PATENT DOCUMENT

Publication Number: US-9680205-B2
Application Number: US-201414468217-A
Country: US
Kind Code: B2

Title: Electronic device with peripheral display antenna

Abstract:
An electronic device may be provided with electrical components mounted in a housing. The electronic device may include wireless transceiver circuitry and antenna structures. A display may be mounted in the housing. The display may have a transparent layer such as display cover layer. The display cover layer may have an inner surface with a recess. The recess may be a groove that runs along a peripheral edge of the display cover layer. An antenna structure such as an inverted-F antenna resonating element may be formed from a metal trace on a plastic support structure. The metal trace and support structure may be mounted in the groove with adhesive. The housing may be a metal housing that forms an antenna ground. Springs may be used in forming an antenna feed and an antenna return path that couples the antenna resonating element to ground.

Claims:
What is claimed is: 
     
       1. An electronic device having opposing front and rear faces, comprising:
 a metal housing, wherein the metal housing has a rear wall that forms the rear face of the electronic device and has sidewalls; 
 a display mounted in the housing; 
 a transparent display cover layer that covers the display and that is attached to the sidewalls of the metal housing, wherein the transparent display cover layer has an interior surface with a recess; 
 an antenna having an antenna resonating element in the recess and an antenna ground formed from the metal housing, wherein the antenna resonating element comprises a metal trace on a plastic antenna trace support structure, the plastic antenna trace support structure has an adhesive gap spacer that is configured to separate the plastic antenna trace support structure from an interior surface of the recess by a gap; and 
 adhesive in the gap that attaches the plastic antenna trace support structure and the metal trace in the recess to the interior surface of the transparent display cover layer. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the transparent display cover layer comprises a layer selected from the group consisting of: a glass layer and a sapphire layer. 
     
     
       3. The electronic device defined in  claim 2  wherein the recess comprises a groove. 
     
     
       4. The electronic device defined in  claim 3  wherein the antenna resonating element comprises an inverted-F antenna resonating element. 
     
     
       5. The electronic device defined in  claim 1 , wherein the antenna resonating element is coupled to the metal housing by a spring that forms a return path for the antenna. 
     
     
       6. The electronic device defined in  claim 2  wherein the electronic device comprises a wristwatch device. 
     
     
       7. The electronic device defined in  claim 1  further comprising a force sensor interposed between the transparent display cover layer and the metal housing. 
     
     
       8. An electronic device having opposing front and rear faces, comprising:
 a metal housing, wherein the metal housing has a rear wall that forms the rear face of the electronic device and has sidewalls; 
 a display mounted in the housing; 
 a transparent display cover layer that covers the display and that is attached to the sidewalls of the metal housing, wherein the transparent display cover layer has an interior surface with a recess; 
 an inverted-F antenna having an inverted-F antenna resonating element in the recess and an antenna ground formed from the metal housing, wherein the inverted-F antenna resonating element comprises a metal trace formed on a plastic antenna trace support structure; 
 a flex circuit that is configured to convey radio-frequency signals for the antenna; and 
 a screw that passes through an opening in the flex circuit, secures the flex circuit and the plastic antenna trace support structure to a given one of the sidewalls, and shorts the metal trace to the given one of the sidewalls. 
 
     
     
       9. The electronic device defined in  claim 8  wherein the recess comprises a groove, the plastic antenna trace support structure has an adhesive gap spacer that is configured to separate the plastic antenna trace support structure from an interior surface of the groove by a given gap, and the electronic device further comprises adhesive in the gap that attaches the plastic antenna trace support structure and the metal trace to the groove. 
     
     
       10. The electronic device defined in  claim 9  further comprising an opaque masking layer interposed between the adhesive and the inner surface of the groove. 
     
     
       11. The electronic device defined in  claim 10  wherein the metal trace has portions forming first and second spring contacts. 
     
     
       12. The electronic device defined in  claim 11  further comprising a first spring that presses against the first spring contact and a second spring that presses against the second spring contact. 
     
     
       13. The electronic device defined in  claim 12  further comprising a plastic spring biasing structure that presses the first and second springs against the first and second spring contacts. 
     
     
       14. The electronic device defined in  claim 13  further comprising a screw that screws the plastic spring biasing structure to the metal housing and that electrically couples the first spring to the metal housing so that the first spring forms a return path for the inverted-F antenna. 
     
     
       15. The electronic device defined in  claim 14  further comprising a flexible printed circuit having a signal path shorted to the second spring, wherein the second spring forms a positive antenna feed terminal for the inverted-F antenna. 
     
