Dynamically adjustable antennas for wearable devices

DYNAMICALLY ADJUSTABLE ANTENNAS FOR WEARABLE DEVICES

<technical-field></technical-field>

This application claims priority to US Patent Application Serial No. 15/442,463, filed February 24, 2017, which is incorporated herein by reference in its entirety.

The present application relates to an electronic device, and more particularly, to an electronic device having a wireless communication circuitry.

Electronic devices often include wireless communication circuitry. For example, cellular telephones, computers, and other devices often include antennas and wireless transceivers to support wireless communications.

It can be difficult to form antenna structures of an electronic device with desired properties. In some wireless devices, antennas are bulky. In other devices, the antennas are compact but sensitive to the position of the antennas relative to external objects. If care is not taken, the antennas may be detuned and may emit radio signals with greater or less power than desired, or otherwise not performing as expected.

Accordingly, it would be desirable to be able to provide improved wireless communication circuitry for wireless electronic devices.

An electronic device, such as a wrist watch, may have a housing having metal parts, such as metal sidewalls. A display may be mounted on the front of the device. The back side of the electronic device may be formed using a dielectric back housing wall.

The electronic device may include wireless communication circuitry. The wireless communication circuitry may include radio frequency transceiver circuitry and an antenna. The antenna may include an antenna ground. Antenna ground may be formed using metal housing sidewalls and/or a conductive layer on a printed circuit board in the electronic device. The antenna may include an antenna resonating element formed from conductive traces patterned on or over the interior surface of the dielectric rear housing wall. The radio frequency transceiver circuitry may use the antenna to transmit and receive radio frequency signals through the dielectric rear housing wall. The impedance matching circuitry may be used to match the impedance of the antenna to the remainder of the wireless communication circuitry.

The antenna may be subjected to over-the-air (OTA) loading variations through the dielectric rear housing wall. For example, the particular way the user wears the electronic device, the user's physiology, the amount of moisture adjacent the dielectric back housing wall, and other environmental factors can affect the way the antenna is loaded through the dielectric back housing wall. . Additional loading variations may be caused by the user's hand/wrist touching the metal enclosure that forms part of the antenna structure. Moreover, the material of the wristband may also contribute to loading variations. The processing circuitry may collect received signal strength information and/or phase and magnitude information from the received radio frequency signals. The processing circuitry may track the location of the electronic device over time. The processing circuitry may accumulate user statistics associated with the way the user operates the electronic device over time.

The received signal strength information collected by the processing circuitry may include, for example, Received Signal Strength Indicator (RSSI) values as a function of time and location of the electronic device. The processing circuitry may determine, based on the collected received signal strength information, accumulated user statistics, and/or the collected phase and magnitude information, whether a change in loading of the antenna through the dielectric rear housing wall has occurred. If the processing circuitry determines that a change in the loading of the antenna has occurred, the processing circuitry may adjust the impedance matching circuitry to compensate for the change in the loading of the antenna through the dielectric rear housing wall. In this way, the processing circuitry allows the antenna to be impedance matched to the remainder of the wireless communication circuitry in real time regardless of any variable antenna loading conditions that may arise as a result of the antenna being positioned on the dielectric rear housing wall of the electronic device. can guarantee Ensuring satisfactory impedance matching for the antenna over time may mitigate any potential antenna detuning or degradation of antenna efficiency as a result of variable antenna loading conditions.

1 is a front perspective view of an exemplary electronic device in accordance with one embodiment; 2 is a schematic diagram of an exemplary electronic device in accordance with an embodiment. 3 is a diagram of exemplary wireless circuitry within an electronic device in accordance with one embodiment. 4 is a cross-sectional side view of an exemplary electronic device having an antenna that transmits wireless signals through the back of the electronic device, in accordance with one embodiment. 5 is a cross-sectional side view of an exemplary electronic device showing how an antenna on the back of the device and a user's wrist can direct electromagnetic energy away from the device, according to one embodiment. 6 is a diagram of exemplary circuitry that may be used to gather antenna performance information and adjust impedance matching circuitry for the antenna, according to one embodiment. 7 is a flow diagram of exemplary steps that may be included in operating an electronic device having adjustable wireless circuitry to compensate for different antenna loading conditions, according to one embodiment. 8 is a flow diagram of example steps that may be performed by an electronic device in determining whether to adjust an impedance matching circuit to compensate for different antenna loading conditions, according to one embodiment. 9 and 10 are flow diagrams of example steps that may be performed by an electronic device when adjusting an impedance matching circuit to compensate for different antenna loading conditions, according to one embodiment. 11 is an exemplary plot of received signal strength information collected by an electronic device that may be processed to determine whether to adjust an impedance matching circuit according to an embodiment. 12 illustrates how received signal strength information collected by an exemplary electronic device may be filtered and compared to predetermined received signal strength patterns to determine whether to adjust an impedance matching circuit, according to an embodiment. It is a drawing that shows 13 is a Smith chart showing exemplary impedances associated with operation of an antenna in an electronic device when operated under different antenna loading conditions according to one embodiment. 14 is a graph of exemplary antenna frequency responses that may be exhibited by an antenna when operating under different impedance matching circuit settings in accordance with one embodiment.

An electronic device such as electronic device 10 of FIG. 1 may be provided with wireless communication circuitry. Wireless communication circuitry may be used to support wireless communication in multiple wireless communication bands.

Electronic device 10 may be a computing device, such as a laptop computer, computer monitor, including embedded computer, tablet computer, cellular phone, media player, or other handheld or portable electronic device, smaller device, such as a wristwatch device, pendant (pendant) devices, headphones or earpiece devices, devices embedded in glasses or other equipment worn on the user's head, or other wearable or small devices, televisions, computer displays, not including embedded computers; A gaming device, navigation device, electronic equipment with a display may be an embedded system, such as a system mounted in a kiosk or automobile, equipment implementing the functionality of two or more of these devices, or other electronic equipment. . In the exemplary configuration of FIG. 1 , device 10 is a wearable device such as a wrist watch. Other configurations for device 10 may be used, if desired. The example of FIG. 1 is merely an example.

In the example of FIG. 1 , device 10 includes a display, such as display 14 . Display 14 may be mounted within a housing such as housing 12 . Housing 12, which may sometimes be referred to as an enclosure or case, is made of plastic, glass, ceramic, fiber composite, metal (eg, stainless steel, gold, silver, aluminum, etc.), other suitable materials, or any two of these materials. It may be formed by a combination of the above. Housing 12 may be formed using a unitary construction in which some or all of housing 12 is machined or molded as a single structure, or may be formed using multiple structures (eg, an inner frame structure, forming outer housing surfaces). one or more structures, etc.). Housing 12 may have metal sidewalls, such as sidewalls 12W, or sidewalls formed from other materials. Examples of metal materials that may be used to form the sidewalls 12W include stainless steel, aluminum, silver, gold, a metal alloy, or any other desired conductive material.

The display 14 may be formed on the front side of the device 10 . Housing 12 may have a rear housing wall, such as a rear wall 12R, opposite the front of device 10 . The rear housing wall 12R may form the back surface of the device 10 . Housing sidewalls 12W may surround a perimeter of device 10 (eg, housing sidewalls 12W may extend around peripheral edges of device 10 ). The rear housing wall 12R may be formed of a dielectric. Examples of dielectric materials that may be used to form the rear housing wall 12R include plastic, glass, sapphire, ceramic, wood, polymer, combinations of these materials, or any other desired dielectrics. The rear housing wall 12R and/or the display 14 have a length (eg, parallel to the x-axis of FIG. 1 ) and a width (eg, parallel to the y-axis) of the device 10 . It may extend over some or all. The housing sidewall 12W may extend over some or all of the height of the device 10 (eg, parallel to the z-axis).

Display 14 may include a layer of conductive capacitive touch sensor electrodes or other touch sensor components (eg, resistive touch sensor component, acoustic touch sensor component, force-based touch sensor component, light-based touch sensor). component, etc.), or it may be a display that is not touch sensitive. The capacitive touch screen electrodes may be formed of an array of indium tin oxide pads or other transparent conductive structures.

Display 14 is an array of display pixels formed of liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light emitting diode display pixels, an array of electrowetting display pixels, or other display may include display pixels based on technologies.

Display 14 may be protected using a display cover layer. The display cover layer may be formed of a transparent material, such as glass, plastic, sapphire or other crystalline dielectric materials, ceramic, or other transparent materials. The display cover layer may, for example, extend over substantially all of the length and width of the device 10 .

Device 10 may include buttons such as button 18 . Device 10 may have any suitable number of buttons (eg, a single button, more than one button, two or more buttons, five or more buttons, etc.). The buttons may be located (eg) in openings in housing 12 (eg, in side wall 12W or back wall 12R) or in openings in display 14 . The buttons may be rotary buttons, sliding buttons, buttons actuated by depressing a movable button member, combinations thereof, and the like. Button members for buttons, such as button 18, may be formed of metal, glass, plastic, or other materials. Button 18 may sometimes be referred to as a crown in scenarios where device 10 is a wristwatch device.

Device 10 may be coupled to a strap, such as strap 16 , if desired. Strap 16 may be used to hold device 10 against a user's wrist (as an example). In the examples of FIG. 1 , the strap 16 is connected to opposite sides 8 of the device 10 . The housing walls 12W on the sides 8 of the device 10 may include attachment structures (eg, a lug or other attachment mechanism) for securing the strap 16 to the housing 12 . can Strap 16 may be formed of any desired materials (eg, a metal material, a dielectric material, or combinations of metal and dielectric materials). For example, the metal materials in the strap 16 may include stainless steel, aluminum, silver, gold, a metal alloy, or any other desired conductive material. The dielectric materials in the strap 16 may include plastic, polymer, ceramic, leather, rubber, cloth or other fabric, glass, or any other desired dielectric materials.

If desired, strap 16 may be removable. For example, a user may replace strap 16 with a different strap having similar or different materials. If desired, strap 16 may be adjustable. For example, the strap 16 may be secured with a clasp, buckle, or strap 16 to allow the user to adjust the length of the strap 16 and/or while the user wears the device 10 . It may include other adjustable structures that allow adjusting how tight it will be on the user's wrist. Configurations that do not include a strap may also be used with the device 10 .

A schematic diagram illustrating example components that may be used in device 10 is shown in FIG. 2 . As shown in FIG. 2 , device 10 may include control circuitry, such as storage and processing circuitry 28 . Storage and processing circuitry 28 may include hard disk drive storage, non-volatile memory (eg, flash memory, or other electrically programmable read-only memory configured to form a solid state drive), volatile memory (eg, static or dynamic random access memory). Processing circuitry within storage and processing circuitry 28 may be used to control operation of device 10 . Such processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, and the like.

