PATENT DOCUMENT

Publication Number: US-10181640-B2
Application Number: US-201615234907-A
Country: US
Kind Code: B2

Title: Electronic device antennas

Abstract:
An electronic device such as a wristwatch may have a housing with metal portions such as metal sidewalls. The housing may form an antenna ground for an antenna. An antenna resonating element for the antenna may be formed from a stack of capacitively coupled component layers such as a display layer, touch sensor layer, and near-field communications antenna layer at a front face of the device. An additional antenna may be formed from a peripheral resonating element that runs along a peripheral edge of the device and the antenna ground. A rear face antenna may be formed using a wireless power receiving coil as a radio-frequency antenna resonating element or may be formed from metal antenna traces on a plastic support for light-based components.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing having a metal housing wall that forms at least part of an antenna ground for an antenna; 
 a display cover layer; 
 a stack of capacitively coupled electrical component layers that are overlapped by the display cover layer and that form an antenna resonating element for the antenna; and 
 an antenna feed for the antenna having a positive antenna feed terminal coupled to the stack of capacitively coupled electrical component layers and having a ground antenna feed terminal coupled to the antenna ground. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the stack of capacitively coupled electrical component layers comprises a display layer. 
     
     
       3. The electronic device defined in  claim 2  wherein the stack of capacitively coupled electrical component layers comprises a touch sensor layer interposed between the display layer and the display cover layer. 
     
     
       4. The electronic device defined in  claim 3  wherein the stack of capacitively coupled electrical component layers comprises a near-field communications antenna layer. 
     
     
       5. The electronic device defined in  claim 4  wherein the display layer comprises an organic light-emitting diode display layer interposed between the near-field communications antenna layer and the touch sensor layer. 
     
     
       6. The electronic device defined in  claim 5  further comprising near-field communications circuitry coupled to the near-field communications antenna layer. 
     
     
       7. The electronic device defined in  claim 6  wherein the near-field communications antenna layer comprises loops of metal traces and wherein the near-field communications circuitry includes a printed circuit, a near-field communications transceiver on the printed circuit that is coupled to the loops of metal traces, and a metal shielding can that overlaps the near-field communications transceiver. 
     
     
       8. The electronic device defined in  claim 7  wherein the positive antenna feed terminal is coupled to the metal shielding can. 
     
     
       9. The electronic device defined in  claim 8  further comprising:
 an additional printed circuit; and 
 a flexible printed circuit coupled between the printed circuit in the near-field communications circuitry and the additional printed circuit, wherein the additional printed circuit serves as an inductive path coupling the antenna resonating element to the ground. 
 
     
     
       10. The electronic device defined in  claim 9  further comprising a battery between the additional printed circuit and the near-field communications antenna layer. 
     
     
       11. The electronic device defined in  claim 10  further comprising radio-frequency transceiver circuitry coupled to the antenna that is configured to transmit and receive antenna signals at frequencies above 960 MHz using the antenna. 
     
     
       12. The electronic device defined in  claim 1  further comprising radio-frequency transceiver circuitry coupled to the antenna that is configured to transmit and receive cellular telephone signals using the antenna. 
     
     
       13. The electronic device defined in  claim 12  wherein the stack of capacitively coupled component layers comprise a display layer. 
     
     
       14. The electronic device defined in  claim 13  further comprising a strap coupled to the housing. 
     
     
       15. An electronic device, comprising:
 a structure that forms an antenna ground for an antenna; 
 a display that forms at least part of an antenna resonating element for the antenna; and 
 an antenna feed for the antenna having a positive antenna feed terminal coupled to the display and having a ground antenna feed terminal coupled to the antenna ground. 
 
     
     
       16. The electronic device defined in  claim 15  further comprising:
 a display cover layer that overlaps that display; and 
 a touch sensor that is capacitively coupled to the display and that forms part of the antenna resonating element. 
 
     
     
       17. The electronic device defined in  claim 16  further comprising a near field communications layer that is capacitively coupled to the touch sensor and that forms part of the antenna resonating element. 
     
     
       18. The electronic device defined in  claim 17  further comprising near-field communications circuitry having a shielding can, wherein the positive antenna feed is coupled to the display through the shielding can. 
     
