PATENT DOCUMENT

Publication Number: US-12206163-B2
Application Number: US-202217865241-A
Country: US
Kind Code: B2

Title: Electronic devices having antennas that radiate through three-dimensionally curved cover layers

Abstract:
An electronic device may have a cover layer and an antenna. A dielectric adapter may have a first surface coupled to the antenna and a second surface pressed against the cover layer. The cover layer may have a three-dimensional curvature. The second surface may have a curvature that matches the curvature of the cover layer. Biasing structures may exert a biasing force that presses the antenna against the dielectric adapter and that presses the dielectric adapter against the cover layer. The biasing force may be oriented in a direction normal to the cover layer at each point across dielectric adapter. This may serve to ensure that a uniform and reliable impedance transition is provided between the antenna and free space through the cover layer over time, thereby maximizing the efficiency of the antenna.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a cover layer having a first three-dimensionally curved surface; 
 a first dielectric having a second three-dimensionally curved surface; 
 an antenna comprising an antenna resonating element and an antenna ground, wherein the antenna resonating element is configured to radiate through the cover layer and the first dielectric, the antenna resonating element comprising first, second, and third arms configured to radiate in different first, second, and third frequency bands, respectively; 
 a second dielectric having a first surface oriented in a first direction and a second surface oriented in a second direction different than the first direction, wherein the antenna resonating element is disposed on the first surface of the second dielectric and at least some of the antenna ground is disposed on the second surface of the second dielectric; 
 a third dielectric configured to press the second dielectric against the first dielectric; and 
 an alignment hole that extends through the third dielectric. 
 
     
     
       2. The electronic device of  claim 1 , wherein the second three-dimensionally curved surface extends parallel to the first three-dimensionally curved surface. 
     
     
       3. The electronic device of  claim 1 , wherein the cover layer comprises glass and the first dielectric comprises plastic. 
     
     
       4. The electronic device of  claim 1 , wherein the first three-dimensionally curved surface is aspherically curved. 
     
     
       5. The electronic device of  claim 1 , wherein the antenna ground is shorted to a system ground using a conductive fastening structure. 
     
     
       6. The electronic device of  claim 1 , wherein the first arm forms a loop-shaped path and has first and second portions, the second arm has third and fourth portions, the third arm has a fifth portion, the third portion is parallel to the first portion, and the fifth portion is parallel to the fourth and second portions. 
     
     
       7. An electronic device comprising:
 a housing comprising a three-dimensionally curved cover layer; 
 a first dielectric, having a first surface facing the three-dimensionally curved cover layer and a second surface opposite the first surface; 
 an antenna configured to radiate through the three-dimensionally curved cover layer and the first dielectric; 
 a substrate, wherein the antenna is disposed on a portion of a surface of the substrate; 
 a biasing structure, wherein the substrate is adhered to the biasing structure and the biasing structure is mounted to a portion of the housing; and 
 an alignment hole that extends through the substrate and the biasing structure. 
 
     
     
       8. The electronic device of  claim 7 , wherein the first surface is three-dimensionally curved. 
     
     
       9. The electronic device of  claim 8 , wherein the second surface is planar. 
     
     
       10. The electronic device of  claim 8 , wherein the second surface is curved about a single axis. 
     
     
       11. The electronic device of  claim 8 , wherein the second surface is three-dimensionally curved. 
     
     
       12. The electronic device of  claim 8 , wherein the first surface extends parallel to the three-dimensionally curved cover layer. 
     
     
       13. The electronic device of  claim 7 , wherein the portion of the surface of the substrate is a curved portion. 
     
     
       14. The electronic device of  claim 13 , wherein the substrate comprises a flexible printed circuit and the antenna comprises a conductive trace on the flexible printed circuit. 
     
     
       15. The electronic device of  claim 7 , wherein the three-dimensionally curved cover layer comprises glass. 
     
     
       16. The electronic device of  claim 7 , wherein the biasing structure exerts a uniform biasing force across an entire lateral area of the antenna. 
     
     
       17. An electronic device comprising:
 a glass cover layer that has a first non-zero curvature about a first axis and a second non-zero curvature about a second axis oriented non-parallel with respect to the first axis; 
 a dielectric layer pressed against the glass cover layer; 
 an antenna comprising an antenna resonating element, wherein the antenna is pressed against the dielectric layer and is configured to radiate through the glass cover layer and the dielectric layer; 
 a biasing structure, wherein the biasing structure exerts a biasing force against the antenna, a first interface between the glass cover layer and the dielectric layer is free of adhesive, and a second interface between the dielectric layer and the antenna resonating element is free of adhesive; and 
 an alignment hole that extends through the biasing structure. 
 
     
     
       18. The electronic device of  claim 17 , wherein the antenna comprises a conductive trace on a flexible printed circuit. 
     
     
       19. The electronic device of  claim 17 , wherein the glass cover layer has a surface, the surface has the first non-zero curvature about the first axis and the second non-zero curvature about the second axis, the second non-zero curvature is different than the first non-zero curvature, the antenna resonating element is formed on a substrate, and the first and second axes are parallel to a bottom surface of the substrate.