     
       16. The electronic device defined in  claim 15  further comprising an impedance matching circuit mounted on the flexible printed circuit, wherein the first spring is embedded at least partly within the plastic spring biasing structure. 
     
     
       17. The electronic device defined in  claim 15  further comprising:
 a printed circuit board; and 
 electrical components mounted to the printed circuit board, wherein the flexible printed circuit has a tail that is coupled to the printed circuit board. 
 
     
     
       18. The electronic device defined in  claim 12  wherein the display comprises an organic light-emitting diode display. 
     
     
       19. The electronic device defined in  claim 8 , further comprising a flexible printed circuit cable that electrically connects the metal trace to wireless transceiver circuitry. 
     
     
       20. An electronic device having opposing front and rear faces, comprising:
 a metal housing, wherein the metal housing has a rear wall that forms the rear face of the electronic device and has sidewalls; 
 a display mounted in the housing; 
 a transparent display cover layer that covers the display and that is attached to the sidewalls of the metal housing, wherein the transparent display cover layer has an interior surface with a recess; 
 an antenna having an antenna resonating element in the recess and an antenna ground formed from the metal housing, wherein the recess comprises a ring-shaped groove that runs along a periphery of the display and the antenna resonating element runs along some but not all of the ring-shaped groove.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless communications circuitry. 
     Electronic devices often include wireless communications circuitry. Radio-frequency transceivers are coupled to antennas to support communications with external equipment. During operation, a radio-frequency transceiver uses an antenna to transmit and receive wireless signals. 
     It can be challenging to incorporate wireless components such as antenna structures within an electronic device. If care is not taken, an antenna may consume more space within a device than desired or may exhibit unsatisfactory wireless performance. 
     It would therefore be desirable to be able to provide improved antennas for electronic devices. 
     SUMMARY 
     An electronic device may be provided with electrical components mounted in a housing. The electrical components may include a wireless transceiver, an antenna, and other wireless circuitry. 
     A display may be mounted in the housing. The electronic device may have opposing front and rear faces. The display may form the front face of the device and the housing may have a rear wall that forms the rear face of the device. The display may have a transparent layer such as display cover layer that is mounted to housing sidewalls. 
     The display cover layer may have an inner surface with a recess. The recess may have the shape of a groove that runs along a peripheral edge of the display cover layer. 
     An antenna structure such as an inverted-F antenna resonating element may be formed from a metal trace on a plastic antenna support structure. The metal trace and support structure may be mounted in the groove with adhesive. The housing may be a metal housing that forms an antenna ground. An inverted-F antenna may be formed from the metal antenna trace in the groove and the metal housing serving as antenna ground. 
     Springs may be used in forming an antenna feed and an antenna return path. An antenna feed terminal may be formed using a spring on a flexible printed circuit. A return path that couples the antenna resonating element to ground may be formed from another spring. The return path spring may be embedded within a plastic spring biasing structure. The spring biasing structure may be secured to the metal housing using screws. When the spring biasing structure is attached to the housing, the springs may be pressed against contacts formed from portions of the metal trace on the plastic antenna support structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative electronic device with a planar display in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device with a curved display in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative electronic device with a display having a curved layer mounted to a planar layer in accordance with an embodiment. 
         FIG. 6  is a perspective view of an illustrative display layer showing how the interior surface of the display layer may be provided with a recess such as a peripheral groove in accordance with an embodiment. 
         FIG. 7  is a top view of an illustrative antenna of the type that may have an antenna resonating element mounted within a display groove in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of a portion of an electronic device showing how a flexible printed circuit cable may be used to couple radio-frequency transceiver circuitry on a printed circuit board to an antenna structure mounted in a peripheral display groove in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of a portion of an electronic device structure having a groove in which an antenna resonating element has been mounted in accordance with an embodiment. 
         FIG. 10  is a perspective view of an illustrative antenna resonating element and associated flexible printed circuit and antenna feed structures in accordance with an embodiment. 
         FIG. 11  is a perspective view of a portion of an illustrative antenna resonating element showing how contacts may be formed to mate with springs carrying antenna signals in accordance with an embodiment. 