The storage and processing circuitry 28 may be used to execute software on the device 10 , such as an internet browsing application, a voice-over-internet-protocol (VOIP) phone call application, an email application, a media playback application, operating system functions, and the like. can To support interaction with external equipment, storage and processing circuitry 28 may be used to implement communication protocols. Communication protocols that may be implemented using the storage and processing circuitry 28 include the Internet Protocol, wireless local area network protocol (eg, IEEE 802.11 protocolsometimes referred to as Wi-Fi®), and other short-range wireless communications such as the Bluetooth® protocol. protocols for links, cellular telephony protocols, MIMO protocols, antenna diversity protocols, and the like.

The input/output circuitry 44 may include input/output devices 32 . Input/output devices 32 may be used to allow data to be supplied to device 10 and to provide data from device 10 to external devices. Input/output devices 32 may include user interface devices, data port devices, and other input/output components. For example, input/output devices 32 may include a touch screen, non-touch sensor display, buttons, scroll wheel, touch pad, key pad, keyboard, microphone, camera, button, speaker, status indicator, light source, audio jack and Other audio port components, digital data port devices, light sensors, light emitting diodes, motion sensors (accelerometers), capacitive sensors, proximity sensors, magnetic sensors, force sensors (eg, force coupled to the display to detect pressure applied to the display) sensor) and the like.

As shown in FIG. 2 , electronic device 10 may wirelessly communicate with external equipment 52 via wireless links, such as wireless link 54 . External equipment 52 may be a cellular telephone network base station, wireless local area network equipment (eg, wireless routers and/or wireless access points), peer devices, other portable electronic devices such as cellular telephones or wireless headsets, and other May include external equipment. Link 54 may be a cellular telephone link, a wireless local area network link, or a communication link supported using other types of wireless communication.

The input/output circuit unit 44 may include a wireless circuit unit 34 . The wireless circuitry 34 may include a wireless power receiver 48 and a coil 50 for receiving power wirelessly transmitted from the wireless power adapter. To support wireless communication, wireless circuitry 34 may include one or more antennas such as radio frequency (RF) transceiver circuitry, power amplifier circuitry, low noise input amplifiers, passive RF components, antennas 40 formed of one or more integrated circuits; It may include a transmission line, and other circuitry for processing RF radio signals. Wireless signals may also be transmitted using light (eg, using infrared communication).

The radio circuitry 34 may include radio frequency transceiver circuitry 56 for handling various radio frequency communication bands. For example, circuitry 34 may include transceiver circuitry 36 , 38 , 42 , 46 . Transceiver circuitry 36 may be a wireless local area network transceiver circuitry capable of handling the 2.4 GHz and 5 GHz bands for Wi-Fi® (IEEE 802.11) communication and capable of handling the 2.4 GHz Bluetooth® communication band. Circuitry 34 includes (as an example) a low communication band of 700 to 960 MHz, a midband of 1400 MHz or 1500 MHz to 2170 MHz (eg, a midband with a peak at 1700 MHz), and 2170 or 2300 to 2300 MHz. For handling wireless communication in frequency ranges, such as the high band of 2700 MHz (eg, the high band with a peak at 2400 MHz) or other communication bands between 700 MHz and 2700 MHz, or other suitable frequencies Cellular telephone transceiver circuitry 38 may be used. The circuit unit 38 may process voice data and non-voice data. Wireless communication circuitry 34 may include circuitry for other short-range and long-range wireless links, if desired. For example, wireless communication circuitry 34 may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceiver, near field communication (NFC) transceiver circuitry 46 (e.g., 13.56 MHz or other suitable NFC transceiver operating at a frequency) and the like. The radio circuitry 34 may include satellite navigation system circuitry such as global positioning system (GPS) receiver circuitry 42 for receiving GPS signals at 1575 MHz or for processing other satellite positioning data. In Wi-Fi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to carry data over tens or hundreds of feet. In cellular telephone links and other long-distance links, wireless signals are typically used to convey data over thousands of feet or miles.

The wireless circuitry 34 may include antennas 40 . The antennas 40 may be formed using any suitable antenna types. For example, the antennas 40 may include a loop antenna structure, a patch antenna structure, an inverted-F antenna structure, a slot antenna structure, a planar inverted-F antenna structure, a spiral antenna structure, a monopole antenna structure, a dipole antenna structure, or any of these designs. It may include antennas having resonant elements formed from hybrids or the like. Different types of antennas may be used for different bands or combinations of bands. For example, one type of antenna may be used to form a local radio link antenna, while another type of antenna is used to form a remote radio link antenna. If desired, space can be conserved within device 10 by using a single antenna to handle two or more different communication bands. For example, a single antenna 40 in device 10 may have a Wi-Fi® or Bluetooth® communication band at 2.4 GHz, a GPS communication band at 1575 MHz, and/or 700-960 MHz, 1400-2170 MHz, and 2170 MHz. to one or more cellular telephony bands from 2700 MHz to 2700 MHz.

In practice, however, the typical size required for an antenna increases as the desired frequency for operation decreases (ie, as the corresponding wavelength increases). Also, space is difficult to obtain in compact electronic devices such as device 10 (eg, particularly as the demand for smaller and more aesthetically pleasing device form factors increases). Without care, satisfactory antenna coverage in all communication bands of interest, particularly for relatively low frequencies (ie relatively long wavelengths), such as the low band cellular telephone frequencies from 700 to 960 MHz, can be achieved in a compact electronic device. It can be difficult to offer them.

3 is a diagram showing how transceiver circuitry 56 within radio circuitry 34 may be coupled to antenna structures 40 using paths such as path 60 . Wireless circuitry 34 may be coupled to control circuitry 28 . Control circuitry 28 may be coupled to input/output devices 32 . Input/output devices 32 may supply output from device 10 and receive input from sources external to device 10 .

To provide antenna structures 40 with the ability to cover communication frequencies of interest, antenna structures 40 include circuitry such as filter circuitry (eg, one or more passive filters and/or one or more tunable filter circuits). can do. Discrete components such as capacitors, inductors, and resistors may be incorporated into the filter circuitry. Capacitive structures, inductive structures, and resistive structures may also be formed from patterned metal structures (eg, part of an antenna). If desired, antenna structures 40 may include tunable circuits such as tunable components 62 for tuning antennas across communication bands of interest. Tunable components 62 may include tunable inductors, tunable capacitors, or other tunable components. Tunable components such as these include switches and networks of fixed components, distributed metal structures for generating associated distributed capacitances and inductances, variable solid state devices for generating variable capacitance and inductance values, tunable filters, or other suitable tunable structures.

During operation of device 10 , control circuitry 28 generates control signals on one or more paths, such as path 64 , that adjust inductance values, capacitance values, or other parameters associated with tunable components 62 . By issuing, it is possible to tune the antenna structures 40 to cover the desired communication bands.

Path 60 may include one or more radio frequency transmission lines. As an example, signal path 60 of FIG. 3 may be a transmission line having first and second conductive paths, such as paths 66 and 68, respectively. Path 66 may be a positive signal line and path 68 may be a ground signal line. Lines 66 and 68 may form (eg) portions of a coaxial cable, a stripline transmission line, and/or a microstrip transmission line. A matching network formed of components such as inductors, resistors, and capacitors may be used to match the impedance of the antenna structures 40 to the impedance of the transmission line 60 . The matching network components may be provided as discrete components (eg, surface mount technology components), or may be formed from a housing structure, a printed circuit board structure, a trace on a plastic support, or the like. Matching network components may be interposed on line 60 , for example. Matching network components may be adjusted using control signals received from control circuitry 28, if desired. Components such as these may also be used to form filter circuitry within the antenna structures 40 .

Transmission line 60 may be connected directly to the antenna resonant element for antenna 40 and to ground, or near-field used to feed indirectly to the resonant element for antenna 40 . -coupled) can be coupled to antenna feed structures. As an example, the antenna structures 40 may include an inverted-F antenna, a loop antenna, a patch antenna, a slot antenna, or a positive antenna feed terminal, such as terminal 70 , and a grounded antenna feed terminal, such as a grounded antenna feed terminal 72 . It is possible to form another antenna having an antenna feed portion having a. The positive transmission line conductor 66 may be coupled to the positive antenna feed terminal 70 , and the ground transmission line conductor 68 may be coupled to the ground antenna feed terminal 72 . If desired, antenna 40 may include an antenna resonant element that is fed indirectly using near-field coupling. In a near-coupled arrangement, the transmission line 60 is coupled to a near-coupled antenna feed structure used to indirectly feed antenna structures, such as an antenna resonating element. These examples are illustrative only, and in general, any desired antenna feed arrangement may be used.

4 is a cross-sectional side view of an exemplary device 10 showing how an antenna 40 may be formed within the device 10 . The plane of the page of FIG. 4 may be, for example, the XZ plane of FIG. 1 .

As shown in FIG. 4 , the device 10 may have conductive housing sidewalls 12W extending from the back to the front of the device 10 . Display 14 may form the front side of device 10 , while dielectric back housing wall 12R forms the back side of device 10 . Metal housing sidewalls 12W may be used to form part of the antenna ground to antenna 40 if desired.

The display 14 may include a display cover layer 86 and a display module 84 . Display module 84 may include active display components such as touch sensors, pixels, or other light emitting components that emit light through display cover layer 86 . Display cover layer 86 may extend over some or substantially all of the length and width of device 10 . The display cover layer 86 may include a transparent portion that allows light emitted by the display module 172 to pass therethrough (eg, such that the light can be viewed by a user). If desired, an opaque masking layer, such as an ink layer, may be formed along the portion of the display cover layer 86 that extends beyond the display module 84 to hide internal components of the device 10 from view.

Strap 16 may be secured to housing sidewalls 12W using corresponding attachment structures 88 . The attachment structures 88 may include a lug, a spring structure, or any other desired attachment mechanisms. Strap 16 may be formed using any desired materials (eg, a metal material, a dielectric material, or combinations of metal and dielectric materials). If desired, strap 16 may be removed from attachment structures 88 (eg, such that a user of device 10 may exchange among different straps having similar or different materials).

Device 10 may include printed circuit board structures such as printed circuit board 80 . Printed circuit board 80 may be a rigid printed circuit board, a flexible printed circuit board, or may include both flexible and rigid printed circuit board structures. Printed circuit board 80 may sometimes be referred to herein as main logic board 80 . Electrical components 82 may be mounted to main logic board 80 . Electrical components 82 may include, for example, transceiver circuitry 56 , one or more input/output devices 32 , some or all of control circuitry 28 ( FIG. 2 ), portions of housing 12 , or any It may include other desired components. Main logic board 80 may include one or more conductive layers, such as conductive layer 76 . Conductive layer 76 may form part of an antenna ground to antenna 40 , for example. Accordingly, conductive layer 76 may sometimes be referred to herein as grounded layer 76 , grounded layer 76 , grounded conductor 76 , or grounded conductor 76 .

