PATENT DOCUMENT

Publication Number: US-12015200-B2
Application Number: US-202117468525-A
Country: US
Kind Code: B2

Title: Interface structures for wireless communication devices

Abstract:
A wireless communication system may include an electronic device having an antenna element. The antenna element may convey radio-frequency signals greater than 10 GHz across a dielectric housing wall. A dielectric matching structure may be interposed between the antenna element and the dielectric housing wall. The wireless communication system may include external equipment having an antenna element communicatively coupled to the electronic device antenna element to convey firmware testing, debugging, restore, and/or other data via a near-field wireless communication link. The external equipment may be configured to receive the electronic device at an opening. A dielectric matching structure may be provided at the external equipment between the dielectric housing wall and the external equipment antenna element. The interior surface of the dielectric housing wall may have planar, convex, or concave portions.

Claims:
What is claimed is: 
     
       1. An electronic device having first and second faces, comprising:
 a housing having a housing wall at the first face; 
 a display mounted to the housing and disposed at the second face; 
 an antenna resonating element configured to form a near-field wireless communication link with external equipment by conveying radio-frequency signals at a frequency greater than 10 GHz through the housing wall; 
 a dielectric matching layer interposed between the antenna resonating element and the housing wall, wherein the dielectric matching layer is interposed between the antenna resonating element and a first portion of the housing wall, the first portion of the housing wall is surrounded by a second portion of the housing wall, the first portion of the housing wall differs from the second portion of the housing wall in at least one physical property, the housing wall has a ledge portion that partly defines a cavity overlapping the antenna resonating element, and the first portion of the housing wall overlaps the cavity; and 
 an air gap interposed between the antenna resonating element and the housing wall, wherein the air gap, the dielectric matching layer, and the housing wall form a channel through which the radio-frequency signals are conveyed. 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the housing wall is formed from a first material having a first dielectric constant and the dielectric matching layer is formed from a second material having a second dielectric constant less than the first dielectric constant. 
     
     
       3. The electronic device defined in  claim 2 , further comprising:
 an additional dielectric matching layer interposed between the antenna resonating element and the dielectric matching layer. 
 
     
     
       4. The electronic device defined in  claim 3 , wherein the additional dielectric matching layer is formed from a third material having a third dielectric constant less than the second dielectric constant. 
     
     
       5. The electronic device defined in  claim 4 , wherein the dielectric matching layer and the additional dielectric matching layer have respective thicknesses and respective dielectric constants based on a thickness and a dielectric constant of the housing wall. 
     
     
       6. The electronic device defined in  claim 2 , wherein the first dielectric constant of the first material forming the housing wall is greater than 10. 
     
     
       7. The electronic device defined in  claim 1 , wherein the housing wall is configured to rest on the external equipment to form the near-field wireless communication link. 
     
     
       8. The electronic device defined in  claim 1  further comprising:
 a wireless communication module disposed in the housing having a substrate and a radio-frequency integrated circuit mounted to the substrate, wherein the antenna resonating element comprises a conductive patch on the substrate. 
 
     
     
       9. The electronic device defined in  claim 1 , wherein the at least one physical property comprises a material property, the first portion of the housing wall is formed from a first material having a first dielectric constant, and the second portion of the housing wall is formed from a second material having a second dielectric constant greater than the first dielectric constant. 
     
     
       10. The electronic device defined in  claim 1 , wherein the at least one physical property comprises a dimensional property, the first portion of the housing wall has a thickness different than a thickness of the second portion of the housing wall. 
     
     
       11. The electronic device defined in  claim 10 , wherein the first portion of the housing wall has a protrusion along an interior surface of the housing wall. 
     
     
       12. The electronic device defined in  claim 10 , wherein the first portion of the housing wall has a recess along an interior surface of the housing wall. 
     
     
       13. The electronic device defined in  claim 1 , wherein the air gap is interposed between the antenna resonating element and the dielectric matching layer. 
     
     
       14. The electronic device defined in  claim 1 , wherein the housing wall has a first dielectric constant greater than a second dielectric constant of the dielectric matching layer and the second dielectric constant of the dielectric matching layer is greater than a third dielectric constant of the air gap. 
     
     
       15. An electronic device having first and second faces, comprising:
 a housing having a housing wall at the first face; 
 a display mounted to the housing and disposed at the second face; 
 an antenna resonating element configured to form a near-field wireless communication link with external equipment by conveying radio-frequency signals at a frequency greater than 10 GHz through the housing wall; and 
 a dielectric matching layer interposed between the antenna resonating element and a first portion of the housing wall, wherein the first portion of the housing wall is surrounded by a second portion of the housing wall, the first portion of the housing wall has a thickness different than a thickness of the second portion of the housing wall, and the first portion of the housing wall comprises a recess at an interior surface of the housing wall. 
 
     
     
       16. An electronic device having first and second faces, comprising:
 a housing having a housing wall at the first face; 
 a display mounted to the housing and disposed at the second face; 
 an antenna resonating element configured to form a near-field wireless communication link with external equipment by conveying radio-frequency signals at a frequency greater than 10 GHz through the housing wall; and 
 a dielectric matching layer interposed between the antenna resonating element and a first portion of the housing wall, wherein the first portion of the housing wall is surrounded by a second portion of the housing wall, the first portion of the housing wall differs from the second portion of the housing wall in at least one physical property, the housing wall has a ledge portion that partly defines a cavity overlapping the antenna resonating element, and the first portion of the housing wall overlaps the cavity. 
 
     
     
       17. The electronic device defined in  claim 16 , wherein the at least one physical property comprises at least one of a material property and a dimensional property.