Description:
This application is a continuation of U.S. patent application Ser. No. 17/008,862, filed Sep. 1, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates to electronic devices, and more particularly, to electronic devices with wireless communications circuitry. 
     Electronic devices are often provided with wireless communications capabilities. An electronic device with wireless communications capabilities has wireless communications circuitry with one or more antennas. Wireless transceiver circuitry in the wireless communications circuitry uses the antennas to transmit and receive radio-frequency signals. 
     It can be challenging to form a satisfactory antenna for an electronic device. If care is not taken, differential impedance loading across the antenna may cause the antenna to exhibit unsatisfactory wireless performance. 
     SUMMARY 
     An electronic device may include a housing and wireless circuitry. The housing may include a three-dimensionally curved dielectric cover layer. The wireless circuitry may include an antenna. The antenna may include an antenna ground and an antenna resonating element on an antenna carrier. A dielectric adapter may be mounted to the antenna carrier overlapping the antenna resonating element. The antenna may radiate through the dielectric adapter and the three-dimensionally curved dielectric cover layer. 
     The dielectric adapter may have a first surface coupled to the antenna resonating element. The first surface may be planar or may be curved about a single axis. The dielectric adapter may have an opposing second surface that is pressed flush against an interior surface of the three-dimensionally curved dielectric cover layer. The second surface may be a three-dimensionally curved surface. The second surface may have a three-dimensional curvature that matches the three-dimensional curvature of the three-dimensionally curved dielectric cover layer. 
     The antenna carrier may include biasing structures. The biasing structures may include first and second rigid substrates and a foam member interposed between the first and second rigid substrates. The biasing structures may exert a biasing force that presses the antenna resonating element against the dielectric adapter and that presses the dielectric adapter against the three-dimensionally curved dielectric cover layer. The dielectric adapter may transfer the biasing force to the three-dimensionally curved dielectric cover layer. The biasing force may be oriented in a direction normal to the three-dimensionally curved dielectric cover layer at each point across dielectric adapter. This may serve to ensure that a uniform and reliable impedance transition is provided between the antenna and free space over time, thereby maximizing the efficiency of the antenna. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an illustrative electronic device having an antenna in accordance with some embodiments. 
         FIG.  2    is a top view of an illustrative antenna in accordance with some embodiments. 
         FIG.  3    is a cross-sectional side view of an illustrative electronic device having a three-dimensionally curved cover layer and an antenna mounted behind the three-dimensionally curved cover layer in accordance with some embodiments. 
         FIG.  4    is a perspective view of an illustrative dielectric adapter for providing a smooth impedance transition between an antenna on a planar substrate and a three-dimensionally curved cover layer in accordance with some embodiments. 
         FIG.  5    is a perspective view of an illustrative dielectric adapter for providing a smooth impedance transition between an antenna on a curved substrate and a three-dimensionally curved cover layer in accordance with some embodiments. 
         FIG.  6    is a perspective view showing how illustrative biasing structures may press an antenna and a dielectric adapter against a three-dimensionally curved cover layer to provide a smooth impedance transition between the antenna and the three-dimensionally curved cover layer in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG.  1    may be provided with wireless circuitry. The wireless circuitry may include antennas. Electronic device  10  may 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, goggles, or other equipment worn on a user&#39;s head such as a head mounted (display) device, or other types of wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, a gaming controller, a remote control device, a peripheral 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 wireless base station or access point, equipment that implements the functionality of two or more of these devices, or other electronic equipment. 
     As shown in  FIG.  1   , device  10  may include control circuitry  12 . Control circuitry  12  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. 
     Control circuitry  12  may include processing circuitry such as processing circuitry  14 . Processing circuitry  14  may be used to control the operation of device  10 . Processing circuitry  14  may include on 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  12  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  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, data, instructions, or code. Software code stored on storage circuitry  16  may be executed by processing circuitry  14 . 
     Control circuitry  12  may be used to run software on device  10  such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, control circuitry  12  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  12  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, 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), etc. Each communication 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  18 . Input-output circuitry  18  may include input-output devices  20 . Input-output devices  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. Input-output devices  20  may include user interface devices, data port devices, and other input-output components. For example, input-output devices  20  may include touch sensors, displays (e.g., touch-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), 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  using wired or wireless connections (e.g., some of input-output devices  20  may be peripherals that are coupled to a main processing unit or other portion of device  10  via a wired or wireless link). 
     Input-output circuitry  18  may include wireless circuitry  22  to support wireless communications. Wireless circuitry  22  may include radio-frequency (RF) transceiver circuitry  24  formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas such as antenna  40 , transmission lines such as transmission line  26 , and other circuitry for handling wireless RF signals. Wireless signals can also be sent using light (e.g., using infrared communications). While control circuitry  12  is shown separately from wireless circuitry  22  in the example of  FIG.  1    for the sake of clarity, wireless circuitry  22  may include processing circuitry that forms a part of processing circuitry  14  and/or storage circuitry that forms a part of storage circuitry  16  of control circuitry  12  (e.g., portions of control circuitry  12  may be implemented on wireless circuitry  22 ). As an example, control circuitry  12  (e.g., processing circuitry  14 ) may include baseband processor circuitry or other control components that form a part of wireless circuitry  22 . 