Conductive layer 76 may, if desired, be shorted (grounded) to metal housing sidewalls 12W (eg, antenna ground to antenna 40 may be connected to conductive layer 76 and metal housing sidewalls). (12W)). Conductive layer 76 is a metal foil, stamped sheet metal, patterned conductive traces on the surface of main logic board 80 , conductive traces on a flexible printed circuit mounted to main logic board 80 , metal housing It can be formed using parts, or any other desired conductive structures. If desired, conductive layer 76 may be formed (embedded) within main logic board 80 (eg, conductive layer 76 may be stacked between dielectric layers of logic board 80 ). . In other suitable arrangements, the conductive layer 76 may be omitted.

As shown in FIG. 4 , the rear housing wall 12R may extend substantially the entire length and width of the device 10 . The rear housing wall 12R may be formed of any desired dielectric material. For example, rear housing wall 12R may be formed of plastic, glass, sapphire, ceramic, wood, polymer, combinations of these materials, or any other desired dielectric materials. The rear housing wall 12R may be optically opaque or optically transparent, or may include both an optically opaque portion and an optically transparent portion.

The antenna 40 may include antenna structures 74 . The antenna structures 74 can be, for example, some or all of the antenna resonating element for the antenna 40 (eg, an inverted-F antenna resonating element arm, a planar inverted-F antenna resonating element, a patch antenna resonating element). element, dipole antenna resonant element, monopole antenna resonant element, etc.). In one suitable embodiment, the antenna resonating element 74 may be formed of conductive traces that are patterned directly on the inner surface of the dielectric housing wall 12R (eg, the patterned conductive traces are the dielectric housing). may be in direct contact with the inner surface of the wall 12R). If desired, the antenna resonating element 74 may be formed using a conductive foil, or other conductive structures disposed in direct contact with the rear housing wall 12R. In another suitable arrangement, the antenna resonating element 74 is a flexible printed circuit board, or other dielectric substrate positioned over (eg, vertically spaced from and overlapping with) the rear housing wall 12R or in direct contact therewith. may be formed of conductive traces on the The antenna resonant element traces 74 may be formed using any desired conductive material (eg, aluminum, copper, metal alloy, stainless steel, gold, etc.).

The example of FIG. 4 in which the rear housing wall 12R is formed using dielectric materials is illustrative only. If desired, the rear housing wall of device 10 may include a combination of conductive and dielectric materials. For example, a portion of the rear housing wall may be formed of metal, while another portion of the rear housing wall is formed of a dielectric (eg, a portion of the rear housing wall formed of the dielectric may be formed of a length of the device 10 ). and a portion of the width, but not all of it). The dielectric portion of the rear housing wall may include, for example, a dielectric window in a conductive portion of the rear housing wall (eg, the rear housing wall may be a dielectric portion of the rear housing wall or a dielectric of the rear housing wall) may include a metal frame for other structures surrounding the part). The rear housing wall may include multiple dielectric windows if desired.

The positive antenna feed terminal 70 of the antenna 40 may be coupled to a portion of the antenna resonating element traces 74 to feed radio frequency antenna signals to the antenna 40 . Ground antenna feed terminal 72 may be coupled to antenna ground for antenna 40 . In the example of FIG. 4 , the grounded antenna feed terminal 72 is coupled to the metal housing sidewall 12W. If desired, the grounded antenna feed terminal 72 may be coupled to the conductive layer 76 or any other grounded structures. If desired, one or more additional portions of antenna resonating element traces 74 may be connected to antenna ground (eg, housing wall 12W, conductive layer 76 , and/or using other conductive paths (not shown)) or other grounded structures). Such conductive paths may, for example, form a return (short circuit) path to the antenna 40 (eg, in scenarios where the antenna 40 is an inverted-F antenna or a planar inverted-F antenna).

In scenarios where the antenna resonating element traces 74 are patterned directly on the rear housing wall 12R, the rear housing wall 12R will serve as a mechanical support structure or carrier structure for the antenna resonating element 74 . can The antenna resonating element traces 74 may conform to the shape of the inner surface of the dielectric rear housing wall 12R. In the example of FIG. 4 , the interior surface of the dielectric rear housing wall 12R is (eg, to increase the total volume for components within the device 10 compared to scenarios where the interior surface of the wall 12R is flat). It has a slightly curved shape. The antenna resonating element traces 74 may thus be formed in a curved surface in direct contact with the rear housing wall 12R. In another suitable arrangement, the antenna resonating element traces 74 may be formed on a flexible printed circuit or other substrate placed in contact with or laminated over the rear housing wall 12R.

The antenna 40 may receive and/or transmit radio frequency signals via the rear housing wall 12R. Radio frequency signals transmitted by antenna 40 may be shielded from electrical components 82 by, for example, conductive layer 76 and main logic board 80 . Similarly, conductive layer 76 and main logic board 80 may shield antenna 40 from components 82 to mitigate electromagnetic interference between antenna 40 and components 82 .

If desired, other components (eg, one or more sensors 32 such as light sensors, proximity sensors, touch sensors, etc.) may be mounted to rear housing wall 12R. For example, the antenna resonating element traces 74 may surround or be formed around the perimeter of other components mounted to the rear housing wall 12R. In one suitable arrangement, the coil 50 ( FIG. 2 ) is placed in contact with the rear housing wall 12R to receive wireless power (eg, wireless charging signals) via the dielectric rear housing wall 12R. can be In this scenario, the antenna resonating element traces 74 may surround the coil 50 at the inner surface of the rear housing wall 12R.

By forming the antenna 40 adjacent the rear housing wall 12R, the vertical height H of the device 10 (while still allowing the antenna 40 to exhibit satisfactory antenna efficiency) allows the antenna resonating element to be present in the device 10. It may be shorter than the height that would be possible in scenarios located elsewhere on the image. As an example, the vertical height H may be 11.4 mm or less, less than 15 mm, 8 to 11.4 mm, or any other desired height while still allowing the antenna 40 to operate with satisfactory antenna efficiency. Forming the antenna 40 along the back side of the device 10 may also allow for a reduction in the size of the inactive area of the display 14 (as shown by arrow I), which ) can transmit radio frequency signals through the back of the device 10 without fear that the signals will be blocked by the display module 84 .

Forming the antenna 40 along the rear housing wall 12R also ensures that the perimeter of the antenna resonating element 74 is sufficient to allow coverage of relatively low frequencies, such as those in the cellular telephone band of 700 to 960 MHz. can be allowed to be large. In general, the antenna 40 is capable of receiving radio frequency signals above 700 MHz, such as IEEE 802.11 communications, Bluetooth®, and/or other wireless local area network communications that may be handled by the peripheral antenna 40P (as an example). signals at 2.4 GHz and/or 5 GHz for low-band cellular telephony signals (eg, cellular telephony at frequencies between 700 MHz and 960 MHz), mid-band, high-band, and 960-2700 MHz cellular telephone signals and GPS signals in other bands above 960 MHz, such as cellular telephone and GPS signals in 2.4 GHz and/or for IEEE 802.11 communication, Bluetooth®, and/or other wireless local area network communication or 5 GHz, and any other desired bands. By using a single antenna 40 to cover all of these bands, space that would otherwise be occupied by additional antennas in device 10 is used for other electronic device components, or without sacrificing antenna efficiency. It may be used to further reduce the size of the device 10 (eg, dimensions H and/or I in FIG. 4 ).

Indeed, the performance of the antenna 40 may be optimized by the presence of an external object adjacent the rear housing wall 12R. For example, the presence of the user's wrist 90 adjacent the rear housing wall 12R when the user is wearing the device 10 may improve the performance of the antenna 40 . During operation, the antenna resonating element 74 may transmit and/or receive radio frequency signals having an electric field E oriented perpendicular to the surfaces of the back surface 12R and wrist 90 . These signals may sometimes be referred to as surface waves that propagate outward and along the surface of the wrist 90 (eg, antenna resonating element traces 74 and wrist 90 as a waveguide that directs the surface wave outward). can play a role).

5 is a cross-sectional side view showing how electromagnetic signals transmitted by the antenna 40 can propagate outward due to the presence of the user's wrist. As shown in Fig. 5, the contour lines 92 represent contours of a constant electric field magnitude. The magnitude of the electric field generated by the antenna 40 is highest in the space between the device 10 and the wrist 90 . The signals may propagate along the surface of the wrist 90 and the resonant element trace 74 in an outward direction away from the device 10 , as shown by path 98 . This may allow signals to be properly received by external communications equipment (eg, equipment 52 in FIG. 2 ) even if antenna 40 is positioned close to wrist 90 and is typically oriented away from the external communications equipment. have. Indeed, the presence of the wrist 90 may serve to enhance the propagation of electromagnetic waves compared to situations where the wrist 90 is not present. For example, the radio frequency signals emitted by the antenna 40 may not be properly directed in the absence of the wrist 90 , resulting in poor or unsatisfactory radio link quality with external equipment. However, in the presence of the wrist 90 , the signals may be properly directed as shown by arrow 98 , allowing satisfactory link quality to be obtained. The example of FIG. 5 is merely an example. In general, the electric field patterns may have any desired shape or configuration.

When performing a wireless communication operation, the antenna 40 may be loaded through the rear housing wall 12R by external objects in the vicinity of the rear housing wall 12R. If care is not taken, the antenna 40 may exhibit an altered frequency response to the free space environment when an external object, such as the wrist 90, enters the vicinity of the antenna 40 (e.g., the impedance of the antenna changes to the rear wall). Antenna 40 can be detuned as it changes due to loading from object 90 through 12R). Also, different types of objects or materials may load the antenna 40 by different amounts. Similarly, adjustments to the orientation or distance of a foreign object relative to the rear housing wall 12R may load the antenna 40 by different amounts. During normal operation of the device 10 by the end user, these loading variations may occur, for example, when the user adjusts the position or orientation of the device 10 on his/her wrist (eg, tightening the strap 16 or When the user adjusts the distance between their wrist and the antenna 40 (by loosening), when the user replaces the strap 16 with a different strap, when a different user wears the device 10 (eg, Because different users may have different wrist physiology that affects the loading of the antenna 40 differently), (eg, with sweat or water, such as when the user is swimming while wearing the device 10 ). ) when the strap 16 or wrist 90 gets wet, or when a portion of the user's clothing, such as a shirt sleeve, is disposed between or removed from the device 10 and wrist 90 . These examples are merely examples. In general, certain environmental factors may load antenna 40 by different amounts through housing wall 12R.

Such environmental loading variations can change the impedance of the antenna 40 to the transmission line 60 . If care is not taken, these variations can create impedance discontinuities between the antenna 40 and the remainder of the wireless communication circuitry 34 . The impedance discontinuity may cause some radio frequency energy to be reflected at the boundary between the antenna 40 and the remainder of the wireless communication circuitry 34 instead of being used to carry signals with the external equipment 52 ( FIG. 2 ). have. If these environmental loading variations are not compensated for, the antenna 40 may detune as the environmental loading variations change over time, reducing overall antenna efficiency and communication link quality during normal operation of the device 10 .

