Conductive ink-based parasitic elements for device antennas

Abstract

A wearable device is provided. A wearable device includes a printed circuit board, a conductive housing, an antenna defined by a gap between the printed circuit board and the conductive housing, a cover having an outer surface, and a tag. The tag includes a film and a parasitic element. A parasitic element is located between the membrane and an outer surface of the cap, and may be bonded to the cap during an injection molding process. In addition, parasitic elements may be disposed between multiple layers printed or otherwise applied to the label.

Description

Technical Field

[0001] The present disclosure relates generally to wearable devices. More specifically, the present disclosure relates to a wearable device that includes a parasitic element to improve the performance (eg, radiation efficiency) of an antenna of the wearable device. Background Art

[0002] Modern electronic devices often include one or more radio frequency (RF) antennas to facilitate wireless communication with other electronic devices. Antennas may be included in electronic devices, such as wearable devices, so that the device may be equipped with LTE, global positioning system (GPS), Wi-Fi, and Bluetooth capabilities. Often, particularly in the case of wearable devices, antenna signals may have a tendency to radiate from the device toward the user's skin, rather than outward into the environment, which may negatively impact the performance of the device depending on how the device is used.

[0003] Therefore, there is a need for a wearable device that includes a means for directing radiation from the device toward the environment rather than toward the user's skin. Summary of the invention

[0004] Aspects and advantages of embodiments of the present disclosure will be set forth in part in the following description, or may be learned from the description, or may be learned through practice of the embodiments.

[0005] In one aspect, a wearable device is provided. The wearable device includes a printed circuit board, a conductive housing, an antenna, a cover having an outer surface, and a tag including a film and a parasitic element. In addition, the parasitic element is located between the film and the outer surface of the cover.

[0006] In some implementations, the parasitic element can include a conductive ink layer.

[0007] In some implementations, the label can be insert molded onto the outer surface of the cover.

[0008] In some implementations, the label can include a decorative ink layer between the film and the parasitic element.

[0009] In some implementations, the label can include a non-conductive masking ink layer between the decorative ink layer and the parasitic element.

[0010] In some implementations, the label can include a first insulating ink layer.

[0011] In some implementations, the label can include a first gloss layer between the non-conductive masking ink layer and the first insulating ink layer.

[0012] In some implementations, the tag can include a second insulating ink layer, wherein the parasitic element can be located between the first insulating ink layer and the second insulating ink layer.

[0013] In some implementations, the label can include an adhesive layer, wherein the adhesive layer can connect the label to the outer surface of the cover.

[0014] In some implementations, the label can include a second gloss layer between the second insulating ink layer and the adhesive layer.

[0015] In some implementations, the antenna can be a slot antenna defined by a gap between the printed circuit board and the conductive housing.

[0016] In some implementations, the parasitic element is electrically grounded to the printed circuit board via a radio frequency ground, a direct current ground, or a matching circuit.

[0017] In another aspect, a tag for a wearable device including an antenna is provided. The tag includes multiple layers, including a film, a decorative ink layer, a non-conductive masking ink layer, a first insulating ink layer, a parasitic element, and a second insulating ink layer. In addition, the multiple layers of the tag are applied to the film, and the parasitic element includes a conductive ink layer.

[0018] In some implementations, the label can include an adhesive layer.

[0019] In some implementations, the label can include a first gloss layer.

[0020] In some implementations, a portion of the conductive ink layer can be exposed and have no additional layers printed thereon.

[0021] In some implementations, the tag can be configured to be joined to the plastic cover during the insert molding process.

[0022] In another aspect, a method of forming a tag for a wearable device including an antenna is provided. The method includes printing one or more layers of non-conductive masking ink onto a film, printing one or more layers of conductive ink onto the film to define a parasitic element, printing an adhesive layer onto the film to form a tag, and forming the tag into a shape that matches the shape of a cover to which the tag is to be applied.

[0023] In some implementations, the label can be bonded to the outer surface of the cover during the insert molding process, and the adhesive layer can bond the label to the cover.

[0024] In some implementations, the method can include printing one or more decorative ink layers onto the film.

[0025] In some implementations, the method can include printing one or more layers of insulating ink onto the film.

[0026] In some implementations, the method can include trimming the label to remove any excess portions.

[0027] These and other features, aspects and advantages of various embodiments of the present disclosure will be better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate example embodiments of the present disclosure and, together with the description, serve to explain the relevant principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] A detailed discussion of the embodiments for those skilled in the art is set forth in this specification with reference to the accompanying drawings, in which:

[0029] Figure 1 A wearable device according to some implementations of the present disclosure is depicted.

[0030] Figure 2 A conductive housing for a wearable device according to some implementations of the present disclosure is depicted.

[0031] Figure 3 Depicted is a side view of a wearable device according to some implementations of the present disclosure, with a bottom cover of a housing assembly of the wearable device removed.

[0032] Figure 4 Depicted is a side view of a wearable device with a housing assembly of the wearable device removed, according to some implementations of the present disclosure.

[0033] Figure 5 Depicted is a printed circuit board positioned within a conductive housing of a wearable device according to some implementations of the present disclosure.

[0034] Figure 6 Depicted is a printed circuit board for a wearable device according to some implementations of the present disclosure.

[0035] Figure 7 Depicted is a slot antenna defined by a gap between a conductive housing and a printed circuit board of a wearable device, according to some implementations of the present disclosure.

[0036] Figure 8 Depicted are parasitic elements grounded to a printed circuit board of a wearable device, according to some implementations of the present disclosure.

[0037] Fig. 9 Depicted is a parasitic element of a radio frequency ground to a printed circuit board of a wearable device according to some implementations of the present disclosure.

[0038] Fig.10 Depicted is a side view of a wearable device including a parasitic element disposed between a membrane and a bottom cover of a housing assembly according to some implementations of the present disclosure.

[0039] Fig.11 Depicts a tag including a thin film and a parasitic element according to some implementations of the present disclosure and Fig.10 An enlarged cross-sectional view of the bottom cover.

[0040] Fig.12 Depicted are some implementations according to the present disclosure including Fig.11 Top view of the film and parasitic element tabs with the bottom cover removed.

