PATENT DOCUMENT

Publication Number: US-10263335-B2
Application Number: US-201715700565-A
Country: US
Kind Code: B2

Title: Electronic device antennas having shared structures for near-field communications and non-near field communications

Abstract:
An electronic device may be provided with wireless circuitry. The wireless circuitry may include antenna structures such as an antenna resonating element arm and an antenna ground. A split return path may be coupled between the antenna resonating element arm and the antenna ground. The antenna structures may form one or more inverted-F antennas when operated at non-near-field communications frequencies. The antenna structures may be coupled to near-field communications transceiver circuitry using a conductive path. When operated at near-field communications frequencies, near-field communications signals may be conveyed using the conductive path, the antenna resonating element arm, the return path, and the antenna ground. A capacitor may be coupled between the conductive path and an antenna ground. The capacitor may short non-near-field communications signals to the antenna ground and block near-field communications signals from passing from the conductive path to the antenna ground.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 antenna structures having an antenna resonating element arm and an antenna ground; 
 non-near-field communications transceiver circuitry coupled to the antenna resonating element arm and configured to convey non-near-field communications signals using the antenna structures; 
 near-field communications transceiver circuitry coupled to the antenna resonating element arm through a conductive path, wherein the near-field communications transceiver circuitry is configured to convey near-field communications signals using the antenna structures and the conductive path; and 
 a capacitor coupled between the conductive path and the antenna ground, wherein the capacitor is configured to short the non-near-field communications signals to the antenna ground and to block the near-field communications signals from passing from the conductive path to the antenna ground. 
 
     
     
       2. The electronic device defined in  claim 1 , further comprising an inductor interposed in the conductive path between the near-field communications transceiver circuitry and the antenna resonating element arm. 
     
     
       3. The electronic device defined in  claim 2 , wherein the inductor is coupled between a node on the conductive path and the antenna resonating element arm and the capacitor is coupled between the node and the antenna ground. 
     
     
       4. The electronic device defined in  claim 3 , wherein the capacitor has a capacitance between 30 pF and 100 pF. 
     
     
       5. The electronic device defined in  claim 3 , wherein the capacitor and inductor are mounted on a flexible printed circuit board. 
     
     
       6. The electronic device defined in  claim 5 , wherein the capacitor is coupled between the node on the conductive path and a fastener that electrically couples the capacitor to the antenna ground and mechanically attaches the flexible printed circuit to the antenna ground. 
     
     
       7. The electronic device defined in  claim 6 , wherein the conductive path is coupled to a feed pad on a rigid printed circuit board. 
     
     
       8. The electronic device defined in  claim 7 , further comprising an additional fastener that attaches the flexible printed circuit board to the rigid printed circuit board. 
     
     
       9. The electronic device defined in  claim 8 , further comprising a balun on the rigid printed circuit board that is coupled to the feed pad. 
     
     
       10. The electronic device defined in  claim 1 , further comprising:
 a housing having peripheral conductive housing structures, wherein the antenna resonating element arm is formed from a segment of the peripheral conductive housing structures. 
 
     
     
       11. An electronic device comprising:
 an antenna ground; 
 an antenna resonating element arm that is configured to convey non-near-field communications signals in a first frequency band; 
 a return path coupled between the antenna resonating element arm and the antenna ground; 
 a conductive path coupled to the antenna resonating element arm, wherein the conductive path, at least a portion of the antenna resonating element arm, at least a portion of the return path, and at least a portion of the antenna ground form a conductive loop path that is configured to convey near-field communications signals in a second frequency band; and 
 an electronic component that is coupled between the conductive path and the antenna ground, wherein the electronic component is configured to form a short circuit between the conductive path and the antenna ground in the first frequency band and to form an open circuit in the second frequency band. 
 
     
     
       12. The electronic device defined in  claim 11 , further comprising:
 near-field communications transceiver circuitry coupled to the conductive path. 
 
     
     
       13. The electronic device defined in  claim 12 , wherein the conductive path comprises a node coupled between the near-field communications transceiver circuitry and the antenna resonating element arm and the electronic component is coupled between the node and the antenna ground, the electronic device further comprising:
 an additional electronic component coupled between the node and the antenna resonating element arm. 
 