Description:
BACKGROUND 
     This relates generally to electronic devices, including electronic devices with wireless circuitry. 
     Electronic devices are sometimes provided with wired connectors that enable wired connections to external equipment. Among other issues, some wired connector structures can be bulky and take up excess space within the electronic devices. It can be desirable to provide wireless circuitry in place of wired connectors. 
     To satisfy consumer demand for small form factor electronic devices, manufacturers are continually striving to implement wireless circuitry using compact structures. Because antennas in the wireless circuitry have the potential to interfere with each other and with other components in a wireless communication device, care must be taken when incorporating antennas into an electronic device to ensure that the wireless circuitry is able to exhibit satisfactory performance. It can be desirable to provide improved wireless circuitry for electronic devices. 
     SUMMARY 
     An electronic device may include a housing and wireless circuitry mounted within the housing. The wireless circuitry may include an antenna element that is configured to convey radio-frequency signals through a housing wall in the housing at one or more frequencies greater than 10 GHz such as at a frequency band including 60 GHz, at other centimeter and millimeter wave frequency bands, at terahertz wave frequency bands, etc. The housing wall may be formed from one or more dielectric materials with relatively high dielectric constants such as dielectric constants greater than 5, greater than 7, greater than 10, greater than 20, etc. In these illustrative configurations, it may be challenging to effectively convey the radio-frequency signals through the housing wall. 
     The electronic device may be provided with one or more dielectric (impedance) matching layers between the antenna element and the housing wall. The number of dielectric matching layers, the thickness of each dielectric matching layer, and the dielectric constant of each dielectric matching layer may be configured to reduce signal reflection caused by the impedance mismatch between the housing wall and the surrounding air medium in scenarios where the dielectric matching layers are omitted. 
     In some illustrative configurations, the electronic device may for a near-field wireless communication link with external equipment having wireless circuitry with a corresponding antenna element. If desired, the external equipment may help test, debug, configure, restore, and/or otherwise update the firmware of the electronic device using the wireless communication link. The conveyance of radio-frequency signals by the external equipment antenna element (with the corresponding electronic device antenna element) may be affected by the presence of the electronic device housing wall. One or more dielectric matching layers may be provided on the external equipment to interpose between the external equipment antenna element and the electronic device housing wall. The one or more dielectric matching layer may similarly be configured to reduce signal reflection associated with the housing wall. 
     If desired, the electronic device may be provided with a modified housing wall portion aligned with the communication channel between the antenna elements instead of or in addition to the dielectric matching layers in the communication channel. As an example, the housing wall may include a dielectric window formed from a material having a lower dielectric constant than the surrounding portions of the housing wall. As another example, the housing wall may have a planar interior surface and a planar exterior surface. If desired, the inner surface may be modified to have a concave surface portion or a convex surface portion that overlaps the antenna elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram of an illustrative wireless communication system in accordance with some embodiments. 
         FIG.  2    is a block diagram of illustrative wireless circuitry in accordance with some embodiments. 
         FIG.  3    is a cross-sectional view of an illustrative wireless communication module in accordance with some embodiments. 
         FIG.  4    is a top-down view of the wireless communication module of  FIG.  3    in accordance with some embodiments. 
         FIG.  5    is a perspective view of an illustrative electronic device in the wireless communication system of  FIG.  1    in accordance with some embodiments. 
         FIG.  6    is a cross-sectional view of an illustrative peripheral portion of an electronic device incorporating a wireless communication module in accordance with some embodiments. 
         FIG.  7    is a cross-sectional view of an illustrative portion of external equipment in the wireless communication system of  FIG.  1    incorporating a wireless communication module in accordance with some embodiment. 
         FIG.  8    is a diagram of illustrative intervening layers in a communication channel between two antenna elements in accordance with some embodiments. 
         FIG.  9    is a diagram of an illustrative housing wall having a portion through which an antenna element conveys radio-frequency signals in accordance with some embodiments. 
         FIGS.  10 A and  10 B  are diagrams of an illustrative housing wall having a convex surface through which an antenna element conveys radio-frequency signals in accordance with some embodiments. 
         FIGS.  11 A and  11 B  are diagrams of an illustrative housing wall having a concave surface through which an antenna element conveys radio-frequency signals in accordance with some embodiments. 
         FIG.  12    is a perspective view of an illustrative region of a housing wall containing a cavity aligned with an antenna element in accordance with some embodiments. 
         FIG.  13    is a cross-sectional view of an illustrative region of a housing wall containing a cavity aligned with an antenna element in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative system such as wireless communication system  8  may include one or more electronic devices such as electronic devices  10 - 1  and  10 - 2  and any other electronic device(s). Electronic devices in system  8  may each be a computing device such as a laptop computer, a desktop 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, a wireless internet-connected voice-controlled speaker, a home entertainment device, a remote control device, a gaming controller, a peripheral user input device, a wireless base station or access point, a wireless power device, firmware testing, debugging, or restoring equipment, equipment that implements the functionality of two or more of these devices, or other electronic equipment. 
     As shown in the functional block diagram of  FIG.  1   , an illustrative device  10 - 1  may include components located on or within an electronic device housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, metal alloys, etc.), other suitable materials, or a combination of these materials. In some situations, parts or all of housing  12  may be formed from dielectric or other low-conductivity material (e.g., glass, ceramic, plastic, sapphire, etc.). In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10 - 1  may include control circuitry  14 . Control circuitry  14  may include storage such as storage circuitry  16 . Storage circuitry  16  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. Storage circuitry  16  may include storage that is integrated within device  10 - 1  and/or removable storage media. 
     Control circuitry  14  may include processing circuitry such as processing circuitry  18 . Processing circuitry  18  may be used to control the operation of device  10 - 1 . Processing circuitry  18  may include on one or more processors, microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, central processing units (CPUs), etc. Control circuitry  14  may be configured to perform operations in device  10 - 1  using hardware (e.g., dedicated hardware or circuitry), firmware, and/or software. Software code for performing operations in device  10 - 1  may be stored on storage circuitry  16  (e.g., storage circuitry  16  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, firmware, data, instructions, or code. Software code stored on storage circuitry  16  may be executed by processing circuitry  18 . 
     Control circuitry  14  may be used to run software on device  10 - 1  such as 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  14  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  14  include internet protocols, wireless local area network (WLAN) 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 wireless personal area network (WPAN) protocols, IEEE 802.11ad protocols (e.g., ultra-wideband protocols), cellular telephone protocols (e.g., 3G protocols, 4G (LTE) protocols, 3GPP Fifth Generation (5G) New Radio (NR) protocols, etc.), antenna diversity protocols, satellite navigation system protocols (e.g., global positioning system (GPS) protocols, global navigation satellite system (GLONASS) protocols, etc.), antenna-based spatial ranging protocols (e.g., radio detection and ranging (RADAR) protocols or other desired range detection protocols for signals conveyed at millimeter and centimeter wave frequencies), or any other desired communications 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 - 1  may include input-output circuitry  20 . Input-output circuitry  20  may include input-output devices  22 . Input-output devices  22  may be used to allow data to be supplied to device  10 - 1  and to allow data to be provided from device  10 - 1  to external devices. Input-output devices  22  may include user interface devices, data port devices, and other input-output components. For example, input-output devices  22  may include touch sensors, displays (e.g., touch-sensitive and/or force-sensitive displays), light-emitting components such as displays without touch sensor capabilities, buttons (mechanical, capacitive, optical, etc.), scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, audio jacks and other audio port components, digital data port devices, motion sensors (accelerometers, gyroscopes, and/or compasses that detect motion), capacitance sensors, proximity sensors, magnetic sensors, force sensors (e.g., force sensors coupled to a display to detect pressure applied to the display), temperature sensors, etc. In some configurations, keyboards, headphones, displays, pointing devices such as trackpads, mice, and joysticks, and other input-output devices may be coupled to device  10 - 1  using wired or wireless connections. 