         FIG. 12  is a cross-sectional side view of a spring biasing structure and associated screw for attaching the biasing structure to an electronic device housing that serves as antenna ground in accordance with an embodiment. 
         FIG. 13  is a top view of an illustrative spring that may be used to form a return path in an inverted-F antenna in accordance with an embodiment. 
         FIG. 14  is a side view of illustrative antenna structures showing how springs and a support structure may be used in forming an antenna feed and return path in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of an illustrative electronic device having a near-field communications antenna mounted in a recess in an electronic device structure such as a display layer in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may contain wireless circuitry. Device  10  may contain wireless communications circuitry that operates in long-range communications bands such as cellular telephone bands and wireless circuitry that operates in short-range communications bands such as the 2.4 GHz Bluetooth® band and the 2.4 GHz and 5 GHz WiFi® wireless local area network bands (sometimes referred to as IEEE 802.11 bands or wireless local area network communications bands). Device  10  may also contain wireless communications circuitry for implementing near-field communications, light-based wireless communications (e.g., infrared light communications and/or visible light communications), satellite navigation system communications, or other wireless communications. Illustrative configurations for the wireless circuitry of device  10  in which wireless communications are performed over a 2.4 GHz communications band and/or 5 GHz communications band (e.g., a Bluetooth® and/or WiFi® link) are sometimes described herein as an example. 
     Electronic device  10  may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     In the example of  FIG. 1 , device  10  includes a display such as display  14  mounted in housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Device  10  may have opposing front and rear faces surrounded by sidewalls. Display  14  may have a planar or curved outer surface that forms the front face of device  10 . The lower portion of housing  12 , which may sometimes be referred to as rear housing wall  12 R, may form the rear face of housing  12 . Rear housing wall  12 R may have a planar exterior surface (e.g., the rear of housing  12  may form a planar rear face for housing  12 ) or rear housing wall  12 R may have a curved exterior surface or an exterior surface of other suitable shapes. Sidewalls  12 W may have vertical exterior surfaces (e.g., surfaces that run vertically between display  14  and rear housing wall  12 R), may have curved surfaces (e.g., surfaces that bow outwardly when viewed in cross section), may have beveled portions, may have profiles with straight and/or curved portions, or may have other suitable shapes. Device  10  may have a rectangular display and rectangular outline, may have a circular shape, or may have other suitable shapes. 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels or other light-emitting diodes, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Device  10  may include buttons such as button  16 . There may be any suitable number of buttons in device  10  (e.g., a single button, more than one button, two or more buttons, five or more buttons, etc. Buttons may be located in openings in housing  12  or in an opening in a display (as examples). 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  16  may be formed from metal, glass, plastic, or other materials. 
     A schematic diagram showing illustrative components that may be used in device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry such as storage and processing circuitry  30 . Storage and processing circuitry  30  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  30  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processor integrated circuits, application specific integrated circuits, etc. 
     Storage and processing circuitry  30  may be used to run software on device  10 . For example, software running on device  10  may be used to process input commands from a user that are supplied using input-output components such as buttons, a touch screen such as display  14 , force sensors (e.g., force sensors that are activated by pressing on display  14  or portions of display  14 ), accelerometers, light sensors, and other input-output circuitry. To support interactions with external equipment, storage and processing circuitry  30  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  30  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, etc. 
     Device  10  may include input-output circuitry  44 . Input-output circuitry  44  may include input-output devices  32 . Input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include user interface devices, data port devices, and other input-output components. For example, input-output devices may include touch screens, displays without touch sensor capabilities, buttons, force sensors, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, motion sensors (accelerometers), capacitance sensors, proximity sensors (e.g., a capacitive proximity sensor and/or an infrared proximity sensor), magnetic sensors, and other sensors and input-output components. 