     Transceiver circuitry  24  may include transceiver circuitry for handling transmission and/or reception of radio-frequency signals in various radio-frequency communications bands. For example, transceiver circuitry  24  may handle wireless local area network (WLAN) communications bands such as the 2.4 GHz and 5 GHz Wi-Fi® (IEEE 802.11) communications bands, wireless personal area network (WPAN) communications bands such as the 2.4 GHz Bluetooth® communications band, cellular telephone communications bands such as a cellular low band (LB) (e.g., 600 to 960 MHz), a cellular low-midband (LMB) (e.g., 1400 to 1550 MHz), a cellular midband (MB) (e.g., from 1700 to 2200 MHz), a cellular high band (HB) (e.g., from 2300 to 2700 MHz), a cellular ultra-high band (UHB) (e.g., from 3300 to 5000 MHz, or other cellular communications bands between about 600 MHz and about 5000 MHz or higher (e.g., 3G bands, 4G LTE bands, 5G New Radio Frequency Range 1 (FR1) bands below 10 GHz, 5G New Radio Frequency Range 2 (FR2) bands at millimeter and centimeter wavelengths between 20 and 60 GHz, etc.), a near-field communications (NFC) band (e.g., at 13.56 MHz), satellite navigations bands (e.g., an L1 global positioning system (GPS) band at 1575 MHz, an L5 GPS band at 1176 MHz, a Global Navigation Satellite System (GLONASS) band, a BeiDou Navigation Satellite System (BDS) band, etc.), an ultra-wideband (UWB) communications band supported by the IEEE 802.15.4 protocol and/or other UWB communications protocols (e.g., a first UWB communications band at 6.5 GHz and/or a second UWB communications band at 8.0 GHz), Industry, Science, and Medical (ISM) bands, unlicensed communications bands around 6 GHz such as a communications band that includes frequencies from about 5.925 GHz to 7.125 GHz, other communications bands up to about 8-9 GHz, and/or any other desired communications bands. The communications bands handled by transceiver circuitry  24  may sometimes be referred to herein as frequency bands or simply as “bands,” and may span corresponding ranges of frequencies. 
     In scenarios where transceiver circuitry  24  includes UWB transceiver circuitry, the UWB transceiver circuitry may support 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 radio-frequency 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 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). The ultra-wideband transceiver circuitry may operate (i.e., convey radio-frequency signals) in frequency bands such as an ultra-wideband communications band between about 5 GHz and about 8.5 GHz (e.g., a 6.5 GHz UWB communications band, an 8 GHz UWB communications band, and/or at other suitable frequencies). 
     In general, transceiver circuitry  24  may cover (handle) any desired frequency bands of interest. Transceiver circuitry  24  may convey radio-frequency signals using antenna  40  (e.g., antenna  40  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  40  may transmit the radio-frequency signals by radiating the radio-frequency signals into free space (or to freespace through intervening device structures such as a dielectric cover layer). Antenna  40  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  40  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. 
     Antennas such as antenna  40  may be formed using any suitable antenna types. For example, antenna  40  may include a resonating element formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, monopole antenna structures, strip antenna structures, dipole antenna structures, hybrids of these designs, etc. Parasitic elements may be included in antennas  40  to adjust antenna performance. If desired, antenna  40  may be provided with a conductive cavity that backs the antenna resonating element of antenna  40  (e.g., antenna  40  may be a cavity-backed antenna). Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. In some configurations, different antennas may be used in handling different bands for radio-frequency transceiver circuitry  24 . Alternatively, a given antenna  40  may cover one or more bands. 
     As shown in  FIG.  1   , transceiver circuitry  24  may be coupled to antenna feed  32  of antenna  40  using transmission line  26 . Antenna feed  32  may include a positive antenna feed terminal such as positive antenna feed terminal  34  and may include a ground antenna feed terminal such as ground antenna feed terminal  36 . Transmission line  26  may be formed from metal traces on a printed circuit, cables, or other conductive structures. Transmission line  26  may have a positive transmission line signal path such as path  28  that is coupled to positive antenna feed terminal  34 . Transmission line  26  may have a ground transmission line signal path such as path  30  that is coupled to ground antenna feed terminal  36 . Path  28  may sometimes be referred to herein as signal conductor  28  and path  30  may sometimes be referred to herein as ground conductor  30 . 
     Transmission line paths such as transmission line  26  may be used to route antenna signals within device  10  (e.g., to convey radio-frequency signals between radio-frequency transceiver circuitry  24  and antenna feed  32  of antenna  40 ). Transmission lines in device  10  may include coaxial cables, microstrip transmission lines, stripline transmission lines, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, transmission lines formed from combinations of transmission lines of these types, etc. Transmission lines in device  10  such as transmission line  26  may be integrated into rigid and/or flexible printed circuit boards. In one suitable arrangement, transmission lines such as transmission line  26  may also include transmission line conductors (e.g., signal conductors  28  and ground conductors  30 ) integrated within multilayer laminated structures (e.g., layers of a conductive material such as copper and a dielectric material such as a resin that are laminated together without intervening adhesive). The multilayer laminated structures may, if desired, be folded or bent in multiple dimensions (e.g., two or three dimensions) and may maintain a bent or folded shape after bending (e.g., the multilayer laminated structures may be folded into a particular three-dimensional shape to route around other device components and may be rigid enough to hold its shape after folding without being held in place by stiffeners or other structures). All of the multiple layers of the laminated structures may be batch laminated together (e.g., in a single pressing process) without adhesive (e.g., as opposed to performing multiple pressing processes to laminate multiple layers together with adhesive). Filter circuitry, switching circuitry, impedance matching circuitry, and other circuitry may be interposed within the paths formed using transmission lines such as transmission line  26  and/or circuits such as these may be incorporated into antenna  40  (e.g., to support antenna tuning, to support operation in desired frequency bands, etc.). 
     Electronic device  10  may be provided with electronic device housing  38 . Housing  38 , 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. Housing  38  may be formed using a unibody configuration in which some or all of housing  38  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure covered with one or more outer housing layers). Configurations for housing  38  in which housing  38  includes support structures (a stand, leg(s), handles, frames, etc.) may also be used. In one suitable arrangement that is described herein as an example, housing  38  includes a three-dimensionally curved dielectric cover layer. Antenna  40  may transmit radio-frequency signals through the three-dimensionally curved dielectric cover layer and/or may receive radio-frequency signals through the three-dimensionally curved dielectric cover layer. 