     
       19. The electronic device defined in  claim 18  further comprising metal spring fingers, wherein the shielding can has a portion that is coupled to the metal spring fingers. 
     
     
       20. An electronic device, comprising:
 a housing having metal sidewalls that form at least part of an antenna ground for an antenna; 
 a display in the housing; 
 a display cover layer that overlaps the display; 
 a touch sensor that is interposed between the display and the display cover layer, wherein at least the touch sensor and the display are capacitively coupled and form an antenna resonating element for the antenna; and 
 cellular telephone transceiver circuitry configured to transmit and receive antenna signals using the antenna.

Description:
BACKGROUND 
     This relates to electronic devices, and more particularly, to antennas for electronic devices with wireless communications circuitry. 
     Electronic devices are often provided with wireless communications capabilities. To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to implement wireless communications circuitry such as antenna components using compact structures. At the same time, there is a desire for wireless devices to cover a growing number of communications bands. 
     Because antennas have the potential to interfere with each other and with components in a wireless device, care must be taken when incorporating antennas into an electronic device. Moreover, care must be taken to ensure that the antennas and wireless circuitry in a device are able to exhibit satisfactory performance over a range of operating frequencies. 
     It would therefore be desirable to be able to provide improved wireless communications circuitry for wireless electronic devices. 
     SUMMARY 
     An electronic device such as a wristwatch may have a housing with metal portions such as metal sidewalls. A display may be mounted on a front face of the device. Light-based components such as light-emitting diodes and detectors may be mounted on a rear face of the device. 
     The housing may form an antenna ground. The antenna ground and an antenna resonating element may be used in forming an antenna at the front face of the device. The antenna resonating element may be formed from a stack of capacitively coupled component layers at the front face of the device. The stack of component layers may include the display layer, a touch sensor layer, and a near-field communications antenna layer. 
     A peripheral antenna may be formed from a peripheral resonating element that runs along a peripheral edge of the device and the antenna ground. The peripheral antenna may be used to handle wireless local area network signals. 
     A rear face antenna may be formed by using a wireless power receiving coil as a radio-frequency antenna resonating element for cellular telephone signals or may be formed from metal antenna traces on a plastic support for the light-based components. 
     Cellular telephone signals may be transmitted and received using the antennas at the front and rear faces. Signals at frequencies above 960 MHz may be handled using the front face antenna, signals from 700-960 MHz may be handled using the rear face antenna, or these antennas may be used to handle signals at other frequencies. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of an illustrative monopole antenna in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 5  is a rear perspective view of illustrative layers of capacitively coupled components in an illustrative electronic device in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of components that may be used in forming an electronic device antenna in accordance with an embodiment. 
         FIG. 7  is a perspective view of an illustrative shielding can having a portion that may be used in coupling an antenna feed terminal to the components of  FIG. 6  in accordance with an embodiment. 
         FIG. 8  is a perspective view of an illustrative set of spring fingers that may be used to couple a positive antenna feed terminal to the shielding can of  FIG. 7  in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of a rear portion of an electronic device having structures that may form an antenna in accordance with an embodiment. 
         FIG. 10  is a schematic diagram of an illustrative wireless power coil of the type that may be used as a cellular telephone antenna in accordance with an embodiment. 
         FIG. 1I  is a perspective view of illustrative wireless circuitry for an electronic device having a wireless power coil used as a cellular telephone antenna in accordance with an embodiment. 
         FIG. 12  is a perspective view of an illustrative support structure of the type that may be used as an antenna carrier for an electronic device antenna in accordance with an embodiment. 
         FIG. 13  is a top view of an illustrative electronic device with a peripheral antenna that runs along a peripheral edge of the device in accordance with an embodiment. 
         FIG. 14  is a perspective view of an illustrative antenna resonating element for the antenna of  FIG. 13  in accordance with an embodiment. 