     Input-output circuitry  44  may include wireless communications circuitry  34  for communicating wirelessly with external equipment. Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless communications circuitry  34  may include radio-frequency transceiver circuitry  90  for handling various radio-frequency communications bands. For example, circuitry  34  may include wireless local area network transceiver circuitry that may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications, wireless transceiver circuitry that may handle the 2.4 GHz Bluetooth® communications band, cellular telephone transceiver circuitry for handling wireless communications in communications bands between 700 MHz and 2700 MHz or other suitable frequencies (as examples), or other wireless communications circuits. If desired, wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, satellite navigation system receiver circuitry, etc. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. To conserve power, it may be desirable in some embodiments to configure wireless communications circuitry  34  so that transceiver  90  handles exclusively short-range wireless links such as 2.4 GHz links and/or 5 GHz links (e.g., Bluetooth® and/or WiFi® links). Other configurations may be used for wireless circuitry  34  if desired (e.g., configurations with coverage in additional communications bands). 
     Wireless communications circuitry  34  may include one or more antennas such as antenna  40 . Antenna  40  may be formed using any suitable antenna type. For example, antenna  40  may be an antenna with a resonating element that is formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, hybrids of these designs, etc. 
     Transmission line paths such as transmission line  92  may be used to couple antenna  40  to transceiver circuitry  90 . Transmission line  92  may be coupled to antenna feed structures associated with antenna structures  40 . As an example, antenna structures  40  may form an inverted-F antenna or other type of antenna having an antenna feed with a positive antenna feed terminal such as terminal  98  and a ground antenna feed terminal such as ground antenna feed terminal  100 . Positive transmission line conductor  94  may be coupled to positive antenna feed terminal  98  and ground transmission line conductor  96  may be coupled to ground antenna feed terminal  92 . Other types of antenna feed arrangements may be used if desired. The illustrative feeding configuration of  FIG. 2  is merely illustrative. 
     Transmission line  92  may include coaxial cable paths, 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. Filter circuitry, switching circuitry, impedance matching circuitry, and other circuitry may be interposed within the transmission lines, if desired. Circuits for impedance matching circuitry may be formed from discrete components (e.g., surface mount technology components) or may be formed from housing structures, printed circuit board structures, traces on plastic supports, etc. Components such as these may also be used in forming filter circuitry. 
     Electrical components for forming circuitry such as storage and processing circuitry  30  and input-output circuitry  44  of  FIG. 2  may be mounted in housing  12 . Consider, as an example, the cross-sectional side view of device  10  of  FIG. 3 .  FIG. 3  is a cross-sectional side view of a device such as device  10  of  FIG. 1  taken along line  18  and viewed in direction  20 . As shown in  FIG. 3 , display  14  of device  10  may be formed from a display module such as display module  102  (sometimes referred to as a display) mounted under a cover layer such as display cover layer  112  (as an example). Display  14  (display module  102 ) may be a liquid crystal display, an organic light-emitting diode display, a plasma display, an electrophoretic display, a display that is insensitive to touch, a touch sensitive display that incorporates and array of capacitive touch sensor electrodes or other touch sensor structures, or may be any other type of suitable display. Display cover layer  112  may be layer of clear glass, a transparent plastic member, a transparent crystalline member such as a sapphire layer, a ceramic, fused silica, a transparent layer formed from one or more different types of materials, or other clear structure. Layer  112  may form the front face of device  10 . If desired, the outermost layer of display  14  (e.g., display layer  112 ) may be used as a substrate for an array of color filter elements (i.e., layer  112  may be a color filter layer), as a substrate for thin-film transistor circuitry (i.e., layer  112  may be a thin-film transistor layer), or may be a substrate that includes both thin-film transistor circuitry and color filter circuitry (as examples). 
     Device  10  may have inner housing structures that provide structural support to device  10  and/or that serve as mounting platforms for printed circuits and other structures. Structural internal housing members may sometimes be referred to as housing structures and may be considered to form part of housing  12 . 
     Electrical components  106  for forming circuitry such as circuitry  30  and  44  may be mounted within the interior of housing  12 . Components  106  may be mounted to printed circuits such as printed circuit  104 . Printed circuit  104  may be a rigid printed circuit board (e.g., a printed circuit board formed from fiberglass-filled epoxy or other rigid printed circuit board material) or may be a flexible printed circuit (e.g., printed circuit formed from a sheet of polyimide or other flexible polymer layer). Patterned metal traces within printed circuit board  104  may be used to form signal paths between components  106 . If desired, components such as connectors may be mounted to printed circuit  104 . Cables such as one or more flexible printed circuit cables may have mating connectors and may couple circuitry on printed circuits such as printed circuit  104  to display  102 , to antenna(s)  40  ( FIG. 2 ), etc. Flexible printed circuit cables may also be mounted to boards such as board  104  using solder or other conductive material. 
