Patent Description:
The invention relates to a device, comprising a printed circuit board ("PCB"); and a metal structure configured to be both an antenna and an input control, wherein the metal structure is located at a distance from the PCB and oriented such that the metal structure is substantially parallel to the PCB, wherein the metal structure is coupled to the PCB via at least a first coupling such that metal structure is substantially parallel to the PCB, wherein an electric field extends between the PCB and the metal structure, and the first coupling is an antenna feed and a connection for the input, wherein the device is configured to be worn on a human body, wherein the electric field extends in a direction transverse to a tangent of a longitudinal surface of the human body when the device is being worn on the human body.

The device may further include a second coupling configured to be an antenna ground pin or an impedance tuning stub.

The metal structure may be located closer to the at least one second surface of the housing than the at least one first surface of the housing. The metal structure may have a central region and a perimeter, wherein the metal structure curves from the central region towards the PCB at the perimeter. The input control may be a touchpad.

The PCB may be configured to shield the metal structure from the human body. The electric field may be configured to propagate around the human body. When the metal structure receives an input, the metal structure may be configured to detect a change in capacitance.

The technology disclosed may generally relate to wearable devices or accessories that connect to a host device. The wearable device may be, for example, one or more earbuds, glasses, virtual reality (VR) headsets, motorcycle helmets, etc. Each accessory may have an antenna that connects the accessory to a host device, such as a smart phone. The antenna may be located within a housing of the accessory. The accessory may also include an input control, such as touchpad or touch input, for receiving user commands. The antenna and touchpad may be combined, or integrated, such that the antenna and touchpad are one component within the housing of the accessory. The combination antenna and touchpad may be, in some examples, referred to as an antenna radiator. The antenna radiator may function as both an antenna and a touchpad as the antenna and the touchpad do not experience cross talk even though they are combined into one element.

By combining the antenna and touchpad into one element, the antenna radiator may be larger within the housing of the accessory than each component would be if they were placed within the housing separately. The combination antenna radiator may eliminate the need to create room for two separate components, i.e. the antenna and the touchpad. Thus, the overall size of the combined antenna and touchpad, or the antenna radiator, may be enlarged within the housing as compared to an accessory that has the antenna and touchpad as two separate components. The physical size of the antenna and touchpad may be directly correlated to the functional performance of wireless radio and the touch sensor. Thus, the increased side may correlate to increased performance. The antenna radiator may, additionally or alternatively, allow for a lower profile of the housing as the housing no longer needs to have room for two separate components. In some examples, the combination antenna radiator may enable both elements, the antenna and touchpad, to be co-located at their most preferred area or location within the device to maximize their respective performance.

The antenna radiator may be coupled to a printed circuit board ("PCB") within the housing of the accessory. The PCB may be located between the housing and antenna radiator such that the PCB may act as a shield to prevent antenna loss. For example, antenna loss may occur when the antenna radiator touches or comes close to touching human body. In particular, the human body acts as a dielectric that may degrade or weaken antenna components. Therefore, by placing the PCB between the housing surface closest to where the accessory would touch the human body and the antenna radiator, the PCB may help prevent the antenna radiator from touching the human body, thereby preventing antenna loss. According to some examples, the antenna radiator may be coupled to the battery or any grounded metal structure within device <NUM>.

The antenna radiator is coupled to the PCB by one or more contact points. One contact functions as both the feed of an antenna as well as the input of touch sensor. Other contacts may function as antenna grounding or impedance tuning stub that can be totally isolated from touch sensing functionality. According to some examples, the contact points may be one or more spring clips. A first spring clip functions as both an antenna feed and a connection for the input control. A second spring clip may function as an antenna ground.

An electromagnetic field may extend or propagate between and/or around the PCB and the antenna radiator. The electromagnetic field that propagates around the PCB and the antenna radiator, as opposed to propagating directly between the PCB and the antenna radiator, may allow for enhanced coupling between accessories, such as when the accessory is a pair of earbuds. Additionally or alternatively, the electric field that propagates around the PCB and the antenna radiator, also referred to as the fringe electric field, may allow for better coupling between the accessory and the host device.