     
     
       14. The electronic device defined in  claim 13 , wherein the electronic component comprises a capacitor. 
     
     
       15. The electronic device defined in  claim 13 , wherein the additional electronic component comprises an inductor. 
     
     
       16. The electronic device defined in  claim 15 , wherein the electronic component comprises a capacitor. 
     
     
       17. An electronic device comprising:
 an inverted-F antenna resonating element arm; 
 an antenna ground; 
 non-near-field communications transceiver circuitry that conveys non-near-field communications signals using the inverted-F antenna resonating element arm; 
 a split return path coupled between the inverted-F antenna resonating element arm and the antenna ground; and 
 near-field communications transceiver circuitry that is coupled to the inverted-F antenna resonating element arm and that conveys near-field communications signals using the inverted-F antenna resonating element arm, at least some of the split return path, and at least some of the antenna ground. 
 
     
     
       18. The electronic device defined in  claim 17 , wherein the split return path includes a first conductive path coupled between a first terminal on the inverted-F antenna resonating element arm and a second terminal on the antenna ground and a second conductive path coupled between the first terminal and a third terminal on the antenna ground that is different than the second terminal. 
     
     
       19. The electronic device defined in  claim 18 , wherein the first conductive path of the split return path includes a first inductor and the second conductive path of the split return path includes a second inductor. 
     
