stable radio frequency performance. The potting inner shell forms an integral protective layer that buffers vibrations and impacts during wear, prevents internal component displacement or loosening, prevents changes in the relative position of the conformal coupling area and the metal outer shell 1, and ensures the stability of electromagnetic coupling. Simultaneously, it isolates dust and moisture, improving the device's environmental adaptability and service life.

[0048] In addition, the potting structure allows the internal components to form a stable whole with the annular metal shell 1, which is suitable for the wearable use of smart rings and does not affect the resonant coupling between the antenna FPC3 and the metal shell 1. While enhancing the structural reliability, it also ensures the radiation performance of the antenna.

[0049] In some embodiments, the annular metal outer shell 1 can be configured as an open ring, and the glued inner shell can also be matched with glued to form an open ring, making it more convenient for the user to wear.

[0050] According to the second aspect of this application, such as Figure 6As shown, an antenna design method is provided, applied to a smart ring in the first aspect. The design method includes: S601, determining the self-resonant frequency of the annular metal shell 1 based on the size parameters and relative positions of the annular metal shell 1, the battery assembly 2, and the rigid-flex PCB 4; S602, adjusting the size parameters of the antenna FPC 3 to match the resonant frequency formed by the antenna FPC 3 with one of the self-resonant frequencies of the annular metal shell 1; S603, adjusting the resonant frequency formed by the antenna FPC 3 in the wearing state to the target frequency band through impedance matching adjustment, and simultaneously determining the specific form and parameters of the matching circuit.

[0051] Specifically, in this embodiment, the first step is to collect or select various dimensional parameters of the annular metal shell 1, battery component 2 and rigid-flexible plate 4 based on the key structural parameters of the smart ring, and at the same time confirm the actual relative assembly positions of the three inside the ring. Combining the structural parameters and spatial layout, the self-resonant frequency of the annular metal shell 1 is accurately determined by actual measurement or simulation. This frequency is jointly determined by the structural characteristics of the metal shell 1 and the spatial influence of the surrounding components.

[0052] The second step involves obtaining the self-resonant frequency of the annular metal shell 1, and then adjusting the size parameters of the antenna FPC3 with frequency matching as the core objective. By changing the length, width, and other dimensions of its key structures, the resonant frequency formed by the antenna FPC3 is controlled, ultimately achieving precise matching between the resonant frequency formed by the antenna FPC3 and one of the self-resonant frequencies of the annular metal shell 1. This completes the core antenna design and meets the design requirements of miniaturized wearable devices.

[0053] The self-resonant frequency of a metal casing is an objective physical parameter, influenced by its width, outer diameter, other components, and user wearing habits. It's highly likely it won't be on the desired target frequency band. Therefore, impedance matching is necessary to alter the antenna structure's frequency response, allowing the target frequency band, which isn't initially at its optimal resonant position, to achieve optimal radiation. Impedance matching adjusts the impedance of the target frequency band to its optimal matching position for better radiation. Objectively, the impedance matching process makes the resonant frequency (i.e., the optimal radiation frequency) "appear" to have been moved to an adjacent target frequency band.

[0054] The aforementioned design method is based on the actual structural parameters of the smart ring, ensuring that the antenna design is compatible with the product's structure. The precisely matched resonant frequency effectively excites the annular metal shell 1 to become an auxiliary radiator, solving the shielding problem of the metal shell 1 from the design source and improving the antenna radiation effect. The method achieves frequency matching simply by adjusting the size of the antenna FPC3, without altering the core structure of the ring. It is simple to operate and highly adaptable, allowing for flexible adjustments to annular metal shells 1 of different sizes. By only changing the antenna FPC size, it meets the production design requirements of matching the dimensions of each component in products with different wearing circumferences of the smart ring. Simultaneously, it significantly reduces the trial-and-error costs of antenna design, improves R&D efficiency, and balances design rationality with production practicality.

