PATENT DOCUMENT

Publication Number: US-11134141-B1
Application Number: US-202016899463-A
Country: US
Kind Code: B1

Title: Electronic devices having shared coil structures

Abstract:
An electronic device may have a housing, a battery, a conductive coil, near-field communications circuitry, amplifier circuitry, and wireless charging circuitry. The housing may have a housing wall. The conductive coil may be adhered to the housing wall. The conductive coil may be coiled around a magnet. The amplifier circuitry may drive audio signals and/or haptic signals onto the conductive coil that cause the conductive coil to vibrate the housing wall. The near-field communications circuitry may convey near-field communications signals through the housing wall using the conductive coil. The wireless charging circuitry may receive wireless power for charging the battery through the housing wall using the conductive coil. If desired, the conductive coil may include a first set of windings that lie within a surface extending along the housing wall and/or a second set of vertically-stacked windings that extend away from the housing wall.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a housing; 
 a battery in the housing; 
 a conductive coil in the housing; 
 amplifier circuitry coupled to the conductive coil and configured to drive audio signals onto the conductive coil; 
 near-field communications circuitry coupled to the conductive coil and configured to convey near-field communications signals using the conductive coil; 
 wireless charging circuitry coupled to the conductive coil, wherein the wireless charging circuitry is configured to receive wireless power using the conductive coil and to charge the battery using the received wireless power; 
 switching circuitry having a first port coupled to the conductive coil, a second port coupled to the amplifier circuitry, a third port coupled to the near-field communications circuitry, and a fourth port coupled to the wireless charging circuitry; and 
 control circuitry configured to control the switching circuitry to selectively couple the second, third, and fourth ports to the first port. 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the control circuitry is configured to control the switching circuitry to concurrently couple two of the second, third, and fourth ports to the first port. 
     
     
       3. The electronic device defined in  claim 1 , wherein the control circuitry is configured to control the switching circuitry to concurrently couple each of the second, third, and fourth ports to the first port. 
     
     
       4. The electronic device defined in  claim 1 , further comprising:
 an antenna that is separate from the conductive coil; and 
 radio-frequency transceiver circuitry coupled to the antenna, wherein the radio-frequency transceiver circuitry is configured to receive radio-frequency signals at a frequency greater than 600 MHz using the antenna. 
 
     
     
       5. The electronic device defined in  claim 4 , wherein the control circuitry is configured to control, responsive to receiving the radio-frequency signals using the antenna, the switching circuitry to couple the first port to the second port and the amplifier circuitry to drive the audio signals onto the conductive coil through the switching circuitry. 
     
     
       6. The electronic device defined in  claim 4 , wherein the radio-frequency transceiver circuitry comprises an ultra-wideband communications transceiver and wherein the frequency is greater than 5 GHz. 
     
     
       7. The electronic device defined in  claim 1 , wherein the housing has a front wall, a rear wall, and a sidewall extending from the rear wall to the front wall, the electronic device further comprising:
 a layer of adhesive that adheres the conductive coil to the front wall. 
 
     
     
       8. The electronic device defined in  claim 7 , further comprising:
 a magnet, wherein the conductive coil is coiled around the magnet, wherein, when the amplifier circuitry drives the audio signals onto the conductive coil, the conductive coil is configured to form a voice coil and the front wall is configured to form a speaker diaphragm for the voice coil, and wherein the speaker diaphragm is configured to vibrate to emit an audible sound responsive to the audio signals being driven onto the conductive coil. 
 
     
     
       9. The electronic device defined in  claim 8 , wherein the amplifier circuitry is configured to drive haptic signals onto the conductive coil and wherein, when the amplifier circuitry drives the haptic signals onto the conductive coil, the conductive coil is configured to vibrate the front wall to produce a vibration alert. 
     
     
       10. The electronic device defined in  claim 7 , wherein the conductive coil comprises flattened windings and vertically-stacked windings, the flattened windings being coupled to the front wall by the layer of adhesive. 
     
     
       11. An electronic device comprising:
 a housing having a housing wall; 
 a magnet in the housing; 
 a conductive coil in the housing and coiled around the magnet; 
 a layer of adhesive that attaches the conductive coil to the housing wall; and 
 amplifier circuitry coupled to the conductive coil, wherein the amplifier circuitry is configured to drive audio signals onto the conductive coil and wherein, when the conductive coil is driven by the audio signals, the conductive coil is configured to vibrate the housing wall to produce an audible sound. 
 
     
     
       12. The electronic device defined in  claim 11 , wherein the conductive coil comprises a first set of windings that lie within a surface extending along the housing wall, wherein the layer of adhesive attaches the first set of windings to the housing wall, and wherein the electronic device further comprises:
 near-field communications circuitry coupled to the conductive coil and configured to convey near-field communications signals through the housing wall using the conductive coil. 
 
     
     
       13. The electronic device defined in  claim 12 , wherein the conductive coil further comprises a second set of windings that are vertically-stacked and that extend from the first set of windings and away from the housing wall. 
     
     
       14. The electronic device defined in  claim 13 , further comprising:
 a logic board, wherein the amplifier circuitry is mounted to the logic board; 
 device components on the logic board, wherein the device components are separated from the second set of windings by a cavity and wherein the conductive coil further comprises a third set of windings that fill the cavity; 
 a battery mounted to the logic board; and 
 wireless charging circuitry mounted to the logic board and coupled to the conductive coil, wherein the wireless charging circuitry is configured to receive wireless charging signals through the conductive wall using the conductive coil and wherein the wireless charging circuitry is configured to charge the battery using the wireless charging signals. 
 
     
     
       15. The electronic device defined in  claim 11 , wherein the conductive coil comprises a first and second sets of windings, wherein the adhesive layer attaches the first set of windings to the housing wall and wherein the first set of windings are vertically-stacked and extend away from the housing wall, the electronic device further comprising:
 a logic board, wherein the amplifier circuitry is mounted to the logic board; 
 device components on the logic board, wherein the device components are separated from the first set of windings by a cavity and wherein the second set of windings are vertically-stacked and located within the cavity; 
 a battery mounted to the logic board; and 
 wireless charging circuitry mounted to the logic board and coupled to the conductive coil, wherein the wireless charging circuitry is configured to receive wireless charging signals through the conductive wall using the conductive coil and wherein the wireless charging circuitry is configured to charge the battery using the wireless charging signals. 
 
     
     
       16. The electronic device defined in  claim 11 , wherein the amplifier circuitry is configured to drive haptic signals onto the conductive coil and wherein, when the conductive coil is driven by the haptic signals, the conductive coil is configured to vibrate the housing wall to produce a haptic vibration. 
     
     
       17. The electronic device defined in  claim 16 , wherein the coil surrounds an opening, wherein the housing wall has a first portion that overlaps the opening and a second portion that surrounds the first portion, wherein the first portion of the housing wall has a first density, and wherein the second portion of the housing wall has a second density that is less than the first density. 
     
     
       18. The electronic device defined in  claim 16 , wherein the coil surrounds an opening, wherein the housing wall has a first portion that overlaps the opening and a second portion that surrounds the first portion, wherein the electronic device further comprises a layer of material that is attached to the first portion of the housing wall and that does not overlap the second portion of the housing wall, and wherein, when the conductive coil is driven by the haptic signals, the first portion of the housing wall and the additional layer of material are configured to vibrate to produce the haptic vibration. 
     
     
       19. An electronic device comprising:
 a housing having a housing wall; 
 a magnet in the housing; 
 a first conductive coil adhered to the housing wall, wherein the first conductive coil is coiled around the magnet and extends away from the housing wall; 
 a second conductive coil adhered to the housing wall, wherein the second conductive coil is coiled around the first conductive coil and lies within a surface that extends along the housing wall; 
 amplifier circuitry coupled to the first conductive coil and configured to drive signals onto the first conductive coil, the first conductive coil being configured to vibrate the housing wall when driven by the signals; and 
 near-field communications circuitry coupled to the second conductive coil and configured to convey near-field communications signals through the housing wall using the second conductive coil.