     The outermost layer of display  14  such as display cover layer  112  is preferably a transparent display layer that is formed from transparent structures that allow light from display  102  to pass through layer  112 . This allows images on display  102  to be viewed by viewer  108  in direction  110  during operation of device  10 . 
     In the example of  FIG. 3 , transparent display cover layer  112  has planar inner and outer surfaces. If desired, one or more of the surfaces of display  14  may be curved (e.g., concave, convex, etc.). As shown in the illustrative cross-sectional side view of  FIG. 4 , for example, display  14  may have a convex outer surface. In this type of configuration, display cover layer  112  may have a planar inner surface or a curved inner surface (as shown in  FIG. 4 ). 
     As shown in  FIG. 5 , display cover layer  112  may have more than one layer. In the  FIG. 5  example, display cover layer  112  has an outer layer such as layer  112 - 1  and an inner layer such as layer  112 - 2 . Layer  112 - 1  may have a convex outer surface and a planar inner surface (as an example). Layer  112 - 2  may have opposing planar outer and inner surfaces (as an example). Adhesive  121  (e.g., optically clear adhesive) may be used to attach layers  112 - 1  and  112 - 2  together. Display structure  102  (e.g., an organic light-emitting diode display or other display module) may be mounted to the interior surface of lower layer  112 - 2  (e.g., a planar inner surface) using adhesive or other attachment mechanisms. 
     It may be desirable to create recesses in structures such as housing  12  and/or display  14 . As an example, a recess such as groove  116  of  FIG. 6  may be formed in inner surface  114  of display cover layer  112 . Groove  116  may run along one or more peripheral edges of display cover layer  112 . In the  FIG. 6  example, display cover layer  112  has a rectangular shape and four peripheral edges. Groove  116  runs along all four peripheral edges of display cover layer  112 . Configurations in which recesses such as groove  116  of  FIG. 6  have other shapes may also be used, if desired (e.g., configurations in which recess  116  runs along a single edge of display cover layer  112 , configurations in which recess  116  runs along two edges of display cover layer  112 , configurations in which recess  116  runs along three edges of display cover layer  112 , etc.). If desired, display  14  may be circular and recess  116  may form a circular or semicircular groove that runs along the curved edges of display  14  (e.g., recess  116  may be a circular groove or may form a groove that has a curved shape that runs along part of a curved peripheral edge in display  14 ). Recesses such as groove  116  may be formed by machining, etching, molding, water jet cutting, abrasion using fine particles of grit, or other fabrication techniques. The cross-sectional shape of groove  116  may be square, rectangular, or semicircular, may have curved shapes, may have shapes with straight sides and/or curved sides, etc. 
     One or more antennas for device  10  may be formed from an antenna resonating element that is fully or partly mounted in a recess such as recess  116 . In the illustrative configuration of  FIG. 7 , antenna  40  is an inverted-F antenna that has an antenna resonating element located within recess  116 . Inverted-F antenna  40  of  FIG. 7  has antenna resonating element  122  and antenna ground (ground plane)  124 . Antenna ground  124  may be formed from a metal housing structure (e.g., housing  12  in a configuration in which some or all of housing  12  is metal), may be formed from conductive traces on a printed circuit board, may be formed from ground structures in other devices (e.g., display  102 ), and/or may be implemented using other suitable ground structures. Antenna resonating element  122  may have a main resonating element arm such as arm  120 . The length of arm  120  (which is sometimes referred to as a resonating element arm or resonating element) may be selected so that antenna  40  resonates at desired operating frequencies. For example, if the length of arm  120  may be a quarter of a wavelength at a desired operating frequency for antenna  40 . Antenna  40  may also exhibit resonances at harmonic frequencies. 
     Arm  120  may be formed from a metal trace on an antenna support. Metal trace  120  may be coupled to ground  124  by return path  126 . Return path  126  may be formed from a metal spring or other conductive structure. Antenna feed  128  may include positive antenna feed terminal  98  and ground antenna feed terminal  100  and may be coupled parallel to return path  126  between the metal trace of resonating element arm  120  and ground  124 . If desired, inverted-F antennas such as illustrative antenna  40  of  FIG. 7  may have more than one resonating arm branch (e.g., to create multiple frequency resonances to support operations in multiple communications bands) or may have other antenna structures (e.g., parasitic antenna resonating elements, tunable components to support antenna tuning, etc.). For example, one end of arm  120  may form a high-band branch that resonates at 5 GHz and another end of arm  120  may form a low-band branch that resonates at 2.4 GHz. 