[0055] In this application, matching the resonant frequency of the antenna FPC3 with one of the self-resonant frequencies of the annular metal shell 1 does not mean that the two frequencies completely overlap, but also includes the case where the frequencies are similar or tend to be consistent. As long as the frequency matching degree can meet the requirement that radio frequency energy is effectively transferred to the annular metal shell 1 through electromagnetic coupling, exciting the metal shell 1 to resonate and act as an auxiliary radiator of the antenna, so as to achieve a stable electromagnetic wave radiation effect.

[0056] In this scheme, the core of matching is to enable the antenna FPC3 and the annular metal shell 1 to form an effective resonant coupling, rather than the strict requirement that the frequency values ​​be completely identical. Because in actual product design, processing, assembly and wearing, the frequency will be slightly offset by factors such as structural tolerances and human body influence. Therefore, as long as the frequency points of the two are within a reasonable range that can achieve effective coupling radiation, they are within the scope of this matching.

[0057] Optionally, one of the self-resonant frequencies of the annular metal casing 1 is set to the self-resonant frequency closest to the target frequency band.

[0058] Specifically, in this embodiment, in step S602, the closest self-resonant frequency of the annular metal shell 1 to the target frequency band is used as the matching reference for the resonant frequency of the antenna FPC3. This can significantly reduce the range and difficulty of adjusting the frequency of the antenna FPC3, reduce design trial and error costs, and improve the overall R&D and debugging efficiency of the antenna. At the same time, matching the closest self-resonant frequency can minimize the frequency adjustment amplitude, reduce the radio frequency energy loss caused by large parameter adjustments, ensure the electromagnetic coupling efficiency between the antenna FPC3 and the metal shell 1, and allow the metal shell 1 to be more efficiently excited as an auxiliary radiator.

[0059] In addition, the design is adapted to the slight frequency shift caused by human wear and environmental factors in actual use, and reserves a reasonable margin for frequency adjustment to ensure that the antenna resonant frequency of the smart ring can still stably fall within the target frequency band in actual wear scenarios, continuously ensuring the stability and reliability of antenna radiation performance, and taking into account both design convenience and actual use effect.

[0060] Optionally, such as Figure 2 As shown, antenna FPC3 has a conformal coupling region. Adjusting the dimensional parameters of antenna FPC3 includes adjusting the length and / or width of the conformal coupling region.

[0061] Specifically, the resonant frequency of the antenna FPC3 is related not only to its own length and width, but also to the dimensions of the annular metal casing 1, the distance from the conformal coupling region of the antenna FPC3 to the metal casing 1, and the distance from the antenna itself to the battery assembly 2. However, when the relative positions of the key components of a product are determined, the resonant frequency of the antenna FPC3 can be adjusted by changing the length and width of the conformal coupling region, and the optimal antenna FPC3 design can be found through simulation and actual measurement.

[0062] The resonant frequency of antenna FPC3 is related to its length and width. Once the distances from the conformal coupling region of antenna FPC3 to the metal casing 1 and from the battery assembly 2 to the metal casing 1 are determined, the resonant frequency formed by antenna FPC3 can be adjusted by changing the length of the coupling region on antenna FPC3 (the distance between the BC lines) to make it coincide with the resonant frequency of the annular metal casing 1. The copper layer region of the conformal coupling region is an approximately rectangular area. The length is determined through simulation and actual measurement to achieve the resonant frequency of antenna FPC3 coinciding with the resonant frequency of the metal casing 1. The width is a maximum value that can be used after considering assembly requirements (casing thickness, assembly gap).

[0063] In this embodiment, the conformal coupling region is Figure 2 The BC segment shown in the figure allows for adjustment of the length and / or width of the conformal coupling region of the antenna FPC3. This enables direct and efficient control of the resonant frequency point formed by the antenna FPC3, quickly achieving precise matching with the self-resonant frequency point of the annular metal shell 1, significantly improving frequency tuning efficiency and reducing ineffective design operations.

[0064] Meanwhile, this adjustment method does not require modification to other areas of the antenna FPC3 or the core internal structure of the ring, adapting to the small internal space of the smart ring and balancing design convenience with structural compactness. Furthermore, frequency adaptation can be achieved by fine-tuning the coupling area size, maximizing the conformal fit between the coupling area and the metal shell 1, further ensuring the stability of electromagnetic coupling and the efficiency of radio frequency energy transfer.