Description:
This application claims the benefit of provisional application No. 62/878,664, filed Jul. 25, 2019, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices and, more particularly, to electronic devices with conductive coil structures. 
     BACKGROUND 
     Electronic devices such as tablet computers, cellular telephones, telephones, computers, watches, and other devices contain conductive coil structures that perform different functions. For example, conductive coil structures are often used to form a voice coil for an acoustic speaker, to form an inductive coil for performing wireless charging, or to form an inductive antenna for performing near-field communications. 
     In practice, conductive coil structures such as these can be bulky and can consume an excessive amount of space within an electronic device. At the same time, electronic devices with small sizes have become increasingly popular. 
     To ensure that an electronic device has a compact size, it may be desirable to eliminate unnecessary components. Minimizing device size in this way can be challenging, particularly when conductive coil structures are required for performing multiple different functions for the electronic device. 
     SUMMARY 
     An electronic device may have a housing, a battery, a conductive coil, near-field communications circuitry, amplifier circuitry, and wireless charging circuitry. Switching circuitry may couple the near-field communications circuitry, the amplifier circuitry, and the wireless charging circuitry to the conductive coil. Control circuitry may control the switching circuitry to activate one or more of the near-field communications circuitry, amplifier circuitry, and wireless charging circuitry at any given time. 
     The housing may have a housing wall. The conductive coil may be adhered to the housing wall. The conductive coil may be coiled around a magnet. The amplifier circuitry may drive audio signals and/or haptic signals onto the conductive coil that cause the conductive coil to vibrate the housing wall. The near-field communications circuitry may convey near-field communications signals through the housing wall using the conductive coil. The wireless charging circuitry may receive wireless power for charging the battery through the housing wall using the conductive coil. If desired, the conductive coil may include a first set of windings that lie within a surface extending along the housing wall and/or a second set of vertically-stacked windings that extend away from the housing wall. The conductive coil may include a third set of vertically-stacked windings that fill a cavity between the second set of windings and other components in the device. 
     If desired, the device may include at least first and second conductive coils that are adhered to the housing wall. The first conductive coil may, for example, be coiled around the magnet and may extend away from the housing wall. The second conductive coil may be coiled around the first conductive coil and may lie within a surface that runs along the housing wall. The amplifier circuitry may drive the audio signals and/or the haptic signals onto the first conductive coil to vibrate the housing wall. The near-field communications circuitry may convey near-field communications signals through the housing wall using the second conductive coil. The wireless charging circuitry may receive wireless power using the first and/or second conductive coils. One or more of the near-field communications circuitry, wireless charging circuitry, and amplifier circuitry may be omitted if desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative electronic device that may be provided with shared coil structures in accordance with some embodiments. 
         FIG. 2  is a schematic diagram of illustrative input-output circuitry that includes a conductive coil shared by acoustic and haptic amplifier circuitry, near-field communications circuitry, and wireless charging circuitry in accordance with some embodiments. 
         FIG. 3  is a cross-sectional side view of an illustrative electronic device having shared coil structures in accordance with some embodiments. 
         FIG. 4  is a top-down view of an illustrative coil that includes flattened windings to optimize near-field communications efficiency in accordance with some embodiments. 
         FIG. 5  is a cross-sectional side view of an illustrative coil that includes both flattened windings and vertically-stacked windings in accordance with some embodiments. 
         FIG. 6  is a cross-sectional side view of an illustrative coil that includes include multiple layers of vertically-stacked windings to optimize wireless charging efficiency in accordance with some embodiments. 
         FIG. 7  is a cross-sectional side view of an illustrative coil that includes both flattened windings and multiple layers of vertically-stacked windings in accordance with some embodiments. 
         FIG. 8  is a schematic diagram showing how illustrative input-output circuitry may include multiple coils that are shared by any combination of acoustic and haptic amplifier circuitry, near-field communications circuitry, and wireless charging circuitry in accordance with some embodiments. 
         FIG. 9  is a cross-sectional side view showing how an illustrative electronic device may include both a first coil having vertically stacked windings and a second coil having flattened windings in accordance with some embodiments. 
         FIGS. 10-12  are tables of illustrative operating states for an electronic device of the type shown in  FIGS. 1-9  in accordance with some embodiments. 
         FIG. 13  is a flow chart of illustrative steps that may be performed by control circuitry to adjust an electronic device between operating states of the types shown in  FIGS. 10-12  in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices and other items may be provided with a housing and one or more conductive coils. The housing may include a housing wall. The conductive coil may be attached to the housing wall using a layer of adhesive. The conductive coil may be coiled around a magnet. The magnet may be mounted to a logic board or other structures within the electronic device. 
     The electronic device may include acoustic/haptic amplifier circuitry, near-field communications circuitry, and/or wireless charging circuitry that each use the coil to transmit and/or receive information. For example, the amplifier circuitry may drive audio signals onto the coil that cause the coil to vibrate the housing wall to produce an audible sound. The amplifier circuitry may also drive haptic signals onto the coil that cause the coil to vibrate the housing wall to produce a haptic vibration alert. The near-field communications circuitry may convey radio-frequency near-field communications signals through the housing wall using the coil. The wireless charging circuitry may receive wireless charging signals through the housing wall using the coil. The wireless charging circuitry may charge a battery in the device using the received wireless charging signals. Switching circuitry may be used to activate the acoustic/haptic amplifier circuitry, the near-field communications circuitry, and the wireless charging circuitry at different times or to concurrently activate two or more of these components at once. Sharing the conductive coil in this way may serve to minimize space consumption within the device. 
     If desired, the conductive coil may include a set of flattened windings that lie within a surface that runs along the housing wall and/or a set of vertically-stacked windings that extend from the housing wall towards the logic board. In some scenarios, device components on the logic board may be separated from the set of vertically-stacked windings by a cavity. If desired, the conductive coil may include an additional set of vertically-stacked windings that fill the cavity. The set of flattened windings may serve to optimize near-field communications antenna efficiency for the coil. The set(s) of vertically-stacked windings may serve to optimize wireless charging efficiency for the device. If desired, two or more coils may be provided in the electronic device. The near-field communications circuitry, amplifier circuitry, and wireless charging circuitry may share one or more of the coils and/or may use one or more of the coils as dedicated coils for transmitting and/or receiving information. 
     An illustrative electronic device that may be provided with shared conductive coil structures is shown in  FIG. 1 . Electronic device  10  of  FIG. 1  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, wireless tag device, wireless tracking device (e.g., a tracking tag), or other miniature or wearable device, a larger handheld device such as a cellular telephone, a media player, or other small portable device. Device  10  may also be a set-top box, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, a wireless access point, a wireless base station, an electronic device incorporated into a kiosk, building, or vehicle, or other suitable electronic equipment. 
     Device  10  may interact with other electronic devices or other electronic equipment in a system such as system  12  of  FIG. 1 . For example, device  10  may receive wireless power from wireless charging equipment  14  in the form of wireless charging signals  42  (e.g., radio-frequency signals transmitted over-the-air to charge device  10 ). Device  10  may also convey radio-frequency signals such as radio-frequency signals  46  and/or  44  with external communications equipment  16 . 