     The bandwidth of antennas such as antenna  40  of  FIG. 7  may be affected by the separation between ground  124  and antenna resonating element  122  (i.e., the distance between metal trace  120  and housing  12  in a configuration in which ground  124  is formed from housing  12 ). By providing recesses such as recess  116  in display cover layer  112 , the distance between ground  124  and antenna resonating element  120  can be enhanced without overly increasing the size of device  10  and housing  12 . 
     A cross-sectional side view of antenna  40  taken through an edge portion of device  10  is shown in  FIG. 8 . As shown in  FIG. 8 , display  14  may include display cover layer  112  and display module (display)  102 . Active area AA of display module  102  may have an array of pixels (e.g., organic light-emitting diode pixels in a configuration in which display module  102  is an organic-light-emitting diode display, etc.) for displaying images. Inactive display border area IA may form a ring that runs around the periphery of display  14  (e.g., a rectangular ring in configurations in which display  14  has a rectangular shape, a circular ring in configuration in which display  14  is circular, etc.). 
     A near-field communications loop antenna may be formed under display  102 . The near-field communications loop antenna may be formed from metal traces  132  on a substrate such as printed circuit  130 . Metal traces  132  may be coils that form multiple concentric loops for the near-field communications loop antenna. Metal traces  132  may be overlapped by active area AA and/or inactive area IA of display  102 . A magnetic shielding layer such as ferrite layer  134  may be formed under printed circuit  130  and may prevent magnetic fields from the near-field communications antenna from inducing eddy currents in underlying conductive structures such as metal traces in printed circuit  104 . 
     Components may be mounted in the interior of device  10  between ferrite layer  134  and printed circuit  104 . As shown in  FIG. 8 , for example, a component such as component  136  may overlap printed circuit  104 . Component  136  may be an electromechanical actuator (e.g., a haptic feedback device, a piezoelectric actuator, a solenoid, a vibrator for issuing alerts, a device for imparting other vibrations or motions to device  10 , etc.) or may be any other suitable electrical component(s). 
     Antenna  40  may be coupled to electrical components  106  on printed circuit  104  using cable  150 . Cable  150  may be a flexible printed circuit cable, a coaxial cable, or other signal path (e.g., a path forming transmission line  92 ). Connector  153  may be used to couple cable  150  to printed circuit  104 . Antenna  40  may be formed from an antenna resonating element such as antenna resonating element  122  of  FIG. 7  and antenna ground  124  of  FIG. 7 . Antenna ground  124  may be formed from conductive structures in device  10  such as portions of housing  12  (e.g., metal housing  12 ). 
     The antenna resonating element for antenna  40  may be formed from metal traces on a plastic antenna support structure such as antenna trace support structure  148 . To hide internal device components from view in direction  110  by user  108 , peripheral portions of the inner surface of display cover layer  112  may be coated with a layer of opaque masking material. For example, portions of display cover layer  112  that overlap inactive border region IA of display  102  may be covered with opaque masking layer  146 . Layer  146  may overlap inactive display border IA and may cover groove  116  and portions of housing  12  up to the outermost edge of display cover layer  112  (as an example). Opaque masking layer  146  may be formed from black ink, white ink, polymers that are black, white, or have other colors, metals, etc. 
     As shown in  FIG. 8 , a component such as force sensor  142  may be coupled between the outer portion of display cover layer  112  and housing  12 . Force sensors such as force sensor  142  may be used to detect when a user presses on display cover layer  112  to supply user input to device  10 . Adhesive or other attachment mechanisms may be used in mounting sensor  142  in device  10  (see, e.g., adhesive layer  138  and adhesive layer  144 ). Adhesive such as layers  138  and  144  and/or other fastening mechanisms may be used to attach display cover layer  12  to sidewalls  12 W of housing  12 . 
     Antenna trace support structure  148  may be formed from a plastic carrier structure such as a polymer structure formed from liquid crystal polymer or other dielectric support structure. Metal traces on flexible printed circuit cable  150  may form transmission line  92 . 
     As shown in  FIG. 9 , antenna trace support structure  148  may be secured within groove  116  in display cover layer  112  using adhesive  152 . Opaque masking layer  146  (e.g., black ink) may be interposed between adhesive  152  and inner surface  156  of groove  116 . Antenna resonating element  122  may be formed from metal trace  120  on support structure  148 . Metal traces may be formed for resonating element  122  using laser-enhanced deposition (e.g., techniques in which selected portions of the surface of structure  148  are activated by application of laser light following which metal is electrochemically deposited on the active regions) or using other deposition and patterning techniques (e.g., shadow masks and evaporation, physical or chemical vapor deposition followed by selected laser ablation or etching, etc.). 
     Adhesive  152  may be thermally cured adhesive and/or adhesive that is cured by application of light (e.g., ultraviolet light). Support structure  148  may have an elongated shape extending along a longitudinal axis (into the plane in the example of  FIG. 9 ). The longitudinal axis of antenna trace support structure  148  may be aligned with the longitudinal axis of groove  116 . 