     Input-output circuitry  20  may include wireless circuitry  24  to support wireless communications and/or radio-based spatial ranging operations. Wireless circuitry  24  may include one or more antennas  30 . Wireless circuitry  24  may also include one or more radios  26 . Each radio  26  may include circuitry that operates on signals at baseband frequencies (e.g., baseband processor circuitry), signal generator circuitry, modulation/demodulation circuitry (e.g., one or more modems), radio-frequency transceiver circuitry (e.g., radio-frequency transmitter circuitry, radio-frequency receiver circuitry, mixer circuitry for downconverting radio-frequency signals to baseband frequencies or intermediate frequencies between radio and baseband frequencies and/or for upconverting signals at baseband or intermediate frequencies to radio-frequencies, etc.), amplifier circuitry (e.g., one or more power amplifiers and/or one or more low-noise amplifiers (LNAs)), analog-to-digital converter (ADC) circuitry, digital-to-analog converter (DAC) circuitry, control paths, power supply paths, signal paths (e.g., radio-frequency transmission lines, intermediate frequency transmission lines, baseband signal lines, etc.), switching circuitry, filter circuitry, and/or any other circuitry for transmitting and/or receiving radio-frequency signals using antenna(s)  30 . The components of each radio  26  may be mounted onto a respective substrate or integrated into a respective integrated circuit, chip, package (e.g., system-in-package), or system-on-chip (SOC). If desired, the components of multiple radios  26  may share a single substrate, integrated circuit, chip, package, or SOC. 
     Antennas  30  may be formed using any desired antenna structures. For example, antennas  30  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. Filter circuitry, switching circuitry, impedance matching circuitry, and/or other antenna tuning components may be adjusted to adjust the frequency response and wireless performance of antennas  30  over time. Wireless circuitry  24  may include any desired number of antennas  30 . 
     Transceiver circuitry in radios  26  may convey radio-frequency signals using one or more antennas  30  (e.g., antenna(s)  30  may convey the radio-frequency signals for the transceiver circuitry). The term “convey radio-frequency signals” as used herein means the transmission and/or reception of the radio-frequency signals (e.g., for performing unidirectional and/or bidirectional wireless communications with external wireless communications equipment). Antenna(s)  30  may transmit the radio-frequency signals by radiating the radio-frequency signals into free space (or to free space through intervening device structures such as a dielectric cover layer). Antenna(s)  30  may additionally or alternatively receive the radio-frequency signals from free space (e.g., through intervening devices structures such as a dielectric cover layer). The transmission and reception of radio-frequency signals by antenna(s)  30  each involve the excitation or resonance of antenna currents on an antenna resonating element in the antenna by the radio-frequency signals within the frequency band(s) of operation of the antenna. 
     Radios  26  may use antennas  30  to transmit and/or receive radio-frequency signals within different frequency bands at radio frequencies (sometimes referred to herein as communications bands or simply as a “bands”). The frequency bands handled by radios  26  may include wireless local area network (WLAN) frequency bands (e.g., Wi-Fi® (IEEE 802.11) or other WLAN communications bands) such as a 2.4 GHz WLAN band (e.g., from 2400 to 2480 MHz), a 5 GHz WLAN band (e.g., from 5180 to 5825 MHz), a Wi-Fi® 6E band (e.g., from 5925-7125 MHz), and/or other Wi-Fi® bands (e.g., from 1875-5160 MHz), wireless personal area network (WPAN) frequency bands such as the 2.4 GHz Bluetooth® band or other WPAN communications bands, cellular telephone frequency bands (e.g., bands from about 600 MHz to about 5 GHz, 3G bands, 4G LTE bands, 5G New Radio Frequency Range 1 (FR1) bands below 10 GHz, 5G New Radio Frequency Range 2 (FR2) bands between 20 and 60 GHz, etc.), other centimeter or millimeter wave frequency bands between 10-300 GHz, near-field communications (NFC) frequency bands (e.g., at 13.56 MHz), satellite navigation frequency bands (e.g., a GPS band from 1565 to 1610 MHz, a Global Navigation Satellite System (GLONASS) band, a BeiDou Navigation Satellite System (BDS) band, etc.), ultra-wideband (UWB) frequency bands that operate under the IEEE 802.15.4 protocol and/or other ultra-wideband communications protocols, communications bands under the family of 3GPP wireless communications standards, communications bands under the IEEE 802.XX family of standards, and/or any other desired frequency bands of interest. 
     Each radio  26  may transmit and/or receive radio-frequency signals according to a respective radio access technology (RAT) that determines the physical connection methodology for the components in the corresponding radio. One or more radios  26  may implement multiple RATs if desired. As just one example, the radios  26  in device  10 - 1  may include a UWB radio for conveying UWB signals using one or more antennas  30 , a Bluetooth (BT) radio for conveying BT signals using one or more antennas  30 , a Wi-Fi radio for conveying WLAN signals using one or more antennas  30 , a cellular radio for conveying cellular telephone signals using one or more antennas  30  (e.g., in 4G frequency bands, 5G FR1 bands, and/or 5G FR2 bands), and an NFC radio for conveying NFC signals using one or more antennas  30 . This example is merely illustrative and, in general, radios  26  may include any desired combination of radios for covering any desired combination of RATs. 
     Wireless circuitry  24  may include wireless power circuitry such as wireless power (receiving) circuitry  32  and coil structures such as one or more coils  34 . Device  10 - 1  may use wireless power circuitry  32  and coil  34  to receive wirelessly transmitted power (e.g., wireless charging signals) from a wireless power adapter (e.g., a wireless power transmitting device). 
     The wireless power adapter may pass AC currents through the wireless power transmitting coil to produce a time-varying electromagnetic (e.g., magnetic) field that is received as wireless power (wireless charging signals) by coil  34  in device  10 - 1 . Wireless power circuitry  32  may include converter circuitry such as rectifier circuitry that generate a DC voltage for powering device  10 - 1  from the wireless charging signals. The DC voltage produced by the rectifier circuitry in wireless power circuitry  32  can be used in charging an energy storage device such as a battery and/or can be used in powering other components in device  10 - 1 . 
     While control circuitry  14  is shown separately from wireless circuitry  24  in the example of  FIG.  1    for the sake of clarity, wireless circuitry  24  may include processing circuitry (e.g., one or more processors) that forms a part of processing circuitry  18  and/or storage circuitry that forms a part of storage circuitry  16  of control circuitry  14  (e.g., portions of control circuitry  14  may be implemented on wireless circuitry  24 ). 
     Radios  26  may use antennas  30  to transmit and/or receive radio-frequency signals to convey wireless communication data between device  10 - 1  and one or more other external wireless communication equipment or devices. In the illustrative example of  FIG.  1   , system  8  includes electronic device  10 - 2  (sometimes referred to herein as external equipment  10 - 2  or electronic equipment  10 - 2 ), which may have one or more of the same elements as described above in connection with electronic device  10 - 1 . In particular, as shown in  FIG.  1   , electronic device  10 - 2  may include wireless circuitry such as wireless circuitry  54  having one or more radios such as radios  56  and one or more antennas such as antennas  60 . 
     Devices  10 - 1  and  10 - 2  may be communicatively coupled via one or more communication links  66  via respective wireless circuitry. Wireless communication data may be conveyed between devices  10 - 1  and  10 - 2  bidirectionally or unidirectionally. As examples, devices  10 - 1  and  10 - 2  may form a half-duplex communication link or a full-duplex communication link. 
     Configurations in which devices  10 - 1  and  10 - 2  form a near-field wireless communication link  66  are described herein as illustrative examples. The near-field nature of wireless communication link  66  refers to the relatively short distance through which devices  10 - 1  and  10 - 2  may be wirelessly communicatively coupled. As examples, respective wireless circuitry (antennas) on devices  10 - 1  and  10 - 2  may be separated by a distance less than ten centimeters, less than five centimeters, less than four centimeters, less than two centimeters, etc., or across a distance of greater than one centimeter, greater than two centimeters, greater than five centimeters, etc. These examples are merely illustrative. If desired, wireless communication link  66  may be established across other distances. 
     Configurations in which device  10 - 2  implements firmware update equipment such as equipment configured to perform firmware testing, debugging, restoring, and/or other functions relating to the firmware of device  10 - 1  are described herein as illustrative examples. If desired, device  10 - 2  may be or implement equipment or devices having other functionalities. 