     Wireless charging equipment  14  may be an electronic device such as a wireless charging mat that has a charging surface (e.g., a planar charging surface) that receives portable devices to be charged (e.g., device  10 ), a tablet computer or other portable electronic device with wireless power transmitting circuitry (e.g., one of devices  10  that has wireless power transmitting circuitry), or other wireless power transmitting device. External communications equipment  16  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, wireless tag device, wireless tracking device (e.g., a tracking tag), or other miniature or wearable device, a larger handheld device such as a cellular telephone, a media player, or other small portable device. External communications equipment  16  may also be a set-top box, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, a wireless access point, a wireless base station, an electronic device incorporated into a kiosk, building, or vehicle, a near field communications point of sale terminal for handling wireless payments, a near field communications reader associated with security equipment (e.g., a door opener, a badge reader, etc.), other near field communications equipment, or other suitable electronic equipment. Wireless charging equipment  14  and/or external communications equipment  16  may be omitted from system  12  if desired. 
     Device  10  may include control circuitry  28 . Control circuitry  28  may include storage such as storage circuitry  24  and processing circuitry such as processing circuitry  26 . Storage circuitry  24  may include 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  26  may be used to control the operation of device  10 . Processing circuitry  26  may include one or more microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, central processing units (CPUs), etc. Control circuitry  28  may be configured to perform operations in device  10  using hardware (e.g., dedicated hardware or circuitry), firmware, and/or software. Software code for performing operations in device  10  may be stored on storage circuitry  24  (e.g., storage circuitry  24  may include non-transitory (tangible) computer readable storage media that stores the software code). The software code may sometimes be referred to as program instructions, software, data, instructions, or code. Software code stored on storage circuitry  24  may be executed by processing circuitry  26 . 
     Control circuitry  28  may be used to run software on device  10  such as external node location applications, satellite navigation applications, 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, control circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol or other WPAN protocols, IEEE 802.11ad protocols, cellular telephone protocols, MIMO protocols, antenna diversity protocols, satellite navigation system protocols (e.g., global positioning system (GPS) protocols, global navigation satellite system (GLONASS) protocols, etc.), IEEE 802.15.4 ultra-wideband communications protocols or other ultra-wideband communications protocols, near-field communications (NFC) protocols, etc. Control circuitry  28  may also be used in implementing wireless charging protocols. Each communications protocol may be associated with a corresponding radio access technology (RAT) that specifies the physical connection methodology used in implementing the protocol. 
     Device  10  may include input-output circuitry  20 . Input-output circuitry  20  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 (e.g., wireless charging equipment  14  and/or external communications equipment  16 ). As shown in  FIG. 1 , input-output circuitry  20  may include acoustic/haptic circuitry  30 , wireless charging circuitry  32 , near-field communications circuitry  34 , other wireless communications circuitry  36 , and one or more conductive coils  22 . This example is merely illustrative and, if desired, one or more of acoustic/haptic circuitry  30 , wireless charging circuitry  32 , near-field communications circuitry  34 , and other wireless communications circuitry  36  may be omitted. 
     Coils  22  may be inductive coils that are used by one or more of acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and near-field communications circuitry  34  to transmit and/or receive information (e.g., using radio-frequency signals, audible sound, and/or haptic vibrations). In practice, inductors such as coils  22  consume space within electronic device  10 . To minimize the amount of space consumed by coils  22 , device  10  can use shared and/or co-located coil configurations. For example, one or more coils  22  in device  10  may be shared between acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and/or near-field communications circuitry  34 . By using the coil(s) for multiple purposes (e.g., to transmit and/or receive information using two or more of acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and/or near-field communications circuitry  34 ), duplication of resources and the size of device  10  can be minimized. Coils  22  may therefore sometimes be referred to herein as shared coils  22  or shared coil structures  22 . 
     Acoustic/haptic circuitry  30  may include driver circuitry such as one or more amplifiers. The output of the driver circuitry (amplifiers) may be coupled to one or more coils  22 . The driver circuitry may drive audio signals and/or haptic (vibrate) signals onto coil(s)  22 . Control circuitry  28  may control acoustic/haptic circuitry  30  to produce the audio and haptic signals that are driven onto coil(s)  22 . When driven with audio signals, coil(s)  22  may cause a diaphragm to move, thereby producing audible sound  38 . Similarly, when driven with haptic signals, coil(s)  22  may cause the diaphragm to move, thereby producing physical (mechanical) vibrations that may be felt by a user of device  10  and/or external communications equipment  16 . In this way, coil(s)  22  may function as an audio speaker and/or a haptic output device (e.g., a vibrator) that is controlled by acoustic/haptic circuitry  30  (e.g., coils  22  may include a type of coil that is sometimes referred to as a voice coil). 
     Near-field communications circuitry  34  may use one or more coils  22  to transmit and/or receive near-field communications signals to support communications between device  10  and external communications equipment  16  (e.g., a near-field communications reader or other external near-field communications equipment). Near-field communications may involve inductively coupled near field communications in which both the transmitter and receiver have associated inductors (e.g., coils such as coils  22 ) that are electromagnetically coupled (as shown schematically by radio-frequency signals  44  of  FIG. 2 ). Radio-frequency signals  44  may therefore sometimes be referred to herein as near-field communications signals  44 . 
     Near-field communications links typically are formed over distances of 20 cm or less (e.g., device  10  must be placed in the vicinity of the near-field communications reader for effective communications). With one suitable arrangement, near-field communications can be supported using signals at a frequency of 13.56 MHz or other frequencies below 600 MHz. Near-field communications circuitry  34  may include near-field communications transceiver circuitry that transmits and/or receives near-field communications signals  44  (e.g., near-field communications circuitry  34  may perform bidirectional communications in which data is both transmitted and received by near-field communications circuitry  34  using coils  22 ), near-field communications matching circuitry (e.g., impedance matching circuitry that matches the impedance of the near-field communications transceiver circuitry to the impedance of coil(s)  22  at the frequency of near-field communications signals  44 ), balun circuitry (e.g., circuitry that converts between differential and single-ended signals), and/or any other desired circuitry for supporting the transmission and reception of near-field communications signals  44 . 
     Wireless charging equipment  14  may receive power from sources such as an AC power source, a battery, etc. Power supply circuitry on wireless charging equipment  14  may convert the AC power to DC power for powering the circuitry of wireless charging equipment  14 . During operation, wireless charging equipment  14  may use radio-frequency circuitry to generate wireless power such as wireless charging signals  42  that are wirelessly transmitted to device  10  using inductor circuitry such as one or more wireless power transmitting coils on wireless equipment  14 . Wireless charging circuitry  32  on device  10  can receive the transmitted wireless charging signals  42  using inductor circuitry such as coil(s)  22  and can convert these received signals into power for device  10 . For example, system  12  may use resonant inductive coupling (near field electromagnetic coupling) between coil(s)  22  and a corresponding wireless power transmitting coil in wireless charging equipment  14  to transfer power from wireless charging equipment  14  to device  10 . An illustrative frequency for wireless charging signals  42  is 200 kHz. Other frequencies may be used, if desired (e.g., frequencies in the kHz range, the MHz range, or in the GHz range, frequencies of 1 kHz to 1 MHz, frequencies of 1 kHz to 100 MHz, etc.). 
     As AC currents associated with wireless charging signals  42  pass through one or more wireless power transmitting coils on wireless charging equipment  14 , a time varying electromagnetic (e.g., magnetic) field is produced that is received by one or more corresponding receiver coils such as coil(s)  22  in device  10 . When the time varying electromagnetic field is received by coil(s)  22 , corresponding alternating-current currents are induced in the coil(s). Wireless charging circuitry  32  may include converter circuitry such as rectifier circuitry. The rectifier circuitry may include rectifying components such as synchronous rectification metal-oxide-semiconductor transistors arranged in a bridge network, and may convert received AC signals (received alternating-current signals associated with wireless charging signals  42 ) from coil(s)  22  into DC voltage signals for powering device  10 . 