[0041] Fig.13 Depicted are cross-sectional perspective views of a printed circuit board, slot antenna, bottom cover, parasitic element, and membrane of a wearable device according to some implementations of the present disclosure.

[0042] Fig.14 Depicted Fig.13 , which shows in greater detail the slot antenna and the opening in the bottom cover for connecting the parasitic element to the printed circuit board according to some implementations of the present disclosure.

[0043] Fig.15 One configuration for mechanically connecting a parasitic element to a printed circuit board is depicted in accordance with some implementations of the present disclosure.

[0044] Fig.16 Another configuration for mechanically connecting a parasitic element to a printed circuit board is depicted in accordance with some implementations of the present disclosure.

[0045] Fig.17 Depicted are methods of assembling a wearable device according to some implementations of the present disclosure, which may include a membrane, a parasitic element, a plastic cover, a printed circuit board, a slot antenna, a conductive housing, and a display. DETAILED DESCRIPTION

[0046] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are shown in the accompanying drawings. Each example is provided by way of explanation of the present invention rather than by way of limitation. In fact, it will be apparent to those skilled in the art that various modifications and changes may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to encompass such modifications and changes within the scope of the appended claims and their equivalents.

[0047] As used herein, the terms "about," "approximately," or "generally," when used to modify a value, indicate that the value may be increased or decreased by 5% and remain within the disclosed embodiment. In addition, when multiple ranges are provided, the present invention contemplates any combination of the minimum and maximum values ​​described in the multiple ranges. For example, if a range of "from about 20% to about 80%" and "from about 30% to about 70%" is described, the present invention also encompasses a range of "from about 20% to about 70%" or a range of "from about 30% to about 80%."

[0048] An example aspect of the present disclosure relates to a wearable device that can be worn, for example, on a user's wrist or elsewhere on the user's body. The wearable device may include an antenna, a conductive housing (e.g., a metal housing), a circuit board (e.g., a printed circuit board) located within the conductive housing, a cover (e.g., a plastic cover), and a tag including a film and a parasitic element. In addition, although the present disclosure contemplates any type of antenna, it should be understood that in some implementations, the antenna may be a slot antenna defined by a gap (e.g., a 0.1 mm gap to about 5 mm gap) between the conductive housing and the printed circuit board. The slot antenna may have signals operating on multiple different frequency bands. For example, the slot antenna may operate on one or more global navigation satellite systems (GNSS) (e.g., global positioning system (GPS), GLONASS, Galileo, etc.) bands. For example, one or more global navigation satellite system bands may include one or more GPS bands (e.g., 1164 MHz to 1189 MHz, 1563 MHz to 1587 MHz, 1215 MHz to 1240 MHz). However, since the wearable device must be compact enough to be worn on the user's wrist, the distance between the antenna and the user's wrist may be small, which in some cases may affect the performance (e.g., radiation efficiency) of the slot antenna on one or more GPS frequency bands. Specifically, too much signal may often be radiated directly through the cover onto the user's wrist, which may negatively affect GPS performance.

[0049] It should also be understood that the antenna may operate on other frequency bands, such as those used in LTE, Wi-Fi, and Bluetooth applications that are well known to those of ordinary skill in the art.

[0050] Regardless of the specific application for which the antenna of the wearable device is used, the wearable device includes a parasitic element. The parasitic element may be located or positioned between an outer surface of the cover and a film, wherein the film and the parasitic element and other layers form a tag. The parasitic element is placed as close to the user's wrist as possible to direct RF (e.g., GPS) signals from the wrist to the open space. The parasitic element is also metal-based (e.g., comprising conductive ink) and has a low resistance (e.g., less than about 1 ohm over the length of the parasitic element). In addition, the distance between the parasitic element and the user's wrist and the distance between the parasitic element and the system ground (e.g., the device's printed circuit board (PCB)) are precisely controlled within a certain range because if the parasitic element is too close to the PCB, the parasitic element will not radiate effectively at the desired frequency and will not enhance the performance of the antenna. For example, the distance D1 between the parasitic element and the user's wrist (see Fig.10 ) may range from about 0.15 mm to about 2.5 mm, such as from about 0.2 mm to about 2.25 mm, such as from about 0.25 mm to about 2 mm. Therefore, when the wearable device is worn by a user, the parasitic element is configured and arranged to be located at a distance D1 from the user's wrist. At the same time, the distance D2 between the parasitic element and the system ground at PCB 300 (see Fig.14 ) may range from about 1.25 mm to about 3.5 mm, such as from about 1.5 mm to about 3 mm, such as from about 1.75 mm to about 2.75 mm.

[0051] In addition, the parasitic element can be applied as one of a series of layers printed onto a film surrounding the outer surface of a cover of the wearable device to form a tag. The film (e.g., a clear in-mold label (IML) film), the parasitic element, and the other layers of the tag can then be stamped, formed into the shape of the outer surface of the cover, and insert molded onto the outer surface of the cover to provide a low-profile design in which the parasitic element is close to the user's wrist and away from the system ground (e.g., at PCB 300), thereby improving antenna performance. For example, a tag including a parasitic element can have a thickness T (see Fig.11), which ranges from about 0.1 mm to about 0.5 mm, such as from about 0.125 mm to about 0.3 mm, such as from about 0.15 mm to about 0.25 mm. In addition, the label may include multiple printed layers, which may include, but are not limited to, a decorative ink layer, a non-conductive masking ink layer, a first glossy layer, a first insulating ink layer, a conductive ink layer, a second insulating ink layer, a second glossy layer, and an adhesive layer, wherein each of the layers described may itself include multiple layers. The decorative ink layer is visible from the outside of the wearable device through the transparent film, and the masking ink layer is used to hide other layers of the label, such as a conductive ink layer that forms a parasitic element. The insulating ink layer can add electrical stability to the parasitic element, and the glossy ink layer can protect the conductive ink layer and the decorative ink layer from the effects of heat during the embedding molding process (where the various layers of the label (including the parasitic element) are bonded to the plastic bottom cover of the wearable device). In addition, the adhesive layer bonds the label to the outer surface of the plastic cover.