     
       20. The electronic device defined in  claim 19 , wherein the first and second inductors are adjustable.

Description:
BACKGROUND 
     This relates to electronic devices, and more particularly, to antennas for electronic devices with wireless communications circuitry. 
     Electronic devices such as portable computers and cellular telephones are often provided with wireless communications capabilities. For example, electronic devices may use long-range wireless communications circuitry such as cellular telephone circuitry to communicate using cellular telephone bands. Electronic devices may use short-range wireless communications circuitry such as wireless local area network communications circuitry to handle communications with nearby equipment. Electronic devices may also be provided with satellite navigation system receivers and other wireless circuitry such as near-field communications circuitry. Near-field communications schemes involve electromagnetically coupled communications over short distances, typically 20 cm or less. 
     To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to implement wireless communications circuitry such as antenna components using compact structures. At the same time, there is a desire for wireless devices to cover a growing number of communications bands. For example, it may be desirable for a wireless device to cover a near-field communications band while simultaneously covering additional non-near-field (far-field) bands such cellular telephone bands, wireless local area network bands, and satellite navigation system bands. 
     Because antennas have the potential to interfere with each other and with components in a wireless device, care must be taken when incorporating antennas into an electronic device. Moreover, care must be taken to ensure that the antennas and wireless circuitry in a device are able to exhibit satisfactory performance over a range of operating frequencies. 
     It would therefore be desirable to be able to provide improved wireless communications circuitry for wireless electronic devices. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry. The wireless circuitry may include antenna structures. 
     The antenna structures may be coupled to non-near-field communications circuitry such as cellular telephone transceiver circuitry. When operated at non-near-field communication frequencies, the antenna structures may be configured to serve as one or more non-near-field antennas. As an example, the antenna structures may be configured to form one or more inverted-F antennas when operated at non-near-field communications frequencies such as frequencies above 600 MHz. The antenna structures may include an antenna resonating element arm that resonates at non-near-field communications frequencies and an antenna ground. A split return path may be coupled between the antenna resonating element arm and the antenna ground. 
     The antenna structures may also be coupled to near-field communications circuitry such as near-field communications transceiver circuitry using a conductive path. When operated at near-field communications frequencies, near-field communications signals may be conveyed using the conductive path, at least a portion of the antenna resonating element arm, at least a portion of the return path, and at least a portion of the antenna ground. 
     A capacitor may be coupled between the conductive path and an antenna ground. The capacitor may short non-near-field communications signals to the antenna ground and block near-field communications signals from passing from the conductive path to the antenna ground. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of illustrative circuitry in an electronic device in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of illustrative wireless communications circuitry in accordance with an embodiment. 
         FIG. 4  is a schematic diagram of an illustrative inverted-F antenna in accordance with an embodiment. 
         FIG. 5  is a top view of illustrative antenna structures in an electronic device that can be used to handle both non-near-field communications and near-field communications in accordance with an embodiment. 
         FIG. 6  is a top view of an illustrative flexible printed circuit board that may be used to form a near-field communications feed path in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative flexible printed circuit board that may be used to form a near-field communications feed path in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands. 
     The wireless communications circuitry may include antenna structures. The antenna structures may include antennas for cellular telephone communications and/or other far-field (non-near-field) communications. Circuitry in the antenna structures may allow the antenna structures to form a near-field communications loop antenna to handle near-field communications. The antennas antenna structures may include loop antenna structures, inverted-F antenna structures, strip antenna structures, planar inverted-F antenna structures, slot antenna structures, hybrid antenna structures that include antenna structures of more than one type, or other suitable antenna structures. Conductive structures for the antenna structures may, if desired, be formed from conductive electronic device structures. 
     The conductive electronic device structures may include conductive housing structures. The housing structures may include peripheral structures such as peripheral conductive structures that run around the periphery of an electronic device. The peripheral conductive structure may serve as a bezel for a planar structure such as a display, may serve as sidewall structures for a device housing, may have portions that extend upwards from an integral planar rear housing (e.g., to form vertical planar sidewalls or curved sidewalls), and/or may form other housing structures. 
     Gaps may be formed in the peripheral conductive structures that divide the peripheral conductive structures into peripheral segments. One or more of the segments may be used in forming one or more antennas for electronic device  10 . Antennas may also be formed using an antenna ground plane and/or an antenna resonating element formed from conductive housing structures (e.g., internal and/or external structures, support plate structures, etc.). 
     Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, or other small portable device. Device  10  may also be a set-top box, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, or other suitable electronic equipment. 