     In practice, the number of frequency bands that are used to convey radio-frequency signals for device  10  tends to increase over time. In some scenarios, device  10  may include a different respective antenna  40  for handling each of these bands. However, increasing the number of antennas  40  in device  10  may consume an undesirable amount of space, power, and other resources in device  10 . If desired, a given antenna  40  in device  10  may handle communications in multiple frequency bands to optimize resource consumption within device  10 . In one suitable arrangement that is described herein as an example, a given antenna  40  in device  10  may be configured to handle WLAN frequency bands at 2.4 GHz and 5.0 GHz, unlicensed bands around 6 GHz (e.g., between 5.925 and 7.125 GHz), and/or UWB communications bands at 6.5 GHz and 8.0 GHz. However, it can be challenging to provide an antenna  40  with structures that exhibit sufficient bandwidth to cover each of these frequency bands (e.g., from below 2.4 GHz to above 9.0 GHz) with satisfactory antenna efficiency, particularly when the size of the antenna is constrained by the form factor of device  10 . 
       FIG.  2    is a diagram of an illustrative antenna  40  that may exhibit a sufficiently wide bandwidth so as to cover each of these frequency bands with satisfactory antenna efficiency. As shown in  FIG.  2   , antenna  40  may include an antenna resonating element such as antenna resonating element  46  and ground structures such as antenna ground  42 . Antenna resonating element  46  may sometimes be referred to herein as antenna radiating element  46  or antenna element  46 . Antenna ground  42  may sometimes be referred to herein as ground plane  42  or ground structures  42 . 
     Antenna resonating element  46  and antenna ground  42  may be formed from conductive traces patterned onto a lateral surface such as surface  45  of an underlying dielectric substrate such as dielectric antenna carrier  44  (sometimes referred to herein as antenna support structure  44  or dielectric support structure  44 ). Dielectric antenna carrier  44  may be formed from plastic, ceramic, foam, adhesive, combinations of these, or any other dielectric materials. If desired, antenna ground  42  and/or antenna resonating element  46  may be formed from conductive traces patterned onto a flexible printed circuit that is layered over surface  45  of dielectric antenna carrier  44 . Surface  45  may be planar or curved, may have planar and curved portions, or may have any other desired geometry. Examples in which surface  45  is curved are described herein as an example. Surface  45  may be curved if desired. 
     Antenna  40  may be fed using antenna feed  32 . Antenna feed  32  may be coupled between antenna resonating element  46  and antenna ground  42  (e.g., across gap  58  at surface  45  of dielectric antenna carrier  44 ). For example, antenna resonating element  46  may have a feed segment such as feed segment  72 . Feed segment  72  may extend along a corresponding longitudinal axis (e.g., a longitudinal axis oriented parallel to the X-axis of  FIG.  2   ) and may be separated from antenna ground  42  by gap  58 . Positive antenna feed terminal  34  of antenna feed  32  may be coupled to feed segment  72  whereas ground antenna feed terminal  36  is coupled to antenna ground  42  (e.g., at opposing sides of gap  58 ). 
     Antenna resonating element  46  may have multiple arms or branches. In the example of  FIG.  2   , antenna resonating element  46  includes a first arm (branch)  52  extending from feed segment  72 , a second arm (branch)  50  extending from first arm  52 , and a third arm  48  extending from feed segment  72 . Arms  52 ,  50 , and  48  may sometimes be referred to herein as antenna resonating element arms or antenna arms. 
     As shown in  FIG.  2   , first arm  52  may have a first segment  74  extending from an end of feed segment  72  (e.g., first segment  74  may have a first end at the end of feed segment  72  that is opposite to antenna feed  32 ). First segment  74  may extend at a non-parallel angle (e.g., a perpendicular angle) with respect to feed segment  72  (e.g., the longitudinal axis of first segment  74  may extend parallel to the Y-axis of  FIG.  2    and perpendicular to the longitudinal axis of feed segment  72 ). First arm  52  may have a second segment  76  extending from an end of first segment  74  (e.g., first segment  74  may have a second end opposite feed segment  72 , and second segment  76  may have a first end at the second end of first segment  74 ). Second segment  76  may extend at a non-parallel angle (e.g., a perpendicular angle) with respect to first segment  74  (e.g., the longitudinal axis of second segment  76  may extend parallel to the X-axis and feed segment  72  and may extend perpendicular to the longitudinal axis of first segment  74  of  FIG.  2   ). 
     First arm  52  may also have a third segment  78  extending from an end of second segment  76  (e.g., second segment  76  may have a second end opposite first segment  74 , and third segment  78  may have a first end at the second end of second segment  76 ). Third segment  78  may extend at a non-parallel angle (e.g., a perpendicular angle) with respect to second segment  76  (e.g., the longitudinal axis of third segment  78  may extend parallel to the Y-axis and the longitudinal axis of first segment  74  of  FIG.  2   ). Third segment  78  may have a second end opposite second segment  76 . The second end of third segment  78  may be coupled to antenna ground  42  (e.g., at a grounding location). This may configure first arm  52  to form a loop-shaped path  56  (with feed segment  72  and antenna ground  42 ) for antenna currents flowing between positive antenna feed terminal  34  and ground antenna feed terminal  36 . Loop-shaped path  56  (sometimes referred to herein as loop path  56 ) may run around central opening  77  at surface  45  of dielectric antenna carrier  44 . 
     Second arm  50  may have a first segment  80  extending from the second end of segment  74  of first arm  52  and extending from the first end of segment  76  of first arm  52  (e.g., first segment  80  of second arm  50  may have a first end at the ends of segments  74  and  76  of first arm  52 ). First segment  80  of second arm  50  may extend parallel to segment  76  of first arm  52  (e.g., first segment  80  of second arm  50  may extend along a longitudinal axis oriented parallel to the longitudinal axis of segment  76  of first arm  52 ). Second arm  50  may have a second segment  82  extending from an end of first segment  80  to tip  84  of second arm  50  (e.g., first segment  80  may have a second end at second segment  82  of second arm  50 ). Second segment  82  of second arm  50  may extend at a non-parallel angle with respect to first segment  80  of second arm  50  (e.g., along a longitudinal axis parallel to the Y-axis). First segment  80  of second arm  50  may be separated from segment  76  of first arm  52  (e.g., along the entire length of first segment  80 ) by gap  64 . Second segment  82  of second arm  50  may also be separated from segment  78  of first arm  52  by gap  64  if desired. Gap  64  may form a distributed capacitance along the length of first segment  80  of second arm  50  (e.g., a distributed capacitance between segment  80  of second arm  50  and segment  76  of first arm  52 ). The distributed capacitance formed by gap  64  may be used to tune the frequency response of first arm  52  and/or second arm  50 . 