[0065] Optionally, such as Figures 1 to 2 As shown, the dimensional parameters of the annular metal shell 1 include one or more of the following: the annular width of the annular metal shell 1, the outer diameter of the annular metal shell 1, and the radial thickness of the annular metal shell 1.

[0066] Specifically, in practical design, the outer diameter and outer surface width (ring width) of the annular metal shell 1 have a significant impact on the resonant characteristics of the ring-shaped structure. That is, the larger the outer diameter (longer the circumference) and the narrower the outer surface width of the annular metal shell 1, the lower its self-resonant frequency tends to be. It is important to note that in product design, an ideal annular or ring structure cannot generally be used directly. It is necessary to incorporate different thicknesses and widths in certain areas based on the ring structure. For example, according to the ID design, there may be raised shapes in certain areas (width, radial thickness), and possible local openings (for collecting ambient light information or applying proximity sensors, etc.). Furthermore, adding radial grooves to the edge of the annular structure is also a common assembly design method to assist in the positioning of other components and the completion of the assembly process. In addition, the annular metal shell 1 can also be located outside the concentric circle of the wearing circumference; that is, the center of the wearing circumference can deviate from the center of the annular metal shell 1. These variations will differ from the ideal annular structure, but the antenna radiation principle remains the same, and the antenna can be designed according to the method provided in this patent.

[0067] In practical design, one can first select ring-shaped metal shells 1 with different wearing circumferences, such as... Figure 1 As shown, the dashed boxes represent the desired wearing circumference for each element, i.e., the confirmed ring width, the outer diameter of the annular metal shell 1, and the radial thickness. The ring width is obtained by balancing the ID design and the internal space of the ring. The outer diameter of the metal shell 1 is calculated from the wearing circumference to obtain the wearing diameter, which is then multiplied by twice the product's single-sided thickness. The product's single-sided thickness refers to the radial width of the product in the radial direction. Besides the radial thickness of the metal shell 1, the product's single-sided thickness is mainly a balance between the product's ID design and ensuring sufficient internal space to implement the preset circuit functions. The radial thickness of the metal shell 1 is a value obtained by balancing the strength of the metal shell and the processing precision.

[0068] The quantification of key dimensional parameters of the ring-shaped metal shell 1 allows for precise adaptation of antenna design to different wearing circumferences and shell structure designs of smart rings. This enables rapid adjustment of antenna FPC3 parameters, significantly improving the design efficiency of antennas for multiple ring sizes. Furthermore, clear parameter definitions provide clear standards for product processing and assembly, reducing the impact of structural tolerances on self-resonant frequencies, ensuring consistent antenna performance in mass production, balancing the convenience of design and development with the stability of mass production, and adapting to the miniaturized and multi-size characteristics of smart rings.

[0069] Optionally, such as Figures 1 to 2 As shown, the dimensional parameters of the rigid-flex plate 4 include the length of the rigid-flex plate 4 and / or the minimum radial distance between the rigid-flex plate 4 and the annular metal shell 1.

[0070] Specifically, from an antenna design perspective, the key parameters of the rigid-flex board 4 are the design of its antenna FPC3 section and the minimum radial distance between the entire circuit board assembly and the annular metal casing 1 after assembly. Since electronic products generally try to use the same hardware component (ring products typically use a single circuit board assembly) to match different structural dimensions, only necessary adjustments are made to the antenna FPC3 section. This effectively improves production efficiency. In other words, utilizing the bendable nature of the rigid-flex board 4, without considering differences in the antenna FPC3, the same rigid-flex board 4 can be used to adapt to all combinations of the metal casing 1 and battery assembly 2.

[0071] In actual design, the distance between the rigid-flex board 4 and the DE line, the identical length of multiple rigid PCB areas 42, and the length of the flexible board 41 connecting each rigid PCB area 42 can be adjusted. The adjustment must meet the following conditions: the usable circuit area must be sufficient to achieve the product's preset functions, and there must be a certain radial distance between the bent portion of the flexible board 41 and the metal casing 1. The latter is actually part of the clearance area of ​​the ring-shaped metal antenna. To ensure that the conformal coupling area completely fits onto the ring-shaped metal casing 1 and maintains a consistent radial distance, double-sided adhesive is generally used to fix the conformal coupling area of ​​the antenna FPC3 to the inner surface of the ring structure.