<FIG> and <FIG> illustrate different perspective views of an antenna radiator within a housing of an accessory <NUM>. As used herein, an accessory may be used to refer to any electronic device that is coupled to a host device or another accessory and is capable of receiving inputs from a user. Examples of accessories may include earbuds, smartwatches, headsets, other wearable electronics, etc. Accessories may further include other electronic devices, such as a laptop, hub, tablet, etc. The accessory <NUM> shown in <FIG> and <FIG> is an earbud, however, this is merely one example and is not intended to be limiting.

Accessory <NUM> may include a housing <NUM>, a PCB <NUM>, an antenna radiator <NUM>, and spring clips <NUM>, <NUM>. The antenna radiator <NUM> may be a combined antenna and touchpad. Thus, the antenna radiator <NUM> may function as both the antenna and the touchpad. Accessory <NUM> may include additional components, such as one or more processors (e.g., a central processing unit (CPU)), memory (e.g., RAM and internal hard drives) storing data and instructions, a display (e.g., a monitor having a screen, a touchscreen, or other devices such as a smartwatch display that is operable to display information), and user input devices (e.g., a keyboard, touchscreen or microphone).

Housing <NUM> may be shaped to be worn on a human body. For example, at least one first surface of the housing may be shaped to come in contact with the body and at least one second surface of the housing may be shaped to be exposed when the accessory <NUM> is worn on the body. The first surface and the second surface may be opposite each other. Housing <NUM> may house the internal components of accessory <NUM>. For example, within housing <NUM> may be PCB <NUM>, the antenna radiator <NUM>, spring clips <NUM>, <NUM>, and any additional components, as described above. As shown, a portion of housing <NUM> is removed such that the internal components of the accessory <NUM> may be visible.

PCB <NUM> may be located within housing <NUM>. In some examples, PCB <NUM> may be located closer to the first surface than the second surface of housing <NUM>. That is, PCB <NUM> may be located closer to the human body when accessory <NUM> is being worn as compared to other components.

The positioning of antenna radiator <NUM> is important as the human body is a dielectric such that the human body may degrade, or weaken, the functioning of antenna components. According to some examples, the antenna radiator <NUM> may be located within housing <NUM> between PCB <NUM> and the second surface of housing <NUM>. That is, the antenna radiator <NUM> may be located closer to the second surface of housing <NUM>, i.e. the exposed surface of housing <NUM> when accessory <NUM> is worn on the body. In such an example, the PCB <NUM> may shield, or isolate, the antenna radiator <NUM> from the body such that the antenna radiator <NUM> experiences less loss effect from the body. Additionally or alternatively, centering the antenna radiator <NUM> with the PCB <NUM> and closer to the second surface of housing <NUM> than the first surface of housing <NUM> internally within housing <NUM> may make the antenna radiator <NUM>. Posi therefore, the antenna and touchpad, function more efficiently and less susceptible to wearing conditions, as compared to accessories that have antennas along the perimeter of the housing or those susceptible to placement on the human body.

For example, when accessory <NUM> is an earbud, as shown, antenna radiator <NUM> may be located centrally within the housing <NUM> such that antenna radiator <NUM> may not come in contact with the human body. In some examples, antenna radiator <NUM> and, therefore, the antenna and touchpad, may have a maximum amount of clearance from the user's body within the given volume defined by the housing <NUM> of the device <NUM>. The location of antenna radiator <NUM> may reduce the dieletric loading effect from the human body and, therefore, may reduce variability due to wearing tolerance and rotation of the accessory.

As shown in <FIG> and <FIG>, antenna radiator <NUM> may by a solid structure having a circular shape. The structure may be a metal structure. The shape of the antenna radiator may change based on the shape of the accessory <NUM> and/or housing <NUM>. Thus, antenna radiator <NUM> may have a square, rectangular, oblong, etc. shape and having a circular shape, as shown, is merely one example and is not intended to be limiting.

According to some examples, antenna radiator <NUM> may have portions of the structure cut out. The cut outs may create a pattern in antenna radiator <NUM>. This may create a lighter and/or less expensive antenna radiator <NUM> without compromising the performance of the antenna radiator <NUM>. Additionally or alternatively, the antenna pattern on antenna radiator <NUM> may be made in a meshed form. The meshed form may reduce the touch capacitance of the antenna radiator <NUM> without sacrificing or reducing the antenna radiation performance.