     The DC voltages produced by the rectifier circuitry in wireless charging circuitry  32  can be used in powering (charging) an energy storage device such as battery  18  and can be used in powering other components in device  10  (e.g., acoustic/haptic circuitry  30 , near-field communications circuitry  34 , other wireless communications circuitry  36 , control circuitry  28 , etc.). In this example, battery  18  is rechargeable using wireless charging signals  42 . In another suitable arrangement, battery  18  may be a removable battery that can be removed and replaced by a user upon depletion of charge. Wireless charging circuitry  32  may be omitted in this scenario. 
     Other wireless communications circuitry  36  may include transceiver circuitry for supporting radio-frequency non-near-field communications with external communications equipment  16  (e.g., using radio-frequency signals such as radio-frequency signals  46  that operate in the far field domain). For example, other wireless communications circuitry  36  may include ultra-wideband (UWB) transceiver circuitry that supports communications using the IEEE 802.15.4 protocol and/or other ultra-wideband communications protocols. Ultra-wideband radio-frequency signals may be based on an impulse radio signaling scheme that uses band-limited data pulses. Ultra-wideband signals may have any desired bandwidths such as bandwidths between 499 MHz and 1331 MHz, bandwidths greater than 500 MHz, etc. The presence of lower frequencies in the baseband may sometimes allow ultra-wideband signals to penetrate through objects such as walls. In an IEEE 802.15.4 system, a pair of electronic devices (e.g., device  10  and external communications equipment  16 ) may exchange wireless time stamped messages. Time stamps in the messages may be analyzed to determine the time of flight of the messages and thereby determine the distance (range) between the devices and/or an angle between the devices (e.g., an angle of arrival of incoming radio-frequency signals). Ultra-wideband transceiver circuitry may operate (convey radio-frequency signals) in communications bands such as one or more ultra-wideband communications bands between about 5 GHz and about 8.3 GHz (e.g., a 6.5 GHz UWB communications band, an 8 GHz UWB communications band, and/or bands at other suitable frequencies). 
     If desired, other wireless communications circuitry  36  may also include non-UWB transceiver circuitry. The non-UWB transceiver circuitry may handle communications bands other than UWB communications bands such as 2.4 GHz and 5 GHz bands for Wi-Fi® (IEEE 802.11) communications or communications in other wireless local area network (WLAN) bands, the 2.4 GHz Bluetooth® communications band or other wireless personal area network (WPAN) bands, and/or cellular telephone frequency bands such as a cellular low band (LB) from 600 to 960 MHz, a cellular low-midband (LMB) from 1410 to 1510 MHz, a cellular midband (MB) from 1710 to 2170 MHz, a cellular high band (HB) from 2300 to 2700 MHz, a cellular ultra-high band (UHB) from 3300 to 5000 MHz, or other communications bands between 600 MHz and 5000 MHz or other suitable frequencies (as examples). Other wireless communications circuitry  36  may include 60 GHz transceiver circuitry (e.g., millimeter wave transceiver circuitry), circuitry for receiving television and radio signals, paging system transceivers, optical transceiver circuitry, etc. 
     Other wireless communications circuitry  36  may transmit and/or receive radio-frequency signals  46  using one or more antennas  40 . Antennas  40  may be separate from coil(s)  22  and may radiate radio-frequency signals in the far field domain. Antennas  40  may be formed using any suitable types of antenna structures. 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, dipole antenna structures, monopole antenna structures, hybrids of two or more of these designs, etc. 
     The example of  FIG. 1  is merely illustrative. Device  10  may convey radio-frequency signals  46  and near-field communications signals  44  with the same external communications equipment  16  or may convey signals  44  and  46  to different external communications devices. If desired, input-output circuitry  20  may include other input-output devices (not shown in  FIG. 1  for the sake of clarity) such as user interface devices, data port devices, touch screens, displays without touch sensor capabilities, buttons, joysticks, 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, position and orientation sensors (e.g., sensors such as accelerometers, gyroscopes, and compasses), capacitance sensors, proximity sensors (e.g., capacitive proximity sensors, light-based proximity sensors, etc.), fingerprint sensors, etc. In one suitable arrangement that is sometimes described herein as an example, device  10  may be formed without any display (e.g., without an LCD display, touch screen display, any other type of display having display pixel circuitry, etc.) to minimize the manufacturing cost and complexity for device  10 . This may also allow device  10  to exhibit a relatively small size while consuming relatively little power (e.g., device  10  may be only a few centimeters or less in diameter). 
     Control circuitry  28  may control acoustic/haptic circuitry  30  to transmit audio and/or haptic signals over coil(s)  22 , may control wireless charging circuitry  32  to receive wireless charging signals  42  over coil(s)  22  and to charge battery  18  using the received wireless charging signals, and may control near-field communications circuitry  34  to transmit and/or receive near-field communications signals  44  using coil(s)  22 . As one example, control circuitry  28  may control acoustic/haptic circuitry  30  to drive coil(s)  22  to issue an audible alert and/or a vibration alert upon receipt of a control signal from external communications equipment  16  (e.g., as conveyed over near-field communications signals  44  or radio-frequency signals  46 ) or upon detection of any other desired trigger condition at control circuitry  28  (e.g., based on software running on device  10 ). In this arrangement, the audio and/or vibration alert may help a user of external communications equipment  16  to locate device  10 . If desired, control circuitry  28  may control acoustic/haptic circuitry  30  to drive coil(s)  22  to convey any desired information to a user of device  10  and/or external communications equipment  16 . 
     As another example, control circuitry  28  may control wireless charging circuitry  32  to charge battery  18  using wireless charging signals  42  received by coil(s)  22  upon detection of wireless charging signals  42  (e.g., control circuitry  28  may include power monitoring circuitry that monitors coil(s)  22  for the receipt of wireless charging signals  42 ), upon receipt of a control signal from external communications equipment  16  to begin wireless charging (e.g., as conveyed over near-field communications signals  44  or radio-frequency signals  46 ), periodically, and/or upon detection of any other desired trigger condition. Similarly, control circuitry  28  may control near-field communications circuitry  34  to transmit or receive data using coil(s)  22  upon receipt of near-field communications signals  44  (e.g., when a user swipes device  10  over external communications equipment  16  or when a user swipes external communications equipment  16  over device  10 ), upon detection of wireless charging signals  42 , upon receipt of a control signal from external communications equipment  16  (e.g., as conveyed over near-field communications signals  44  or radio-frequency signals  46 ), periodically, and/or upon detection of any other desired trigger condition. Data conveyed using near-field communications signals  44  may, for example, be used to pair device  10  to external communications equipment  16  for subsequent communications using radio-frequency signals  46 , to identify device  10  to a user of external communications equipment  16  (e.g., so that the user can determine the identity of device  10  upon swiping external communications equipment  16  over device  10 , etc.), or for performing any other desired operations for system  12 . 
     Control circuitry  28  may selectively activate (enable) one or more of acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and near-field communications circuitry  34  to transmit and/or receive wireless signals using coil(s)  22  at any given time.  FIG. 2  is a schematic diagram showing how control circuitry  28  may selectively activate one or more of these components for use with a single coil  22 . 
     As shown in  FIG. 2 , input-output circuitry  20  may include a logic board such as logic board  50 . Logic board  50  may be a printed circuit board (e.g., a rigid printed circuit board or flexible printed circuit), an integrated circuit package, or any other desired substrate. Control circuitry  28 , near-field communications (NFC) transceiver circuitry  54  (sometimes referred to herein as an NFC transceiver), acoustic/haptic source circuitry  52 , and battery charger circuitry  56  may be mounted to logic board  50 . This is merely illustrative and, if desired, two or more of these components may be mounted to separate logic boards or substrates. 
     Acoustic/haptic source circuitry  52  may be coupled to acoustic/haptic amplifier (driver) circuitry  68  over path  62 . Acoustic/haptic source circuitry  52  and acoustic/haptic amplifier circuitry  68  may form part of acoustic/haptic circuitry  30  of  FIG. 1 . NFC transceiver circuitry  54  may be coupled to NFC matching network (circuitry)  70  over path  64 . NFC transceiver circuitry  54  and NFC matching network  70  may form part of near-field communications circuitry  34  of  FIG. 1 . Battery charger circuitry  56  may be coupled to wireless charging converter (circuitry)  72  over path  66 . Battery charger circuitry  56  and wireless charging converter  72  may form part of wireless charging circuitry  32  of  FIG. 1 . 