[0072] In different versions of the rigid-flex PCB 4, the rigid-flex PCB 4 components have the same design between the DE lines, but different designs between the AD lines. The AC lines form the conformal coupling region of the FPC, and the distance between the BC lines is the length of the copper layer region within the conformal coupling region, which is a key adjustment parameter for the antenna FPC 3. The design of these parameters is detailed in the antenna coupling region design section of step A3.

[0073] However, in actual products, the differences in the antenna components need to be considered. When using different ring-shaped housings, a corresponding antenna FPC should be designed for each size ring to achieve optimal antenna performance. In practical design, a balance can be struck between the two: that is, while minimizing the impact on the actual antenna radiation effect, try to use the same antenna FPC3 design to reduce the number of hardware (rigid-software board 4 components) versions.

[0074] Optionally, such as Figure 1 As shown, the dimensional parameters of the battery assembly 2 include the radial thickness of the battery assembly 2 and / or the radial distance from the battery assembly 2 to the inner surface of the annular metal casing 1.

[0075] Specifically, the shape of battery component 2 is mainly determined by its length (arc length), thickness, and bending radius. As the circumference of the smart ring changes, it is usually impossible to use the same battery component 2 to fit all the shells. Therefore, each structure with a different wearing size requires a battery component 2 with a different radius of curvature. In actual design, the impact of battery component 2 on antenna design is not reflected in its shape parameters (i.e., length, thickness, bending radius), but rather in the radial distance between battery component 2 and the ring-shaped metal shell 1.

[0076] In practical design, it is necessary to maintain a distance between the battery assembly 2 and the metal casing 1 and the conformal coupling area. As the distance increases, the overall radiation effect of the antenna will increase. However, it is generally difficult to provide sufficient distance in practice, because this means a reduction in the actual battery volume or an increase in the radial thickness of the product. Therefore, each product needs to balance the clearance space, battery space, and product thickness.

[0077] Optionally, the antenna design method also includes: adjusting the resonant frequency point formed by the antenna FPC3 through impedance matching, so that when the smart ring is worn, the resonant frequency point formed by the antenna FPC3 is within the target frequency band.

[0078] Specifically, in this embodiment, the antenna design method for each wearing circumference can be used to obtain the antenna design for other smart rings under various wearing circumferences. The only difference in the assembly of these antenna designs is the length of the copper layer region of the conformal coupling area on the antenna FPC3 and its corresponding matching circuit.

[0079] Wearing the device causes a low-frequency shift in the antenna's resonant frequency. By adjusting the resonant frequency formed by the antenna FPC3 through impedance matching, the frequency can be precisely pulled back into the target frequency band, ensuring the antenna's radiation performance during wearable use. This step requires no modification to the hardware structure; frequency calibration is achieved solely through circuit tuning. It is convenient and highly adaptable, while also mitigating the impact of environmental factors in the basic design. This makes the antenna's performance more stable and reliable in real-world usage scenarios, effectively improving the smart ring's RF communication performance and balancing design integrity with the actual user experience.

[0080] Furthermore, in practice, because the self-resonant frequency of the metal casing 1 has a wide bandwidth, the variation of the conformal coupling region on the antenna FPC3 along its length has a limited impact on the coupling efficiency within a certain range, which is reflected in the limited change in its radiation performance. Utilizing this effect, the conformal coupling region on the same circuit board assembly can typically be adapted to multiple combinations of metal casings 1 and their corresponding key components. For example, the same antenna FPC3 can be designed to adapt to products with three different perimeters: 48mm, 52mm, and 56mm, while another antenna FPC3 can be designed to adapt to products with 60mm and 64mm perimeters.