To compensate for these antenna impedance variations, the storage and processing circuitry 28 controls the adjustable matching circuitry coupled to the antenna 40 so that the antenna 40 is loaded through the wall 12R regardless of how it is loaded. (40) can be ensured to suitably match the rest of the radio circuitry (34). If desired, the storage and processing circuitry 28, in addition to the adjustable matching circuitry, tunes, to cover the desired frequency bands of interest and to compensate for any detuning of the antenna 40 due to loading of the antenna by external objects. Possible components 62 ( FIG. 3 ) can be adjusted.

The storage and processing circuitry 28 may use any desired information to determine when and how to adjust the adjustable matching circuitry to compensate for variations in antenna loading. For example, the control circuitry 28 may adjust the matching circuitry based on instructions received from external equipment, such as a wireless base station or access point. If desired, the control circuitry 28 may adjust the matching circuitry based on the current operating state of the device 10 . For example, the control circuitry 28 may determine a usage scenario (eg, whether the device 10 is being used to browse the Internet, connect a phone call, email whether it is being used to transmit, whether it is being used to access GPS, etc.). As another example, the control circuitry 28 may identify sensor data used to identify how to adjust the matching circuitry (eg, light sensor data, proximity sensor data, touch sensor data, the user's body data indicating how close to the housing wall 12R, etc.). As another example, the control circuitry 28 controls the antenna 40 , which can be used to characterize the performance of the antenna 40 , for example, with antenna performance information that can be used to identify how to adjust the matching circuitry. collected performance metric data). If desired, information about a user's habits of the device 10 (sometimes referred to herein as user statistics) may also be processed to determine how to adjust the matching circuitry. In general, the control circuitry 28 is configured to identify when to adjust the matching circuitry (eg, when an antenna loading variation occurs) and to identify how to adjust the matching circuitry (eg, to identify potential changes in antenna loading). Any desired combination of this or other information may be processed in a manner to mitigate the detuning artifact).

Exemplary circuitry for gathering and processing antenna performance information to determine how to adjust the antenna 40 to compensate for antenna loading variations is shown in FIG. As shown in FIG. 6 , the wireless communication circuitry 34 includes one or more antennas 40 , front end circuitry 112 , radio frequency combiner circuitry 110 , power amplifier circuitry 108 , and low noise amplifier circuitry 114 . , a transceiver circuit unit 56 , and a received signal strength measurement circuit unit 122 .

The storage and processing circuitry 28 may include baseband processor circuitry, storage such as non-volatile or volatile memory, and control circuitry for controlling the wireless communication circuitry 34 to transmit and/or receive radio frequency signals. have. The digital data signals to be transmitted by device 10 may be generated by one or more baseband processors within circuitry 28 . Circuitry 28 may modulate digital data signals according to a desired communication protocol (eg, a desired cellular telephone standard and modulation scheme, wireless local area network protocol, etc.), and transmit/receive circuitry 56 (eg, corresponding output signals for transmission (to one or more transmitters 102 in transceiver circuitry 56 ). Transceiver circuitry 56 may include mixer circuitry that up-converts output signals to radio frequency and transmits radio frequency signals to radio frequency power amplifier (PA) circuitry 108 . If desired, transceiver circuitry 56 may include digital-to-analog converter circuitry that converts the output signals to corresponding analog signals.

Control circuitry within storage and processing circuitry 28 may provide a voltage (Vcc) (eg, power supply voltage (Vcc) or power amplifier bias from time to time herein) provided to power amplifier circuitry 108 via control path 118 . voltage (referred to as Vcc) can be adjusted. The bias voltage Vcc may be used as a power supply voltage for one or more active power amplifier stages within the power amplifier circuitry 108 . During data transmission, the power amplifier circuitry 108 may amplify the output power of the transmission signals TX to a level high enough to ensure sufficient signal transmission.

The output of the power amplifier circuitry 108 may be coupled to a radio frequency front end circuitry 112 via a radio frequency coupler 110 . Front end circuitry 112 may include tunable impedance matching circuitry, such as tunable matching network 111 . The adjustable impedance matching circuitry 111 includes passive and/or active (tunable) components, such as resistors, inductors, and capacitors, that are adjusted to ensure that the antenna 40 is impedance matched to the remainder of the circuitry 34 . may include networks of Storage and processing circuitry 28 may provide control signals CTRL via control path 116 to adjustable matching circuitry 111 in front end 112 .

In some scenarios, the processing circuitry 28 controls the matching circuitry 111 to indicate a particular predetermined impedance that is selected based solely on the frequency of the signals to be transmitted via the antenna 40 . For example, processing circuitry 28 may store factory-calibrated data for matching circuitry 111 that identifies specific settings for matching circuitry 111 that correspond to each possible operating frequency. have. Once the processing circuitry 28 determines the frequency to be used for wireless communication, the matching circuitry 111 is placed in the corresponding setting identified by the factory-calibrated data. However, making such a priori adjustment based solely on the frequency to be used does not account for any potential antenna loading variations through the rear housing wall 12R occurring during normal operation. Processing circuitry 28 can thus perform dynamic adjustment of matching circuitry 111 in real time based on how antenna 40 is being loaded through rear housing wall 12R (eg, circuitry 28 ). ) to change the impedance of the antenna 40 to match the impedance of the rest of the radio circuitry 34 in real time regardless of the loading conditions of the antenna 40 ).

As an example, when an external object, such as a wrist 90 ( FIG. 5 ) comes in close proximity to the antenna 40 , the antenna 40 may no longer match the impedance of the antenna 40 to the rest of the circuitry 34 . It can be loaded so that The storage and processing circuitry 28 may control the impedance of the adjustable impedance matching network 111 to match the antenna 40 loaded by the wrist 90 . Once the matching network 111 matches the antenna 40 , potential detuning as a result of changes in antenna loading can be mitigated and antenna efficiency can be maximized. As another example, the antenna 40 can be loaded by a first amount when the device 10 is oriented in the position 94 relative to the user's wrist 90 ( FIG. 5 ), and the device 10 is positioned at the position ( 96) when oriented in the second amount. The control circuitry 28 may place the matching circuitry 111 in a first setting that mitigates a first amount of antenna loading when the device 10 is in the position 94 , and the device 10 is in the position 96 ) may place the circuitry 111 in a second setting that mitigates a second amount of antenna loading when at . The storage and processing circuitry 28 may additionally or alternatively, if desired (eg, to adjust the tunable components 62 of FIG. 2 ), route 124 to compensate for different antenna loading conditions. It is possible to provide control signals to the antenna 40 through the

If desired, front circuitry 112 may include radio frequency switching circuitry (eg, multiplexing circuitry), filtering circuitry (eg, duplexers and diplexers), or other circuitry such as any other desired radio frequency front end circuitry. may include. If desired, filtering circuitry in the front end 112 may be used to route the input (receive) and output (transmit) signals based on their frequency. For example, the filtering circuitry in the front end 112 may transmit (uplink) signals TX received from the combiner 110 to the antenna 40 and receive (down) received by the antenna 40 . link) signals RX on the receive path 113 . If desired, low noise amplifier (LNA) circuitry 114 may be interposed on the receive path 113 . The low noise amplifier circuit unit 114 may amplify the received signals RX on the path 113 . The amplified receive signals RX may be routed to transceiver circuitry 56 (eg, to one or more receiver circuitry 106 within transceiver circuitry 56 ). Transceiver circuitry 56 converts signals received via path 113 to baseband circuitry within storage and processing circuitry 18 (eg, after down-converting the signals to a baseband frequency using mixer circuitry). can provide

The combiner 110 may be used to tap antenna signals flowing to and from the antenna 40 . The tapped antenna signals from combiner 110 may be processed using a receiver in transceiver circuitry 56 or a separate receiver. As shown in FIG. 6 , the combiner 110 may provide the tapped antenna signals TX to the feedback receiver 104 via the feedback path 120 . The storage and processing circuitry 28 may control the combiner 110 using the control path 119 . For example, storage and processing circuitry 28 may cause combiner 110 to send a tapped version (sometimes referred to as forward signals) of signals TX being transmitted by power amplifier 108 to a receiver ( 104 , or a corresponding tapped version of the transmitted signals TX reflected from the antenna 40 (sometimes referred to as reverse signals) to the receiver 104 .

The tapped signals may be down-converted and provided to storage and processing circuitry 28 . The storage and processing circuitry 28 may process the tapped signals to generate antenna performance metric information, such as phase and magnitude measurements of the impedance of the antenna 40 . For example, by processing the forward and reverse signals for the antenna 40 , the storage and processing circuitry 28 may collect information about the phase and magnitude of the impedance of the antenna 40 in real time. The phase and magnitude measurements may include complex impedance data, such as scattering parameter (so-called "S-parameter") values representing the complex impedance of the antenna 40 . Measurements of the S-parameters may include, for example, measured reflection coefficient parameter values (so-called S11 values) representing the amount of radio frequency signals that are reflected back towards the combiner 110 from the antenna 40 during signal transmission. .

The phase and magnitude of the impedance of the antenna 40 depends on whether the operation of the antenna 40 is affected by the operating environment of the device 10 (eg, the presence of an external object determines the loading of the antenna 40 ). It can be used to determine whether it has been tuned or changed). For example, the storage and processing circuitry 28 detects fluctuations in the collected phase and magnitude information (eg, S11 measurements of excessively high magnitude, etc.), so that the antenna 40 is decoupled by the presence of an external object. Can identify when tuned/loaded. The storage and processing circuitry 28 determines that the antenna 40 may cause loading of the antenna 40 (eg, the user adjusting the strap 16 , changing the strap 16 , the wrist 90 ). When detecting that the device 10 has been detuned (due to adjusting the orientation of the device 10 with respect to the strap 16 getting wet, a different user wearing the device 10, etc.), the circuitry 28 detunes the Control signals CTRL may be issued via path 116 to adjust the impedance matching network 111 to compensate for After the impedance matching network 111 is adjusted, the antenna 40 is impedance matched with the rest of the wireless communication circuitry 34 and antenna efficiency is maximized.

If desired, other performance metric information, such as received signal strength information, may be used to determine how to adjust circuitry 111 in response to variations in antenna loading. The received signal strength measurement circuitry 122 in the wireless communication circuitry 34 may receive the signals RX from the low-noise amplifier circuitry 114 . The measurement circuit unit 122 may collect information indicating the received signal strength of the signals RX. For example, the measurement circuitry 122 may collect received signal strength indicator (RSSI) values from the received signals RX. In one suitable arrangement, circuitry 122 may include diode detector circuitry that converts the received radio frequency signal to a known voltage level for extracting RSSI values. The RSSI values may be sent to storage and processing circuitry 28 . The RSSI values collected by the measurement circuitry 122 may be accumulated and stored on the circuitry 28 as the collected RSSI data 126 . The collected RSSI data 126 may be stored on the circuitry 28 in a data structure such as, for example, a database file.