[0052] In addition, the parasitic element can be electrically connected to the printed circuit board. For example, the parasitic element can be electrically connected to the ground plane of the printed circuit board. For example, the parasitic element can be directly connected to the printed circuit board at a first position on the printed circuit board. In addition, the parasitic element can be DC grounded to the printed circuit board at a second position on the printed circuit board. The first position and the second position can be spaced apart from each other along the printed circuit board. In addition, the printed circuit board can include a first fastener (e.g., a spring clip, a reinforcing pin, a compression spring, etc.) located at the first position and a second fastener (e.g., a spring clip, a reinforcing pin, a compression spring, etc.) located at the second position to couple the parasitic element to the printed circuit board via a first opening and a second opening located at the first position and the second position, respectively. For example, the first contact of the parasitic element and / or the second contact of the parasitic element can be mechanically coupled and / or electrically coupled to the printed circuit board via the first fastener and the second fastener, respectively, rather than via a soldered connection.

[0053] The parasitic element can be radio frequency (RF) grounded to the printed circuit board at a plurality of different locations. In this way, one or more currents are induced in the parasitic element when the antenna (e.g., slot antenna) operates at one or more frequency bands, which can improve the performance (e.g., radiation efficiency) of the antenna at one or more frequency bands. In addition, the parasitic element can improve the radiation efficiency of the antenna at one or more frequency bands by at least about 2 decibels, such as at least about 3 decibels, such as at least about 4 decibels.

[0054] The parasitic element can be electrically grounded to the printed circuit board. For example, in some implementations, the parasitic element can be RF grounded to multiple locations of the printed circuit board. In this way, when the antenna (e.g., the slot antenna) operates on one or more frequency bands, one or more currents are induced on the parasitic element, which can improve the performance (e.g., radiation efficiency) of the antenna on the one or more frequency bands. In addition, the parasitic element can improve the radiation efficiency of the antenna on the one or more frequency bands by at least about 2 decibels, such as at least about 3 decibels, such as at least about 4 decibels.

[0055] In some implementations, the parasitic element may be electrically grounded to the printed circuit board via a matching circuit. It should be understood that the matching circuit may include various electronic components (e.g., capacitors, inductors, resistors, switching devices, etc.) to facilitate electrically grounding the parasitic element to the printed circuit board. In alternative implementations, the parasitic element may be directly grounded (DC) to the printed circuit board.

[0056] Now referring to the accompanying drawings, Figure 1 A wearable device 100 according to some implementations of the present disclosure is depicted. As shown, the wearable device 100 can be worn, for example, on a user's wrist 102. For example, the wearable device 100 can include a band 104 and a housing assembly 110. The housing assembly 110 can be coupled to the band 104. In this manner, the band 104 can be fastened to the user's wrist 102 to secure the housing assembly 110 to the user's wrist 102.

[0057] In some implementations, the wearable device 100 may include a display 112 that can display content (e.g., time, date, etc.) to the user. In some implementations, the display 112 may include an interactive display (e.g., a touch screen or a touch-free screen). In such implementations, the user can interact with the wearable device 100 via the display 112 to control the operation of the wearable device 100. Alternatively or in addition, the wearable device 100 may include one or more input devices 114 that can be manipulated by the user to interact with the wearable device 100. For example, the one or more input devices 114 may include a mechanical button that can be manipulated (e.g., pressed) to interact with the wearable device 100. In some implementations, the one or more input devices 114 can be manipulated to control the operation of a backlight (not shown) associated with the display 112. It should be understood that the one or more input devices 114 can be configured to allow the user to interact with the wearable device 100 in any suitable manner. For example, in some implementations, the one or more input devices 114 can be manipulated by the user to navigate through one or more menus on the display 112.

[0058] In some implementations, the wearable device 100 can be designed to be worn by a user (e.g., continuously). When worn, the wearable device 100 can collect data about activities performed by the user or about the user's physiological state. Such data may include data representing the surrounding environment around the user or the user's interaction with the environment. For example, the data may include motion data about the user's movement, ambient light, ambient noise, air quality, etc. and / or physiological data obtained by measuring various physiological characteristics of the user (such as heart rate, sweat level, body temperature, etc.).

[0059] Reference now Figure 2 , according to some implementations of the present disclosure, a side view of a housing assembly 110 of a wearable device 100 is provided. As shown, the housing assembly 110 may include a conductive housing 120. The conductive housing 120 may be attached to a band 104 for securing the housing assembly 110 to a user's wrist 102 ( Figure 1 ). The housing assembly 110 may include a bottom cover 122 coupled to the conductive housing 120. In some implementations, the bottom cover 122 may be coupled to the bottom of the conductive housing 120. In this way, when the housing assembly 110 is secured to the user's wrist 102 via the band 104, the bottom cover 122 may contact (e.g., touch) the user's wrist 102 ( Figure 1 ).

[0060] The conductive housing 120 may include any suitable conductive material. For example, in some implementations, the conductive housing 120 may include a metal housing. The bottom cover 122 may include an insulating material. For example, in some implementations, the bottom cover 122 may include a plastic cover.

[0061] In some implementations, the wearable device 100 can include an electrocardiogram (ECG) electrode 200. As shown, the ECG electrode 200 can be positioned within an opening (e.g., a cutout) defined by the bottom cover 122. In this way, when the housing assembly 110 is secured to the user's wrist 102 via the band 104, the ECG electrode 200 can be positioned on the user's wrist 102 ( Figure 1 ). When the ECG electrode 200 is close enough to the user's wrist 102, the ECG electrode 200 can be electrically connected to the user's wrist 102. In addition, it should be understood that when the ECG electrode 200 is electrically connected to the user's wrist 102, the wearable device 100 can determine one or more health indicators (e.g., heart rate) of the user based at least in part on data obtained via the ECG electrode 200.

[0062] Reference now Figure 3 and Figure 4 , a side view of the wearable device 100 is provided according to some implementations. Figure 3 The bottom cover 122 ( Figure 2 ) Side view of the wearable device 100 with the wearable device 100 removed. Figure 4 Depicted is a housing assembly 110 ( Figure 2 ) is removed. As shown, in some implementations, the display 112 can include a display trace (e.g., an ITO coating) 116 and a touch trace (e.g., an ITO coating) 118. The wearable device 100 can also include one or more electrodes 124 to collect and store data about any number of parameters (skin electrodermal activity, etc.) that can be communicated to the user.