Antenna radiator <NUM> may have a curvature. For example, antenna radiator may have a central region <NUM> and a perimeter <NUM>. The antenna radiator <NUM> may curve from the central region <NUM> towards the PCB <NUM> at the perimeter. The curvature of the antenna radiator <NUM> may be convex. According to some examples, the curvature of antenna radiator <NUM> may correspond to or substantially follow the curvature of housing <NUM> of the accessory <NUM>. Thus, in some examples, the antenna radiator <NUM> may not curve or the antenna radiator <NUM> may have a concave curvature.

The antenna radiator <NUM> may be sized such that the perimeter <NUM> of the antenna radiator <NUM> is located at a distance from housing <NUM>. That is, antenna radiator <NUM> may have a size that is smaller than the opening in housing <NUM> in which the antenna radiator <NUM> is placed. The size of antenna radiator <NUM> may reduce false touch by pulling away from the housing <NUM> of the accessory <NUM>. Additionally or alternatively, the size of antenna radiator <NUM> may provide minimal, if any, additional protrusion from housing <NUM>. In some examples, the size of antenna radiator <NUM> may lower the susceptibility to finger gesture of inputs, such as pause, play, etc..

The antenna radiator <NUM> may be coupled to the PCB <NUM> via at least one contact point, such as a spring clip110. According to some examples not covered by the appended claims, there may be two contact points, such as first and second spring clips <NUM>, <NUM>. Thus, the radio-frequency ("RF") circuitry to the antenna and the touch sensor circuitry for the touchpad may both be connected to the antenna radiator <NUM>. This may allow the antenna and touchpad to work independently without having their respective signals cross talking. For example, the antenna RF signal may not impact or interfere with the touch sensor signals and vice versa. The antenna radiator <NUM> may be coupled to the PCB <NUM> such that antenna radiator <NUM> is substantially parallel to the PCB.

A first spring clip <NUM>- may function as both an antenna feed and an input for a touch sensor. The device <NUM> may include decoupling circuitry to be implemented at spring clip <NUM> in order to make both the radio system and touch sensor system function properly and independently while sharing the same metal structure <NUM>. Combining the antenna feed with the circuitry for receiving the signal for an input into one spring clip <NUM>, may increase the efficiency of the accessory <NUM>. Moreover, overall manufacturing costs may be reduced as one component, spring clip <NUM>, may have two functions, being the antenna ground and being the circuitry for receiving signals indicating a touch input. A second spring clip <NUM> may function as an antenna ground pin or impedance tuning sub. A capacitor with calculated capacitance value may be implemented on spring clip <NUM> to prevent touch input signal being shorted to ground.

<FIG> illustrates an example of an electric field extending between the PCB and the antenna radiator. The electric field <NUM> may extend between PCB <NUM> and antenna radiator <NUM>. The portion of the electric field that remains between PCB <NUM> and antenna radiator <NUM> may be the vertical electric field <NUM> and the portion of the electric field <NUM> that extends beyond or outside of the PCB <NUM> and antenna radiator <NUM> may be the fringe electric field <NUM>.

The antenna radiator described herein may reduce the electromagnetic field concentration as compared to a traditional monopole antenna. For example, the antenna's opening carries the strongest electric field of an antenna which is responsible for radiation. The antenna's opening of the planar antenna radiator described herein may be wider than the antenna's opening for traditional monopole antenna. This may smooth out the concentration of the electric field of an antenna, and, therefore, help reduce the variation due to the loading effects from the human body tissues, which may be high permittivity materials.

The vertical electric field <NUM> may extend between PCB <NUM> and antenna radiator <NUM>. The vertical electric field <NUM> may maximize the surface wave that propagates along the surface of antenna radiator <NUM>. As the surface wave is maximized, the sensitivity for cross-head and cross-body linkage may increase. Cross-head linkage may occur between two earbuds, such as a right and left earbud. Cross-body linkage may occur between a left and/or right earbud and a host device, such as a smartphone.