     Third arm  48  may have a first segment  68  extending from feed segment  72  (e.g., first segment  68  of third arm  48  may have a first end at feed segment  72 ). First segment  68  of third arm  48  may extend at a non-parallel angle (e.g., a perpendicular angle) with respect to feed segment  72  (e.g., the longitudinal axis of first segment  68  of third arm  48  may be oriented parallel to the longitudinal axes of segments  74  and  78  of first arm  52  and segment  82  of second arm  50 ). Third arm  48  may also have a second segment  70  extending from a second end of first segment  68  to tip  66  of third arm  48 . Second segment  70  of third arm  48  may extend at a non-parallel angle (e.g., a perpendicular angle) with respect to first segment  68  (e.g., second segment  70  may extend along a longitudinal axis oriented parallel to the longitudinal axes of feed segment  72 , segment  76  of first arm  52 , and segment  80  of second arm  50 ). In other words, third arm  48  may be an L-shaped strip (e.g., an L-shaped arm) extending from feed segment  72 . A portion of second segment  70  of third arm  48  (e.g., at tip  66 ) may be separated from second arm  50  by gap  62 . 
     During signal transmission, antenna feed  32  receives radio-frequency signals from transceiver circuitry  24  of  FIG.  1   . Corresponding (radio-frequency) antenna currents may flow on antenna resonating element  46  and antenna ground  42 . The antenna currents may radiate the radio-frequency signals (e.g., as wireless signals) that are transmitted into free space. During signal reception, antenna resonating element  46  may receive (wireless) radio-frequency signals from free space. Corresponding antenna currents are then produced on antenna resonating element  46 . The radio-frequency signals corresponding to the antenna currents are then transmitted to transceiver circuitry  24  ( FIG.  1   ) via antenna feed  32 . 
     The lengths of first arm  52 , second arm  50 , third arm  48 , and/or feed segment  72  may be selected so that antenna  40  operates in (handles) desired frequency bands of interest. For example, the length of antenna  40  from positive antenna feed terminal  34  to ground antenna feed terminal  36  through feed segment  72 , segments  74 ,  76 , and  78  of first arm  52 , and antenna ground  42  (e.g., the length of loop path  56 ) may be selected to configure antenna resonating element  46  to resonate in a first frequency band. The length of loop path  56  may, for example, be approximately equal to (e.g., within 15% of) one-half of the effective wavelength corresponding to a frequency in the first frequency band. The effective wavelength is equal to a free space wavelength multiplied by a constant value that is determined based on the dielectric constant of dielectric antenna carrier  44 . The first frequency band may, for example, include frequencies between about 5.0 GHz and 6.0 GHz (e.g., for conveying signals in a 5.0 GHz wireless local area network band and/or unlicensed frequencies within the first frequency band). The first frequency band may sometimes be referred to herein as the midband of antenna  40 . 
     During signal transmission, antenna currents in the first frequency band may flow along loop path  56  (e.g., along the perimeter of the conductive structures forming loop path  56 ). Loop path  56  may radiate corresponding (wireless) radio-frequency signals in the first frequency band. Similarly, during signal reception, radio-frequency signals received from free space in the first frequency band may cause antenna currents in the first frequency band to flow along loop path  56 . In this way, feed segment  72 , segments  74 ,  76 , and  78  of first arm  52 , and the portion of antenna ground  42  extending from segment  78  to ground antenna feed terminal  36  may form a loop antenna resonating element for antenna  40  (e.g., first arm  52  may form part of the loop antenna resonating element). If desired, gap  64  may introduce a (distributed) capacitance to loop path  56  that serves to tune the frequency response of loop path  56  in the first frequency band. Increasing the width of gap  64  may decrease this capacitance whereas decreasing the width of gap  64  may increase the capacitance. Gap  64  may, for example, have a width of 0.01-0.10 mm (e.g., approximately 0.05 mm), 0.01-0.50 mm, greater than 0.50 mm, etc. 
     At the same time, the length of antenna resonating element  46  from positive antenna feed terminal  34  to tip  84  of second arm  50  through feed segment  72 , segment  74  of first arm  52 , and segments  80  and  82  of second arm  50  (e.g., the length of path  60 ) may be selected to configure antenna resonating element  46  to resonate in a second frequency band. The length of path  60  may, for example, be approximately equal to (e.g., within 15% of) one-quarter of the effective wavelength corresponding to a frequency in the second frequency band. The second frequency band may, for example, include frequencies below 2.5 GHz (e.g., for conveying signals in a 2.4 GHz wireless local area network band). The second frequency band may sometimes be referred to herein as the low band of antenna  40 . 
     During signal transmission, antenna currents in the second frequency band may flow along path  60  between positive antenna feed terminal  34  and tip  84  (e.g., along the perimeter of the conductive structures forming path  60  of antenna resonating element  46 ). Path  60  may radiate corresponding (wireless) radio-frequency signals in the second frequency band. Similarly, during signal reception, radio-frequency signals received from free space in the second frequency band may cause antenna currents in the second frequency band to flow along path  60 . Segments  76  and  78  of first arm  52  may form a return path to antenna ground  42  for the antenna currents in the second frequency band (e.g., portions of first arm  52  may form a return path to ground for second arm  50  in the second frequency band while concurrently resonating in the first frequency band with the remainder of loop path  56 ). In this way, second arm  50  and first arm  52  may collectively form an inverted-F antenna resonating element in the second frequency band for antenna  40  (e.g., first arm  52  may form both part of a loop antenna resonating element in the first frequency band and part of an inverted-F antenna resonating element in the second frequency band). If desired, gap  64  may introduce a (distributed) capacitance to second arm  50  that serves to tune the frequency response of path  60  in the second frequency band. 
     In addition, the length of third arm  48  (e.g., path  54 ) may be selected to configure antenna resonating element  46  to resonate in a third frequency band. The length of third arm  48  (e.g., path  54 ) may, for example, be approximately equal to (e.g., within 15% of) one-quarter of the effective wavelength corresponding to a frequency in the third frequency band. The third frequency band may, for example, include frequencies between about 5.0 GHz and 9.0 GHz (e.g., for conveying signals in a 5.0 GHz wireless local area network band, for conveying signals in an unlicensed band such as a frequency band between 5.925 and 7.125 GHz, for conveying signals in a 6.5 GHz UWB communications band, and/or for conveying signals in an 8.0 GHz UWB communications band). The third frequency band may sometimes be referred to herein as the high band of antenna  40 . Third arm  48  may sometimes be referred to herein as the high band arm of antenna  40 . Second arm  50  may sometimes be referred to herein as the low band arm of antenna  40 . First arm  52  may sometimes be referred to herein as the midband arm of antenna  40 . 