[0063] The wearable device 100 may include a housing assembly 110 (see Figure 2 ) within the printed circuit board 300. For example, in some implementations, a first portion of the printed circuit board 300 can be positioned within the conductive housing 120, and a second portion of the printed circuit board 300 can be positioned within the bottom cover 122 (see Figure 2 ). The printed circuit board 300 may include a plurality of electronic components (not shown) disposed thereon. In some implementations, the printed circuit board 300 may include a shielding cover 302 covering at least a portion of the printed circuit board 300. In this way, the shielding cover 302 may cover one or more of the plurality of electronic components disposed on the printed circuit board 300. Alternatively or in addition, the printed circuit board 300 may include one or more charging pins 304. In this way, the wearable device 100 may be coupled to a charging circuit (not shown) via one or more charging pins 304 to facilitate charging an energy storage device (e.g., a battery) of the wearable device 100.

[0064] In some implementations, the conductive housing 120 may define openings (e.g., cutouts) for one or more electrodes 124. In this way, the one or more electrodes 124 may be visible to the user. In some implementations, the one or more electrodes 124 may include electrodermal activity (EDA) electrodes. In such implementations, the user may contact (e.g., touch) the one or more electrodes 124 to facilitate measuring one or more health indicators of the user (e.g., heart rate, blood pressure, EDA, etc.). It should be understood that the one or more electrodes 124 may be electrically coupled to the printed circuit board 300.

[0065] Reference now Figure 5 , the printed circuit board 300 can be positioned relative to the conductive housing 120 such that a gap 400 is defined between the conductive housing 120 and the printed circuit board 300. The gap 400 can extend around a portion or the entire perimeter of the printed circuit board 300. In other words, at least some portion of the printed circuit board 300 cannot contact (e.g., touch) the conductive housing 120.

[0066] In some implementations, the width 402 of the gap 400 defined between the conductive housing 120 and the printed circuit board 300 can range from about 0.5 mm to about 10 mm, such as from about 1 mm to about 7.5 mm, such as from about 1.5 mm to about 5 mm. In some implementations, the width 402 of the gap 400 can vary around the perimeter of the printed circuit board 300. For example, the width 402 of the gap 400 between the conductive housing 120 and the printed circuit board 300 at a first portion of the perimeter of the printed circuit board 300 can be different (e.g., wider, narrower) than the width 402 of the gap 400 between the conductive housing 120 and the printed circuit board 300 at a second portion of the perimeter of the printed circuit board 300. In some implementations, the printed circuit board 300 can touch the conductive housing 120.

[0067] Reference now Figure 6 and Figure 7 In some implementations, the perimeter of the printed circuit board 300 may include a copper-free or ground-keep-out area 306. It should be understood that the ground-keep-out area 306 may include an area of ​​the printed circuit board 300 where electronic components (e.g., resistors, capacitors, etc.) cannot be placed. In some implementations, the width 308 of the ground-keep-out area 306 of the printed circuit board 300 may range from 0.1 mm to about 2 mm, such as from about 0.2 mm to about 1.9 mm, such as from about 0.3 mm to about 1.8 mm. As will be discussed below, the ground-keep-out area 306 may act as an electrical gap. In some implementations, the ground-keep-out area 306 will surround the entire perimeter of the printed circuit board 300. In some implementations, the ground-keep-out area 306 will only surround a portion of the perimeter of the printed circuit board 300.

[0068] In some implementations, an antenna, such as slot antenna 500 (shown in dashed lines), can be defined by gap 400 between conductive housing 120 and printed circuit board 300. Additionally, in some implementations, antenna 500 can be further defined by an electrical gap that spans a width 308 of ground keep out area 306 of printed circuit board 300. In such implementations, the width of slot antenna 500 can span a width 402 ( Figure 5 ) and the width 308 of the ground keep out area 306 of the printed circuit board 300. For example, in some implementations, the width of the slot antenna 500 can range from about 0.5 mm to about 10 mm, such as from about 0.75 mm to about 9 mm, such as from about 1 mm to about 8 mm.

[0069] The slot antenna 500 can operate on multiple different frequency bands. For example, the slot antenna 500 can operate on one or more global navigation satellite system (GNSS) bands. In some implementations, one or more GNSS bands may include one or more GPS bands. One or more GPS bands may include at least one of the following: a first GPS band ranging from about 1164 megahertz (MHz) to about 1189 MHz, a second GPS band ranging from about 1563 MHz to about 1587 MHz, and a third GPS band ranging from about 1215 MHz to about 1240 MHz. In addition, in addition to one or more GPS bands, the antenna 500 can also be configured to radiate on one or more frequency bands associated with cellular communications (e.g., 4G, 5G) or wireless local area communications (e.g., Wi-Fi or personal area networks (e.g., Bluetooth)). However, it should be understood that the slot antenna 500 can operate on a frequency band associated with any suitable communication standard.

[0070] In some implementations, the slot antenna 500 may include a first ground contact 502 and a second ground contact 504. The first ground contact 502 may couple the conductive housing 120 to the ground of the printed circuit board 300 at a first location. Conversely, the second ground contact 504 may couple the conductive housing 120 to the ground of the printed circuit board 300 at a second location. In some implementations, the first location and the second location may correspond to opposite sides of the printed circuit board 300. However, it should be understood that the first ground contact 502 and the second ground contact 504 may be coupled to the ground of the printed circuit board 300 at any suitable location to adjust the length of the slot antenna 500. For example, the first ground contact 502 and the second ground contact 504 may be positioned to shorten the slot antenna 500. Alternatively, the first ground contact 502 and the second ground contact 504 may be positioned to lengthen the slot antenna 500.