     Adhesive gap formation structures such as protrusions  154  may be formed at one or more locations along the length of support structure  148 . Protrusions  154  may have heights equal to the amount of gap that is desired between the surface of support structure  148  and inner surface  156  of groove  116 . If insufficient space is provided or if too much space is provided for adhesive  152 , the joint formed by adhesive  152  may not be satisfactory. By including protrusions  154  along the surface of support structure  148 , a desired gap will be created between support structure  148  and groove surface  156  prior to adhesive curing. Protrusion  154  therefore serves as an adhesive gap spacer that ensures that plastic antenna trace support structure  148  is separated from the interior surface of groove  116  by an appropriately sized adhesive gap. The adhesive gap will be filled with a suitable amount of adhesive  152  by virtue of the fixed spacing established by the size of protrusions  154 . If desired, other techniques may be used to help ensure that a satisfactory amount of adhesive  152  is interposed between support structure  148  (and therefore metal trace  120  of resonating element  122 ) and inner surface  156  of groove  116  in display cover layer  112 . The configuration of  FIG. 9  in which adhesive spacer structures are formed from portions of support structures  148  that protrude outwardly such as protrusion  154  of  FIG. 9  is merely illustrative. 
     A perspective view of structures associated with antenna  40  is shown in  FIG. 10 . As shown in  FIG. 10 , antenna resonating element  122  may be formed from a metal trace on the upper surface of a dielectric support structure such as plastic antenna trace support structure  148 . Support structure  148  may have a shape that mates with groove  116  or part of groove  116  on the underside of display cover layer  112 . Portions of trace  120  such as portions  166  and  168  may form contact pads that mate with springs or other conductive feed and return path structures for antenna  40 . Portions  166  and  168  may, for example, extend downwardly along the inner sidewall surface of dielectric support structures  148 . Portions  166  and  168  may be integral portions of trace  120  and may extend downwards from the portion of resonating element trace  120  on the upper surface of support structure  148 . Portions  166  and  168  may form antenna resonating element contacts for resonating element  120  at first and second respective locations along the length of resonating element  120 . 
     Conductive structures such as metal springs  162  and  164  may be used to form connections with antenna resonating element  120 . Metal spring  162  may, for example, be used in forming return path  126 , whereas metal spring  164  may be used in forming antenna feed  128  ( FIG. 7 ). Metal spring  162  may have a first portion that presses against portion  166  of trace  120  (i.e., metal spring  162  may mate with contact  166 ), thereby forming an electrical connection between spring  162  and antenna resonating element trace  120 . Metal spring  162  may also have a second portion that is electrically coupled to antenna ground  124  (e.g., housing  12 ). For example, metal screws  160  may be used to short metal spring  162  to housing  12 . When mounted in device  10  in this way, metal spring  162  forms a return path such as return path  126  of  FIG. 7  that couples antenna resonating element  120  to ground  124 . Metal spring  164  may have an end that is pressed against mating contact  168 , thereby forming feed terminal  98  in antenna feed  128 . Metal spring  164  may have an opposing end that is coupled to a positive transmission line signal trace such as path  94  on flexible printed circuit  150 . 
     Flexible printed circuit  150  may have metal traces for signal paths such as positive signal path  94  and ground signal path  96  for transmission line  92 . With one suitable arrangement, spring  162  is partly embedded within a plastic support structure such as plastic spring biasing structure  170  and is electrically coupled to metal housing  12  via screws  160 , whereas spring  164  is soldered to a contact on flexible printed circuit  150  and is pressed towards trace  120  via spring biasing structure  170 . If desired, both spring  162  and spring  164  may be soldered to respective contacts on flexible printed circuit  150 , both spring  162  and spring  164  may be fully and/or partly embedded within plastic spring biasing structure  170 , or spring  162  and/or spring  164  may be supported using other mounting structures (e.g., metal brackets, dielectric supports, printed circuit substrates, etc.). 
     If desired, filter circuitry, impedance matching circuitry, and/or other circuit components may be interposed in transmission line path  92 . For example, circuitry such as circuitry  158  (e.g., an impedance matching circuit or other circuitry such as filter circuitry, antenna tuning circuitry, switching circuitry, etc.) may be mounted to printed circuit  150  and coupled to the signal lines in transmission line path  92 . 