The vertical electric field <NUM> may not be vertical when the accessory is in use. When the accessory is an earbud, the vertical electric field <NUM> is perpendicular to the tangential vertical surface of the human body. In particular, the vertical electric field <NUM> is perpendicular to the tangential vertical surface of the user's ear or cheek. Thus, the vertical electric field <NUM> may be horizontal, or at any other angle, when the accessory is being worn.

The fringe electric field <NUM> may propagate and/or radiate outwardly from the edge of PCB <NUM> to the edge of antenna radiator <NUM>. As the fringe electric field <NUM> radiates from the PCB <NUM> to the antenna radiator <NUM>, the strength of the fringe electric field <NUM> may decrease as the distance away from the PCB <NUM> and the antenna radiator <NUM> increases. The fringe electric field <NUM> may allow for connectivity and/or increased connectivity between accessories and/or between an accessory and a host device. For example, when the accessory is a pair of earbuds, the fringe electric field <NUM> from the right earbud may propagate around the user's head and be used to connect the right earbud to the left earbud. Additionally or alternatively, the fringe electric field <NUM> from the left earbud may propagate around the user's head and be used to connect the left earbud to the right earbud. In some examples, the fringe electric field <NUM> from the accessory may propagate and be used to connect the accessory to the host device. In such an example, the fringe electric field <NUM> from a pair of earbuds may propagate around the user and be used to connect to the host device, which may be a smartphone in the user's hands.

<FIG> illustrates an example of the fringe electric field propagating around a user's head. The user <NUM> may be wearing a right and left earbud 300a, 300b. The fringe electric field <NUM> of the right earbud 300a may propagate around right earbud 300a and user <NUM>. While not shown, the left earbud 300b may have a fringe electric field propagating around left earbud 300b and user <NUM>.

The propagation of fringe electric field <NUM> may increase the connectivity between the right earbud 300a and left earbud 300b and/or between the right earbud 300a and the host device (not shown). In particular, the propagation of the fringe electric field <NUM> around the human body and/or across the human body may be stronger at locations further away from the accessory than an electric field from a monopole antenna. The increased strength of the fringe electric field <NUM> may increase the connectivity for cross-head linkage between right earbud 300a and left earbud 300b as well as for cross-body linkage between right earbud 300a and a host device (not shown).

The size, shape, and placement of the antenna radiator described herein may provide the user a better experience when interacting with the accessory housing the antenna radiator. In particular, by combining the function of the antenna and the touchpad into one element, the overall size of the accessory may decrease and/or there may be few protrusions extending from the accessory as there only needs to be room for one component instead of two. Moreover, by combining the function of the antenna and the touchpad into one element, the antenna radiator, allows for the size of the antenna and touchpad to be increased within the housing of the device. According to some examples, combining the function of the antenna and the touchpad into one element may allow both components to co-locate at their best performance benefitting location. This may improve antenna efficiency by having an increased antenna aperture and/or volume.

The placement of the antenna radiator within the housing of the accessory may reduce the frequency loading effect from the user's body. Moreover, the internal placement of the antenna radiator may reduce the likelihood of the antenna radiator from coming in contact with the human body which may prevent the human body from weakening the antenna components.

Claim 1:
A device (<NUM>), comprising:
a printed circuit board, PCB, (<NUM>, <NUM>); and
a metal structure (<NUM>, <NUM>) configured to be both an antenna and an input control,
wherein the metal structure (<NUM>, <NUM>) is located at a distance from the PCB (<NUM>, <NUM>) and oriented such that the metal structure (<NUM>, <NUM>) is substantially parallel to the PCB (<NUM>, <NUM>),
wherein the metal structure (<NUM>, <NUM>) is coupled to the PCB (<NUM>, <NUM>) via at least a first coupling (<NUM>) such that the metal structure (<NUM>, <NUM>) is substantially parallel to the PCB (<NUM>, <NUM>),
wherein an electric field (<NUM>) is configured to extend between the PCB (<NUM>, <NUM>) and the metal structure (<NUM>, <NUM>),
wherein the first coupling (<NUM>) is an antenna feed and a connection for the input control,
and wherein the device (<NUM>) is configured to be worn on a human body, characterized in that the electric field (<NUM>) extends in a direction transverse to a tangent of a longitudinal surface of the human body when the device (<NUM>) is being worn on the human body.