         FIG. 15  is a perspective view of an illustrative antenna with an antenna resonating element of the type shown in  FIG. 14  coupled to radio-frequency transceiver circuitry in accordance with an embodiment. 
         FIG. 16  is a table showing illustrative operating modes for the antenna of  FIG. 15  in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may be provided with wireless circuitry. The wireless circuitry may include antennas. Antennas such as cellular telephone antennas and wireless local area network and satellite navigation system antennas may be formed from electrical components such as displays, touch sensors, near-field communications antennas, wireless power coils, peripheral antenna resonating elements, and device housing structures. 
     Electronic device  10  may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a wristwatch. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     In the example of  FIG. 1 , device  10  includes a display such as display  14 . Display  14  has been mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). Housing  12  may have metal sidewalls or sidewalls formed from other materials. 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from 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 display pixels based on other display technologies. 
     Display  14  may be protected using a display cover layer. The display cover layer may be formed from a transparent material such as glass, plastic, sapphire or other crystalline dielectric materials, ceramic, or other clear materials. 
     Device  10  may, if desired, be coupled to a strap such as strap  16 . Strap  16  may be used to hold device  10  against a user&#39;s wrist (as an example). Configurations that do not include straps may also be used for device  10 . 
     A schematic diagram showing illustrative 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 storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, MIMO protocols, antenna diversity protocols, etc. 
     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 allow data to be provided 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 touch screens, displays without touch sensor capabilities, buttons, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, light-emitting diodes, motion sensors (accelerometers), capacitance sensors, proximity sensors, magnetic sensors, force sensors (e.g., force sensors coupled to a display to detect pressure applied to the display), etc. 
     Input-output circuitry  44  may include wireless circuitry  34 . Wireless circuitry  34  may include coil  50  and wireless power receiver  48  for receiving wirelessly transmitted power from a wireless power adapter. To support wireless communications, wireless circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas such as antennas  40 , transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless circuitry  34  may include radio-frequency transceiver circuitry  90  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  36 ,  38 ,  42 , and  46 . Transceiver circuitry  36  may be wireless local area network transceiver circuitry that may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and that may handle the 2.4 GHz Bluetooth® communications band. Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in frequency ranges such as a low communications band from 700 to 960 MHz, a midband from 1400 MHz or 1500 MHz to 2170 MHz (e.g., a midband with a peak at 1700 MHz), and a high band from 2170 or 2300 to 2700 MHz (e.g., a high band with a peak at 2400 MHz) or other communications bands between 700 MHz and 2700 MHz or other suitable frequencies (as examples). Circuitry  38  may handle voice data and non-voice data. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) transceiver circuitry  46  (e.g., an NFC transceiver operating at 13.56 MHz or other suitable frequency), etc. Wireless 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 handling other satellite positioning data. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, monopole antennas, dipoles, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. In some configurations, different antennas may be used in handling different bands for cellular telephone transceiver circuitry  38 . For example, a first antenna may handle a low band at 700-960 MHz for transceiver circuitry  38  and a second antenna may handle satellite navigation system frequencies and cellular telephone communications at frequencies above 960 MHz for transceiver circuitry  38 . 