     Device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material (e.g., glass, ceramic, plastic, sapphire, etc.). In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be mounted on the front face of device  10 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. The rear face of housing  12  (i.e., the face of device  10  opposing the front face of device  10 ) may have a planar housing wall. The rear housing wall may have slots that pass entirely through the rear housing wall and that therefore separate housing wall portions (and/or sidewall portions) of housing  12  from each other. The rear housing wall may include conductive portions and/or dielectric portions. If desired, the rear housing wall may include a planar metal layer covered by a thin layer or coating of dielectric such as glass, plastic, sapphire, or ceramic. Housing  12  (e.g., the rear housing wall, sidewalls, etc.) may also have shallow grooves that do not pass entirely through housing  12 . The slots and grooves may be filled with plastic or other dielectric. If desired, portions of housing  12  that have been separated from each other (e.g., by a through slot) may be joined by internal conductive structures (e.g., sheet metal or other metal members that bridge the slot). 
     Display  14  may include pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable pixel structures. A display cover layer such as a layer of clear glass or plastic may cover the surface of display  14  or the outermost layer of display  14  may be formed from a color filter layer, thin-film transistor layer, or other display layer. Buttons such as button  24  may pass through openings in the cover layer if desired. The cover layer may also have other openings such as an opening for speaker port  26 . 
     Housing  12  may include peripheral housing structures such as structures  16 . Structures  16  may run around the periphery of device  10  and display  14 . In configurations in which device  10  and display  14  have a rectangular shape with four edges, structures  16  may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges (as an example). Peripheral structures  16  or part of peripheral structures  16  may serve as a bezel for display  14  (e.g., a cosmetic trim that surrounds all four sides of display  14  and/or that helps hold display  14  to device  10 ). Peripheral structures  16  may, if desired, form sidewall structures for device  10  (e.g., by forming a metal band with vertical sidewalls, curved sidewalls, etc.). 
     Peripheral housing structures  16  may be formed of a conductive material such as metal and may therefore sometimes be referred to as peripheral conductive housing structures, conductive housing structures, peripheral metal structures, or a peripheral conductive housing member (as examples). Peripheral housing structures  16  may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, or more than two separate structures may be used in forming peripheral housing structures  16 . 
     It is not necessary for peripheral housing structures  16  to have a uniform cross-section. For example, the top portion of peripheral housing structures  16  may, if desired, have an inwardly protruding lip that helps hold display  14  in place. The bottom portion of peripheral housing structures  16  may also have an enlarged lip (e.g., in the plane of the rear surface of device  10 ). Peripheral housing structures  16  may have substantially straight vertical sidewalls, may have sidewalls that are curved, or may have other suitable shapes. In some configurations (e.g., when peripheral housing structures  16  serve as a bezel for display  14 ), peripheral housing structures  16  may run around the lip of housing  12  (i.e., peripheral housing structures  16  may cover only the edge of housing  12  that surrounds display  14  and not the rest of the sidewalls of housing  12 ). 
     If desired, housing  12  may have a conductive rear surface or wall. For example, housing  12  may be formed from a metal such as stainless steel or aluminum. The rear surface of housing  12  may lie in a plane that is parallel to display  14 . In configurations for device  10  in which the rear surface of housing  12  is formed from metal, it may be desirable to form parts of peripheral conductive housing structures  16  as integral portions of the housing structures forming the rear surface of housing  12 . For example, a rear housing wall of device  10  may be formed from a planar metal structure and portions of peripheral housing structures  16  on the sides of housing  12  may be formed as flat or curved vertically extending integral metal portions of the planar metal structure. Housing structures such as these may, if desired, be machined from a block of metal and/or may include multiple metal pieces that are assembled together to form housing  12 . The planar rear wall of housing  12  may have one or more, two or more, or three or more portions. Peripheral conductive housing structures  16  and/or the conductive rear wall of housing  12  may form one or more exterior surfaces of device  10  (e.g., surfaces that are visible to a user of device  10 ) and/or may be implemented using internal structures that do not form exterior surfaces of device  10  (e.g., conductive housing structures that are not visible to a user of device  10  such as conductive structures that are covered with layers such as thin cosmetic layers, protective coatings, and/or other coating layers that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide structures  16  from view of the user). 
     Display  14  may have an array of pixels that form an active area AA that displays images for a user of device  10 . An inactive border region such as inactive area IA may run along one or more of the peripheral edges of active area AA. 
     Display  14  may include conductive structures such as an array of capacitive electrodes for a touch sensor, conductive lines for addressing pixels, driver circuits, etc. Housing  12  may include internal conductive structures such as metal frame members and a planar conductive housing member (sometimes referred to as a backplate) that spans the walls of housing  12  (i.e., a substantially rectangular sheet formed from one or more metal parts that is welded or otherwise connected between opposing sides of member  16 ). The backplate may form an exterior rear surface of device  10  or may be covered by layers such as thin cosmetic layers, protective coatings, and/or other coatings that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide the backplate from view of the user. Device  10  may also include conductive structures such as printed circuit boards, components mounted on printed circuit boards, and other internal conductive structures. These conductive structures, which may be used in forming a ground plane in device  10 , may extend under active area AA of display  14 , for example. 
     In regions  22  and  20 , openings may be formed within the conductive structures of device  10  (e.g., between peripheral conductive housing structures  16  and opposing conductive ground structures such as conductive portions of housing  12 , conductive traces on a printed circuit board, conductive electrical components in display  14 , etc.). These openings, which may sometimes be referred to as gaps, may be filled with air, plastic, and/or other dielectrics and may be used in forming slot antenna resonating elements for one or more antennas in device  10 , if desired. 