     Input-output circuitry  20  may include switching circuitry  48 . Switching circuitry  48 , acoustic/haptic amplifier circuitry  68 , NFC matching network  70 , and/or wireless charging converter  72  may be mounted to logic board  50  or formed separately from logic board  50 . Switching circuitry  48  may include any desired number of one or more switches arranged in any desired manner (e.g., switching circuitry  48  may include a network of switches, a switch matrix, etc.). Switching circuitry  48  may have a first port  74  coupled to acoustic/haptic amplifier circuitry  68 , a second port  76  coupled to NFC matching network  70 , and a third port  78  coupled to wireless charging converter  72 . Switching circuitry  48  may also have a port that is coupled to the coil leads  80  of a corresponding coil  22 . In the example of  FIG. 2 , input-output circuitry  20  includes a single coil  22 . This is merely illustrative and, in general, any desired number of coils  22  may be coupled to switching circuitry  48 . 
     Control circuitry  28  may be coupled to acoustic/haptic source circuitry  52 , NFC transceiver circuitry  54 , and battery charger circuitry  56  over control paths  58 . Control circuitry  28  may be coupled to switching circuitry  48  over control path  60 . Control circuitry  28  may convey control signals CTRL to switching circuitry  48  over control path  60  to control which of acoustic/haptic amplifier circuitry  68 , NFC matching network  70 , and wireless charging converter  72  is coupled to coil  22  and thus which of acoustic/haptic circuitry  30 , wireless charging circuitry  32 , or near-field communications circuitry  34  of  FIG. 1  is active at any given time. 
     For example, control circuitry  28  may place switching circuitry  48  in a first state in which switching circuitry  48  only couples port  74  to coil  22  while ports  76  and  78  are decoupled from coil  22 . In this state, acoustic/haptic circuitry  30  ( FIG. 1 ) is active (enabled) whereas wireless charging circuitry  32  and near-field communications circuitry  34  are inactive (disabled). Control circuitry  28  may control acoustic/haptic source circuitry  52  to produce audio signals and/or haptic signals that are conveyed to amplifier circuitry  68  over path  62 . Amplifier circuitry  68  may amplify the audio signals and/or haptic signals, which are then driven onto coil  22  through switching circuitry  48 . When driven with the amplified audio signals, coil  22  may cause a diaphragm to move, producing audible sound  38  of  FIG. 1 . The audible sound may be, for example, between 200 and 20,000 Hz to accommodate the natural response of the human ear. When driven with the amplified haptic signals, coil  22  may cause the diaphragm to move at a different frequency and/or with a different intensity or magnitude (e.g., with a different wave pattern), producing a physical vibration that can be felt by a user. In one suitable arrangement, amplifier circuitry  68  may provide greater gain when the haptic signals are driven onto coil  22  than when the audio signals are driven onto coil  22 . If desired, amplifier circuitry  68  may concurrently drive coil  22  using both audio signals and haptic signals. 
     The example of  FIG. 2  is merely illustrative. In another suitable arrangement, input-output circuitry  20  may include separate haptic amplifier and acoustic amplifier circuitry. In this scenario, control circuitry  28  may control switching circuitry  48  to couple the haptic amplifier circuitry to coil  22  when coil  22  is being used to produce a physical vibration and may control switching circuitry  48  to couple the audio amplifier circuitry to coil  22  when coil  22  is being used to produce an audible sound. 
     In another example, control circuitry  28  may place switching circuitry  48  in a second state in which switching circuitry  48  only couples port  76  to coil  22  while ports  74  and  78  are decoupled from coil  22 . In this state, near-field communications circuitry  34  ( FIG. 1 ) is active (enabled). Control circuitry  28  may control NFC transceiver circuitry  54  to transmit radio-frequency signals to coil  22  through path  64 , NFC matching network  70 , and switching circuitry  48 . Coil  22  may wirelessly transmit the radio-frequency signals (e.g., as near-field communications signals  44  of  FIG. 1 ). NFC matching network  70  may ensure that the impedance of path  64  is matched to the impedance of coil  22  (e.g., to maximize the efficiency of coil  22  for near-field transmission). Similarly, NFC transceiver circuitry  54  may receive radio-frequency signals (e.g., near-field communications signals  44  of  FIG. 1 ) via coil  22 , switching circuitry  48 , and NFC matching network  70 . 
     In yet another example, control circuitry  28  may place switching circuitry  48  in a third state in which switching circuitry  48  only couples port  78  to coil  22  while ports  74  and  76  are decoupled from coil  22 . In this state, wireless charging circuitry  32  ( FIG. 1 ) is active (enabled). Coil  22  may receive wireless charging signals  42  ( FIG. 1 ). Wireless charging converter  72  may receive the wireless charging signals from coil  22  and may convert the wireless charging signals into a DC voltage. For example, wireless charging converter  72  may include rectifier circuitry that converts the AC wireless charging signals into the DC voltage. Battery charger circuitry  56  may use the converted signals (e.g., the DC voltage) to charge battery  18 . In the example of  FIG. 2 , battery  18  is mounted to logic board  50 . This is merely illustrative and, in general, battery  18  may be mounted elsewhere in device  10 . If desired, battery charger circuitry  56  and/or wireless charging converter  72  may include bridge circuits, voltage dividers, buck converters, switched capacitor converters, and/or any other desired circuitry for controlling the charging of battery  18  using the wireless charging signals received by coil  22 . 
     If desired, control circuitry  28  may control switching circuitry  48  to simultaneously couple two or three of ports  74 ,  76 , and  78  to coil  22 . This may allow acoustic/haptic amplifier circuitry  68  (e.g., acoustic/haptic circuitry  30  of  FIG. 1 ), NFC matching network  70  (e.g., near-field communications circuitry  34  of  FIG. 1 ), and/or wireless charging converter  72  (e.g., wireless charging circuitry  32  of  FIG. 1 ) to be active at any given time. In this way, the same coil  22  may be shared by these components to sequentially and/or concurrently produce audible sound (e.g., sound  38  of  FIG. 1 ), produce a haptic alert or vibration, transmit and/or receive wireless data using near-field communications signals, and/or receive wireless charging signals for charging battery  18 . 
       FIG. 3  is a cross-sectional side view showing how coil  22  may be mounted within device  10 . As shown in  FIG. 3  the components of device  10  may be enclosed within an electronic device housing such as housing  82 . Housing  82 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts or all of housing  82  may be formed from dielectric or other low-conductivity material (e.g., glass, ceramic, plastic, sapphire, etc.). In other situations, housing  82  or at least some of the structures that make up housing  82  may be formed from metal elements. 
     In one suitable arrangement that is described herein as an example, housing  82  may have a substantially cylindrical shape in which sidewall  82 E extends circumferentially around central axis  101  (e.g., sidewall  82 E may be a continuously curved cylindrical sidewall or may have any other desired shape following any desired path). Sidewall  82 E may extend from rear wall  82 R to front wall  82 F of housing  82 . Sidewall  82 E, rear wall  82 R, and front wall  82 F may be formed from a single integral piece of dielectric and/or metal material (e.g., in a unibody configuration) or may be formed from two or more pieces of dielectric and/or metal materials. In one suitable arrangement, rear wall  82 R is flat (e.g., planar) whereas front wall  82 F is curved (e.g., dome-shaped, hemispherical, etc.). This is merely illustrative and, in general, front wall  82 F and rear wall  82 R may have any desired planar or non-planar (e.g., free-form curved) shapes. Front wall  82 F need not have the same shape as rear wall  82 R. Front wall  82 F and rear wall  82 R may have lateral outlines (e.g., in the X-Y plane of  FIG. 3 ) that are circular, elliptical, square, rectangular, combinations of these, or any other lateral shapes. Front wall  82 F and rear wall  82 R may each have a diameter (in the X-Y plane) of 0.5-5 cm, 1-6 cm, 1-3 cm, less than 8 cm, less than 5 cm, less than 4 cm, less than 3 cm, or less than 2 cm, as examples. Sidewall  82 E may have a height (e.g., parallel to the Z-axis) of 0.1-1 cm, 0.2-0.8 cm, 0.5-2 cm, less than 2 cm, less than 1 cm, or less than 0.5 cm, as examples. Housing  82  need not be cylindrical and may, in general, have any desired shape. 
     If desired, attachment structures such as attachment structures  83  may be provided at or on rear wall  82 R. Attachment structures  83  may include adhesive, one or more suction cups, screws, clips, pins, springs, magnets, or any other desired fastening structures. Attachment structures  83  may serve to hold housing  82  in place on an underlying surface or object (not shown in  FIG. 3  for the sake of clarity). For example, attachment structures  83  may be used to attach (secure) housing  82  and thus device  10  to another electronic device (e.g., a laptop, tablet, keyboard, mouse, stylus, mobile phone, gaming device, television, headset, headphones, etc.), furniture, keys, other household objects, pets, clothing, etc. When secured to an underlying surface or object in this way, device  10  may help external equipment (e.g., external communications equipment  16  of  FIG. 1 ) to identify the location of the underlying surface or object. This example is merely illustrative. Attachment structures  83  may be omitted or formed internally within housing  82  if desired. 
     As shown in  FIG. 3 , logic board  50  may be mounted within housing  82 . Coil  22  may be mounted within housing  82  at a location between front wall  82 F and upper surface  86  of logic board  50 . Coil  22  may be secured to region  96  of front wall  82 F using adhesive  102 . Other components such as components  88  may be mounted to upper surface  86  of logic board  50 . Other components such as components  90  may be mounted to lower surface  84  of logic board  50 . Other components  88  and other components  90  may include portions of input-output circuitry  20  ( FIG. 1 ), control circuitry  28 , battery  18 , and/or any other desired components within device  10 . 