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0082] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A smart ring, characterized in that, include: An annular housing, the annular housing comprising an annular metal outer shell (1). Battery assembly (2), wherein the battery assembly (2) is disposed inside the annular metal casing (1); The circuit board assembly is disposed inside the annular metal shell (1) and includes an antenna FPC (3) and a rigid-flex board (4). The antenna FPC (3) is connected to the first end of the rigid-flex board (4), and the second end of the rigid-flex board (4) is connected to the first end of the battery assembly (2). The antenna FPC (3) is electromagnetically coupled to the annular metal shell (1), and the resonant frequency of the antenna FPC (3) is matched with the self-resonant frequency of the annular metal shell (1), so that the annular metal shell (1) serves as an auxiliary radiator of the antenna.

2. The smart ring according to claim 1, characterized in that, The antenna FPC (3) includes an FPC insulating layer (31) and a metal layer (32) disposed on or inside the FPC insulating layer (31). The metal layer (32) is attached to the inner ring surface of the annular metal shell (1) to form a conformal coupling area. The metal layer (32) is insulated from the annular metal shell (1). The FPC insulation layer (31) and the metal layer (32) are connected to the first end of the rigid-flex plate (4).

3. The smart ring according to claim 2, characterized in that, The rigid-flex board (4) includes an antenna matching circuit, a feed source, a high-frequency isolation circuit, and a GND network; The metal layer (32) is connected to the antenna matching circuit, the antenna matching circuit is connected to the feed source, the high-frequency isolation circuit and the GND network are connected and connected to the annular metal shell (1) through the conductive connector (5).

4. The smart ring according to claim 2, characterized in that, The metal layer (32) is recessed inward relative to the FPC insulating layer (31), and the edges of the metal layer (32) and the FPC insulating layer (31) are rounded.

5. The smart ring according to claim 2, characterized in that, The conformal coupling region is attached to the inner surface of the annular metal casing (1) with double-sided adhesive, and an insulating support structure is filled between the second end of the battery assembly (2) and the antenna FPC (3); and / or, The distance between the conformal coupling region and the inner surface of the annular metal shell (1) is constant.

6. The smart ring according to claim 1, characterized in that, The battery assembly (2) is configured as an arc shape, the circuit board assembly is configured as a multi-angle shape, and at least part of the antenna FPC (3) extends between the second end of the battery assembly (2) and the annular metal shell (1) so that the battery assembly (2) and the circuit board assembly together form an annular structure.

7. The smart ring according to claim 1, characterized in that, The annular housing further includes a potting inner shell, which is disposed inside the annular metal outer shell (1) and covers the battery assembly (2) and the circuit board assembly; and / or, The annular metal shell (1) is configured as an open ring.

8. An antenna design method, applied to the smart ring according to any one of claims 1-7, characterized in that, The design method includes: The self-resonant frequency of the annular metal shell (1) is determined based on the size parameters and relative positions of the annular metal shell (1), the battery assembly (2), and the rigid-flexible plate (4); By adjusting the size parameters of the antenna FPC (3), the resonant frequency point formed by the antenna FPC (3) is matched with one of the self-resonant frequencies of the annular metal shell (1).

9. The antenna design method according to claim 8, characterized in that, One of the self-resonant frequencies of the annular metal shell (1) is set to the self-resonant frequency closest to the target frequency band.

10. The antenna design method according to claim 8, characterized in that, The antenna FPC (3) has a conformal coupling region, and adjusting the dimensional parameters of the antenna FPC (3) includes: Adjust the length and / or width of the conformal coupling region.

11. The antenna design method according to claim 8, characterized in that, The dimensional parameters of the annular metal shell (1) include one or more of the following: the annular width of the annular metal shell (1), the outer diameter of the annular metal shell (1), and the radial thickness of the annular metal shell (1); And / or, the dimensional parameters of the rigid-flex plate (4) include the length of the rigid-flex plate (4) and / or the minimum radial distance between the rigid-flex plate (4) and the annular metal shell (1); And / or, the dimensional parameters of the battery assembly (2) include the radial thickness of the battery assembly (2) and / or the radial distance of the battery assembly (2) to the inner surface of the annular metal casing (1).

12. The antenna design method according to claim 8, characterized in that, Also includes: By adjusting the resonant frequency of the antenna FPC (3) through impedance matching, the resonant frequency of the antenna FPC (3) is within the target frequency band when the smart ring is worn.

Images