[0071] Reference now Figure 8 and Fig. 9 According to some implementations of the present disclosure, a wearable device (e.g., Figure 1 The parasitic element 600 may be configured to increase the radiation of the RF signal when the wearable device 100 is worn on the user's wrist. In some implementations, the parasitic element 600 may be completely disposed in the housing component 110 ( Figure 1 In an alternative implementation, the parasitic element 600 may be partially positioned within the housing assembly 110. For example, a first portion of the parasitic element 600 may be positioned within the housing assembly 110, while a second portion of the parasitic element 600 may be positioned outside the housing assembly 110.

[0072] The parasitic element 600 can be electrically connected to the printed circuit board 300. For example, the parasitic element 600 can be electrically connected to the ground plane of the printed circuit board 300. In some implementations, the parasitic element 600 can be DC grounded to the printed circuit board 300 at multiple locations. For example, the parasitic element 600 can be DC grounded to the printed circuit board 300 at a first location 602 and a second location 604 on the printed circuit board 300. As shown, the first location 602 and the second location 604 can be spaced apart from each other along the printed circuit board 300. It should be understood that in some implementations, the parasitic element 600 can be DC grounded to the printed circuit board at more than two locations (e.g., the first location 602, the second location 604) on the printed circuit board 300.

[0073] In some implementations, the parasitic element 600 can be coupled to the printed circuit board 300 via one or more matching circuits. For example, in some implementations, the parasitic element 600 can be RF-grounded to the printed circuit board 300 at a first location 602 on the printed circuit board 300 via a first RF bypass capacitor 610. Additionally, the parasitic element 600 can be RF-grounded to the printed circuit board 300 at a second location 604 on the printed circuit board 300 via a second RF bypass capacitor 612. It should be understood that the RF bypass capacitors (e.g., the first RF bypass capacitor 610 and the second RF bypass capacitor 612) can electrically isolate the parasitic element 600 from electrical ground at DC and low frequencies (e.g., non-RF frequencies). In some implementations, the parasitic element 600 can be coupled to the printed circuit board at a first location 602 via a first matching circuit that can be composed of one or more inductors and capacitors. Additionally, the parasitic element 600 can be coupled to the printed circuit board 300 at a second location 604 via a second matching circuit that can be composed of one or more inductors and capacitors.

[0074] The parasitic element 600 can improve the performance (e.g., radiation efficiency) of the slot antenna 500 at one or more frequency bands. For example, since the parasitic element 600 is electrically coupled (e.g., RF ground, DC ground) to the printed circuit board 300 at multiple locations (e.g., the first location 602, the second location 604), the slot antenna 500 can induce one or more currents on the parasitic element 600 when the slot antenna 500 operates at one or more frequency bands. It should be understood that the slot antenna 500 inducing one or more currents on the parasitic element 600 can improve the performance (e.g., radiation efficiency) of the slot antenna 500 at one or more frequency bands. For example, in some implementations, the radiation efficiency of the antenna 500 can be increased by at least 2 decibels, such as at least about 3 decibels, such as at least about 4 decibels, which is at least partially due to the parasitic element 600 being electrically coupled to the printed circuit board 300 at multiple locations (e.g., the first location 602, the second location 604).

[0075] In some implementations, the printed circuit board 300 can include a first fastener (e.g., a spring clip) at a first location 602 thereon and a second fastener at a second location thereon. In this manner, the parasitic element 600 can be mechanically coupled to the printed circuit board 300 at the first location 602 and the second location 604 via the first fastener and the second fastener, respectively, as discussed in more detail below.

[0076] Reference now Fig.10 , showing a cross-sectional view of a wearable device 100 according to some implementations of the present disclosure. According to some implementations of the present disclosure, the wearable device 100 includes a parasitic element 600, which forms a layer of the tag 150 and is disposed between the film 128 and the bottom cover 122 of the housing assembly 110. Specifically, the parasitic element 600 can be disposed between the outer surface 123 of the bottom cover 122 and the film 128, and the bottom cover can be formed of a plastic material. In addition, the bottom cover 122 is coupled to the conductive housing 120, which can be attached to the band 104, which is used to secure the housing assembly 110 to the user's wrist 102. The parasitic element is positioned at a distance D1 from the user's wrist 102. The distance D1 between the parasitic element 600 and the user's wrist 102 may range from about 0.15 mm to about 2.5 mm, such as from about 0.2 mm to about 2.25 mm, such as from about 0.25 mm to about 2 mm, to improve the radiation efficiency of the slot antenna 500 of the wearable device 100 .

[0077] Reference now Fig.11 , which is Fig.10 1 and an enlarged cross-sectional view of a bottom cover 122 and a label 150 including a film 128, a parasitic element 600, and additional layers. After the various additional layers and the parasitic element 600 are printed or otherwise applied to the film 128, a label (e.g., an in-mold label (IML)) 150 may be insert molded onto the outer surface 123 of the bottom cover 122, as shown. The total thickness T of the label 150 (including the film 128, the parasitic element 600, and the additional layers) may range from about 0.1 mm to about 0.5 mm, such as about 0.125 mm to about 0.3 mm, such as about 0.15 mm to about 0.25 mm.

[0078] Each layer of the tag 150 will now be discussed in more detail, where it should be understood that each layer described below may itself include more than one layer, such as 2 or more layers, such as 3 or more layers, such as 4 or more layers. In some embodiments, each layer may be composed of 2 to 10 layers, while in other embodiments, each layer may only include 1 single layer. In addition, the total resistance over the length of the parasitic element 600 may be less than about 2.5 ohms, such as less than about 1.5 ohms, such as less than about 1 ohm.

[0079] To form the label 150, a decorative ink layer 130 may first be applied to the film 128. Because the film 128 is transparent, the decorative ink layer 130 may be visible to a user or observer from the bottom 129 of the wearable device 100. It should be understood that the decorative ink layer 130 may be printed or applied to only a portion of the film 128, depending on the particular design, text, etc. that the user or other observer of the wearable device 100 desires to see. Any suitable ink of any desired color may be used for the decorative ink layer 130, but it is understood that the decorative ink layer 130 is non-conductive.