     Coil  22  may be located within a cavity or volume defined by other components  88  (e.g., coil  22  may conform to the shape of the surrounding components  88  and front housing wall  82 F). Coil  22  may include windings  112  of metal wire (e.g., copper wire) or other conductive material that are circumferentially wrapped around central axis  101  and that terminate at coil leads  80 . Coil leads  80  may be coupled to contact pads, conductive pins, or other conductive interconnect structures on logic board  50  (e.g., for coupling to switching circuitry  48  of  FIG. 2 ). Windings  112  may be vertically stacked under front wall  82 F (e.g., parallel to the Z axis of  FIG. 3  so that the coil forms a solenoid). The windings  112  of coil  22  may have any desired lateral outline (in the X-Y plane) such as a circular lateral outline, an elliptical lateral outline, a square lateral outline, a rectangular lateral outline, a triangular lateral outline, a freeform lateral outline that conforms to the volume defined by other components  88 , a polygonal lateral outline, combinations of these, etc. 
     The windings  112  of coil  22  may surround cavity  94 . A stationary magnet such as magnet  104  may be mounted to upper surface  86  of logic board  50 . For example, a layer of adhesive such as adhesive  100  may be used to attach (adhere) magnet  104  to upper surface  86  or other components in device  10 . Magnet  104  may be a permanent magnet or any other desired magnet structure. When coil  22  is driven by audio signals using acoustic/haptic amplifier circuitry  68  of  FIG. 2  (e.g., when acoustic/haptic circuitry  30  of  FIG. 1  is actively using coil  22  to emit sound as a speaker), the audio signals produce a current that flows through windings  112  of coil  22 . Magnet  104  magnetically interacts with the magnetic field produced by this current to cause coil  22  to mechanically move up and down. Because coil  22  is affixed to front wall  82 F using adhesive  102 , the motion of coil  22  also causes region  96  of front wall  82 F to mechanically move up and down, as shown by arrow  108 . This motion may produce audible sound  38  that is emitted by device  10  (e.g., region  96  of front wall  82 F may form a speaker diaphragm for coil  22 ). In this way, coil  22  and front wall  82 F may serve as an audio speaker for device  10  (e.g., where coil  22  is a voice coil and cavity  94  serves as an acoustic cavity for the speaker). If desired, the dimensions of cavity  94  may be selected to help tune the audio (frequency) response of sound  38 . 
     When coil  22  is driven by haptic signals using acoustic/haptic amplifier circuitry  68  of  FIG. 2  (e.g., when acoustic/haptic circuitry  30  of  FIG. 1  is actively using coil  22  to vibrate to emit a vibration alert or other haptic information), the haptic signals produce a current that flows through windings  112  of coil  22 . Magnet  104  magnetically interacts with the magnetic field produced by this current to cause coil  22  to mechanically move up and down. Because coil  22  is affixed to front wall  82 F using adhesive  102 , the motion of coil  22  also causes region  96  of front wall  82 F to mechanically move up and down. The haptic signals may, for example, cause coil  22  to move with a greater magnitude and/or with a different frequency or waveform than the audio signals, thereby causing region  96  of front wall  82 F to vibrate up and down, as shown by arrow  110 . This vibration may, for example, be greater in magnitude than the motion produced by audio signals driven onto coil  22  (e.g., as shown by arrow  108 ). This motion may produce a haptic vibration that can be physically felt by a user. 
     If desired, front wall  82 F may be formed from a first material outside of region  96  and from a second material that is denser than the first material within region  96 . For example, the portion of front wall  82 F outside of region  96  may be formed from plastic whereas region  96  of front wall  82 F is formed from a denser plastic, metal, etc. This increased mass (density) may cause the haptic vibration of front wall  82 F to feel more noticeable to a user. In another suitable arrangement, front wall  82 F may be thicker within region  96  than outside of region  96  to increase the mass of region  96  for enhancing the noticeability of the haptic vibration. If desired, a layer of additional material such as optional layer  106  may be layered onto front wall  82 F within region  96  to increase the mass of region  96  for enhancing the noticeability of the haptic vibration. Combinations of these arrangements may be used if desired. 
     As shown in  FIG. 3 , coil  22  may transmit and receive near-field communications signals  44  through front wall  82 F (e.g., when near-field communications circuitry  34  of  FIG. 1  is active). Coil  22  may also receive wireless charging signals  42  through front wall  82 F (e.g., when wireless charging circuitry  32  of  FIG. 1  is active). In this way, the same volume within device  10  may be utilized to produce sound  38 , to produce haptic alerts or other vibrations, to transmit and/or receive near-field communications data, and to wirelessly charge battery  18 . This may serve to optimize space consumption within device  10 . 
     The example of  FIG. 3  is merely illustrative. In general, coil  22  may have other desired shapes or arrangements.  FIG. 4  is a top-down view of coil  22  in an example where the windings  112  of coil  22  are provided in a flattened arrangement. As shown in  FIG. 4 , coil  22  may include flattened windings  112  such as flattened windings  112 ′ extending between coil leads  80 . Flattened windings  112 ′ may lie within a corresponding surface (e.g., a planar surface such as the X-Y surface of  FIG. 4  or a curved surface that conforms to the shape of front wall  82 F of  FIG. 3 ). Flattened windings  112 ′ may surround an opening  114  that is aligned with the underlying magnet  104 . When arranged in this way, coil  22  may, for example, convey near-field communications signals  44  of  FIG. 3  with optimized efficiency (e.g., with greater antenna efficiency than in scenarios where the windings of coil  22  are vertically stacked). 
     The example of  FIG. 4  in which flattened windings  112 ′ follow a rectangular path around opening  114  is merely illustrative. In general, flattened windings  112 ′ may follow a path having any desired shape (e.g., a circular shape, an elliptical shape, a square shape, or any other desired shape having any desired number of straight and/or curved segments). If desired, coil  22  may have both flattened windings and vertically-stacked windings. 
       FIG. 5  is a cross-sectional side view showing how coil  22  may include both flattened windings and vertically-stacked windings. As shown in  FIG. 5 , coil  22  may include flattened windings  112 ′ and vertically-stacked windings  112 ″ extending between coil leads  80 . In the example of  FIG. 5 , coil leads  80  are shown as being coupled to vertically-stacked windings  112 ″. This is merely illustrative and, if desired, coil leads  80  may be coupled to flattened windings  112 ′ or one coil lead may be coupled to flattened windings  112 ′ while the other coil lead is coupled to vertically-stacked windings  112 ″. 
     Flattened windings  112 ′ may be attached to front wall  82 F using adhesive  102 . As shown in  FIG. 5 , flattened windings  112 ′ may lie within a surface that conforms to (e.g., follows) the geometry of front wall  82 F. Vertically-stacked windings  112 ″ may be located between flattened windings  112 ′ and magnet  104 . This is merely illustrative and, if desired, flattened windings  112 ′ may be interposed between vertically-stacked windings  112 ″ and magnet  104 . Flattened windings  112 ′ may sometimes be referred to herein as a set of windings lying along a surface whereas vertically-stacked windings  112 ″ are sometimes referred to herein as a set of windings that are vertically-stacked. When arranged in this way, coil  22  may, for example, convey near-field communications signals  44  of  FIG. 3  with optimized efficiency while also exhibiting optimal audio and/or haptic response (e.g., coil  22  of  FIG. 5  may exhibit greater antenna efficiency than in scenarios where coil  22  includes only vertically-stacked windings and may exhibit superior audio and/or haptic response quality than in scenarios where coil  22  includes only flattened windings  112 ′). Coil  22  of  FIG. 5  may have other shapes. If desired, coil  22  may have multiple layers of vertically-stacked windings. 
       FIG. 6  is a cross-sectional side view showing how coil  22  may include multiple layers of vertically-stacked windings. As shown in  FIG. 5 , coil  22  may include vertically-stacked windings  112 ″. There may be a cavity such as cavity  116  (laterally) interposed between other electrical components  88  and vertically stacked windings  112 ″. If desired, coil  22  may include additional layers (sets) of vertically-stacked windings  112 ′″ located within cavity  116  between other components  88  and vertically-stacked windings  112 ″ (e.g., the windings closest to magnet  104 ). The additional layers of vertically-stacked windings  112 ′″ may be arranged in uniform rows and columns or in any other desired pattern. If desired, the additional layers of vertically-stacked windings  112 ′″ may completely or almost completely fill cavity  116 . The additional layers of vertically-stacked windings  112 ′″ may be adhered to front wall  82 F by adhesive  102  or adhesive  102  may only adhere vertically-stacked windings  112 ″ to front wall  82 F. In the example of  FIG. 5 , coil leads  80  are shown as being coupled to vertically-stacked windings  112 ″. This is merely illustrative and, if desired, coil leads  80  may be coupled to the additional layers of vertically-stacked windings  112 ′″ or one coil lead may be coupled to the additional layers of vertically-stacked windings  112 ′″ while the other coil lead is coupled to vertically-stacked windings  112 ″. 