     In compact electronic devices, space is at a premium. It may therefore be desirable to implement antennas in device  10  using portions of electrical components that would otherwise not be used as antennas and that support additional device functions. As an example, it may be desirable to induce antenna currents in components such as display  14 , so that display  14  and/or other electrical components (e.g., a touch sensor, near-field communications loop antenna, etc.) can serve as an antenna for cellular frequencies and/or other frequencies without the need to incorporate bulky antenna structures in device  10 . As another example, a component such as coil  50 , which receives wireless power signals (generally at frequencies in the kHz-MHz range that are below the 700 MHz lower end of cellular telephone frequencies) can also be used in handling cellular telephone transmissions (e.g., at 700-960 MHz or other suitable frequencies). Peripheral conductive structures such as an antenna resonating element that runs along the periphery of housing  12  may also be used in forming antennas  40  (e.g., to form a wireless local area network antenna, etc.). 
       FIG. 3  is a simplified cross-sectional side view of device  10  showing how an antenna for device  10  may be formed within a cavity formed from housing  12 . Antenna  40 F of  FIG. 3  may have an antenna resonating element such as resonating element  102  coupled to an antenna feed such as feed  100 . Feed  100  may have a positive antenna feed terminal such as positive antenna feed terminal  104  and a ground antenna feed terminal such as ground antenna feed terminal  106 . Positive antenna feed terminal  104  may be coupled to antenna resonating element  102 . Ground antenna feed terminal  106  may be coupled to ground (e.g., to metal sidewall portions of housing  12  and other conductive structures around element  102  such as printed circuit structures to form an antenna cavity in the example of  FIG. 3 ). Feed  100  may be coupled to transceiver circuitry  90  by a transmission line such as a coaxial cable or a flexible printed circuit transmission line. Resonating element  102  may be a monopole antenna resonating element (e.g., antenna  40 F may be a cavity-backed monopole antenna) or other suitable antenna resonating element. 
     As shown in the illustrative configuration of  FIG. 3 , a portion of antenna resonating element  102  such as tip  110  of antenna resonating element  102  may be coupled to ground (e.g., housing  12 ) by inductive path  108  (e.g., a path formed from metal traces on a flexible printed circuit or other suitable signal path). Antenna  40 F may be used to transmit and receive radio-frequency signals in cellular telephone bands and other bands (e.g., bands above 700 MHz, bands above 960 MHz, etc.) or other suitable frequency bands. Additional antennas may also be provided in device  10  to handle these frequency bands and/or other frequency bands. The configuration for antenna  40 F of  FIG. 3  is merely illustrative. 
       FIG. 4  is a cross-sectional side view of an illustrative electronic device such as device  10  of  FIG. 1 . In the illustrative configuration of  FIG. 4 , antenna resonating element  102  of antenna  40 F has been formed from a stack of capacitively coupled electrical components under display cover layer  120  of display  14 . Device  10  may have a housing such as housing  12  (e.g., a housing having metal sidewalls and/or other metal portions) that serves as antenna ground for antenna  40 F. The components under display cover layer  120  that are used in forming antenna resonating element  102  for antenna  40 F may have planar shapes (e.g., planar rectangular shapes, planar circular shapes, etc.) and may include conductive structures formed from metal and/or other conductive material that carry antenna currents. The thin planar shapes of these components and the stacked configuration of  FIG. 4  capacitively couple these components to each other so that they may operate together at radio frequencies to from antenna resonating element  102 . 
     The components that form antenna resonating element  102  may include, for example, planar components such as touch sensor  122 , display panel  124  (sometimes referred to as a display, display layer, or pixel array), and near-field communications antenna  126 , and may include near-field communications circuitry  128 . Touch sensor  122  may be a capacitive touch sensor and may be formed from a polyimide substrate or other flexible polymer layer with transparent capacitive touch sensor electrodes (e.g., indium tin oxide electrodes). Display panel  124  may be an organic light-emitting diode display layer or other suitable display layer. Near-field communications antenna  126  may be formed from a flexible layer that includes a magnetic shielding material (e.g., a ferrite layer or other magnetic shielding layer) and that includes loops of metal traces such as near-field communications loops  140 ). Antenna  40 F may be fed using antenna feed  100 . Feed  100  may have a positive terminal such as terminal  104  that is coupled to antenna resonating element  102  (e.g., to near-field communications circuitry  128  or other portion of the stacked components of  FIG. 4 ). Feed  100  may have a ground terminal such as terminal  106  that is coupled to an antenna ground in device  10  (e.g., metal housing  12 ). 
     Near-field communications circuitry  128  may include a printed circuit substrate such as printed circuit  150 , near-field communications transceiver circuitry  46  and other electrical components (components  152 ) that are mounted to printed circuit  150 , and metal shield can  154 , which overlaps and shield components  152 . 