     In some of these configurations for device  10 - 2 , the wireless communication data being conveyed with device  10 - 1  may include data that has been encoded into corresponding data packets such as wireless data associated with software applications running on device  10 - 1 , wireless data associated with software updates for device  10 - 1 , wireless data associated with testing, debugging, and/or repairing device  10 - 1 , wireless data associated with resetting or restoring device  10 - 1  to a default or factory setting, wireless data associated with a telephone call, a message, streaming media content, or internet browsing, etc. 
     In some of these configurations for device  10 - 2 , wireless circuitry  54  in device  10 - 2  may include wireless power (transmitting) circuitry  62  and coil structures such as one or more coils  64 . Configured in this manner, device  10 - 2  may use wireless power circuitry  62  and coil  64  to transmit wireless power (signals) to device  10 - 1 . 
     In some of these illustrative configurations for device  10 - 2 , device  10 - 2  may include support structures  42  such as platforms, carriers, docks, or other structures to which wireless circuitry and other components (e.g., control circuitry, input-output devices, etc.) for device  10 - 2  are mounted and which are configured to receive device  10 - 1 . As examples, support structures  42  may be formed of plastic, glass, ceramics, fiber composites, metal, other suitable materials, or a combination of these materials. 
     The example of  FIG.  1    is merely illustrative. If desired, system  8  may include any suitable number of electronic devices or equipment (e.g., having similar elements as device  10 - 1  and/or device  10 - 2 ). If desired, device  10 - 1  or device  10 - 2  may be communicatively coupled to one or more of these other electronic devices or equipment instead of or in addition to each other, or may operate in isolation at times. If desired, devices  10 - 1  and  10 - 2  may include any other suitable elements or may omit one or more elements described in connection with  FIG.  1   . 
       FIG.  2    is a functional block diagram of wireless circuitry  24  of  FIG.  1   . As shown in  FIG.  2   , each radio  26  may be coupled to one or more antennas  30  over one or more radio-frequency transmission lines  70 . As an illustrative example, each radio-frequency transmission line  36  may include a ground conductor such as ground conductor  72  and a signal conductor such as signal conductor  74 . A corresponding antenna  30  may include an antenna feed such as antenna feed  76  having ground antenna feed terminal  78  coupled to ground conductor  72  and positive antenna feed terminal  80  coupled to signal conductor  80 . If desired, transmission line  70  may include additional signal conductors coupled to additional positive antenna feed terminals. 
     One or more radio-frequency transmission lines  70  may be shared between radios  26  and/or antennas  30  if desired. Radio-frequency front end (RFFE) modules may be interposed on one or more radio-frequency transmission lines  70 . The radio-frequency front end modules may include substrates, integrated circuits, chips, or packages that are separate from radios  26  and may include filter circuitry, switching circuitry, amplifier circuitry, impedance matching circuitry, radio-frequency coupler circuitry, and/or any other desired radio-frequency circuitry for operating on the radio-frequency signals conveyed over radio-frequency transmission lines  70 . 
     While  FIG.  2    describes one or more radios  26  and one or more antennas  30  in device  10 - 1  ( FIG.  1   ), other electronic devices such as device  10 - 2  and other devices in system  8  may include one or more radios and antennas configured in the same manner. 
     In some illustrative configurations, electronic devices may include high-data-rate wired connectors. These wired connectors can be bulky and take up excess interior space, and require external input-output ports that render the electronic device less secure. It may therefore be desirable to provide wireless circuitry that can establish high-data-rate wireless communication links. 
     However, providing wireless circuitry that operate at relatively high frequencies such as at one or more frequencies greater than 10 GHz such as at a frequency band including 60 GHz, at other centimeter and millimeter wave frequency bands, at terahertz wave frequency bands, etc., thereby allowing for high-data-rate data transfer, can raise significant challenges. As examples, it may be challenging to provide the wireless circuitry at these frequencies in a compact manner to provide space-savings, other components in each wireless device (e.g., other portions of the wireless circuitry, conductive elements, housing structures, etc.) have the potential to interfere with the operation of the wireless circuitry for establishing these wireless communication links, misalignments between the communicating devices (e.g., the respective wireless circuitry) and intervening structures between the respective wireless circuitry can degrade the wireless communication links. As such, one or more of the electronic devices in system  8  ( FIG.  1   ) may be provided with improved wireless circuitry while taking into account one or more of these issues. 
       FIG.  3    is a cross-sectional view of an illustrative wireless communication module such as wireless communication module  82  that can implement wireless circuitry for one or more devices (e.g., devices in system  8  in  FIG.  1   ). Configurations in which wireless communication module  82  operate at one or more frequencies greater than 10 GHz (e.g., at a 60 GHz frequency band, between 10 GHz and 300 GHz for centimeter and millimeter wave frequency bands, between 0.3 THz and 30 THz for terahertz wave frequency bands, etc.) to convey firmware testing data, firmware debugging data, firmware repair data, firmware restore data, and/or device configuration data are described herein as illustrative examples. If desired, wireless communication module  82  may operate at any suitable frequency (e.g., covering one or more suitable frequency bands) and may coney any suitable type of data for the desired function. 
     As shown in  FIG.  3   , module  82  may include a substrate such as substrate  84 . Substrate  84  may include multiple layers  86  and may therefore be referred to as a multi-layer substrate. Some of layers  86  may be formed from one or more non-conductive materials such as dielectric materials, some of layers  86  may be conductive materials such as metallic materials, and some of layers  86  may be formed from other materials such as semiconducting materials. 
     Substrate  84  has first and second opposing surfaces (e.g., top and bottom surfaces in  FIG.  3   ). An antenna resonating element for an antenna such as a conductive (metal) patch element  90  may be disposed on the first surface of substrate  84 . An antenna ground structure for the antenna such as conductive ground layer  92  (sometimes referred to as ground ring  92 ) may also be disposed on the first surface of substrate  84 . Ground layer  92  may surround patch element  90  and be separated from patch element  90  by dielectric gap  91 . Additional antenna ground structures such as ground layer  94  for the antenna may be embedded in substrate  84 . Conductive structures such as conductive vias  96  in substrate  84  may couple (e.g., electrically short) ground layer  92  at the first surface to embedded ground layer  94 . One or more additional intervening conductive ground layers  98  may also be coupled (e.g., electrically shorted) to vias  96 . Configured in this manner, conductive ground structures for the antenna (e.g., ground layers  92 ,  94 , and  98 , and vias  96 ) may surround and define a cavity for patch element  90 . 
     Module  82  may include radio component  88  such as a radio-frequency integrated circuit or an integrated circuit implementing a radio (e.g., radio  26  in  FIG.  1   ) for patch element  90 . The integrated circuit forming radio component  88  may include one or more elements described in connection with radios  26  in  FIG.  1   . Radio component  88  may be mounted to the second side of substrate  84 . Radio component  88  may provide antennas signals along one or more signal paths  104  to the antenna elements (e.g., patch element  90 , ground structures, etc.). As an example, signal paths  104  may form transmission line structures (e.g., signal conductor paths, ground conductor paths, etc.) coupled to the antenna resonating element and the antenna ground. As shown in  FIG.  3   , the antenna may include one or more positive antenna feed terminals such as terminals  102 - 1  and  102 - 2  coupled to patch element  90 . Radio component  88  may provide antenna signals along a first signal conductor formed from signal paths  104  and  100 - 1  coupled to terminal  102 - 1 . Radio component  88  may provide antenna signals along a second signal conductor formed from signals paths  104  and  100 - 2  coupled to terminal  102 - 2 . Radio component  88  may provide one or more ground conductors coupled to antenna ground structures on module  82 . 
     If desired, module  82  may include input-output structures such as input-output pads, input-output ports, input-output pins, etc. on the second surface of substrate  84 . Radio component  88  may be coupled to signal paths  104  via these input-output structures at the second surface (e.g., via solder). These input-output structures may allow module  82  (e.g., radio component  88  in module  82 ) to interface with other components in an electronic device. As an example, module  82  in a device and the control circuitry in the device may be mounted to a shared package substrate. In this example, the control circuitry may be couple to radio component  88  via one or more signal paths to convey data for wireless communication. These signal paths may include metal routing layers in the shared package substrate, a first set of input-output structures connecting the package substrate to module  82 , metal routing layers in substrate  84 , and a second set of input-output structures coupling radio component  88  to the metal routing layers in substrate  84 . 