[0080] Next, a non-conductive masking ink layer 132 may be applied over the decorative ink layer 130. The non-conductive masking ink layer 132 may be used to mask, hide, or obscure the other layers discussed below from being visible to a user or any other observer of the bottom 129 of the wearable device 100, wherein such masking may enhance or highlight the decorative ink layer 130. Additionally, the non-conductive masking ink layer 132 may not be applied over the entire inner surface 131 of the film 128 and the intermediate layers, as various openings 125 (see FIG. 1 ) may be desired, as discussed in more detail below. Fig.12 ) to facilitate external charging of the wearable device 100, or it may be necessary to expose the opening 126 where the sensor 127 can be placed (see Fig.12 )(See Figure 12 to Figure 14 ). The non-conductive masking ink layer 132 can be any suitable color as long as the non-conductive masking ink layer 132 hides the layers that may be printed or applied thereon. In some embodiments, the non-conductive masking ink layer 132 is black, but it should be understood that the color of the non-conductive masking ink layer 132 is not limited to black.

[0081] In addition, a first gloss layer 134 may be applied over the non-conductive masking ink layer 132. In one particular embodiment, the first gloss layer 134 may include four separate gloss layers. When the label 150 is applied to the bottom cover 122 via insert molding, the first gloss layer 134 may be used to protect any of the various layers of the label 150 from heat damage. In some embodiments, the first gloss layer 134 may be completely transparent. In addition, the first gloss layer 134 may not be applied over the entire inner surface 131 of the film 128 and any intermediate layers because, as discussed in more detail below, various openings 125 may be required to facilitate external charging of the wearable device 100, or openings 126 may need to be exposed where sensors 127 may be placed (see Figure 12 to Figure 14 ).

[0082] Next, a first insulating ink layer 136 may be applied over the first gloss layer 134. The first insulating ink layer 136 (as well as the second insulating ink layer 140 discussed below) may be used to sandwich the parasitic element 600 (which is one or more conductive ink layers) and protect it from interference from other layers of the label 150. The first insulating ink layer 136 may be a dielectric ink. In some embodiments, the first insulating ink layer 136 may be completely transparent. In addition, the first insulating ink layer 136 may include from about 40 wt % to about 90 wt %, such as from about 45 wt % to about 85 wt %, such as from about 50 wt % to about 50 wt % of a glycol ether based on the total weight of the first insulating ink layer 136. In one embodiment, the glycol ether may be ethyl diethylene glycolate, but it should be understood that any other suitable glycol ether known to those of ordinary skill in the art may be used. Additionally, the first insulating ink layer 136 may not be applied over the entire inner surface 131 of the film 128 and any intermediate layers because, as discussed in more detail below, various openings 125 may be required to facilitate external charging of the wearable device 100, or openings 126 may need to be exposed where sensors 127 may be placed (see Figure 12 to Figure 14 ).

[0083] After applying the first insulating ink layer 136, a conductive ink layer forming a parasitic element 600 may be applied thereon. The conductive ink layer may be metallic and serve as a parasitic element 600, which helps to enhance the slot antenna 500 of the wearable device 100, thereby generating a stronger RF signal 106. In a particular embodiment, the conductive ink layer forming the parasitic element 600 may include two separate conductive ink layers. The conductive ink layer may be a metal paste. For example, the conductive ink layer may contain silver, copper, gold, aluminum, cobalt, nickel, tungsten, zinc, rhodium, iridium, ruthenium, osmium, palladium, platinum, or a combination thereof. However, it should also be understood that conductive non-metallic materials may also be used. For example, in some embodiments, the conductive ink layer may be in the form of a graphite paste. The metal or conductive non-metallic material may be present in the conductive ink layer in an amount ranging from about 40% by weight to about 85% by weight, such as from about 45% by weight to about 80% by weight, such as from about 50% by weight to about 75% by weight, based on the total weight of the conductive ink layer. The conductive ink layer may also include a polyester resin, an epoxy resin, amorphous silica, or a combination thereof. The polyester resin may be present in an amount ranging from about 1 wt % to about 25 wt %, such as from about 2.5 wt % to about 20 wt %, such as from about 5 wt % to about 15 wt %, based on the total weight of the conductive ink layer. In addition, the epoxy resin may be present in an amount ranging from about 0.05 wt % to about 5 wt %, such as from about 0.075 wt % to about 4 wt %, such as from about 0.1 wt % to about 3 wt %, based on the total weight of the conductive ink layer. In addition, the conductive ink layer may not be applied over the entire inner surface 131 of the film 128 and any intermediate layers, because, as discussed in more detail below, various openings 125 may be required to facilitate external charging of the wearable device 100, or openings 126 may need to be exposed where sensors 127 may be placed (see Figure 12 to Figure 14 ).

[0084] In addition, a second insulating ink layer 140 may be applied over the conductive ink layer forming the parasitic element 600. The second insulating ink layer 140 (as well as the first insulating ink layer 136 discussed above) may be used to sandwich the conductive ink layer forming the parasitic element 600 and protect it from interference from other layers of the label 150. The second insulating ink layer 140 may be a dielectric ink. In some embodiments, the second insulating ink layer 140 may be completely transparent. In addition, the second insulating ink layer 140 may contain from about 40% to about 90% by weight, such as from about 45% to about 85% by weight, such as from about 50% to about 50% by weight of a glycol ether. In one embodiment, the glycol ether may be ethyl diethylene glycolate, but it should be understood that any other suitable glycol ether known to those of ordinary skill in the art may be used. Additionally, the second insulating ink layer 140 may not be applied over the entire inner surface 131 of the film 128 and any intermediate layers because, as discussed in more detail below, various openings 125 may be required to facilitate external charging of the wearable device 100, or openings 126 may need to be exposed where sensors 127 may be placed (see Figure 12 to Figure 14 ). In addition, the second insulating ink layer 140 may not be applied over a portion of the conductive ink layer, so that the resistance of the parasitic element 600 can be measured at one or more exposed sections 624 after injection molding of the bottom cover 122 and before final assembly of the wearable device 100, and the conductive ink layer forming the parasitic element 600 can be connected to the printed circuit board 300 at one or more exposed sections 626 (see Fig.12 ).