     During signal transmission, antenna currents in the third frequency band may flow along path  54  between positive antenna feed terminal  34  and tip  66  (e.g., along the perimeter of the conductive structures forming third arm  48 ). Third arm  48  (e.g., path  54 ) may radiate corresponding (wireless) radio-frequency signals in the third frequency band. Similarly, during signal reception, radio-frequency signals received from free space in the third frequency band may cause antenna currents in the third frequency band to flow along path  54 . In this way, third arm  48  may form a monopole antenna resonating element (e.g., an L-shaped antenna resonating element) in the third frequency band for antenna  40 . If desired, gap  62  may introduce a capacitance to third arm  48  that serves to tune the frequency response of third arm  48  and/or that serves to perform impedance matching for third arm  48  in the third frequency band. 
     When configured in this way, antenna  40  may convey (e.g., transmit and/or receive) radio-frequency signals in each of the first, second, and third frequency bands with satisfactory antenna efficiency. Antenna  40  may, for example, exhibit a wideband response and may exhibit satisfactory antenna efficiency from the lower limit of the second frequency band to the upper limit of the third frequency band (e.g., from below 2.4 GHz to over 9.0 GHz). 
     The example of  FIG.  2    is merely illustrative. In another suitable arrangement, feed segment  72  may be omitted and third arm  48  may extend from antenna ground  42  (e.g., to the left of antenna feed  32  and feed segment  72 ). In yet another suitable arrangement, third arm  48  may be coupled to antenna ground  42  and may be located within central opening  77  of first arm  52 . In general, antenna  40  may have any desired antenna resonating element structures having any desired shape for covering any desired frequencies. 
       FIG.  3    is a cross-sectional side view (e.g., as taken in the direction of arrow  86  of  FIG.  2   ) showing how antenna  40  may be integrated into device  10 . As shown in  FIG.  3   , dielectric antenna carrier  44  may have a curved surface such as surface  45  and at least one additional surface such as bottom surface  100 . Antenna resonating element  46  may be formed from conductive traces patterned directly onto surface  45  of dielectric antenna carrier  44 . Antenna ground  42  may be formed from conductive traces patterned directly onto surface  45  and bottom surface  100  of dielectric antenna carrier  44 . The conductive traces of antenna ground  42  and antenna resonating element  46  may be patterned onto dielectric antenna carrier  44  using a Laser Direct Structuring (LDS) process if desired (e.g., dielectric antenna carrier  44  may be formed from an LDS plastic material). In another suitable arrangement, antenna ground  42  and antenna resonating element  46  may be patterned onto a flexible printed circuit that is layered onto surface  45  of dielectric antenna carrier  44 . 
     Antenna ground  42  and dielectric antenna carrier  44  may include a hole or opening such as hole  102 . A fastening structure such as screw  98  may extend through hole  102  to secure antenna ground  42  and dielectric antenna carrier  44  to other device components such as system ground  104 . Screw  98  may be a conductive screw that serves to short antenna ground  42  to system ground  104  (e.g., system ground  104  may form part of the ground plane for antenna  40 ). Screw  98  may be replaced by any desired conductive fastening structures such as a conductive clip, a conductive spring, a conductive pin, a conductive bracket, conductive adhesive, welds, solder, combinations of these, etc. 
     Device  10  may include a cover layer such as dielectric cover layer  92 . Dielectric cover layer  92  may form part of housing  38  of  FIG.  1    for device  10 . Dielectric cover layer  92  may have an interior surface  94  at the interior of device  10  (e.g., facing dielectric antenna carrier  44 ) and may have an opposing exterior surface  96  at the exterior of device  10 . Interior surface  94  and/or exterior surface  96  may be curved surfaces. Exterior surface  96  may extend parallel to interior surface  94  if desired (e.g., exterior surface  96  and interior surface  94  may have the same curvature). Dielectric cover layer  92  may be formed from any desired dielectric materials such as plastic, ceramic, rubber, glass, wood, fabric, sapphire, combinations of these or other materials, etc. 
     Dielectric antenna carrier  44  may be mounted within device  10  such that surface  45  faces dielectric cover layer  92 . Antenna resonating element  46  may be separated from interior surface  94  of dielectric cover layer  92  or may be pressed against interior surface  94 . Antenna  40  may convey radio-frequency signals  90  through dielectric cover layer  92 . In the example of  FIG.  3   , surface  45  is illustrated as a curved surface. This is merely illustrative. If desired, surface  45  may be curved. 
     Dielectric cover layer  92  may have any desired curvature. In one suitable arrangement, dielectric cover layer  92  is curved about (around) a single axis such as axis  106  (e.g., as shown in the cross-sectional side view of  FIG.  3   ). In this arrangement, dielectric cover layer  92  exhibits a cylindrical curvature (e.g., a bent or folded shape with one bend or fold). However, an arrangement in which dielectric cover layer  92  is three-dimensionally curved is described herein as an example. Dielectric cover layer  92  may therefore sometimes be referred to herein as three-dimensionally curved dielectric cover layer  92 . Three-dimensionally curved dielectric cover layer  92  may be curved about multiple axes such as at least axis  106  and axis  108 . Axes  106  and  108  may both run through the interior of device  10 . Axis  108  may be different from axis  106 . Axis  108  may extend at a nonparallel angle (e.g., an angle greater than 0 and less than 180 degrees) with respect to axis  106  (e.g., axis  108  may be non-parallel or perpendicular with respect to axis  106 ). Axes  108  and  106  may intersect at a point within the interior of device  10  or may be non-intersecting. 
     In other words, three-dimensionally curved dielectric cover layer  92  (e.g., interior surface  94  and/or exterior surface  96 ) may exhibit a non-zero curvature (e.g., a non-zero radius of curvature) about two or more non-parallel axes extending through the interior of device  10 , such as axes  106  and  108 . Two or more of the axes may be parallel if desired. The three-dimensional curve is non-cylindrical. Three-dimensionally curved dielectric cover layer  92  may exhibit the same curvature about axis  106  as about axis  108  or may exhibit more or less curvature about axis  106  than about axis  108 . As examples, three-dimensionally curved dielectric cover layer  92  may be spherically curved (e.g., interior surface  94  and/or exterior surface  96  may be spherical surfaces), aspherically curved (e.g., interior surface  94  and/or exterior surface  96  may be aspherical curved surfaces), freeform curved (e.g., interior surface  94  and/or exterior surface  96  may be freeform curved surfaces), etc. 