     Inductive path  108  may be formed from a flexible printed circuit with metal traces that extend between near-field communications circuitry  128  and printed circuit  130 . At one end of path  108 , path  108  may be coupled to printed circuit  132  of near-field communications circuitry  128  (e.g., using a zero-insertion-force connector or other coupling mechanism). At an opposing end of path  108 , path  108  may be coupled to printed circuit  132  and system-in-package circuitry  134  on printed circuit  132  (see, e.g., circuitry  28  and/or circuitry  44  of  FIG. 2 ). Path  108  may serve as part of antenna  40 F as described in connection with  FIG. 3  and may also carry data and control signals between system-in-package circuitry  134  and other circuitry on printed circuit  132  and the stack of components under display cover layer  120  (e.g., touch sensor layer  122 , display layer  124 , and near-field communications antenna layer  126 ) and near-field communications circuitry  128 . 
     Conductive structures such as metal screw  160  may be used to couple signal traces in printed circuit  132  to ground (e.g., so that path  108  may be coupled to housing  12 ). Components such as vibrator  156  (e.g., an electromagnetic actuator that control circuitry  28  may control to provide alerts to a user) and battery  158  (e.g., a battery that is wirelessly charged using wireless power receiver  48  and coil  50 ) may be interposed between the rear of device  12  (shown as housing  12  in the illustrative arrangement of  FIG. 4 ) and components such as components  122 ,  124 , and  126 . 
     A rear perspective view of illustrative electrical components that may be stacked under display cover layer  120  and that may form antenna resonating element  102  of antenna  40 F is shown in  FIG. 5 . As shown in  FIG. 5 , component stack  168  may include touch sensor layer  122 , display layer  124 , and near-field communications antenna layer  126 . Layer  122 , layer  124 , and layer  126  are stacked next to each other and are therefore capacitively coupled to each other. This allows layers  122 ,  124  and  126  to operate together as an antenna resonating element at radio frequencies (e.g., at cellular telephone frequencies). Layer  122 , layer  124 , and layer  126  may be interconnected with other components in device  10  using connectors  162 . Connectors  162  may be mounted on the underside of layer  126 , on tail  122 T of layer  122 , on tail  124 T of layer  124 , and/or on other suitable structures. Near-field communications circuitry  128  and additional circuitry such as touch sensor processing circuitry  164  and display driver circuitry  166  may be mounted on the underside of near-field communications antenna layer  126  (as an example). Other types of components may be mounted in stack  168  if desired. For example, a force sensor layer may be included in stack  168 . As another example, the functions of two or more of these layers may be consolidated. For example, capacitive touch sensor electrodes for a capacitive touch sensor may be formed from metal traces on organic light-emitting diode display layer  124  and a separate touch sensor layer  122  may be omitted. Near-field communications antenna layer  126  may also be omitted (e.g., in a configuration for device  10  without near-field communications circuitry and/or in a configuration for device  10  in which the near-field communications antenna is located in a different portion of housing  12 ). The configuration of electrical component stack  168  of  FIG. 5  is illustrative. 
       FIG. 6  is a cross-sectional side view of a portion of near-field communications antenna layer  126  and associated near-field communications circuitry  128 . As shown in  FIG. 6 , near-field communications circuitry  128  may include circuitry such as circuitry  170  (see, e.g., near-field communications transceiver circuitry  46  of  FIG. 2 ) that is coupled to near-field communications antenna loops such as traces  140 . There may be any suitable number of loop-shaped traces  140  in the near-field communications antenna of device  10  (e.g., 2-40 loops, more than 5 loops, fewer than 30 loops, etc.). Signal paths  172  (e.g., metal traces in layers  126  and  150 ) may be used in coupling circuitry  170  to traces  140  and in forming a ground for shielding can  154 . Circuitry  170  and additional circuits such as circuits  174  may be housed under shielding can  154 . Flexible printed circuit  109  may be coupled to printed circuit  132  using connector  108 C. 
     Shielding can (shield can)  154  may be formed from metal and may have a tab, clip, or other protruding portion such as portion  154 C that serves as antenna feed terminal  104 . Portion  154  C of can  154  may be received between flexible spring fingers such as metal prongs  176 P in clip  176 . Clip  176  may be coupled to a positive signal path on a flexible printed circuit transmission line or other suitable signal path coupled to transceiver circuitry  90  so that antenna signals may be provided via clip  176  to shielding can  154 . 