     The additional layers of vertically-stacked windings  112 ′″ may effectively increase the amount of conductive material (e.g., copper) within coil  22  and may thereby allow coil  22  to capture more electromagnetic flux passing through cavity  94  than in scenarios where only a single layer of vertically-stacked windings  112 ″ is used. When arranged in this way, coil  22  may, for example, receive wireless charging signals  42  ( FIG. 3 ) with optimized efficiency and may thereby charge battery  18  with optimized charging efficiency (e.g., device  10  of  FIG. 6  may operate with greater charging efficiency than in scenarios where coil  22  includes only a single layer of vertically-stacked windings or where coil  22  includes only flattened windings). The example of  FIG. 6  is merely illustrative. Coil  22  may have other shapes. If desired, the arrangements of  FIGS. 3-6  may be combined (e.g., coil  22  may include flattened windings and multiple layers of vertically-stacked windings). 
       FIG. 7  is a cross-sectional side view showing how coil  22  may include flattened windings and multiple layers of vertically-stacked windings. As shown in  FIG. 7 , coil  22  may include vertically-stacked windings  112 ″, flattened windings  112 ′ attached to front wall  82 F by adhesive  102 , and additional layers of vertically-stacked windings  112 ′ within cavity  116 . Flattened windings  112 ′ may, for example, support optimal near-field communications while vertically-stacked windings  112 ″ and  112 ′ support optimal wireless charging without excessive losses to audio and/or haptic performance. The example of  FIG. 7  is merely illustrative. Coil  22  may have other shapes. Coil leads  80  may be coupled to any portions of coil  22 . 
     In the examples of  FIGS. 2-7 , only a single shared coil  22  is illustrated for the sake of simplicity. If desired, acoustic/haptic amplifier circuitry  68 , NFC matching network  70 , and wireless charging converter  72  of  FIG. 2  may use multiple coils to transmit and/or receive information.  FIG. 8  is a schematic diagram showing how multiple coils may be coupled to switching circuitry  48  of  FIG. 2 . 
     As shown in  FIG. 8 , switching circuitry  48  may be coupled to the coil leads of any desired number N of coils  22  (e.g., switching circuitry  48  may be coupled to coil leads  80 - 1  of coil  22 - 1 , coil leads  80 - 2  of coil  22 - 2 , coil leads  80 -N of coil  22 -N, etc.). Control signals CTRL may be received over control path  60  and may control switching circuitry  48  to selectively activate acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and near-field communications circuitry  34  ( FIG. 1 ) by coupling the corresponding ports  74 ,  76 , and  78  to a given one of coils  22 - 1  through  22 -N. 
     Each coil  22  may be used by only one of ports  74 ,  76 , and  78  or one or more of the coils may be shared by two or more (e.g., all three) of ports  74 ,  76 , and  78 . In one suitable arrangement, there may be four coils, where the first coil receives haptic signals from port  74 , the second coil receives audio signals from port  74  (or from an additional port in scenarios where separate haptic and audio amplifiers are used), the third coil conveys near-field communications signals for port  76 , and the fourth coil receives wireless charging signals for port  78  (e.g., coils  22  need not be shared). In another suitable arrangement, there may be three coils, where the first coil receives haptic signals and audio signals from port  74  (or from two ports in scenarios where separate haptic and audio amplifiers are used), the second coil conveys near-field communications signals for port  76 , and the fourth coil receives wireless charging signals for port  78  (e.g., one of coils  22  may be used to convey both audio signals and haptic signals whereas the other coils are unshared). In another suitable arrangement, there may be two coils, where the first coil receives haptic signals and audio signals from port  74  (or from two ports in scenarios where separate haptic and audio amplifiers are used) and the second coil conveys near-field communications signals for port  76  and wireless charging signals for port  78  (e.g., one of coils  22  may be shared by wireless charging circuitry  32  and near-field communications circuitry  34 ). 
     In another suitable arrangement, there may be two coils, where the first coil receives haptic signals and audio signals from port  74  (or from two ports in scenarios where separate haptic and audio amplifiers are used) and conveys near-field communications signals for port  76  whereas the second coil receives wireless charging signals for port  78  (e.g., one of coils  22  may be shared by acoustic/haptic circuitry  30  and near-field communications circuitry  34  whereas the other coil is only used by wireless charging circuitry  32 ). In yet another suitable arrangement, there may be two coils, where the first coil receives haptic signals and audio signals from port  74  (or from two ports in scenarios where separate haptic and audio amplifiers are used) and wireless charging signals for port  78  whereas the second coil conveys near-field communications signals for port  76  (e.g., one of coils  22  may be shared by acoustic/haptic circuitry  30  and wireless charging circuitry  32  whereas the other coil is only used by near-field communications circuitry  34 ). These examples are merely illustrative and, in general, any desired number of coils may be shared by any desired combination of acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and near-field communications circuitry  34 . 
       FIG. 9  is a cross-sectional side view of device  10  in one particular example where two coils are shared by acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and near-field communications circuitry  34 . As shown in  FIG. 9 , device  10  may include a first coil such as coil  22 - 1  and a second coil such as coil  22 - 2 . Coil  22 - 1  may laterally surround coil  22 - 2  about central axis  101  and cavity  94  (e.g., coils  22 - 1  and  22 - 2  may be concentric about central axis  101 ). In the example of  FIG. 9 , coil  22 - 1  may include flattened windings  112 - 1  (e.g., flattened windings such as flattened windings  112 ′ of  FIGS. 4, 5, and 7 ) that are attached to front wall  82 F by adhesive  102 ′ whereas coil  22 - 2  includes vertically-stacked windings  112 - 2  that are attached to front wall  82 F by adhesive  102 . This is merely illustrative and, if desired, the same layer of adhesive may be used to attach both coils  22 - 1  and  22 - 2  to front wall  82 F. Coil  22 - 1  may have coil leads  80 - 1  that are coupled to switching circuitry  48  of  FIG. 8  whereas coil  22 - 2  has coil leads  80 - 2  that are coupled to switching circuitry  48  of  FIG. 8 . If desired, additional layers of vertically-stacked windings  118  (e.g., the additional layers of vertically-stacked windings  112 ′″ of  FIGS. 6 and 7 ) may be formed as a part of coil  22 - 1  and/or coil  22 - 2  (e.g., for further optimizing wireless charging efficiency for device  10 ). 
     If desired, coil  22 - 1  may only be used by near-field communications circuitry  34 . For example, control circuitry  28  may activate near-field communications circuitry  34  by controlling switching circuitry  48  to couple port  76  to coil  22 - 1  ( FIG. 8 ). Because coil  22 - 1  includes flattened windings  112 - 1 , coil  22 - 1  may provide device  10  with optimal antenna efficiency for conveying near-field communications signals. On the other hand, coil  22 - 2  may be shared by acoustic/haptic circuitry  30  and wireless charging circuitry  32 . For example, control circuitry  28  may activate acoustic/haptic circuitry  30  by controlling switching circuitry  48  to couple port  74  to coil  22 - 2  ( FIG. 8 ). Audio signals and haptic signals driven onto coil  22 - 2  may cause coil  22 - 2  to move up and down, thereby moving front wall  82 F and producing sound or a haptic vibration. Control circuitry  28  may activate wireless charging circuitry  32  (e.g., concurrently with activation of acoustic/haptic circuitry  30  or at a different time) by controlling switching circuitry  48  to couple port  78  to coil  22 - 2  ( FIG. 8 ). Wireless power received by coil  22 - 2  may be used to charge battery  18  or to otherwise power device  10 . 
     This example is merely illustrative. If desired, coil  22 - 1  may be shared by wireless charging circuitry  32  and near-field communications circuitry  34 . Coil  22 - 1  may additionally or alternatively include vertically-stacked windings and/or coil  22 - 2  may additionally or alternatively include flattened windings. Coils  22 - 1  and  22 - 2  may have other shapes or arrangements. Three or more coils may be used if desired. If desired, one or more of coils  22  may also be used to convey radio-frequency signals  46  for other wireless communications circuitry  36  of  FIG. 1  (e.g., coil  22  may be shared by circuitry  30 ,  32 ,  34 , and/or  36  of  FIG. 1 ). 
     In general, any desired combination of audio signals, haptic signals, near-field communications signals, and wireless charging signals may be concurrently or sequentially conveyed by one or more coils  22  (e.g., one or more coils may only convey one of these types of signals at any given time or may convey any combination of two, three, or all of these types of signals at any given time). Control circuitry  28  may control switching circuitry  48  ( FIGS. 2 and 8 ) to control which of these signals are conveyed by the coils at any given time. 