     Conductive housing structures and other conductive structures in device  10  may serve as a ground plane for the antennas in device  10 . The openings in regions  20  and  22  may serve as slots in open or closed slot antennas, may serve as a central dielectric region that is surrounded by a conductive path of materials in a loop antenna, may serve as a space that separates an antenna resonating element such as a strip antenna resonating element or an inverted-F antenna resonating element from the ground plane, may contribute to the performance of a parasitic antenna resonating element, or may otherwise serve as part of antenna structures formed in regions  20  and  22 . If desired, the ground plane that is under active area AA of display  14  and/or other metal structures in device  10  may have portions that extend into parts of the ends of device  10  (e.g., the ground may extend towards the dielectric-filled openings in regions  20  and  22 ), thereby narrowing the slots in regions  20  and  22 . 
     In general, device  10  may include any suitable number of antennas (e.g., one or more, two or more, three or more, four or more, etc.). The antennas in device  10  may be located at opposing first and second ends of an elongated device housing (e.g., at ends  20  and  22  of device  10  of  FIG. 1 ), along one or more edges of a device housing, in the center of a device housing, in other suitable locations, or in one or more of these locations. The arrangement of  FIG. 1  is merely illustrative. 
     Portions of peripheral housing structures  16  may be provided with peripheral gap structures. For example, peripheral conductive housing structures  16  may be provided with one or more gaps such as gaps  18 , as shown in  FIG. 1 . The gaps in peripheral housing structures  16  may be filled with dielectric such as polymer, ceramic, glass, air, other dielectric materials, or combinations of these materials. Gaps  18  may divide peripheral housing structures  16  into one or more peripheral conductive segments. There may be, for example, two peripheral conductive segments in peripheral housing structures  16  (e.g., in an arrangement with two of gaps  18 ), three peripheral conductive segments (e.g., in an arrangement with three of gaps  18 ), four peripheral conductive segments (e.g., in an arrangement with four of gaps  18 , etc.). The segments of peripheral conductive housing structures  16  that are formed in this way may form parts of antennas in device  10 . 
     If desired, openings in housing  12  such as grooves that extend partway or completely through housing  12  may extend across the width of the rear wall of housing  12  and may penetrate through the rear wall of housing  12  to divide the rear wall into different portions. These grooves may also extend into peripheral housing structures  16  and may form antenna slots, gaps  18 , and other structures in device  10 . Polymer or other dielectric may fill these grooves and other housing openings. In some situations, housing openings that form antenna slots and other structure may be filled with a dielectric such as air. 
     In a typical scenario, device  10  may have one or more upper antennas and one or more lower antennas (as an example). An upper antenna may, for example, be formed at the upper end of device  10  in region  22 . A lower antenna may, for example, be formed at the lower end of device  10  in region  20 . The antennas may be used separately to cover identical communications bands, overlapping communications bands, or separate communications bands. The antennas may be used to implement an antenna diversity scheme or a multiple-input-multiple-output (MIMO) antenna scheme. 
     Antennas in device  10  may be used to support any communications bands of interest. For example, device  10  may include antenna structures for supporting local area network communications, voice and data cellular telephone communications, global positioning system (GPS) communications or other satellite navigation system communications, Bluetooth® communications, etc. 
     A schematic diagram showing illustrative components that may be used in device  10  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry such as storage and processing circuitry  28 . Storage and processing circuitry  28  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, multiple-input and multiple-output (MIMO) protocols, antenna diversity protocols, near-field communications (NFC) protocols, etc. 
     Input-output circuitry  30  may include input-output devices  32 . Input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include user interface devices, data port devices, and other input-output components. For example, input-output devices  32  may include touch screens, displays without touch sensor capabilities, buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, position and orientation sensors (e.g., sensors such as accelerometers, gyroscopes, and compasses), capacitance sensors, proximity sensors (e.g., capacitive proximity sensors, light-based proximity sensors, etc.), fingerprint sensors (e.g., a fingerprint sensor integrated with a button such as button  24  of  FIG. 1  or a fingerprint sensor that takes the place of button  24 ), etc. 
     Input-output circuitry  30  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 transceiver circuitry  36 ,  38 , and  42 . Transceiver circuitry  36  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band. Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in frequency ranges such as a low communications band from 700 to 960 MHz, a low-midband from 960 to 1710 MHz, a midband from 1710 to 2170 MHz, a high band from 2300 to 2700 MHz, an ultra-high band from 3400 to 3700 MHz or other communications bands between 600 MHz and 4000 MHz or other suitable frequencies (as examples). 
     Circuitry  38  may handle voice data and non-voice data. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near-field communications (NFC) circuitry, etc. Wireless communications circuitry  34  may include global positioning system (GPS) receiver equipment such as GPS receiver circuitry  42  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless circuitry  34  may include near-field communications circuitry  120 . Near-field communications circuitry  120  may produce and receive near-field communications signals to support communications between device  10  and a near-field communications reader or other external near-field communications equipment. Near-field communications may be supported using loop antennas (e.g., to support inductive near-field communications in which a loop antenna in device  10  is electromagnetically near-field coupled to a corresponding loop antenna in a near-field communications reader). Near-field communications links typically are formed over distances of 20 cm or less (i.e., device  10  must be placed in the vicinity of the near-field communications reader for effective communications). 