The storage and processing circuitry 28 may track the physical location of the device 10 over time. For example, the GPS receiver circuitry 42 ( FIG. 2 ) may receive satellite navigation signals to identify the location of the device 10 over time. As another example, the short-range transceiver 36 may be used to determine the location of the device 10 relative to a wireless base station having a known location. The location of the device 10 relative to the wireless base station may be compared to a known location of the wireless base station to identify the spatial location of the device 10 . In general, any desired methods may be used to identify the location of device 10 . The location of the device 10 may be identified using spatial coordinates, such as latitude, longitude, and/or elevation coordinates, or any other desired spatial coordinates.

When accumulating and storing RSSI data 126, storage and processing circuitry 28 also determines the time each RSSI measurement was made (sometimes referred to herein as acquisition time or RSSI acquisition time) and/or at which time each RSSI measurement was made. The geographic location (sometimes referred to herein as an acquisition location or wearable electronic device acquisition location) of the device 10 at the time made may be identified. For example, the collected RSSI data 126 may include a particular RSSI value measured by the circuitry 122, a corresponding acquisition time at which the RSSI value was measured, and/or the device 10 at which the RSSI value was measured. entries (eg, rows in a data structure or database) each identifying a corresponding wearable electronic device acquisition location that identifies the location of In this manner, the collected RSSI data 126 may be stored as a function of time and space (ie, device location) on the storage and processing circuitry 28 .

If desired, storage and processing circuitry 28 may accumulate and store information regarding habits of one or more users of device 10 as user statistics 128 . User statistics 128 may be maintained in one or more data structures (eg, the same data structure as RSSI data 126 or a different data structure) stored in memory on circuitry 28 . User statistics 128 may relate to location data (eg, information identifying where device 10 is typically located at different times of the day), how the user typically wears device 10 . information, information about a typical configuration of strap 16 when device 10 is worn by a user, information about typical performance of antenna 40 or other components within wireless circuitry (eg, performance metric data); or any other information pertaining to the routine or habits of the user of the device 10 .

If desired, user statistics 128 may include information identifying predetermined patterns of RSSI data as a function of time and/or space. For example, user RSSI patterns 132 may be stored on circuitry 28 . User RSSI patterns 132 may be predetermined patterns of RSSI values as a function of time and/or space associated with typical operation of device 10 by a user. For example, while the user spends the day (e.g., waking up, driving to work, driving home from work, falling asleep, etc.), the RSSI values collected are the antennas during the user's day. It may represent predetermined patterns associated with the performance of (40). User RSSI patterns 132 may serve as a background or baseline measurement used by circuitry 28 to determine when abnormal events have occurred, for example requiring antenna matching adjustments. RSSI patterns 132 may be loaded onto device 10 (eg, using factory-calibrated patterns or settings) during manufacture of device 10 , if desired. If desired, storage and processing circuitry 28 may continuously update (train) user RSSI patterns 132 based on real-time RSSI measurements performed by circuitry 122 . For example, circuitry 28 may update RSSI patterns 132 as it learns the user's behavior or to account for any changes in the user's behavior over time. In this way, RSSI patterns 132 may reflect typical operation of device 10 by a corresponding user. If desired, user RSSI patterns 132 may include patterns associated with typical behavior of multiple users.

If desired, user statistics 128 may include event RSSI patterns stored on circuitry 28 . Event RSSI patterns 134 may be predetermined patterns of RSSI values as a function of time and/or space corresponding to specific events associated with operation of device 10 or actions performed by a user of device 10 . can For example, a given event RSSI pattern 134 may be a sequence of RSSI values as a function of time at a fixed location that is expected or predetermined to be associated with a user removing band 16 (eg, , the so-called band replacement event). As another example, a given event RSSI pattern may be a sequence of RSSI values as a function of time at a fixed location that is expected or predetermined to be associated with a user taking off device 10 from his wrist. As another example, a given event RSSI pattern may be a sequence of RSSI values as a function of time and location expected or predetermined to be associated with a user tightening or loosening the strap 16 (eg, a so-called strap coordination event). As another example, a given event RSSI pattern may be a sequence of RSSI values as a function of time that is expected or predetermined to be associated with the user's wrist 90 getting wet.

Event RSSI patterns 134 may be loaded onto device 10 during manufacture (eg, calibration data) of device 10 , if desired. If desired, the storage and processing circuitry 28 may continuously update (train) the event RSSI patterns 134 based on the real-time RSSI measurements performed by the circuitry 122 . For example, circuitry 28 may update RSSI patterns 134 as it learns how antenna 40 performs while various events or actions are being performed. Each RSSI pattern 134 may include identifier information identifying the type of event it represents (eg, a particular RSSI pattern 134 is labeled as corresponding to a strap replacement event performed by the first user). while other RSSI patterns may be labeled as corresponding to strap adjustment events performed by a second user, etc.). In this way, RSSI patterns 134 may reflect events that may occur during operation of device 10 by a corresponding user. If desired, user RSSI patterns 132 and/or event RSSI patterns 134 may be omitted.

The storage and processing circuitry 28 determines when to adjust the matching circuitry 111 and/or how to adjust the matching circuitry 111 to compensate for different loading conditions of the antenna 40 , the collected RSSI data 126 . ), user RSSI patterns 132 , event RSSI patterns 134 , other user statistics 128 , and/or other information. Match settings 130 for matching circuitry 111 may be stored on storage and processing circuitry 28 . The matching settings 130 may identify specific impedance matching settings for the matching circuitry 111 to be used during communication operations. Matching settings 130 may be stored on one or more data structures on circuitry 28 .

Storage and processing circuitry 28 (eg, based on RSSI data 126 , user RSSI patterns 132 , event RSSI patterns 134 , and/or other information collected by circuitry 122 ) ) to identify a particular loading condition for the antenna 40 at any given time. The processing circuitry 28 may retrieve an appropriate matching setting 130 corresponding to the identified loading condition, and may control the matching circuitry 111 to implement the setting. For example, processing circuitry 28 may place matching circuitry 111 in first setting 130 when processing circuitry 28 identifies that antenna 40 is in the presence of dry wrist 90 . while processing circuitry 28 places matching circuitry 111 in second setting 130 when processing circuitry 28 identifies that antenna 40 is in the presence of wet wrist 90 . .

Matching settings 130 may be loaded onto device 10 during manufacture of device 10 (eg, using factory-calibrated settings), if desired. If desired, storage and processing circuitry 28 may continuously update or overwrite matching settings 130 based on real-time RSSI measurements performed by circuitry 122 . For example, circuitry 28 may update matching settings 130 as it learns which particular settings best match antenna 40 under various loading conditions. In another suitable arrangement, circuitry 28 may sweep through different possible match settings until a satisfactory match setting is found.

In this way, the storage and processing circuitry 28 can continuously monitor the performance of the antenna 40 for changes in antenna loading and can actively adjust the matching circuitry 111 to compensate for such changes in real time. have. Thus, such adjustments can be made by different users operating the device 10 , different orientations of the device 10 on the user's wrist 90 , different strap tightening, different strap materials, on or adjacent to the device 10 . Dynamically and adapts to any potential deterioration in antenna performance that occurs as a result of the presence of water or moisture, or any other environmental fluctuations affecting the loading of the antenna 40 that may occur during normal operation of the device 10 . can be compensated negatively.

The example of FIG. 6 is merely an example. If desired, storage and processing circuitry 28 may use the collected RSSI data in combination with phase and magnitude measurements collected using combiner 110 in determining how to adjust matching circuitry 111 . The combiner 110 and feedback receiver circuitry 104 may be omitted in scenarios where phase and magnitude measurements are not used to adjust the matching circuitry 111 . Similarly, the measurement circuitry 122 may be omitted in scenarios where RSSI measurements are not used to tune the matching circuitry 111 . If desired, the antenna 40 may include a single antenna that transmits the signals TX and forwards the received signals RX to the measurement circuitry 122 . In another suitable arrangement, the first antenna 40 may be used to transmit signals TX from the combiner 110 , while the second antenna 40 transmits the signals RX for collecting RSSI data. ) is used to receive In general, wireless communication circuitry 34 may include any desired circuitry arranged in any desired manner. The circuitry 102 , 104 , 106 within the transceiver circuitry 56 may each be implemented using respective integrated circuits, or may be formed together on one or more shared integrated circuits.

7 is a flow diagram of exemplary steps that may be performed by device 10 when collecting and processing RSSI data for conditioning matching circuitry 111 . The steps of FIG. 7 are, for example, to compensate for variations in antenna loading in real time (eg, optimal antenna regardless of how device 10 is worn, who is wearing device 10 , etc.) so that efficiency is maintained) by the device 10 .

At step 140 , the wireless communication circuitry 34 may initiate wireless communication using factory calibration settings. For example, the storage and processing circuitry 28 may identify a factory calibration match setting 130 that corresponds to a particular frequency to be used for communication. Factory calibration settings may be loaded onto circuitry 28 during fabrication of device 10 . Factory calibration settings, for example, may not provide sufficient impedance matching for antenna 40 under all real-world antenna loading conditions. Wireless communication circuitry 34 may send signals TX to external devices, such as external devices 52 ( FIG. 2 ) (eg, using factory calibration settings) and external devices 52 . Signals RX may be received from

In step 142 , the storage and processing circuitry 28 is configured to generate data from wireless signals received from external devices 52 (eg, as measured by received signal strength measurement circuitry 122 of FIG. 6 ). RSSI values 126 may be collected. The storage and processing circuitry 28 may track the location of the device 10 while RSSI values are being collected. When the device 10 is performing wireless communication, the circuitry 28 may continuously collect and store RSSI values from the received signals as a function of the location of the device 10 and/or as a function of time (step (144)).

Device 10 may also collect user statistics 128 based on transmitted and received signals. For example, the storage and processing circuitry 28 may store information regarding the user's behavior as user statistics 128 (step 146). Behavioral information may include information about where the user is typically located at different times of the day, activities typically performed by the user, or other information associated with user behavior. If desired, one or more sensors within input/output device 32 ( FIG. 2 ) may be used to help track a user's behavior. For example, an ambient light sensor and/or motion sensor on device 10 may be used to identify device locations or times when a user is typically stationary, asleep, moving, or the like. As another example, a strap sensor, proximity sensor, touch sensor, or other sensors may be used to identify when a user removes or adjusts the strap 16 .