     A rear perspective view of shielding can  154  in an illustrative configuration in which portion  154 C has been formed from a strip of metal (e.g., a portion of can  154  and/or an additional strip of metal that is joined to shielding can  154 ). Portion  154 C may have a coating such as coating  178  (e.g., gold, nickel, or other metals) to facilitate good ohmic contact between portion  154 C and prongs  176 P of clip  176  when the coated surface of portion  154 C is received between prongs  176 P. 
     A perspective view of clip  176  in an illustrative configuration in which clip  176  is secured using fasteners such as screws  181  is shown in  FIG. 8 . Clip  176  may be mounted on a plastic support on housing  12  or other suitable support structures. Metal traces in a flexible printed circuit such as flexible printed circuit  182  may route positive antenna feed signals to clip  176 . If desired, impedance matching circuitry and other circuitry may be mounted on printed circuit  182 . 
     Antenna  40 F may be effective at operating through the front of device  10  and may therefore sometimes be referred to as forming a front face antenna for device  10 . If desired, a peripheral conductive member may be used in forming an antenna for device  10  and/or a rear face antenna may be used in forming an antenna for device  10 . 
     Consider, as an example, the side view of the rear of device  10  of  FIG. 9 . In a configuration of the type shown in  FIG. 9 , rear housing wall  12 R may be formed from a material such as plastic, glass, or other dielectric and may have a circular shape or other shape that allows rear wall  12 R to be received within other portions of housing  12  (e.g., metal housing portions such as metal sidewalls, etc.). Coil  50  may be formed from loops of conductive wire, loops of metal traces on a printed circuit, or other loops of conductive signal paths. Rear housing wall  12 R may have a curved outer surface that rests against a user&#39;s body (e.g., wrist  180 ) when device  10  is worn by a user. If desired, rear wall  12 R may have an opening with one or more transparent windows such as window  184 . Light-based components  182  may be mounted in alignment with windows such as window  184 . Components  182  may include light-emitting diodes (e.g., infrared light-emitting diodes, visible light-emitting diodes, etc.) and may include light detectors (e.g., detectors for detecting light that has been emitted by the light-emitting diodes after reflecting from wrist  180 ). Configurations such as these may allow light-based components  182  to be used to monitor a user&#39;s physiological parameters (heart rate, blood oxygen level, etc.). 
     The signal paths in coil  50  and/or other metal structures adjacent to rear wall  12 R such as metal antenna traces on a plastic carrier associated with components  182  or other structures in device  10  may be used in forming a rear face antenna for device  10  (antenna  40 R). During operation, antenna  40 R may transmit and/or receive radio-frequency signals having electric fields that are oriented normal to the surfaces of rear face  12 R and wrist  180 . These signals may sometimes be referred to as creeping waves and may allow antenna  40 R to operate efficiently even in the presence of wrist  180 . 
       FIG. 10  is a circuit diagram of illustrative circuitry that may be used in device  10  to allow radio-frequency transceiver circuitry  90  to use coil  50  as rear face antenna  40 R at radio frequencies (e.g., a cellular telephone frequencies). When receiving wireless power, coil  50  may receive wirelessly transmitted alternating-current signals that have been transmitted from a wireless power adapter or other wireless power transmitting device. Wireless power receiver  48  may have rectifier circuitry that rectifies the received alternating-current wireless power signals to produce direct-current power for device  10 . Matching circuit  190  may be used to couple radio-frequency transceiver circuitry  90  to coil  50 . Radio-frequency transceiver circuitry  90  may operate at frequencies from 700 MHz to 960 MHz (e.g., a low cellular telephone communications band) or at other suitable frequencies (e.g., frequencies above 700 MHz, etc.). At these frequencies, coupling capacitors  192  form short circuits, so that transmitted radio-frequency signals can be applied to the conductive material in coil  50  and so that radio-frequency signals that are received by coil  50  can be conveyed to radio-frequency transceiver  90 . At frequencies above 700 MHz, the conductive paths in coil  50  may form an antenna such as a patch or monopole antenna (e.g., coil  50  does not operate as an inductor at these frequencies). At the lower frequencies associated with wireless power reception (e.g., at frequencies in the range of 1 kHz-100 MHz or other suitable frequencies), capacitors  192  form open circuits and allow wireless power signals to be received that induce current flow around the loops of coil  50 . 