       FIG.  4    is a top-down view of the wireless communication module  82  of  FIG.  3   . As shown in  FIG.  4   , patch element  90  may have a rectangular outline (e.g., a square outline). Accordingly, the rectangle may have two main (central) perpendicular axes  106  and  108 . Antenna feed terminal  102 - 1  may lie along axis  106 . Antenna feed terminal  102 - 2  may lie along axis  108 . Configured in such a manner, patch element  90  may be operable to convey radio-frequency signals having multiple polarizations. As an example, radio-frequency signals conveyed using terminal  102 - 1  may have a first linear polarization, and radio-frequency signals conveyed using terminal  102 - 2  may have a second linear polarization (that is orthogonal to the first linear polarization). 
     These configurations for patch element  90  are merely illustrative. If desired, patch element  90  may have any suitable shape or outline. If desired, one or more antenna feed terminals may be coupled to patch element  90  at one or more suitable locations. If desired, patch element  90  may convey radio-frequency signals of a single polarization or may convey radio-frequency signals of different circular polarizations. 
     As shown in  FIG.  4   , ground layer  92  may be separated from patch element  90  by dielectric gap  91  (e.g., an air gap or a gap filled by non-conductive material). Dielectric gap  91  may run all the way around the periphery of patch element  90 . In other words, ground layer  92  may surround patch element  90  along each of the peripheral edges of patch element  90  and may have edges that run parallel to the corresponding peripheral edges of patch element  90 . If desired, distances separating opposing edges of ground layer  92  and patch element  90  may be the same. In particular, distances  110 - 1  and  110 - 2  and corresponding distances between patch element  90  and ground layer  92  at other peripheral edges may be the same. If desired, one or more of these distances may be different from each other. 
     As shown in  FIG.  4   , module  84  may have a rectangular outline with rounded corners. The rounded corners of module  84  may help accommodate module  84  into cramped spaces. Ground layer  92  may have inner edges that define an edge of gap  91  (e.g., a suitable separation from patch element  90 ). The inner edges of ground layer  92  may also have a rectangular outline with rounded corners to help maintain a suitable separation from patch element  90 . Ground layer  92  may span from the inner edges to outer edges at the peripheral edges of module  82 . This may help with improving the manufacturing process for module  82 . In the example of  FIG.  4   , the rectangular outline of module  82  may have a geometric center, and the outline of patch element  90  may have a geometric center that is offset from the geometric center of module  82 . If desired, other configurations for module  82  may be used. 
     The use of wireless communication module  82  to implement the wireless circuitry for one or more devices in system  8  (e.g., devices  10 - 1  and  10 - 2 ) is merely illustrative. If desired, one or more devices in system  8  may include antenna elements implemented separately from the corresponding radio components such as on a separate module, on a separate substrate, etc. or wireless circuitry implemented in other suitable manners. Illustrative embodiments described herein may be applicable to any of these wireless circuitry configurations. 
     In some configurations described herein as illustrative examples, device  10 - 1  may be a portable device such as a wristwatch device (e.g., a smart watch). If desired, device  10 - 1  may instead be implemented as other portable devices such as a cellular telephone, a tablet device, or another portable computing device, or generally, any other suitable devices or equipment. 
       FIG.  5    is a perspective view of an illustrative portable electronic device that may implement device  10 - 1 . In the example of  FIG.  5   , device  10 - 1  includes a display such as display  112 . Display  112  may be mounted to a housing such as housing  12 . 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 such as sidewalls  12 W or sidewalls formed from other materials. Examples of metal materials that may be used for forming sidewalls  12 W include stainless steel, aluminum, silver, gold, metal alloys, or any other desired conductive material. Sidewalls  12 W may sometimes be referred to herein as housing sidewalls  12 W or conductive housing sidewalls  12 W. 
     Display  112  may be formed at (e.g., mounted on) the front side (face) of device  10 - 1 . Housing  12  may have a rear housing wall on the rear side (face) of device  10  such as rear housing wall  12 R that opposes the front face of device  10 - 1 . Conductive housing sidewalls  12 W may surround the periphery of device  10 - 1  (e.g., conductive housing sidewalls  12 W may extend around peripheral edges of device  10 ). Rear housing wall  12 R may be formed from conductive materials and/or dielectric materials. Examples of dielectric materials that may be used for forming rear housing wall  12 R include plastic, glass, sapphire, ceramic such as zirconia, wood, polymer, combinations of these materials, or any other desired dielectrics. 
     Rear housing wall  12 R and/or display  112  may extend across some or all of the length (e.g., parallel to the X-axis) and width (e.g., parallel to the Y-axis) of device  10 - 1 . Conductive housing sidewalls  12 W may extend across some or all of the height of device  10 - 1  (e.g., parallel to the Z-axis). Conductive housing sidewalls  12 W and/or rear housing wall  12 R may form one or more exterior surfaces of device  10 - 1  (e.g., surfaces that are visible to a user of device  10 - 1 ) and/or may be implemented using internal structures that do not form exterior surfaces of device  10 - 1  (e.g., conductive or dielectric housing structures that are not visible to a user of device  10  such as conductive structures that are covered with layers such as thin cosmetic layers, protective coatings, and/or other coating layers that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide housing walls  12 R and/or  12 W from view of the user). 
     Display  112  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 (OLED) display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. Display  112  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. The display cover layer may extend across substantially all of the length and width of device  10 - 1 , for example. 
     Device  10 - 1  may include buttons such as button  114 . There may be any suitable number of buttons in device  10 - 1 . Buttons may be located in openings in housing  12  (e.g., openings in conductive housing sidewall  12 W or rear housing wall  12 R). Buttons may be rotary buttons, sliding buttons, buttons that are actuated by pressing on a movable button member, etc. Button members for buttons such as button  114  may be formed from metal, glass, plastic, or other materials. 
     Device  10 - 1  may, if desired, be coupled to a strap such as strap  116 . Strap  116  may be used to hold device  10 - 1  against a user&#39;s wrist (as an example). Strap  116  may sometimes be referred to herein as wrist strap  116 . In the example of  FIG.  5   , wrist strap  116  is connected to opposing sides of device  10 - 1 . Conductive housing sidewalls  12 W and/or rear housing wall  12 R may include attachment structures for securing wrist strap  116  to housing  12  (e.g., lugs or other attachment mechanisms that configure housing  12  to receive wrist strap  116 ). Configurations that do not include straps may also be used for device  10 - 1 . 
       FIG.  6    is a partial cross-sectional side view of electronic device  10 - 1  ( FIG.  5   ) showing how an antenna in a wireless communication module may be mounted within device  10 - 1  for conveying radio-frequency signals through rear housing wall  12 R. As shown in  FIG.  6   , a display may form the front face of device  10 - 1 , whereas rear housing wall  12 R forms the rear face of device  10 - 1 . In the example of  FIG.  6   , rear housing wall  12 R is formed from a dielectric material such as glass, sapphire, ceramic such as zirconia, or plastic. This is merely illustrative and, if desired, rear housing wall  12 R may also include conductive portions (e.g., a conductive frame surrounding one or more dielectric windows in rear housing wall  12 R, conductive cosmetic layers, etc.). 
     The display may include a display cover layer  120  over a display module  122 . Display module  122  may, for example, form an active area or portion of the display that displays images and/or receives touch sensor input. The lateral portion of the display that does not include display module  122  (e.g., portions of the display formed from display cover layer  120  but without an underlying portion of display module  122 ) may sometimes be referred to herein as the inactive area or portion of the display. 
     Display module  122  may include conductive components (sometimes referred to herein as conductive display structures) that are used in forming portions of an antenna that radiates through the front face of device  10 - 1  (e.g., an antenna having a radiating element such as a radiating slot element defined by display module  122  and/or conductive housing sidewalls  12 W). The conductive display structures in display module  122  may, for example, have planar shapes (e.g., planar rectangular shapes, planar circular shapes, etc.) and may be formed from metal and/or other conductive material that carries antenna currents for a front-facing antenna in device  10 - 1 . The conductive display structures may include a frame for display module  122 , pixel circuitry, touch sensor electrodes, an embedded near-field communications antenna, etc. 
     Display cover layer  120  may be formed from an optically transparent dielectric such as glass, sapphire, ceramic, or plastic. Display module  122  may display images (e.g., emit image light) through display cover layer  120  for view by a user and/or may gather touch or force sensor inputs through display cover layer  120 . If desired, portions of display cover layer  120  may be provided with opaque masking layers (e.g., ink masking layers) and/or pigment to obscure the interior of device  10 - 1  from view of a user. 