       FIG. 10  shows an exemplary table  120  of different possible operating states for device  10 . In each operating state, one, two, three, four, or none of the audio signals, haptic signals, near-field communications signals, and wireless charging signals are conveyed by the coils (e.g., a single coil as shown in  FIGS. 2-7  or multiple shared and/or dedicated coils as shown in  FIGS. 8 and 9 ). Each row of table  120  illustrates a corresponding operating state. 
     As shown in  FIG. 10 , where the “ACOUSTIC OUTPUT” column is listed as “ACTIVE” in table  120 , acoustic/haptic circuitry  30  of  FIG. 1  is coupled to a given coil and drives audio signals onto that coil. Where the “ACOUSTIC OUTPUT” column is listed as “INACTIVE” in table  120 , acoustic/haptic circuitry  30  of  FIG. 1  is de-coupled from that coil or is otherwise not actively driving audio signals onto the coil. Where the “HAPTIC OUTPUT” column is listed as “ACTIVE” in table  120 , acoustic/haptic circuitry  30  of  FIG. 1  is coupled to a given coil and drives haptic signals to that coil. Where the “HAPTIC OUTPUT” column is listed as “INACTIVE” in table  120 , acoustic/haptic circuitry  30  of  FIG. 1  is de-coupled from that coil or is otherwise not actively driving haptic signals onto the coil. Where the “NFC COMMS” column is listed as “ACTIVE” in table  120 , near-field communications circuitry  34  of  FIG. 1  is coupled to a given coil and is conveying near-field communications signals with that coil. Where the “NFC COMMS” column is listed as “INACTIVE” in table  120 , near-field communications circuitry  34  of  FIG. 1  is de-coupled from that coil or is otherwise not actively conveying near-field communications signals using the coil. Where the “WIRELESS CHARGING” column is listed as “ACTIVE” in table  120 , wireless charging circuitry  32  of  FIG. 1  is coupled to a given coil and is conveying wireless charging signals for charging battery  18 . Where the “WIRELESS CHARGING” column is listed as “INACTIVE” in table  120 , wireless charging circuitry  32  of  FIG. 1  is de-coupled from that coil or is otherwise not actively receiving wireless charging signals using the coil. 
     Control circuitry  28  may place device  10  in one of these operating states by adjusting the state of switching circuitry  48 . For example, when it is desired for device  10  to emit an audible sound (e.g., in response to a software trigger or receiving corresponding control signals via radio-frequency signals  46  of  FIG. 1 ), control circuitry  28  may place device  10  in operating state “B,” when it is desired for device  10  to emit a haptic vibration alert, control circuitry  28  may place device  10  in operating state “C,” when it is desired for device  10  to emit both a haptic vibration alert and an audible sound, control circuitry  28  may place device  10  in operating state “F,” when it is desired to convey near-field communications signals (e.g., in response to receiving near-field communications signals at device  10 ), control circuitry  28  may place device  10  in operating state “D,” when it is desired to wirelessly charge battery  18  (e.g., in response to receiving wireless charging signals at device  10 ), control circuitry  28  may place device  10  in operating state “E,” when it is desired to concurrently perform near-field communications and wireless charging, control circuitry  28  may place device  10  in operating state “H,” etc. The example of  FIG. 10  in which table  120  illustrates each possible combination of concurrent uses for the coils is merely illustrative. If desired, control circuitry  28  may only adjust device  10  between a subset of the states shown in table  120 . For example, in scenarios where the coils do not need to concurrently convey any of the signals, control circuitry  28  may only adjust device  10  between operating states A-E, whereas operating states F-P are unused. 
     In the example of  FIG. 10 , device  10  conveys four types of information using the coils (e.g., audio signals, haptic signals, near-field communications signals, and wireless charging signals). This is merely illustrative and, if desired, device  10  may convey only a subset of these types of information. In one suitable arrangement, device  10  may convey only three of these types of information.  FIG. 11  shows an exemplary table  122  of different possible operating states for device  10  in this scenario. In table  122  of  FIG. 11 , the “FIRST SOURCE,” “SECOND SOURCE,” and “THIRD SOURCE” may each be any of audio signals, haptic signals, near-field communications signals, and wireless charging signals that are to be conveyed by one or more coils. One of these sources may be other wireless communications circuitry  36  in scenarios where other wireless communications circuitry  36  also shares coil  22 . Table  122  illustrates each of the nine possible operating states in which signals from these sources are conveyed individually or concurrently using the coils. If desired, control circuitry  28  may only adjust device  10  between a subset of the operating states shown in table  122 . 
     In another suitable arrangement, device  10  may convey only two of the audio signals, haptic signals, near-field communications signals, and wireless charging signals.  FIG. 12  shows an exemplary table  124  of different operating states for device  10  in this scenario. In table  124 , the “FIRST SOURCE” and “SECOND SOURCE” may each be any of audio signals, haptic signals, near-field communications signals, and wireless charging signals that are to be conveyed by one or more coils. Table  124  illustrates each of the four possible operating states in which signals from these sources are conveyed individually or concurrently using the coils. If desired, control circuitry  28  may only adjust device  10  between a subset of the operating states shown in table  124 . 
       FIG. 13  is a flow chart of illustrative steps that may be performed by control circuitry  28  in adjusting the operating state of device  10 . At step  126  of  FIG. 13 , control circuitry  28  may identify an operating state to be used. Control circuitry  28  may identify the operating state to be used based on software applications running on control circuitry  28 , input received at device  10  (e.g., input provided to device  10  by a user via an input-output device, the reception of wireless charging signals  42 , the reception of near-field communications signals  44 , the reception of radio-frequency signals  46 , etc.). 
     As an example, control circuitry  28  may place device  10  in operating state “B,” “C,” or “F,” or any other operating state of  FIGS. 10-12  where the acoustic and/or haptic output is active in response to receiving radio-frequency signals  46  from external communications equipment  16  (e.g., radio-frequency signals that control device  10  to help a user of external communications equipment  16  to locate device  10 ) or in response to any other trigger condition. Control circuitry  28  may place device  10  in operating state “D,” “G,” “H,” or any other operating state of  FIG. 10-12  where near-field communications circuitry  34  is active in response to receiving near-field communications signals  44  from external communications equipment  16  (e.g., when a user of external communications equipment  16  swipes external communications equipment  16  over device  10 ) or in response to any other trigger condition. In one suitable arrangement, wireless energy in received near-field communications signals  44  may cause switching circuitry  48  to change states to activate near-field communications circuitry  34 . Control circuitry  28  may place device  10  in operating state “E,” “H,” “J,” or any other operating state of  FIG. 10-12  where wireless charging circuitry  32  is active in response to receiving wireless charging signals  42  from wireless charging equipment  14  (e.g., when a user of wireless charging equipment  14  places device  10  on wireless charging equipment  14 ) or in response to any other trigger condition. These examples are merely illustrative. Phase shifts may be applied between the signals provided to different coils to help isolate the coils from each other during concurrent operation if desired. 
     At step  128 , control circuitry  28  may place device  10  in the identified operating state. For example, control circuitry  28  may control switching circuitry  48  of  FIGS. 2 and 8  to place device  10  in the identified operating state. If desired, control circuitry  28  may disable (e.g., power off) acoustic/haptic circuitry  30 , wireless charging circuitry  32 , and/or near-field communications circuitry  34  while not in use to conserve power. Processing may loop back to step  126 , as shown by path  130 , so that control circuitry  28  may continue to update the operating state of device  10  as needed over time. 
     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: 20200611
Publication Date: 20210928
Grant Date: 20210928
Priority Date: 20190725
Inventors: BUSHNELL, TYLER S.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04B5/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/263", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01F27/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F27/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/402", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F27/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F27/2823", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R2209/041", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R9/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/063", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/046", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R7/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R3/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R3/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/248", "inventive": true, "first": false, "tree": "[]"}, {"code": "G08B6/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F27/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0031", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0087", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/72", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/263", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 77887701