       FIG. 11  is a perspective view of a portion of antenna resonating element trace  120  and support structure  148  showing how springs  162  and  166  may mate with resonating element contacts such as return path contact  166  and positive feed terminal contact  168 . Springs  162  and  166  may have any suitable shapes. The illustrative shapes of  FIG. 11  are merely illustrative. As shown in  FIG. 11 , springs  162  may have openings (e.g., circular holes, semicircular holes, grooves, etc.) such as openings  172  and  174 . During assembly, the shafts of screws  160  may be inserted into openings  172  and  174  to attach spring  162  (and biasing structure  170 ) to metal housing  12 . If desired, spring  162  may have a portion such as portion  162 B that bridges spring  164 . When biasing structure  170  is attached to housing  12 , spring  164  may be pressed against contact  168 . In this way, biasing structure  170  presses both springs  162  and  164  into contact with metal trace  120  at different respective locations along the length of metal trace  120 . 
       FIG. 12  is an exploded cross-sectional side view of housing  12  and associated antenna structures in antenna  40 . As shown in  FIG. 12 , flexible printed circuit  150  may be interposed between a spring (e.g., spring  162  in the  FIG. 12  example) and housing  12 . If desired flexible printed circuit  150  may be interposed between a spring such as spring  162  and biasing structure  170 . Portions of spring  162  may contact housing  12  directly and/or may be electrically connected to housing  12  through metal traces in flexible printed circuit  150 . 
     Spring biasing structure  170  may have an opening such as opening  176 . Flexible printed circuit  150  may have an opening such as opening  182 . Spring  162  may have an opening such as opening  174 . Metal housing  12  may have an opening such as threaded opening  178 . Openings such as openings  176 ,  182 ,  174 , and  178  may be circular, semicircular, or may have other suitable shapes and may be aligned with each other to receive the shaft of screw  160  during assembly. When screws  160  are screwed into housing  12 , the return path and antenna feed connections for antenna  40  may be formed using springs  162  and  168  and the metal traces of flexible printed circuit  150 . 
       FIG. 13  is a top view of flexible printed circuit  150 . As shown in  FIG. 13 , flexible printed circuit  150  may have a main portion such as portion  150 B and an extended tail portion such as tail  150 T. Transmission line  92  may be formed from metal traces on flexible printed circuit  150  such as positive signal path  94  and ground signal path  96 . Impedance matching circuit  158  or other circuitry may be interposed in path  92 . Circuitry  158  may be formed from one or more integrated circuits and/or discrete components (e.g., capacitors, resistors, inductors, etc.). 
     Metal traces on flexible printed circuit  150  may be used in forming an electrode such as pad  184 . Spring  164  may be mounted on flexible printed circuit  150  by soldering an end of spring  164  to pad  184  (as an example). Metal traces on flexible printed circuit  150  may also be used in forming electrodes such as electrodes  180 . Electrodes  180  may, as an example, form semicircular contacts surrounding semicircular screw hole openings  182  one on or both exterior surfaces of flexible printed circuit  150 . When installed in device  10 , extended portion  150 T may be coupled to a connector on printed circuit board  104  such as connector  153 . 
     A cross-sectional side view of a portion of antenna  40  when spring biasing structure  170  is mounted to housing  12  is shown in  FIG. 14 . As shown in  FIG. 14 , screws  160  may be screwed into mating threaded openings in housing  12 , thereby pressing structure  170  towards housing  12 . Structures such as springs  162  and  164  may be pressed towards resonating element  120  and/or housing  12  by spring biasing structure  170  as screws  160  are tightened. Spring  162  may be fully or partly embedded within the plastic of structure  170  (e.g., by injection molding). If desired, structure  170  may have a portion such as protrusion  186  that presses spring  164  towards contact  168  on antenna resonating element  120  when structure  170  is screwed into housing  12 . 
       FIG. 15  is a cross-sectional side view of device  10  in an illustrative configuration in which a near-field communications antenna has been mounted in recess  116 . The near-field communications antenna may include one or more coils  190  that form a loop antenna (e.g., in a configuration in which groove  116  runs around the entire periphery of display cover layer  112  and display  14 ). If desired, other components may be mounted in recesses such as recess  116  (e.g., sensors, switching, capacitor electrodes for a capacitive touch sensor, buttons, force sensors, compass sensors, accelerometers, light-based devices such as light sources and light detectors, audio components, vibrators and other actuators, magnetic sensors, temperature sensors, display components, analog and/or digital circuitry for other device functions, etc. There may be multiple recesses  116  in device  10  and each recess may potentially be formed in a different device structure (e.g., one recess may be formed in display cover layer  112  and another recess may be formed in housing  12  or other device structure). Configurations in which recess  116  is formed in housing  12  and display  14  does not contain any recesses may also be used. Recesses may be formed in the shape of grooves, through-holes, circular depressions or depressions of other shapes, recesses with curved sides, recesses with planar sides, recesses with curved and/or straight edges, etc. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20140825
Publication Date: 20170613
Grant Date: 20170613
Priority Date: 20140825
Inventors: LI QINGXIANG
SCHLUB ROBERT W.
DE JONG ERIK G.
OUYANG YUEHUI
YONG SIWEN
SAMARDZIJA MIROSLAV
WANG YIREN
ZHU JIANG
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 55349059