     It may be desirable to remove wired connector structures in an electronic device to provide a seamless exterior device surface, improve device waterproofing, and optimize useable device interior space by removing bulky connector components, etc. As an example, an electronic device can include wired connector ports for receiving for testing, debug, and/or restoring firmware on the electronic device or for other functions. It may be desirable to remove these wired ports and connectors. 
     To preserve the functionalities of the wired connector, it may be desirable to provide wireless circuitry that has one or more of the same functionalities. In the above example, it may be desirable to provide wireless for conveying test, debugging, and/or restoring the firmware of the electronic device. To maintain and/or improve existing applications of wired connection with wireless connections, the wireless connections may convey data using high data rates in a bidirectional wireless communication link. The wireless communication link may be established between wireless circuitry across a distance of less than ten centimeters, less than five centimeters, less than four centimeters, less than two centimeters, etc., or across a distance of greater than one centimeter, greater than two centimeters, greater than five centimeters, etc. Across these distances, the wireless communication link may be referred to as a near-field wireless communication link. The near-field wireless communication link may be formed from conveyance of radio-frequency signals having near-field characteristics. If desired, radio-frequency signals having far-field characteristics may also conveyed to form the wireless communication link. The wireless communication link may convey data using high data rate data transfer operations at speeds of 100 Kilobit per second or more, 1 Megabit per second (Mbps) or more, 100 Mbps or more, at 500 Mbps or more, 1 Gigabit bit per second or more, etc. to satisfactorily replace some wired connections (e.g., wired connection for conveying debug, test, restore and/or other data). 
     The examples of removing and/or replacing wired connections for conveying debug, test, and/or restore data are merely illustrative. If desired, it may be similarly desirable to remove and/or replace other wired connections such as USB wired connections or wired connections based on other protocols, or wired connections for conveying other types of signals with wireless connections. 
     As shown in  FIG.  6   , wireless circuitry such as wireless communication module  82 - 1  (e.g., wireless communication module  82  in  FIGS.  3  and  4   ) having antenna element  90 - 1  may be disposed within device  10 - 1 . If desired, wireless communication module  82 - 1  or other wireless circuitry in device  10 - 1  may be configured to provide the high data rate wireless links for near-field applications. 
     Substrates such as one or more rigid printed circuit boards, one or more flexible printed circuits, one or more package substrates, etc. may be located within the interior of device  10 - 1 . In some illustrative configurations, wireless communication module  82 - 1  may be mounted to a system package substrate implementing a system package (or system-in-package (SIP)). Other device components such as one or more integrated circuits implementing control circuitry  14  or other circuitry, input-output circuitry  20  of  FIG.  1   , etc., may also be mounted to the system substrate or be disposed elsewhere in device  10 - 1 . 
     While replacing wired connectors with wireless circuitry such as wireless communication module  82 - 1  may be desired for the above-mentioned advantages, significant challenges may exist, particularly when providing the high-data-rate wireless communication links. In particular, the wireless circuitry and the corresponding antenna element may convey radio-frequency signals at relatively high frequencies such as at one or more frequencies greater than 10 GHz (e.g., at a 60 GHz frequency band, between 10 GHz and 300 GHz for centimeter and millimeter wave frequency bands, between 0.3 THz and 30 THz for terahertz wave frequency bands, etc.) to support high-data-rate (near-field) wireless communication links. Other device structures may interfere with the conveyance of these radio-frequency signals. 
     Still referring to  FIG.  6   , housing structures such as housing wall  12 R in  FIG.  6    may be formed from one or more materials with relative high dielectric constants such as a dielectric constant great than 3, greater than 5, greater than 7, greater than 10, greater than 20, greater than 30, etc. As examples, housing wall  12 R may be formed from zirconia, sapphire, or liquid crystal, or other suitable dielectric material. Without anything more (e.g., assuming an air gap spanning the distance between module  82 - 1  having antenna element  90 - 1  and housing wall  12 R), when antenna element  90 - 1  conveys radio-frequency signals at one or more frequencies greater than 10 GHz, signal reflectance may be exhibited at the interface between the air and housing wall  12 R. This signal reflectance may be caused by impedance mismatch between the air medium and the dielectric material forming housing wall  12 R and can lead to degradation of wireless communication link  66 . 
     In order to mitigate the effects of signal reflectance due to this mismatch, one or more matching layers  124  (sometimes referred to herein as filler or filled material layers) may be interposed between antenna element  90 - 1  and housing wall  12 R. As examples, one or more matching layers  124  may include a polymer layer such as an elastomer layer (e.g., a silicone rubber layer, a silicone layer, etc.), a plastic layer, a glass layer, a dielectric foam structure, or any other dielectric structures. In general, one or more of these materials may be used to implement matching layers  124  based on their dielectric constants relative to that of housing wall  12 R. The one or more matching layers  124  may include one or more air gap layers, for example, due to the process of manufacturing layers  124  or due to intentionally introducing one or more air gap layers to modify the physical characteristics of the communication channel. 
     One or more layers  124  may be mounted to or adhered to one another and/or to dielectric housing wall  12 R. In some illustrative configurations, housing wall  12 R may include a cavity aligned to antenna element  90 - 1 , and one of more layers  124  may fill the cavity to interpose between antenna element  90 - 1  and a portion of housing wall  12 R. 
     If desired, antenna module  82 - 1  and/or antenna element  90 - 1  may be mounted to or adhered to a top surface of a topmost layer  124 . In some illustrative embodiments, the topmost layer  124  may be an air gap layer. In other words, module  82 - 1  and/or antenna element  90 - 1  may be separated from a topmost solid matching layer  124  by an air gap. 
     Configuration in this manner, one or more matching layers  124  and housing wall  12 R may serve as a portion of the communication channel through which antenna element  90 - 1  may convey radio-frequency signals to and from the exterior of device  10 - 1 . Additional elements in external equipment (e.g., equipment external to device  10 - 1 ) such as device  10 - 2  may serve as another portion of the communication channel to and from which antenna element  90 - 1  conveys radio-frequency signals. 
       FIG.  7    is a cross-sectional view of a portion of external test equipment such as a dock that may implement device  10 - 2 . In particular, device  10 - 2  may be configured to receive device  10 - 1 . As shown in  FIG.  7   , device  10 - 2  may include an opening  132 . Opening  132  may be configured to receive device  10 - 1  such that rear housing wall  12 R may be placed (rests) on the surface defining opening  132 . Device  10 - 2  may include wireless circuitry such as wireless communication module  82 - 2  having antenna element  90 - 2  configured to communicate with antenna element  90 - 1  in communication module  82 - 2  via near-field wireless communication link  66 . 
     Device  10 - 2  may include support structures  128 , sometimes referred to herein as housing structure  128  configured to enclose functional elements in device  10 - 2  such as wireless communication module  82 - 2 . As examples, support structure  128  may include a platform on which functional components such as wireless circuitry, control circuitry, etc. are mounted, antenna mounting and alignment structures configured to fix the position of wireless communication module  82 - 2  and antenna element  90 - 2 , and any other suitable support structures configured to support other elements in device  10 - 2 . 
     As shown in  FIG.  7   , device  10 - 2  may also include one or more matching layers  130 . Similar to matching layers  124  for device  10 - 1 , the one or more matching layers  130  may be interposed between antenna element  90 - 2  in device  10 - 2  and housing wall  12 R in device  10 - 1  when received in opening  132 . As examples, one or more matching layers  130  may include a polymer layer such as an elastomer layer (e.g., a silicone rubber layer, a silicone layer, etc.), a plastic layer, a dielectric glass layer, a dielectric foam structure, or any other dielectric structures. In general, one or more of these materials may be used to implement matching layers  130  based on their dielectric constants relative to that of housing wall  12 R in device  10 - 1 . The one or more matching layers  130  may include one or more air gap layers, for example, due to the process of manufacturing layers  130  or due to intentionally introducing one or more air gap layers to modify the physical characteristics of the communication channel. 
     One or more layers  130  may be mounted to or adhered to one another and/or to antenna module  82 - 2  and/or antenna element  90 - 2 . In the example of  FIG.  7   , a top surface of the topmost layer  130  may define the exterior surface of device  10 - 2  (e.g., may cover a portion of support structures  128 ). As such, when device  10 - 1  is placed in opening  132 , housing wall  12 R may be placed on the top surface of the topmost layer  130  with minimal separation and minimal disruption in the communication channel between antenna elements  90 - 1  and  90 - 2 . 