     In general, it may be desirable to provide a uniform and smooth impedance transition from antenna resonating element  46  through three-dimensionally curved dielectric cover layer  92  and to free space across the entire lateral area of antenna resonating element  46 . This may serve to maximize antenna efficiency for antenna  40  by minimizing signal reflections as radio-frequency signals  90  pass through three-dimensionally curved dielectric cover layer  92 . However, in arrangements where the dielectric cover layer is three-dimensionally curved, it can be particularly difficult to ensure that there is a uniform and smooth impedance transition across the entire lateral area of antenna resonating element  46 . In addition, if care is not taken, mechanical impacts and wear on device  10  over time can introduce non-uniform impedance discontinuities over portions of antenna resonating element  46 . 
     If desired, device  10  may include a dielectric adapter for providing a uniform and smooth impedance transition through three-dimensionally curved dielectric cover layer  92  across the entire lateral area of antenna resonating element  46 . Antenna resonating element  46  may be pressed against three-dimensionally curved dielectric cover layer  92  through the dielectric adapter.  FIG.  4    is a perspective view of an illustrative dielectric adaptor for antenna  40 . 
     As shown in  FIG.  4   , device  10  may include a dielectric adapter such as dielectric adapter  110 . Dielectric adapter  110  (shown in transparency in the example of  FIG.  4   ) may be mounted in device  10  over antenna resonating element  46  (e.g., dielectric adapter  110  may overlap antenna resonating element  46 ). Dielectric adapter  110  may have a first surface  114  and an opposing second surface  112 . Surface  114  may be pressed against antenna resonating element  46 . Surface  112  may be pressed against interior surface  94  of three-dimensionally curved dielectric cover layer  92  ( FIG.  3   ). Dielectric adapter  110  may sometimes be referred to herein as dielectric impedance adapter  110 , dielectric transformer  110 , or dielectric impedance transformer  110 . 
     Surface  112  of dielectric adapter  110  may be a three-dimensionally curved surface. The three-dimensional curvature of surface  112  may be selected to match (conform to) the three-dimensional curvature of three-dimensionally curved dielectric cover layer  92  ( FIG.  3   ) (e.g., surface  112  may extend parallel to interior surface  94  of three-dimensionally curved dielectric cover layer  92  across the entire lateral area of surface  112 ). For example, as shown in  FIG.  4   , surface  112  may be curved about axis  106  and may be curved about axis  108 . In other words, surface  112  may exhibit a non-zero curvature (e.g., radius of curvature) about two or more non-parallel axes extending through the interior of device  10 , such as axes  106  and  108 . As examples, surface  112  may be spherically curved (e.g., in arrangements where the dielectric cover layer is spherically curved), aspherically curved (e.g., in arrangements where the dielectric cover layer is aspherically curved), freeform curved (e.g., in arrangements where the dielectric cover layer is freeform curved), etc. 
     Surface  114  may be pressed flush against an entirety of antenna resonating element  46 . This may ensure that there is a smooth impedance transition (e.g., in each of the frequency bands handled by the antenna) between antenna resonating element  46  and dielectric adapter  110 . When dielectric adapter  110  is pressed against interior surface  94  of three-dimensionally curved dielectric cover layer  92  ( FIG.  3   ), all of surface  112  may be pressed flush against interior surface  94 . This may help to ensure that there is a smooth impedance transition between dielectric adapter  110  and the dielectric cover layer, thereby ensuring that there is a smooth impedance transition from the antenna through the dielectric cover layer and into free space. 
     In general, surface  114  may extend parallel to the surface on which antenna resonating element  46  is formed. In the example of  FIG.  4   , surface  114  is a planar surface. This may ensure that surface  114  is pressed flush against an entirety of antenna resonating element  46  in scenarios where antenna resonating element  46  is printed on a planar surface. In scenarios where antenna resonating element  46  is formed on a curved surface, surface  114  may also be curved. The curvature of surface  114  may be selected to match (conform to) the curvature of the surface on which antenna resonating element  46  is formed. This may ensure that surface  114  is pressed flush against an entirety of antenna resonating element  46  in scenarios where antenna resonating element  46  is printed on a curved surface. 
       FIG.  5    is a perspective view showing how surface  114  may be a curved surface. As shown in  FIG.  5   , surface  114  may be curved about a single axis such as axis  116  (surface  114  is not three-dimensionally curved in this example). In other words, surface  114  may exhibit a non-zero curvature (e.g., radius of curvature) about axis  116 . The curvature may match (conform to) the underlying curvature of the surface on which antenna resonating element  46  is formed. Axis  116  may extend at any desired angle (e.g., parallel to axis  106 , parallel to axis  108 , non-parallel with respect to axis  106  and/or axis  108 , an angle within a plane parallel to the plane that includes axes  106  and  108 , an angle within a plane that is non-parallel with respect to the plane that includes axes  106  and  108 , etc.). When configured in this way, surface  114  is bent or folded in a single direction, around axis  116  (e.g., with a cylindrical curvature). 
     In order to further ensure a reliable smooth impedance transition between antenna resonating element  46  and three-dimensionally curved dielectric cover layer  92 , dielectric antenna carrier  44  ( FIG.  3   ) may include biasing structures. The biasing structures may press antenna resonating element  46  and dielectric adapter  110  against the interior surface of three-dimensionally curved dielectric cover layer  92  with a uniform biasing force across the entire area overlapping the antenna.  FIG.  6    is a perspective view showing how biasing structures in dielectric antenna carrier  44  may press antenna resonating element  46  and dielectric adapter  110  against three-dimensionally curved dielectric cover layer  92 . 
     As shown in  FIG.  6   , dielectric antenna carrier  44  may include a first rigid substrate such as substrate  134  and a second rigid substrate such as substrate  130 . Substrates  130  and  134  may be formed from plastic, glass, ceramic, or any other desired rigid dielectric materials. Dielectric antenna carrier  44  may also include a compressible foam member such as foam member  132 . Foam member  132  may be interposed (e.g., layered) between substrates  130  and  134 . For example, foam member  132  may have a first (top) surface  126  that is pressed against (bottom) surface  124  of substrate  130 . Foam member  132  may also have a second (bottom) surface  128  that is pressed against substrate  134 . 