[0085] Additionally, a second gloss layer 142 may be applied over the second insulating ink layer 140. In one particular embodiment, the second gloss layer may include two separate gloss layers. When the label 150 is applied to the bottom cover 122 via insert molding, the second gloss layer 142 may be used to protect any of the various layers of the label 150 from heat damage. In some embodiments, the second gloss layer 142 is completely transparent. Furthermore, the second gloss layer 142 may not be applied over the entire inner surface 131 of the film 128 and any intermediate layers because, as discussed in more detail below, various openings 125 may be required to facilitate external charging of the wearable device 100, or openings 126 may need to be exposed where sensors 127 may be placed (see Fig.12 ). In addition, the second glossy layer 142 may not be applied over a portion of the conductive ink layer and any intermediate layer, so that the resistance of the parasitic element 600 can be measured at one or more exposed sections 624 after injection molding of the bottom cover 122 and before final assembly of the wearable device 100, and the conductive ink layer forming the parasitic element 600 can be connected to the printed circuit board 300 at one or more exposed sections 626 (see Fig.12 ).

[0086] Next, an adhesive layer 144 may be applied over the second gloss layer 142. The adhesive layer 144 may be used to enhance adhesion of the label 150 to the outer surface 123 of the bottom cover 122 during the insert molding process. In addition, it should be understood that the adhesive layer 144 may not be applied over the entire inner surface 131 of the film 128 and any intermediate layers, because, as discussed in more detail below, various openings 125 may be required to facilitate external charging of the wearable device 100, or it may be necessary to expose the openings 126 where the sensors 127 may be placed (see Figure 12 to Figure 14 ). In addition, the adhesive layer 144 may not be applied over a portion of the conductive ink layer and any intermediate layers, so that the resistance of the parasitic element 600 can be measured at one or more exposed sections 624 after injection molding of the plastic cover 122 and before final assembly of the wearable device 100, and the conductive ink layer forming the parasitic element 600 can be electrically connected to the printed circuit board 300 at one or more exposed sections 626 (see Fig.12 ).

[0087] Now go to Fig.12 , showing some implementations according to the present disclosure including Fig.11 14. A top view of a film 128 and a label 150 of a parasitic element 600, wherein the bottom cover 122 is removed. As shown, the conductive ink layer forming the parasitic element 600 may include one or more exposed sections 624, which are free of the second insulating layer 140, the second gloss layer 142, and the adhesive layer 144, so that the resistance of the parasitic element 600 can be measured after injection molding of the bottom cover 122 and before assembly of the wearable device 100. In addition, as shown, the conductive ink layer forming the parasitic element 600 may include one or more exposed sections 626, which are free of the second insulating layer 140, the second gloss layer 142, and the adhesive layer 144, so that the parasitic element 600 can be electrically connected to the printed circuit board 300 (see FIG. 14) through the opening 620 in the bottom cover 122. Figure 13 to Figure 14 ).

[0088] Still refer to Fig.12, discusses the arrangement of the parasitic element 600 on the cover 122 in more detail. Specifically, the configuration of the parasitic element 600 can be selected to occupy a substantial portion (20%-80%) of the cover 122, and in turn occupy the biosensor hub of the wearable device 100. Although not limited to any particular shape, the shape of the parasitic element 600 can be driven by other factors such as the location of the sensor 127 (e.g., a heart rate monitor sensor) or the location of the injection molding gate used to form the cover 122. The shape of the parasitic element 600 can be selected to balance achieving a larger surface area while also maximizing the clearance with the nearest metal component of the wearable device (e.g., the PCB 300 or the conductive housing 120). Therefore, the parasitic element 600 generally does not extend to the edge of the cover 122 (and therefore does not extend to the edge of the biosensor hub of the wearable device 100) because this area is too close to the conductive housing 120. The maximum dimension of the parasitic element 600 is typically between about 1 / 10 and about 1 / 2 of the wavelength of the lowest frequency enhanced by the parasitic element 600. In addition, it should be understood that there can be multiple parasitic elements 600 that are printed or otherwise disposed on the film 128 to form the tag 150. In other words, the tag 150 can include one or more parasitic elements 600, such as 2, 3, 4, 5, 6, or more parasitic elements 600, wherein it should be understood that the number of parasitic elements 600 can match the number of openings 620 in the bottom cover 122 to allow for access via any desired fasteners or contacts (e.g., such as Figures 13 to 16 The spring clip 614 and reinforcing pin 616 , compression spring 618 , etc. shown connect the parasitic element 600 to the printed circuit board 300 .

[0089] Now go to Figure 13 to Figure 14 , Fig.13 depicts a cross-sectional perspective view of the printed circuit board 300, the slot antenna 500, the bottom cover 122, and the tag 150 (including the parasitic element 600 and the film 128 and the other various layers discussed above) of the wearable device 100, and Fig.14 yes Fig.13 , which shows in more detail the slot antenna 500 and the opening 620 in the bottom cover 122 for connecting the parasitic element 600 to the printed circuit board 300 according to some implementations of the present disclosure. The distance D2 between the parasitic element 600 and the antenna 500 (see Fig.14 ) may range from about 1.25 mm to about 3.5 mm, such as from about 1.5 mm to about 3 mm, such as from about 1.75 mm to about 2.75 mm, in order to optimize the GPS performance of the wearable device 100. The opening 620 in the bottom cover 122 is substantially aligned with the exposed section 626 of the conductive ink layer forming the parasitic element 600 (see Fig.12) for connecting the parasitic element 600 to the printed circuit board 300. The diameter d of the opening 620 may range from about 0.6 mm to about 1.2 mm, such as from about 0.7 mm to about 1.1 mm, such as from about 0.8 mm to about 1 mm. Without being limited by any particular theory, the inventors have found that such a diameter range preserves the strength and integrity of the film 128 while also ensuring that the mechanical connection between the parasitic element 600 and the printed circuit board 300 is sufficient. In addition, a conductive pad 622 in the form of glue, paste, foam or other suitable medium may be applied to the parasitic element 600 such that the conductive pad 622 is aligned with the opening 620 in the bottom cover 122 to enhance the mechanical connection of the parasitic element 600 to the printed circuit board 300 via a fastener in the form of a spring clip 614 and a reinforcing pin 616 or a compression spring 618, as discussed in more detail below (see Figure 15 to Figure 16 ). In addition, conductive pads 623 in the form of glue, paste, foam or other suitable medium may be applied to printed circuit board 300 to also enhance the mechanical connection of parasitic element 600 to printed circuit board 300 via fasteners in the form of spring clips 614 and reinforcing pins 616, compression springs 618, or any other suitable fasteners, as discussed in more detail below (see Figure 15 to Figure 16 ).