     Configurations in which antenna elements  90 - 1  and  90 - 2  are implemented in respective wireless communication modules as described in connection with  FIG.  7    are merely illustrative. If desired, the introduction of one or more (dielectric) matching layers in device  10 - 1  and/or  10 - 2  may generally be applied to two antenna resonating elements configured in any other suitable manner such as when they are not implemented in respective encapsulated modules. 
       FIG.  8    is an illustrative diagram showing how a near-field communication channel may be formed between two antenna resonating elements such as antenna resonating element  90 - 1  in device  10 - 1  and antenna resonating element  90 - 2  in device  10 - 2  (when device  10 - 1  is received at opening  132  on device  10 - 2  in  FIG.  7   ). As shown in  FIG.  8   , dielectric (impedance) matching layers  124  (referring to one or more layers  124 - 1 ,  124 - 2 , . . . ,  124 -N) in device  10 - 1  may each have a dielectric constant and a thickness. As examples, dielectric matching layer  124 - 1  may have a thickness L 1 - 1  and a dielectric constant DK 1 - 1 , and in general, dielectric matching layer  124 -N may have a thickness LN- 1  and a dielectric constant DKN- 1 . Similarly, dielectric matching layers  130  (referring to one or more layers  130 - 1 ,  130 - 2 , . . . ,  130 -N) in device  10 - 2  may each have a dielectric constant and a thickness. As examples, dielectric matching layer  130 - 1  may have a thickness L 1 - 2  and a dielectric constant DK 1 - 2 , and in general, dielectric matching layer  130 -N may have a thickness LN- 2  and a dielectric constant DKN- 2 . 
     As shown in  FIG.  8   , the interposing layers between antenna elements  90 - 1  and  90 - 2  may form a multilayer dielectric structure. The number of interposing layers, the thickness of each layer, and the type of material used for each layer may be determined based on the overall reflection coefficient for the different layers in the multilayer dielectric structure. In other words, the number of interposing layers, and layer characteristics such as dielectric constant of each layer and thickness of each layer may be configured to reduce the overall reflection coefficient (compared to scenarios without these interposing layers adjacent to housing wall  12 R). 
     In some illustrative configurations, a single dielectric matching layer  130 - 1  may be interposed between antenna element  90 - 2  (of device  10 - 2 ) and housing wall  12 R (of device  10 - 1 ). In other words, other dielectric matching layers  130 -N may be omitted. As an example, in these illustrative configurations, housing wall  12 R may be formed from a ceramic material such as zirconia or another dielectric material having a dielectric constant greater than 10, and the single dielectric matching layer  130 - 1  may be formed from a polymer or specifically an elastomer such as silicone rubber, a dielectric substrate, or other suitable dielectric material having a dielectric constant between 2 and 5, between 2 and 6, between 2 and 10, or generally between 1 and the dielectric constant of housing wall  12 R. The single dielectric matching layer  130 - 1  may be mounted to and/or supported by support structures on device  10 - 2  (e.g., support structures  128 ) on one or more sides to overlap antenna element  90 - 2 . The single dielectric matching layer  130 - 1  may define a portion of the exterior surface of device  10 - 2  at which device  10 - 2  receives device  10 - 1  such that housing wall  12 R rests directly on the single dielectric matching layer  130 - 1 . In particular, it may be desirable to provide a polymer or elastic material layer as the single dielectric matching layer  130 - 1  given its mechanical properties and that the single dielectric matching layer  130 - 1  forms at least part of the surface configured to receive device  10 - 1 . If desired, when device  10 - 2  receives device  10 - 1 , device  10 - 2  may be configured to separate housing wall  12 R from the single dielectric matching layer  130 - 1  by an air gap layer. 
     In some illustrative configurations, a single dielectric matching layer  124 - 1  may be interposed between antenna element  90 - 1  (of device  10 - 1 ) and housing wall  12 R (of device  10 - 1 ). In other words, other dielectric matching layers  124 -N may be omitted. As an example, in these illustrative configurations, housing wall  12 R may be formed from a ceramic material such as zirconia or another dielectric material having a dielectric constant greater than 10, and the single dielectric matching layer  124 - 1  may be formed from a dielectric substrate, a polymer such as silicone rubber, or other suitable dielectric material having a dielectric constant between 2 and 5, between 2 and 6, between 2 and 10, or generally between 1 and the dielectric constant of housing wall  12 R. The single dielectric matching layer  124 - 1  may be mounted to an interior surface of housing wall  12 R, or may otherwise be mounted to interpose between antenna element  90 - 1  and housing wall  12 R. 
     In some illustrative configurations, in order to minimize signal reflectance at housing wall  12 R, it may be desirable to provide multiple dielectric matching layers having dielectric constants that increase as the layers approach housing wall  12 R. As an example, dielectric matching layer  124 - 1  may have a first dielectric constant, dielectric matching layer  124 - 2  (between layer  124 - 1  and housing wall  12 R) may have a second dielectric constant greater than the first dielectric constant, dielectric matching layer  124 - 3  (between layer  124 - 2  and housing wall  12 R) may have a third dielectric constant greater than the second dielectric constant, etc. Similarly, dielectric matching layer  130 - 1  may have a first dielectric constant, dielectric matching layer  130 - 2  (further away from housing wall  12 R than dielectric matching layer  130 - 1 ) may have a second dielectric constant less than the first dielectric constant, dielectric matching layer  130 - 3  (further away from housing wall  12 R than dielectric matching layer  130 - 2 ) may have a third dielectric constant greater than the second dielectric constant, etc. These examples are merely illustrative. As described above, the thickness of each of these illustrative layers, along with their dielectric constants, may be configured to reduce signal reflection (compared to scenarios in which matching layers  124  and  130  are omitted). 
     The examples of  FIGS.  6 - 8    are merely illustrative. If desired, the dielectric matching structure between housing wall  12 R and antenna element  90 - 1  may be omitted, and the dielectric matching structure between housing wall  12 R and antenna element  90 - 2  may be implemented in one or more layers. If desired, the dielectric matching structure between housing wall  12 R and antenna element  90 - 2  may be omitted, and the dielectric matching structure between housing wall  12 R and antenna element  90 - 1  may be implemented in one or more layers. 
     In some configurations of device  10 - 1 , there may be physical, mechanical, manufacturing, and/or other constraints that make it challenging to provide one or more matching layers between antenna element  90 - 1  and housing wall  12 R. In some configurations of device  10 - 1 , it may be desirable to further improve the wireless communications link characteristics such as link quality, link directionality, etc. 
     In these scenarios and in other scenarios, the characteristics of housing wall  12 R may be altered to optimize the near-field wireless communication link established by antenna element  90 - 1  in device  10 - 1  (e.g., with antenna element  90 - 2  in device  10 - 2 ). In particular, a first portion of housing wall  12 R overlapping antenna element  90 - 1  may exhibit at least one different physical property than the second portion of housing wall  12 R surrounding the first portion. If desired, the second portion does not overlap antenna element  90 - 1 . The different physical properties may include different material properties (e.g., different dielectric constants), different dimensional properties (e.g., different thicknesses or generally different geometries), or other different physical properties. 
     As shown in  FIG.  9   , housing wall  12 R may include a planar portion of the housing having a first planar surface such as surface  140  and a second planar surface such as surface  142 . Surface  140  may face an exterior of device  10 - 1  and may sometimes be referred to as an exterior surface. While surface  140  faces the exterior of device  10 - 1 , other cosmetic layers and coating layers may cover surface  140 , if desired. Surface  142  may face an interior of device  10 - 1  and may sometimes be referred to as an interior surface. 
     In configurations described herein as illustrative examples, housing wall  12 R may be formed from a material such as zirconia, sapphire, or liquid crystal having a relatively high dielectric constant (e.g., a dielectric constant greater than 5, greater than 10, etc.). When antenna element  90 - 1  conveys radio-frequency signal (at frequencies greater than 10 GHz) through housing  12 R, the radio-frequency signals may exhibit significant signal reflection at the air-wall interface (e.g., at surfaces  142 ). 
     As shown in  FIG.  9   , housing wall  12 R may include a housing wall portion  144  overlapping antenna  90 - 1  that is formed from a material having a lower dielectric constant than the material forming the surrounding portion of housing wall  12 R. This may help reduce signal reflection and improve the quality of signal conveyance and consequently the quality near-field wireless communication link. As an illustrative example, housing wall portion  144  may be formed by filling a window cutout in housing wall  12 R with the lower dielectric constant material. The filled window cutout may be aligned with antenna element  90 - 1  and/or have a same outline as antenna element  90 - 1 , if desired. 