       FIG. 11  is a perspective view of illustrative structures that may be used to route signals to and from coil  50 . In the example of  FIG. 1 , coil  50  has been implemented using a ring-shaped flexible printed circuit with loops of metal traces. A signal path such as flexible printed circuit cable  194  (sometimes referred to as a “coil flex”) may be used to couple printed circuit  202  to coil  50 . Circuitry  200  on printed circuit  202  may include wireless power receiver  48  and wireless transceiver circuitry  90 . When transceiver  90  is using coil  50  as a low-band cellular telephone antenna, coil  50  may be feed using an antenna feed having a positive antenna feed terminal such as feed terminal  196  and a ground antenna feed terminal such as ground antenna feed terminal  198 . Ground antenna feed terminal  198  may be coupled to an antenna ground such as a metal portion of housing  12  (as an example). When wireless power is being received by coil  50 , signals from coil  50  may be routed to wireless power receiver  48  in circuitry  200  via metal traces in flexible printed circuit  194 . 
     If desired, an antenna signal path such as a flexible printed circuit with a transmission line (see, e.g., printed circuit  194 ) may be used to couple transceiver circuitry  90  to metal traces on a plastic support structure or other dielectric structure adjacent to rear housing  12 R. In this type of configuration, the metal traces on the plastic support structure may serve as an antenna resonating element for rear face antenna  40 R. 
     With one illustrative configuration, which is shown in  FIG. 12 , light-based components  182  such as light-emitting diodes  182 E and light detectors  182 D may be mounted within a tray or other support structure such as support member  206  of  FIG. 12 . Member  206  may be formed from a dielectric material such as opaque plastic. The portions of support member  206  that are interposed between light-emitting diodes  182 E and light detectors  182 D may help prevent internal stray light that has been emitted from light-emitting diodes  182 E from reaching light detectors  182 D. Member  206  may be mounted adjacent to rear housing structure  12 R ( FIG. 9 ), so that light-based components  184  are aligned with respective transparent windows such as window  184  ( FIG. 9 ). 
     Metal traces  204  on the surface of plastic member  206  may be used to form an antenna resonating element for antenna  40 R (e.g., a monopole antenna resonating element, an inverted-F antenna resonating element, a patch antenna resonating element, etc.). Metal traces  204  may be formed on the lower surface of member  206  adjacent to housing wall structure  12 R or may be formed on other portions of member  206 . Gaps may be formed in portions of layer  204  (e.g. in portions of layer  204  adjacent to the gap between light-emitting diodes  182 E) to reduce undesired current loops that could reduce efficiency (e.g., when layer  204  is operating as a monopole antenna resonating element). In configurations in which rear face antenna  40 R is formed from metal traces  204  on support member  20 , coil  50  may be used exclusively for receiving wireless power signals. In configurations in which traces  204  are omitted, coil  50  may be used to receive wireless power signals and may be used to form antenna  40 R, as described in connection with  FIG. 10 . 
     In addition to front face antenna  40 F and rear face antenna  40 R, device  10  may have one or more peripheral antennas such as peripheral antenna  40 P of  FIG. 13 . Peripheral antenna  40 P may have a peripheral antenna resonating element such as peripheral antenna resonating element  220 . Antenna resonating element  220  may run alone one, two, or more than two edges of device  10 . Antenna resonating element  220  may be a monopole resonating element or may, if desired, be an inverted-F antenna resonating element having a return path such as path  226  that shorts element  220  to ground in parallel with an antenna feed formed from positive antenna feed terminal  222  and ground antenna feed terminal  224 . If desired, element  220  may be extended and/or additional resonating elements may be formed along the periphery of housing  12 , as indicated by illustrative additional resonating element conductive material  228 . If desired, one or more circuits such as circuits  230  may be coupled between antenna resonating element structures and ground (e.g., tunable circuits, capacitors, inductors, and/or other antenna circuitry). 