If desired, the storage and processing circuitry 28 may update the stored RSSI patterns 132 , 134 based on the collected RSSI data and the collected information regarding user behavior (step 148 ). Storage and processing circuitry 28 may identify and store user RSSI patterns 132 associated with typical use of device 10 by one or more users. The storage and processing circuitry 28 may identify and store event RSSI patterns 134 associated with various events or activities that may affect the loading of the antenna 40 . For example, storage and processing circuitry 28 may store user statistics 128 in the collected RSSI data ( 126) can be compared. The identified pattern may be stored as a given one of the event RSSI patterns 134 . Similarly, the storage and processing circuitry 28 must detune, within the collected RSSI data 126 , patterns typical for the user's normal wear (eg, normal motion of the user's arm or antenna 40 ). patterns associated with other typical user activities that do not). These identified patterns may be stored as user RSSI patterns 132 . Over the lifetime of device 10 , storage and processing circuitry 28 performs user RSSI patterns 132, event RSSI patterns 134, and/or continuously update and refine (eg, train) other user statistics 128 . The example of FIG. 7 is merely an example. If desired, steps 144, 146, and/or 148 may be omitted. Steps 144 , 146 , and/or 148 may be performed concurrently or at different times.

At step 150 , the storage and processing circuitry 28 may process the collected user statistics 128 and the collected RSSI data 126 to determine whether an adjustment to the matching circuitry 111 is necessary. . Adjustments to the matching circuitry may be necessary when detuning of the antenna 40 due to changes in loading conditions of the antenna 40 or the presence of external objects is detected in the collected RSSI data. User statistics 128 may be used, for example, to filter and/or identify patterns in the collected RSSI data 126 that indicate such changes. If desired, step 150 may be performed concurrently with some or all of step 142 (eg, storage and processing circuitry 28 may continue to collect and store data while performing data processing). .

If processing circuitry 28 determines that no adjustment is necessary (eg, no change in antenna loading or antenna detuning has been detected), processing proceeds to step 142 as shown by path 152 . Back to , you can continue to collect and store RSSI data and user statistics. If processing circuitry 28 determines that an adjustment is necessary (eg, when a change in antenna loading or antenna detuning is detected), processing proceeds to step 160 as shown by path 154 . can

At step 160, the storage and processing circuitry 28 may adjust the matching circuitry 111 to compensate for the detected change in antenna loading/detuning. For example, storage and processing circuitry 28 may provide control signals CTRL via path 116 (FIG. 6) to control circuitry 111 to implement a desired matching setting. The wireless communication circuitry 34 may continue to perform wireless communication operations using the adjusted matching setting. Processing may subsequently return to step 142 as shown by path 162 to continue collecting and storing RSSI data and user statistics.

8 is a flow diagram of exemplary steps that may be performed by storage and processing circuitry 28 to determine when to perform an adjustment to matching circuitry 111 . For example, the steps of FIG. 8 may be performed while processing step 150 of FIG. 7 .

At step 170 , processing circuitry 28 may identify, within the collected RSSI data 126 , a sequence of RSSI values as a function of time and/or device location. For example, processing circuitry 28 may identify a most recently collected set of RSSI values from collected RSSI data 126 .

In step 172, processing circuitry 28 may perform filtering operations on the identified RSSI values. For example, the processing circuitry 28 may filter the user RSSI pattern 132 as a function of time from the identified RSSI values as a function of time. User RSSI pattern 132 may be a factory calibrated pattern stored on device 10 during manufacturing and/or may be a pattern stored and updated on device 10 during normal operation (eg, in FIG. 7 ). while processing step 148). In this manner, processing circuitry 28 may filter from the collected RSSI data a baseline that would otherwise be associated with normal operation of device 10 by a user. As another example, processing circuitry 28 may filter a constant baseline RSSI value from the identified RSSI values.

At step 174 , processing circuitry may determine whether a trigger event exists within the filtered RSSI values. As an example, the trigger event may be a glitch in the filtered RSSI values. Processing circuitry 28 may determine that a glitch exists if some of the filtered RSSI values as a function of time have a slope that exceeds a positive slope threshold value or a slope that is below a negative slope threshold value. As another example, the trigger event may be an excessive deviation within the filtered RSSI values. Processing circuitry 28 may determine that an excessive deviation exists if the filtered RSSI values include values that are less than a predetermined minimum threshold RSSI value or greater than a predetermined maximum threshold RSSI value. As another example, processing circuitry 28 may compare the filtered RSSI values to one or more predetermined event RSSI patterns 134 to determine whether one of the event RSSI patterns is present in the filtered RSSI values. have. The predetermined event RSSI patterns 134 may be factory calibrated patterns stored on the device 10 during manufacturing and/or may be patterns stored and updated on the device 10 during normal operation (eg, while processing step 148 of FIG. 7). The processing circuitry 28 determines that a trigger event exists when a particular sequence of filtered RSSI values sufficiently matches a stored event RSSI pattern 134 , such as an RSSI pattern associated with the user removing or adjusting the strap 16 . can be identified. In this scenario, the trigger event may be an event RSSI pattern detected in the filtered data. Stored event RSSI patterns 134 may be, eg, different users wearing device 10 , tightening or loosening strap 16 , strap 16 , device 10 , and/or wrist sequences of RSSI values corresponding to the presence or absence of water or moisture on 90 , a change in position or orientation of device 10 on wrist 90 , and the like.

If desired, processing circuitry 28 may calculate a probability that a trigger event exists based on a combination of the filtered RSSI values, user statistics 128, and/or other information. If the calculated probability exceeds the minimum probability threshold, processing circuitry 28 may determine that a trigger event exists. If the calculated probability is less than or equal to the minimum probability threshold, processing circuitry 28 may determine that a trigger event is not detected. As an example, processing circuitry 28 may identify a relatively large drop in the filtered RSSI values (eg, an excessive deviation of the RSSI values as a function of time that is below a predetermined minimum threshold RSSI value). The processing circuitry 28 combines this information with information identifying that the filtered RSSI values were collected during the afternoon when the device was located at the user's work location, resulting in a strap change trigger event associated with the user changing the strap 16 . It may be determined that the probability that a trigger event such as .

If a trigger event is not detected in the filtered RSSI values (eg, a glitch, excessive deviation, or no predetermined RSSI pattern is present), processing proceeds to step 170 as shown by path 176 . can go back to The processing circuitry 28 then detects the presence of trigger events in the subsequently collected RSSI values as a function of time and/or device location (eg, as updated RSSI values and user statistics are collected during device operation). You can continue to search. If a trigger event is detected, processing may proceed to optional step 180 as shown by path 178 .

In an optional step 180, the processing circuitry 28 may update the stored event RSSI patterns 134 based on the filtered RSSI values. For example, sensor data, user input, or other information may be used to identify that a particular user action or environmental event occurred when a trigger event was detected. The pattern (sequence) of collected RSSI data as a function of time and/or device location associated with that user action or environmental event may be stored as event RSSI pattern 134 on circuitry 28 for further processing. For example, the pattern can be used to identify similar trigger events in the future if desired. Processing may subsequently proceed to step 160 of FIG. 7 , which adjusts the matching network 111 .

9 is a flow diagram of exemplary steps that may be performed by processing circuitry 28 to dynamically adjust matching network 111 in response to detecting a trigger event. For example, the steps of FIG. 9 may be performed while processing step 160 of FIG. 7 .

In step 190 , processing circuitry 28 may perform adjustments to matching circuitry 111 . For example, the processing circuitry 28 may control one or more components within the circuitry 111 to adjust the impedance of the circuitry 111 .

At step 192 , processing circuitry 28 may collect additional RSSI values using the adjusted matching circuitry (eg, while the matching circuitry exhibits adjusted impedance).

In step 194, the processing circuitry 28 may determine whether the performance of the antenna 40 has improved by comparing the additional RSSI values collected with the RSSI values collected before the adjustment is made. For example, processing circuitry 28 may determine that antenna performance has improved if the additional RSSI values are greater than the RSSI values collected prior to adjustment. If the antenna performance has not improved (eg, if the additional RSSI values collected in step 192 are less than or equal to the RSSI values collected prior to adjustment), the process proceeds to step 190 as shown by path 196 . ) and the matching circuitry can be further adjusted. In another suitable arrangement, the adjustments made at step 190 may be reversed and processing may proceed to step 142 of FIG. 7 . If antenna performance has improved, processing may proceed to optional step 200 as shown by path 198 .

The example of FIG. 9 in which the collected RSSI values are compared to previously-collected RSSI values is illustrative only. If desired, processing circuitry 28 may compare the additional RSSI values collected in step 192 to a predetermined threshold value. The predetermined threshold value may be determined by an industry standard, design standard, regulatory standard, manufacturing standard, or any other means. The predetermined threshold value may be, for example, a minimum RSSI value at which a satisfactory link quality between the device 10 and the external equipment 52 can be maintained. If the additional RSSI values are greater than the predetermined threshold value, processing may proceed to optional step 200 as shown by path 198 . If the additional RSSI values are below the predetermined threshold value, processing may return to step 190 as shown by path 196 .

In optional step 200 , processing circuitry 28 may store the adjusted matching network setting as an entry in match settings 130 ( FIG. 6 ). The processing circuitry 28 may use the stored matching network settings to make future adjustments to the circuitry 111 . For example, processing circuitry 28 may use a particular matching network setting 130 whenever a corresponding trigger event that caused a matching circuit adjustment is detected in the future. Processing may subsequently proceed to step 202 .

At step 202 , the wireless communication circuitry 34 may continue communicating using the adjusted matching network settings (eg, processing may proceed to step 142 of FIG. 7 ). In this way, processing circuitry 28 can sweep through many possible settings for matching network 111 while continuing to collect RSSI data until a setting is found that improves or optimizes antenna performance. This example is just an example. In another suitable arrangement, the predetermined matching settings 130 may be used when adjusting the matching network 111 .

10 is a flow diagram of exemplary steps that may be performed by processing circuitry 28 to adjust the matching network 111 based on predetermined matching settings 130 in response to detecting a trigger event. For example, the steps of FIG. 10 may be performed while processing step 160 of FIG. 7 .

Each trigger event may have a type corresponding to the environment/antenna loading factors that caused it to reside in the collected RSSI data. In step 210 , processing circuitry 28 applies filtered RSSI values as a function of time and/or device location, user statistics 128 , user input, sensor data, and/or event RSSI patterns 134 . Based on the detected trigger event type can be identified. Types of trigger events include when a user adjusts the position or orientation of device 10 on his/her wrist (eg, by tightening or loosening strap 16 ), when a user adjusts the position or orientation of device 10 on his/her wrist and the user between his/her wrist and antenna 40 . adjusting the distance of the strap 16 , the user replacing the strap 16 with a different strap, different users wearing the device 10 , the strap 16 , the device 10 , or the wrist 90 getting wet. drying or drying out, when a portion of the user's clothing, such as a shirt sleeve, is disposed between or removed from, device 10 and wrist 90 , or anything that may affect loading of antenna 40 . It may include trigger events associated with other environmental factors.