     Antenna resonating element  46  of antenna  40  may be formed from conductive traces patterned onto a substrate such as flexible printed circuit  118 . Antenna resonating element  46  may be patterned on top surface  114  of flexible printed circuit  118 . Flexible printed circuit  118  may be layered over (top) surface  122  of substrate  130  (e.g., bottom surface  120  of flexible printed circuit  118  may be coupled to surface  122  of substrate  130 ). In another suitable arrangement, flexible printed circuit  118  may be omitted and antenna resonating element  46  may be patterned directly onto substrate  130  (e.g., using an LDS process). Surface  122  of substrate  130  may form surface  45  of  FIGS.  2  and  3   , for example. 
     Dielectric adapter  110  may be mounted to surface  114  of flexible printed circuit  118  (or surface  122  of substrate  130  in scenarios where flexible printed circuit  118  is omitted and antenna resonating element  46  is patterned directly onto surface  122  of substrate  130 ). In other words, surface  114  of dielectric adapter  110  may be in coupled to (e.g., in direct contact with) antenna resonating element  46  and surface  114  of flexible printed circuit  118  (or surface  122  of substrate  130  in scenarios where flexible printed circuit  118  is omitted). Surface  112  of dielectric adapter  110  may be pressed against and in direct contact with interior surface  94  of three-dimensionally curved dielectric cover layer  92 . 
     Foam member  132  may be compressed between substrates  130  and  134  such that foam member  132  exerts an upwards biasing (compression) force against substrate  130 , as shown by arrows  140 . This biasing force may be uniform across the lateral area of antenna resonating element  46 , for example. The biasing force may transfer to three-dimensionally curved dielectric cover layer  92  through substrate  130 , flexible printed circuit  118 , and dielectric adapter  110 . In this way, dielectric antenna carrier  44  may include biasing structures for antenna  40  (e.g., substrates  130  and  134  and foam member  132  may collectively form biasing structures for antenna  40 ). Dielectric antenna carrier  44  may therefore sometimes be referred to herein as biasing structures  44 . 
     Because the three-dimensional curvature of surface  112  matches (conforms to) the three-dimensional curvature of interior surface  94 , the biasing force produced by foam member  132  may cause dielectric adapter  110  to transfer the biasing force to three-dimensionally curved dielectric cover layer  92  in a direction normal (perpendicular) to interior surface  94  at all points across the lateral area of surface  112 , as shown by arrows  142 . Ensuring that the biasing force is transferred in a direction normal to the lateral area of three-dimensionally curved dielectric cover layer  92  may ensure that antenna resonating element  46  remains separated from three-dimensionally curved dielectric cover layer  92  by the same distance over time, regardless of mechanical stress or impact events that occur on device  10 . This may in turn ensure that there is a smooth and uniform impedance transition over time between all of antenna resonating element  46  and free space through three-dimensionally curved dielectric cover layer  92  and dielectric adapter  110 , thereby minimizing impedance discontinuities and signal reflections and maximizing the antenna efficiency for device  10  over time. 
     In the example of  FIG.  6   , surface  114  of dielectric adapter  110  is planar. This is merely illustrative. In another suitable arrangement, surface  114  may be curved (e.g., about a single axis such as axis  116  as shown in  FIG.  5   ). In these scenarios, surface  122  of substrate  130  may have a curvature that matches (conforms to) the curvature of surface  114 . Curving surfaces  114  and  122  about a single axis (e.g., axis  116  of  FIG.  5   ) may allow flexible printed circuit  118  to be curved around the same axis. This is merely illustrative and, in another suitable arrangement, surfaces  114  and  122  may be three-dimensionally curved. In these scenarios, flexible printed circuit  118  may be omitted and antenna resonating element  46  may be patterned directly onto surface  122  of substrate  130  (e.g., because flexible printed circuit  118  may be unable to accommodate such three-dimensional curvature). If desired, foam member  132 , substrate  130 , and/or substrate  134  may be partially or completely replaced by springs, pins, and/or any other desired biasing structures that exert the biasing force associated with arrows  140  against antenna  40  and dielectric adapter  110 . 
     If desired, the materials used to form dielectric adapter  110  may be selected so that dielectric adapter  110  exhibits a desired dielectric constant. The dielectric constant may be selected to help form a smooth impedance transition between antenna  40  and free space through three-dimensionally curved dielectric cover layer  92 . For example, the dielectric constant of dielectric adapter  110  may be selected to be between the dielectric constant of three-dimensionally curved dielectric cover layer  92  and the dielectric constant of flexible printed circuit  118  and/or substrate  130 . If desired, dielectric adapter  110  may have a gradient dielectric constant from surface  114  to surface  112  (e.g., in scenarios where dielectric adapter  110  is formed from plastic). 
     If desired, one or more adhesive layers may be used to couple (adhere or affix) substrate  134  to foam member  132 , to couple foam member  132  to substrate  130 , to couple substrate  130  to flexible printed circuit  118 , to couple flexible printed circuit  118  to dielectric adapter  110 , to couple substrate  130  to dielectric adapter  110 , and/or to couple dielectric adapter  110  to three-dimensionally curved dielectric cover layer  92 . In one suitable arrangement that is sometimes described herein as an example, a first adhesive layer is interposed between foam member  132  and substrate  130  for adhering foam member  132  to substrate  130  and a second adhesive layer is interposed between substrate  130  and flexible printed circuit  118  for adhering flexible printed circuit  118  to substrate  130  (e.g., without adhesive layers between flexible printed circuit  118  and dielectric adapter  110  or between dielectric adapter  110  and three-dimensionally curved dielectric cover layer  92 ). 
     If desired, dielectric antenna carrier  44  may include one or more alignment holes  136 . Each alignment hole  136  may extend through substrate  130 , foam member  132 , and substrate  134 . An alignment pin such as alignment pin  138  may be inserted into each alignment hole  136 . The alignment pins may help to hold dielectric antenna carrier  44  together and in place during assembly and/or during the operation of device  10 . Substrate  134  may be mounted to or replaced by another substrate in device  10 , a printed circuit board in device  10  (e.g., a main logic board, etc.), a portion of the housing for device  10 , a conductive or dielectric support plate or frame for device  10 , and/or any other desired structures in device  10 . 
     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: 20220714
Publication Date: 20250121
Grant Date: 20250121
Priority Date: 20200901
Inventors: JIANG, YI
WU, JIANGFENG
ZHANG, LIJUN
YONG, Siwen
PASCOLINI, MATTIA
RESNICK, SAMUEL A.
MONTEVIRGEN, ANTHONY S.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2291", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q19/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/422", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/2291", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/422", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 80358993