[0090] As mentioned above, Fig.15 Depicted is a configuration for mechanically connecting a parasitic element 600 to a printed circuit board 300 via a spring clip 614 and a reinforcing pin 616 according to some implementations of the present disclosure, wherein conductive pads 622 and 623 are used to enhance the mechanical connection between the components. When the antenna 500 in the wearable device 100 requires a higher frequency (e.g., GPS applications), the spring clip 614 and the reinforcing pin 616 can be used. In addition, Fig.16 Another configuration for mechanically connecting the parasitic element 600 to the printed circuit board 300 via a compression spring 618 is depicted in accordance with some implementations of the present disclosure. For example, in applications where the antenna 500 in a wearable device requires lower frequencies (e.g., LTE applications), the inductance inherent in the compression spring 618 may be desirable.

[0091] Fig.17A method 700 of assembling a wearable device 100 according to some implementations of the present disclosure is depicted, which may include a tag 150, a cover 122, a printed circuit board 300, an antenna 500 (e.g., a slot antenna), a conductive housing 120, and a display 112. For example, in step 702, one or more decorative ink layers 130, non-conductive masking ink layers 132, gloss layers 134 and / or 142, insulating ink layers 136 and / or 140, and a conductive ink layer forming a parasitic element 600 may be printed or otherwise applied to a film 128 to form the tag 150. Then, in step 704, an adhesive layer 144 may be applied to the film 128, where the various layers are printed or otherwise applied to the film. Next, in step 706, the tag 150 may be formed into a desired shape (e.g., a shape corresponding to the shape of the outer surface 123 of the bottom cover 122), after which any excess portions of the tag 150 may be trimmed off in step 708. Thereafter, in step 710, the tag 150 may be molded onto the outer surface 123 of the bottom cover 122, such as via insert molding. Next, in step 712, the parasitic element 600 as part of the tag 150 may be mechanically connected to the printed circuit board 300 positioned above the bottom cover 122. Next, in step 714, the conductive housing 120 may be attached to the bottom cover 122. Furthermore, in step 716, the antenna 500 may be formed by the gap 400 around the printed circuit board 300. Then, in step 718, the display 112 may be attached to the conductive housing 120. Finally, it should be understood that the steps of the above-described method 700 may be performed in any other suitable order as understood by one of ordinary skill in the art.

[0092] Although the subject matter has been described in detail with respect to various specific example embodiments of the subject matter, each example is provided by way of explanation rather than limitation of the present disclosure. Those skilled in the art, after understanding the foregoing, may easily produce changes, modifications, and equivalents to these embodiments. Therefore, the present disclosure does not exclude such modifications, changes, and / or additions to the subject matter that would be readily understood by those of ordinary skill in the art. For example, a feature shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to cover these changes, modifications, and equivalents.

Claims

1. A wearable device, comprising: Printed circuit boards; Conductive housing; antenna; a cover having an outer surface; as well as A label includes a film and a parasitic element, wherein the parasitic element is located between the film and the outer surface of the cover.

2. The wearable device of claim 1, wherein the parasitic element comprises a conductive ink layer.

3. A wearable device as described in claim 1 or 2, wherein the tag is embed-molded onto the outer surface of the cover.

4. A wearable device as claimed in any one of the preceding claims, wherein the tag comprises a decorative ink layer between the film and the parasitic element.

5. The wearable device of claim 4, wherein the tag comprises a non-conductive masking ink layer between the decorative ink layer and the parasitic element.

6. The wearable device of claim 5, wherein the label comprises a first insulating ink layer.

7. The wearable device of claim 6, wherein the tag comprises a first glossy layer between the non-conductive masking ink layer and the first insulating ink layer.

8. The wearable device of claim 6 or 7, wherein the tag comprises a second insulating ink layer, wherein the parasitic element is between the first insulating ink layer and the second insulating ink layer.

9. The wearable device of claim 8, wherein the tag comprises an adhesive layer, wherein the adhesive layer connects the tag to the outer surface of the cover.

10. The wearable device of claim 9, wherein the label comprises a second glossy layer between the second insulating ink layer and the adhesive layer.

11. The wearable device of claim 1, wherein the antenna is a slot antenna defined by a gap between the printed circuit board and the conductive housing.

12. A tag for a wearable device comprising an antenna, the tag comprising a plurality of layers, the plurality of layers comprising a film, a decorative ink layer, a non-conductive masking ink layer, a first insulating ink layer, a parasitic element, and a second insulating ink layer, wherein the plurality of layers of the tag are applied to the film, and wherein the parasitic element comprises a conductive ink layer.

13. The label of claim 12, further comprising an adhesive layer.

14. The label of claim 12 or 13, further comprising a first gloss layer.

15. The tag of any one of claims 12 to 14, wherein a portion of the conductive ink layer is exposed and has no additional layers printed thereon.

16. The tag of any one of claims 12 to 15, wherein the tag is configured to be joined to a plastic cover during an insert molding process.

17. The tag of any one of the preceding claims, wherein the parasitic element is electrically grounded to the printed circuit board via a radio frequency ground, a DC ground, or a matching circuit.

18. A method of forming a tag for a wearable device comprising an antenna, the method comprising: printing one or more layers of non-conductive masking ink onto the film; printing one or more layers of conductive ink onto the film to define parasitic elements; printing an adhesive layer onto the film to form the label; as well as The label is formed into a shape that matches the shape of the cover to which it is applied.

19. The method of claim 18, wherein the label is bonded to an outer surface of the cover during an insert molding process, wherein the adhesive layer bonds the label to the cover.

20. The method of claim 18 or 19, further comprising: One or more decorative ink layers are printed onto the film.

21. The method of any one of claims 18 to 20, further comprising: One or more layers of insulating ink are printed onto the film.

22. The method of any one of claims 18 to 21, further comprising trimming the label to remove any excess.

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