As an example, processing circuitry 28 may cause a strap sensor in device 10 to indicate that strap 16 has been replaced if the filtered RSSI values match an event RSSI pattern 134 associated with replacing strap 16 . Upon detection, or based on any other desired information, it can be identified that a trigger event associated with strap replacement (eg, a strap replacement type trigger event or a strap replacement trigger event) has occurred. For example, processing circuitry 28 may identify the trigger event as a strap replacement triggering event if a relatively large drop in the filtered RSSI values is measured during the afternoon when the device was located at the user's work location. As another example, processing circuitry 28 may indicate that the collected RSSI data included a sharp increase in measured RSSI values over time and the increase occurred during the evening after the user's location was changed from a work location to a home location. In response to identifying that the user has removed the device 10 from his/her wrist, the user may identify as a type of trigger event (eg, user statistics 128 that the set of these conditions indicates that the user can be identified as having a high probability of being associated with removing the device 10 from the wrist of As another example, processing circuitry 28 triggers the user to tighten strap 16 in response to identifying that the collected RSSI values have decreased for a relatively short period of time and also identifying that the device position has not changed during that time period. It can be identified as the type of event. These examples are by way of example only, and in general, the processing circuitry 23, when identifying the type of trigger event, collects RSSI information as a function of device location and/or time, user input, sensor data, event patterns ( 134 ), and any desired combination of other user statistics 128 .

In step 212 , processing circuitry 28 may obtain a particular matching setting 130 corresponding to the identified type of trigger event (eg, a trigger event that corresponds to a user changing strap 16 ). a first matching setting if identified as relevant, a second matching setting if the trigger event is identified as being associated with a user's skin getting wet, a third matching setting if the trigger event is identified as being associated with a different user wearing the device 10 4th match setup, if a trigger event is identified as being associated with device 10 being positioned in orientation 94 of FIG. 5 , fourth match setup if device 10 is positioned in orientation 96 of FIG. 5 . 5 matching settings, etc.). The obtained matching settings 130 may be loaded onto the device 10 during manufacture of the device 10 to be used whenever a corresponding type of trigger event is detected, or the obtained matching settings may be performed in step ( 148 may be stored on processing circuitry 28 during processing.

In step 214, processing circuitry 28 may apply the obtained matching setting 130 to the matching network 111 (eg, circuitry 28 to indicate an impedance associated with the obtained matching setting). A matching network 111 may be configured). Processing may subsequently proceed to optional step 216 .

In an optional step 216, processing circuitry 28 may collect additional RSSI values while the adjusted matching circuitry is configured using the obtained matching network settings. The processing circuitry 28 may determine whether the performance of the antenna 40 has improved by comparing the additional RSSI values collected with the RSSI values collected before the adjustment is made. If antenna performance has not improved (eg, if the additional RSSI values collected in step 216 are less than or equal to the RSSI values collected prior to adjustment), processing may proceed to step 220 .

In step 220, processing circuitry 28 may take appropriate action. For example, processing circuitry 28 may proceed to step 190 of FIG. 9 where it begins sweeping additional matching network settings until a satisfactory setting is found. As another example, the processing circuitry 28 may control the matching circuitry 111 to revert to a previous matching setting, and the process proceeds to step 142 of FIG. 7 where it continues to collect and process user statistics and RSSI values. can proceed. If the antenna performance has improved (eg, if the additional RSSI values collected in step 216 are greater than the RSSI values collected prior to the adjustment), processing may proceed to step 222 . In scenarios where optional step 216 is not performed, processing may proceed directly from step 214 to step 224 .

The example of FIG. 10 in which the collected RSSI values are compared to previously-collected RSSI values is illustrative only. If desired, processing circuitry 28 may compare the additional RSSI values collected in step 216 to a predetermined threshold value. If the additional RSSI values are greater than the predetermined threshold value, processing may proceed to step 224 as shown by path 222 . If the additional RSSI values are below the predetermined threshold value, processing may proceed to step 220 as shown by path 218 .

At step 224 , the wireless communication circuitry 34 may continue communicating using the adjusted matching network settings (eg, processing may proceed to step 142 of FIG. 7 ). In this manner, processing circuitry 28 may select and use predetermined matching settings 130 based on the collected RSSI data. This may allow for faster antenna adjustment than in scenarios where processing circuitry 28 sweeps different settings (eg, as shown in FIG. 9 ), but changes or unpredictable environmental conditions (eg, For example, it may be less adaptable to conditions in which there may not yet be optimized matching settings on circuitry 28 .

11 is an exemplary plot of collected RSSI values as a function of time showing how collected RSSI data 126 may be compared to a predetermined threshold for detecting the presence of a trigger event. 11 , curve 230 represents RSSI values collected at a fixed location and as a function of time (eg, as collected during processing step 144 of FIG. 7 ). The collected RSSI values 230 may change over time while the user wears the device 10 . A relatively small variation in the values 230 may have little effect on the overall performance of the antenna 40 . However, relatively large fluctuations can result in unsatisfactory antenna performance.

Processing circuitry 28 may process RSSI values 230 to identify a trigger event (eg, during processing step 174 of FIG. 8 ). In the example of FIG. 11 , processing circuitry 28 may compare RSSI values 230 to a predetermined threshold value (RTH). The processing circuitry 28 may determine that a trigger event exists because the RSSI values 230 fall below the threshold value RTH. This example is just an example. If desired, processing circuitry 28 may identify a slope of the RSSI values 230 and compare the slope to a predetermined slope threshold to identify the presence of a trigger event. In another suitable arrangement, the processing circuitry 28 may identify the presence and type of a trigger event when the RSSI values 230 match the predetermined event RSSI pattern 134 . The example of FIG. 11 in which RSSI values as a function of time for a set location are processed is merely exemplary. In general, processing circuitry 28 is configured to identify the presence and type of trigger event, either as a function of position at a fixed time or as a function of both position and time (eg, a multidimensional surface of collected RSSI values). RSSI values can be processed.

12 is an exemplary diagram illustrating how processing circuitry 28 may process collected RSSI values using predetermined user and event RSSI patterns to identify the presence of a trigger event.

As shown in FIG. 12 , curve 240 plots RSSI values collected as a function of time (eg, at a fixed device location). Curve 242 shows a particular user RSSI pattern 132 (eg, RSSI values as a function of time accumulated during processing step 148 of FIG. 7 ). User RSSI pattern 242 may represent typical RSSI data as a function of the same location and time values represented by curve 240 . User RSSI pattern 242 may be trained and updated over time as processing circuitry 28 continues to collect information about the user's behavior (eg, as user statistics 128 are updated). have.

The user RSSI pattern 242 may be used to filter the collected RSSI values 240 (eg, while processing step 172 of FIG. 8 ). In the example of FIG. 12 , the user RSSI pattern 242 may be filtered (subtracted) from the collected RSSI values 240 to generate filtered RSSI values 246 as shown by arrow 243 (eg For example, portions 244 of curve 240 that match user pattern 242 may be removed from filtered curve 246). In this way, the user RSSI pattern 242 may serve as a baseline measure for processing the collected RSSI values to identify trigger events.

Processing circuitry 28 may process the filtered RSSI values 246 to determine whether a predetermined event RSSI pattern is present in the filtered data (eg, while processing step 174 of FIG. 8 ). . In the example of FIG. 12 , processing circuitry 28 may identify that portion 250 of filtered RSSI values 246 matches a given event RSSI pattern 248 . Event RSSI pattern 248 may be stored on processing circuitry 28, for example, during processing step 180 of FIG. 8 , processing step 148 of FIG. 7 , or during factory calibration. As an example, event RSSI pattern 248 may be an RSSI pattern associated with a strap tightening trigger event. The presence of the event RSSI pattern 248 in the filtered RSSI data 246 may indicate that the user is tightening the strap 16 . The processing circuitry 28 is subsequently configured (eg, while processing step 210 of FIG. 10 ) for use during a subsequent communication (eg, at least until another trigger event is detected). A matching setting 130 corresponding to the strap tightening trigger event may be identified. In another suitable arrangement, the processing circuitry may sweep through the different matching network settings (eg, while processing the steps of FIG. 9 ) until an optimal matching setting is found. Performing the matching network adjustment may be performed by the matching network 111 even after the environment around the antenna 40 changes the antenna loading (eg, after the loading of the antenna changes as a result of tightening the strap 16 ). (40) can be allowed to match. By providing a suitable match to the antenna 40 , antenna efficiency can be maximized regardless of how the user is wearing the device 10 or who is wearing the device 10 .

The example of FIG. 12 is merely illustrative. In general, the collected RSSI values may have any desired shape as a function of time and/or space. Similarly, user RSSI pattern 242 and event RSSI pattern 248 may have any desired shape.

13 is a Smith chart showing how adjusting the matching circuitry 111 may differently affect antenna performance under certain antenna loading conditions. In the Smith chart of FIG. 13 , the antenna impedances of the antenna 40 are measured as a function of different operating conditions. The 50 ohm antenna impedance is characterized by impedance point 260 in the chart of FIG. 13 . An antenna with an impedance close to point 260 may be considered a good match to a 50 ohm transmission line (eg, transmission line 60 ) in device 10 .

The antenna 40 is tuned to the first matching network setting while the device 10 is operating under the first antenna loading condition (eg, when the device 10 is oriented at position 94 in FIG. 5 ). The impedance within the region 264 of FIG. 13 may be represented. Region 264 may be relatively far from point 260 , indicating a relatively high level of antenna detuning. Processing circuitry 28 may identify such detuning by collecting phase and magnitude information using combiner 110 (FIG. 6) and/or by identifying trigger events in the collected RSSI data. To compensate for this detuning, control circuitry 28 may adjust matching circuitry 111 to tune antenna 40 to a second matching network setting as shown by arrow 268 (eg, , while processing step 160 of FIG. 7 ). After being tuned to the second matching network setup, the antenna 40 may exhibit an impedance within the region 262 . Region 262 is closer to point 260 than region 264 exhibits a lower level of antenna detuning than when operating under a second matching network setup associated with region 262 . In this way, control circuitry 28 may compensate for detuning of antenna 40 caused by varying amounts of antenna loading associated with a user wearing device 10 in different orientations.

However, the antenna 40 may exhibit a different impedance when the device 10 is oriented at the position 96 of FIG. 5 . When a user changes the orientation of device 10 from orientation 94 to orientation 96 , the impedance of antenna 40 is at point 260 , such as area 264 as shown by path 266 . Moving to a region further away from , it may exhibit a relatively high level of antenna detuning. The processing circuitry 28 may subsequently identify such detuning and adjust the matching circuitry 111 to the first matching network setting. This may move the impedance of antenna 40 closer to point 260 to reduce detuning of antenna 40 . In this way, processing circuitry 28 can actively adjust matching circuitry 111 to compensate for variations in loading of antenna 40 during normal operation. This example is just an example. In general, the processing circuitry 28 may execute any suitable event (eg, a user changing the straps, a user tightening the strap 16 , a different user having a different wrist physiology wearing the device 10 ). matching circuitry 111 to compensate for any changes in the antenna loading due to the ) can be adjusted.