     An illustrative configuration for antenna resonating element  220  of antenna  40 P is shown in  FIG. 14 . As shown in  FIG. 14 , resonating element  220  may be formed from a conductive member such as a sheet metal member (strip of sheet metal) embedded in molded plastic antenna carrier  232 . Carrier  232  may be received within a peripheral groove in the underside of display cover layer  120  ( FIG. 4 ) or may be mounted in other peripheral portions of device  10 . Portions of element  220  may form terminals A and B. Terminal A may be located at end  244  of element  220  and terminal B may be located a distance D along the length of element  220  away from end  244  of element  220 . Flexible printed circuit  236  may have a transmission line such as transmission line  238  with a positive signal conductor that is coupled to positive antenna feed terminal  222  and a ground signal conductor that is coupled to ground antenna feed terminal  224 . Feed terminal  224  may be grounded (e.g., to metal housing  12  or other suitable ground structure in device  10 ) using a metal fastener such as screw  240  that is screwed into housing  12  or other electrical connection. Switching circuitry  242  may be used to selectively couple terminals A and B to different portions of flexible printed circuit  236 , thereby allowing antenna  40 P to be placed in different modes of operation (e.g., for antenna tuning, etc.). 
       FIG. 15  is a schematic diagram showing how switching circuitry  242  may include tunable components such as adjustable phase shifter  244 . If desired, circuitry  242  may have other tunable components (e.g., tunable inductors, tunable capacitors, etc.). Switching circuitry  242  may be configured by control signals received at input  246  from control circuitry  28 . Transceiver circuitry  90  (e.g., transceiver circuitry  36  of  FIG. 2  and/or other radio-frequency transceiver circuitry that transmits and/or receives antenna signals using peripheral antenna  40 P) may have terminals X and Y that are coupled to circuitry  242 . Ground terminal C (see. e.g., screw  240  of  FIG. 14 , which may be coupled to metal portions of housing  12  that serve as antenna ground) may also be coupled to circuitry  242 . 
       FIG. 16  is a table showing illustrative modes of operation for antenna  40 P. Antenna  40 P may be configured to operate in different modes of operation such as modes M 1 , M 2 , and M 3  of  FIG. 16  and/or additional modes of operation. The example of  FIG. 16  is merely illustrative. 
     In mode M 1  of the illustrative example of  FIG. 16 , terminal X may be coupled to terminal A and terminal Y may be coupled to terminal B. In this mode, antenna  40 P may operate as an inverted-F antenna. 
     In mode M 2 , switching circuitry  242  may be configured to couple terminal Y to terminal A and to couple terminal X to terminal B. Antenna  40 P in mode M 2  may be an inverted-F antenna. The location of the return path of antenna  40 P may be reversed between modes M 1  and M 2 . 
     In mode M 3 , switching circuitry  242  may be configured to couple terminal B to an open circuit, to couple terminal X to terminal C (ground), and to couple terminal Y to terminal A. In this mode, which may sometimes be referred to as housing ground mode, antenna  40 P may operate as a monopole antenna (as an example). 
     Wireless circuitry  34  may use antennas  40 F,  40 R,  40 P, coil  50 , and near-field communications antenna  126 . Near-field communications transceiver circuitry  46  may use antenna  126  to transmit and receive near-field communications signals (e.g., at 13.56 MHz or other suitable frequency). Coil  50  may be used by wireless power receiver  48  to receive wireless power (e.g., at frequencies below 100 MHz, below 10 MHz, below 1 MHz, above 1 kHz, or other suitable frequencies). Radio-frequency signals above 700 MHz, such as signals at 2.4 GHz and/or 5 GHz for IEEE 802.11 communications, Bluetooth®, and/or other wireless local area network communications may be handled by peripheral antenna  40 P (as an example). Low band cellular telephone signals (e.g., cellular telephone communications at frequencies between 700 MHz and 960 MHz) may be handled by antenna  40 R. Cellular telephone signals and GPS signals in a mid-band, a high band, and other bands that are above 960 MHz such as cellular telephone and GPS signals at 960-2700 MHz may be handled by antenna  40 F. If desired, antenna  40 P may be omitted and antenna  40 F may be used to handle radio-frequency signals at 2.4 GHz and/or 5 GHz for IEEE 802.11 communications, Bluetooth®, and/or other wireless local area network communications. Antenna  40 F and/or other antennas in device  10  may also be used in handling low-band signals (e.g., signals from 700-960 MHz), if desired. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20160811
Publication Date: 20190115
Grant Date: 20190115
Priority Date: 20160811
Inventors: EHMAN, Rex T.
NATH, JAYESH
DI NALLO, CARLO
HORIUCHI, JAMES G.
DE JONG, ERIK G.
SAUERS, JASON C.
BRZEZINSKI, MAKIKO K.
YONG, Siwen
ZHANG, LIJUN
JIANG, YI
WANG, ZHEYU
Martinis, Mario
Da Costa Bras Lima, Eduardo
HAN, XU
PASCOLINI, MATTIA
NESS, TREVOR J.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0031", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/43", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/43", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q11/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0277", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/285", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0249", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/72", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 60107496