     The geometry of interior surface  142  of housing wall  12 R may be helpful to the antenna element  90 - 1  conveying electromagnetic waves (associated with the radio-frequency signals) through housing wall  12 R in an efficient manner. In some illustrative configurations (e.g., for a given thickness and material of housing wall  12 R), the planar interior surface of housing wall  12 R ( FIG.  9   ) may be optimal for signal conveyance.  FIGS.  10 A,  10 B,  11 A, and  11 B  are diagrams showing how housing wall  12 R may have a housing wall portion (overlapped by an antenna element) exhibiting different interior surface geometries. 
     As shown in  FIG.  10 A , housing wall  12 R may have a housing wall portion with a protrusion  148  along surface  142  that define a convex geometry for the interior surface portion aligned with antenna element  90 - 1 . In particular, protrusion  148  (surface  142 ) may protrude toward antenna element  90 - 1  and may be aligned with antenna element  90 - 1 . As shown in  FIG.  10 B , protrusion  148  may have a circular outline or be a dome-shaped protrusion. In other words, the portion of housing wall  12 R having protrusion  148  may have a greater thickness at all points than the surrounding portion of housing wall  12 R. 
     As shown in  FIG.  11 A , housing wall  12 R may have a housing wall portion with a recess  150  along surface  142  that define a concave geometry for the interior surface portion aligned with antenna element  90 - 1 . In particular, recess  150  (surface  142 ) may recede away from antenna element  90 - 1  and may be aligned with antenna element  90 - 1 . As shown in  FIG.  10 B , recess  150  may have a circular outline or be a dome-shaped recess. In other words, the portion of housing wall  12 R having recess  150  may have a smaller thickness at all points than the surrounding portion of housing wall  12 R. 
     Configured in the manner as described in connection with  FIGS.  9 - 11   , the interior surface  142  of housing wall  12  may be configured to exhibit different geometries that define different thicknesses at the portion of housing wall  12  overlapping antenna element  90 - 1 , thereby allowing the electromagnetic waves to focus and maximizing the communication range of antenna element  90 - 1  (e.g., with antenna element  90 - 2 ). In other words, the different interior surfaces  142  may provide a lensing effect for antenna element  90 - 1 . By only modifying the geometry of the interior surface, the exterior surface may still exhibit any desired geometry (e.g., a planar surface) to provide seamless exterior surface for device  10 - 1 . 
       FIG.  12    is a perspective view of an illustrative corner region of housing wall  12 R (e.g., at a corner region of device  10 - 1 ). As shown in  FIG.  12   , housing wall  12 R may have a ledge portion such as ledge  164  that is raised from a lower surface  162  of housing wall  12 R. Lower surface  162  may form a portion of an interior surface of housing wall  12 R. Ledge  164  may be a portion of housing wall  12 R that is coupled (e.g., attached) to sidewalls  12 W. Ledge  164  may run along at least two peripheral sides of device  10 - 1  as shown in  FIG.  12   . If desired, ledge  164  may run along all four peripheral sides of device  10 - 1  (e.g., around the periphery of device  10 - 1 ). As shown in  FIG.  12   , the two portions of ledge  164  running along the two peripheral sides of device  10 - 1  may be joined at a corner of housing wall  12 R. 
     In the example of  FIG.  12   , an opening  160  (sometimes referred to as a depression or cavity) may be formed from a depression in ledge  164  along one of the peripheral sides of device  10 - 1 . In one illustrative configuration, antenna element  90 - 1  may be mounted to ledge  164  of housing wall  12 - 1  and may overlap opening  160 . Configured in this manner, antenna element  90 - 1  may be configured to convey radio-frequency signals through opening  160  and a portion of housing wall  12 R. 
     Opening  160  may have peripheral sides (boundaries) defined by surfaces  166 ,  168 , and  170  of ledge  164 . While opening  160  is shown to be fully enclosed on three sides by surfaces  166 ,  168 , and  170 , this is merely illustrative. If desired, opening  160  through which antenna element  90 - 1  conveys radio-frequency signals may extend away from ledge  164  and surfaces  168  and  170  may only partly define the peripheral boundaries of opening  160 . 
     In the example of  FIG.  12   , cavity  160  is shown to extend from the top surface of ledge  164  to a bottom surface  142  that is coplanar with surface  162 . However, this is merely illustrative. If desired, bottom surface  142  of cavity  160  may still be raised relative to surface  162 . If desired, the depth of cavity  160  (e.g., the position of bottom surface  142 ) and the width and length of depression  160  (e.g., the position of surfaces  166 ,  168 , and  170 ) may configured to allow for wave formation within opening  132  by antenna element  90 . 
     As an illustrative example, the various interior surface geometries (e.g., planar, convex, concave) of the interior surface of housing wall  12 R (as described in connection with  FIGS.  9 - 11   ) may be implemented at interior surface  142  in cavity  160 . The dimensions (e.g., depth) of cavity  160  combined with the geometry of surface  142  in  FIG.  12    may configured to focus the electromagnetic waves or radio-frequency signals. If desired, cavity  160  may be omitted, and/or the various interior surface geometries of the interior surface of housing wall  12 R may be implemented at interior surface  162  away from ledge  164 . 
     In particular, opening  160  may be formed at a corner region of ledge  164 . This may allow antenna element  90 - 1  may be placed near the corner of device  10 - 1  in order to avoid interference from other components within device  10 - 1  and to provide a compact implementation. 
     The configuration of  FIG.  12    is merely illustrative. While different portions of housing wall  12 R as shown to have planar surfaces, this is merely illustrative. If desired, one or more of these surfaces (e.g., surfaces  142 ,  162 ,  166 ,  168 ,  170 , etc.) may be curved surfaces. While opening  160  (and consequently antenna element  90 - 1 ) is shown to be formed in a corner region of ledge  164  in housing wall  12 R, opening  160  and antenna element  90  may instead be disposed in other suitable locations, if desired. 
       FIG.  13    is a cross-sectional view of a cavity region of housing wall  12 R aligned with antenna element  90 - 1  (e.g., the cavity region shown in  FIG.  12   ). As shown in  FIG.  13    and described as an illustrative configuration in connection with  FIG.  12   , opening  160  may have a bottom surface  142  raised relative to interior surface  162 . Distance  172  between interior surface  142  and exterior surface  140  may define the (housing wall) interface through which antenna element  90 - 1  conveys radio-frequency signals. As such, the thickness (as well as the dielectric constant) of the housing wall portion between surfaces  142  and  140  (along with any interposing dielectric matching layers) may be critical to and as such configured to reduce signal reflectance and/or to focus the electromagnetic waves, thereby enabling a satisfactory wireless communication link. 
     As examples, the housing wall portion between surfaces  140  and  142  may have a thickness between greater than 0.1 centimeters, greater than 0.25 centimeters, greater than 0.5 centimeters, greater than 1 centimeter, less than 1.5 centimeters, less than 2 centimeters, less than 3 centimeters, less than 5 centimeters, etc. These examples are merely illustrative (e.g., in an illustrative configuration where the housing wall portion is formed from zirconia, antenna element  90 - 1  is operating in a frequency band including 60 GHz, etc.). If desired, the thickness (as well as the material and shape) of the housing wall portion may be adjusted based on the frequency of operation, the surrounding (dielectric matching) layers, etc. As examples, surface  142  may be raised above surface  162  by different amounts, may be lowered to be a depression from surface  162 , may have lensing portions as such as those described in connection with  FIGS.  10  and  11   , may be overlapped by dielectric matching layers such as those described in connection with  FIG.  6   , etc. 
     While configurations in which antenna elements convey radio-frequency signals to form a near-field communication link across a rear housing wall are described in connection with  FIGS.  6 - 12   , these configurations are merely illustrative. If desired, similar structures as described in  FIGS.  6 - 12    such as dielectric matching structures, housing walls with varying interior surface geometries and with varying materials, etc., may also be implemented for other housing walls or housing structures (e.g., a dielectric sidewall, a display cover layer, etc.) or for any other suitable structures. 
     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: 20210907
Publication Date: 20240618
Grant Date: 20240618
Priority Date: 20210907
Inventors: CHEN, YUE
EFANOV, ANDREW A.
ARVIND, AVEE
AZZOUG, Larbi
NGUYEN, THUY
NOELLERT, WILLIAM J.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/0407", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/422", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/422", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q19/062", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q19/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0407", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/421", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/70", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/421", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/422", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0407", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/70", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 85386594