14 is a graph of exemplary antenna frequency responses that may be exhibited by an antenna when operating under different impedance matching circuit settings in accordance with one embodiment. In particular, FIG. 14 shows the antenna response (voltage standing wave ratio (VSWR)) as a function of operating frequency. As shown in FIG. 14 , the solid curve 270 represents the response of the antenna 40 when operating under the first matching network setting and the first antenna loading condition. For example, the curve 270 may be associated with the first user wearing the device 10 while the matching network 111 is set to the first setting. Antenna 40 may have a relatively high response to midband (MB) and highband (HB) frequencies but a relatively low and detuned response to lowband (LB) frequencies.

Dashed curve 272 represents the response of antenna 40 when operating under the first matching network setup and second antenna loading conditions. For example, the curve 272 may be associated with the second user wearing the device 10 while the matching network 111 is set to the first setting. In this scenario, the antenna 40 may have a relatively high response at low-band frequencies (eg, due to different physiology between the first and second users loading the antenna 40 differently). When the first user is wearing device 10 , processing circuitry 28 may detect a relatively low response of antenna 40 at low-band frequencies (eg, step 150 of FIG. 7 ). using phase and magnitude measurements and/or RSSI values in relation to The processing circuitry 28 may subsequently adjust the matching network 111 to a second setting that compensates for differences in antenna loading due to the first user wearing the device 10 . After adjusting the matching network 111 to the second setting, the antenna 40 may exhibit a response similar to the curve 272 when the device 10 is worn by the first user. If the first user gives device 10 to a second user to wear, the response of antenna 40 will shift to the response shown by curve 270 . The processing circuitry 28 may detect this change and may subsequently adjust the matching network 111 back to the first setting. After adjusting the network 111 to the first setting, the antenna 40 may exhibit a response as shown by the curve 272 . In this way, processing circuitry 28 can actively adjust circuitry 111 to compensate for changes in antenna loading and detuning in real time.

The example of FIG. 14 is merely an example. In general, antenna 40 may operate in any desired number of different frequency bands and may have any desired response as a function of operating frequency. The antenna 40 may be detuned as a result of any change in environmental conditions. Although the examples of FIGS. 1-14 are described with respect to a wristwatch device, similar operations may be performed by any desired electronic device.

Operations of device 10 (eg, operations of FIGS. 7-10 ) may be performed by control circuitry 28 . During operation, this control circuitry (which may sometimes be referred to as processing circuitry, processing and storage, computing equipment, computer, etc.) executes (eg, using dedicated hardware and/or on hardware such as control circuitry 28 ). 7-10 (using software code that is used) to perform the methods and/or other operations of FIGS. The software code for performing these operations may be stored on a non-transitory (tangible) computer-readable storage medium. Software code may sometimes be referred to as software, data, program instructions, instructions, or code. Non-transitory computer-readable storage media may include non-volatile memory such as non-volatile random access memory (NVRAM), one or more hard drives (eg, magnetic drives or solid state drives), one or more removable flash drives or other removable media, or other computer-readable media, or combinations of these computer-readable media. Software stored on the non-transitory computer-readable storage medium may be executed by processing circuitry of the control circuitry 28 . The processing circuitry may include an application specific integrated circuit having processing circuitry, one or more microprocessors, or other processing circuitry.

According to one embodiment, a method of operating a wearable electronic device is provided, the wearable electronic device having a display formed on a front surface of the electronic device, a dielectric rear housing wall formed on a rear surface of the electronic device, an antenna, and processing circuitry, the method comprising: wherein the antenna receives radio frequency signals from external equipment through the dielectric rear housing wall, using processing circuitry to collect information about the amount of loading of the antenna by an external object through the dielectric rear housing wall; and using the processing circuitry to adjust the antenna to compensate for a change in the amount of loading of the antenna by a foreign object through the dielectric rear housing wall.

According to another embodiment, collecting information regarding the amount of loading of the antenna comprises collecting received signal strength indicator (RSSI) values based on radio frequency signals received from external equipment through a dielectric rear housing wall. and adjusting the antenna to compensate for a change in the amount of loading of the antenna by a foreign object through the dielectric rear housing wall comprises adjusting the antenna based on the collected RSSI values.

According to another embodiment, the collecting information regarding the amount of loading of the antenna comprises storing acquisition times associated with each of the collected RSSI values and storing the wearable electronic device acquisition positions associated with each of the collected RSSI values. include

According to another embodiment, adjusting the antenna to compensate for a change in the amount of loading of the antenna by a foreign object through the dielectric rear housing wall comprises the collected RSSI values, the stored acquisition times, and the stored wearable electronic device acquisition location. and adjusting the antenna based on the values.

According to another embodiment, collecting information regarding the amount of loading comprises collecting phase and magnitude measurements of the impedance of the antenna based on radio frequency signals transmitted to the antenna by radio frequency transmitter circuitry on the wearable electronic device. wherein adjusting the antenna to compensate for a change in the amount of loading of the antenna by a foreign object through the dielectric rear housing wall comprises adjusting the antenna based on the collected phase and magnitude measurements of the impedance of the antenna. include

According to another embodiment, a wearable electronic device includes radio frequency transceiver circuitry and impedance matching circuitry coupled between the radio frequency transceiver circuitry and the antenna, wherein the wearable electronic device is configured to change the amount of loading of the antenna by an external object through the dielectric rear housing wall. Adjusting the antenna to compensate includes adjusting the impedance of the impedance matching circuitry.

According to another embodiment, the antenna includes a tunable component, and adjusting the antenna to compensate for a change in the amount of loading of the antenna by a foreign object through the dielectric rear housing wall comprises adjusting the tunable component. include

According to one embodiment, there is provided a wearable electronic device having opposing front and back surfaces, the wearable electronic device comprising: a display having a dielectric back housing wall defining a back surface of the electronic device, and a display cover layer defining a front surface of the electronic device , an antenna resonating element formed of conductive traces overlapping the dielectric rear housing wall, the antenna resonating element being loaded by external objects through the dielectric rear housing wall, wirelessly through the dielectric rear housing wall using the antenna resonating element. In response to detecting a change in loading of the antenna resonating element through the radio frequency transceiver circuitry configured to transmit and receive frequency signals, the impedance matching circuitry coupled between the antenna resonating element and the radio frequency transceiver circuitry, and the dielectric rear housing wall. and storage and processing circuitry configured to adjust the impedance matching circuitry.

According to another embodiment, a wearable electronic device comprises a receive path coupled between the radio frequency transceiver circuitry and the impedance matching circuitry and a receive signal strength measurement circuitry coupled to the receive path, wherein the received signal strength measurement circuitry comprises a radio frequency measurement circuitry on the receive path. and generate received signal strength information based on the signals, and the storage and processing circuitry is configured to detect a change in loading of the antenna resonating element based on the generated received signal strength information.

According to another embodiment, the generated received signal strength information includes received signal strength indicator (RSSI) values, acquisition times associated with each of the RSSI values, and wearable electronic device acquisition locations associated with each of the RSSI values.

According to another embodiment, the storage and processing circuitry is configured to detect a change in the loading of the antenna resonating element by determining whether the RSSI values match a predetermined pattern of RSSI values.

According to another embodiment, radio frequency transceiver circuitry includes a cellular telephone transceiver configured to transmit and receive signals at frequencies between 700 MHz and 960 MHz through a dielectric rear housing wall using an antenna resonant element.

According to another embodiment, the wearable electronic device comprises metal housing sidewalls extending from a dielectric rear housing wall to a display cover layer, a first antenna feed terminal coupled to conductive traces, the conductive traces patterned on the dielectric rear housing wall. , a second antenna feed terminal coupled to the metal housing sidewalls, and a radio frequency transmission line coupling the radio frequency transceiver circuitry to the first and second antenna feed terminals.

According to another embodiment, the antenna resonating element is configured to form a waveguide with the user's wrist while the user wears the wearable electronic device.

According to another embodiment, a wearable electronic device includes a power amplifier circuitry coupled to radio frequency transceiver circuitry, a radio frequency coupler coupled between the power amplifier circuitry and impedance matching circuitry, and a feedback coupled between the radio frequency coupler and the radio frequency transceiver circuitry. a path, wherein the storage and processing circuitry is configured to collect phase and magnitude measurements of the impedance of the antenna resonating element based on feedback signals received by the radio frequency transceiver circuitry from the radio frequency coupler via the feedback path; The processing circuitry is further configured to detect a change in loading of the antenna resonating element based on the collected phase and magnitude measurements.

According to one embodiment, there is provided a method of operating a wearable electronic device, the wearable electronic device comprising: a display formed on a front surface of the electronic device; a dielectric rear housing wall formed on a rear surface of the electronic device; an antenna; impedance matching circuitry coupled to the antenna; and processing circuitry, the method comprising: receiving, using the antenna, radio frequency signals from external equipment through the dielectric rear housing wall; using the processing circuitry, a received signal strength indicator based on the received radio frequency signals ( collecting and storing RSSI) values and corresponding RSSI acquisition times, accumulating, using processing circuitry, user statistics associated with operation of the wearable electronic device by the user over time, using processing circuitry, triggering event processing accumulated user statistics, stored RSSI values, and stored RSSI acquisition times to detect, and in response to detecting a trigger event using processing circuitry, adjusting the impedance matching circuitry.

According to another embodiment, the accumulated user statistics include a user RSSI pattern, and the processing of the accumulated user statistics, the stored RSSI values, and the stored RSSI acquisition times includes: filtering the user RSSI pattern from the stored RSSI values. generating RSSI values, and detecting a trigger event based on the filtered RSSI values.

According to another embodiment, the user statistics include an event RSSI pattern associated with a change in loading of the antenna through the dielectric rear housing wall, wherein detecting the trigger event comprises, within the filtered RSSI values, matching the event RSSI pattern. detecting the sequence of RSSI values.

According to another embodiment, adjusting the impedance matching circuitry includes controlling the impedance matching circuitry to exhibit an adjusted impedance, an additional RSSI value from radio frequency signals received while the impedance matching circuitry exhibits an adjusted impedance. in response to determining that radio frequency performance of the antenna has not improved, representing an additional adjusted impedance, comprising: collecting controlling the impedance matching circuitry to control the impedance matching circuitry, and in response to determining that the radio frequency performance of the antenna has improved, storing a matching setting associated with the adjusted impedance on the storage circuitry.

According to another embodiment, adjusting the impedance matching circuitry comprises: retrieving a matching setting associated with the event RSSI pattern from storage circuitry on the wearable electronic device, the matching setting identifying the adjusted impedance, indicating the adjusted impedance controlling the impedance matching circuitry to determine the impedance matching circuitry; collecting additional RSSI values from the received radio frequency signals while the impedance matching circuitry exhibits the adjusted impedance; determining whether the additional RSSI values exceed a minimum RSSI threshold value. and in response to determining that the additional RSSI value does not exceed the minimum RSSI threshold value, controlling the impedance matching circuitry to indicate the additional adjusted impedance.

The above is merely an example, and various modifications may be made to the described embodiments. The above-described embodiments may be implemented individually or in any combination.