     Wireless communications circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, dipole antenna structures, monopole antenna structures, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. In addition to supporting cellular telephone communications, wireless local area network communications, and other far-field wireless communications, the structures of antennas  40  may be used in supporting near-field communications. The structures of antennas  40  may also be used in gathering proximity sensor signals (e.g., capacitive proximity sensor signals). 
     Radio-frequency transceiver circuitry  90  does not handle near-field communications signals and is therefore sometimes referred to as far-field communications circuitry or non-near-field communications circuitry. Near-field communications transceiver circuitry  120  is used in handling near-field communications. With one suitable arrangement, near-field communications can be supported using signals at a frequency of 13.56 MHz. Other near-field communications bands may be supported using the structures of antennas  40  if desired. Transceiver circuitry  90  may handle non-near-field communications frequencies (e.g., frequencies above 600 MHz or other suitable frequencies). 
     As shown in  FIG. 3 , antenna structures  40  may be coupled to near-field communications circuitry such as near-field communications transceiver  120  and non-near-field communications circuitry such as non-near-field transceiver circuitry  90 . 
     Non-near-field transceiver circuitry  90  in wireless circuitry  34  may be coupled to antenna structures  40  using paths such as path  92 . Near-field communications transceiver circuitry  120  may be coupled to antenna structures  40  using paths such as path  132 . Paths such as path  134  may be used to allow control circuitry  28  to transmit near-field communications data and to receive near-field communications data using a near-field communications antenna formed from structures  40 . 
     Control circuitry  28  may be coupled to input-output devices  32 . Input-output devices  32  may supply output from device  10  and may receive input from sources that are external to device  10 . 
     To provide antenna structures such as antenna(s)  40  with the ability to cover communications frequencies of interest, antenna(s)  40  may be provided with circuitry such as filter circuitry (e.g., one or more passive filters and/or one or more tunable filter circuits). Discrete components such as capacitors, inductors, and resistors may be incorporated into the filter circuitry. Capacitive structures, inductive structures, and resistive structures may also be formed from patterned metal structures (e.g., part of an antenna). If desired, antenna(s)  40  may be provided with adjustable circuits such as tunable components  102  to tune antennas over communications bands of interest. Tunable components  102  may be part of a tunable filter or tunable impedance matching network, may be part of an antenna resonating element, may span a gap between an antenna resonating element and antenna ground, etc. 
     Tunable components  102  may include tunable inductors, tunable capacitors, or other tunable components. Tunable components such as these may be based on switches and networks of fixed components, distributed metal structures that produce associated distributed capacitances and inductances, variable solid state devices for producing variable capacitance and inductance values, tunable filters, or other suitable tunable structures. During operation of device  10 , control circuitry  28  may issue control signals on one or more paths such as path  103  that adjust inductance values, capacitance values, or other parameters associated with tunable components  102 , thereby tuning antenna structures  40  to cover desired communications bands. 
     During operation of device  10 , control circuitry  28  may issue control signals on one or more paths such as path  136  that adjust inductance values, capacitance values, or other parameters associated with tunable components  102 , thereby tuning antenna structures  40  to cover desired communications bands. Active and/or passive components may also be used to allow antenna structures  40  to be shared between non-near-field-communications transceiver circuitry  90  and near-field communications transceiver circuitry  120 . Near-field communications and non-near-field communications may also be handled using two or more separate antennas, if desired. 
     Path  92  may include one or more transmission lines. As an example, signal path  92  of  FIG. 3  may be a transmission line having a positive signal conductor such as line  94  and a ground signal conductor such as line  96 . Lines  94  and  96  may form parts of a coaxial cable, a stripline transmission line, or a microstrip transmission line (as examples). A matching network (e.g., an adjustable matching network formed using tunable components  102 ) may include components such as inductors, resistors, and capacitors used in matching the impedance of antenna(s)  40  to the impedance of transmission line  92 . Matching network components may be provided as 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 in antenna(s)  40  and may be tunable and/or fixed components. 
     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, a slot antenna, a hybrid inverted-F slot antenna or other antenna having an antenna feed  112  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  100 . Other types of antenna feed arrangements may be used if desired. For example, antenna structures  40  may be fed using multiple feeds. The illustrative feeding configuration of  FIG. 3  is merely illustrative. 
     If desired, control circuitry  28  may use an impedance measurement circuit to gather antenna impedance information. Control circuitry  28  may use information from a proximity sensor (see, e.g., sensors  32  of  FIG. 2 ), received signal strength information, device orientation information from an orientation sensor, information about a usage scenario of device  10 , information about whether audio is being played through speaker  26 , information from one or more antenna impedance sensors, or other information in determining when antenna  40  is being affected by the presence of nearby external objects or is otherwise in need of tuning. In response, control circuitry  28  may adjust an adjustable inductor, adjustable capacitor, switch, or other tunable component  102  to ensure that antenna  40  operates as desired. Adjustments to component  102  may also be made to extend the coverage of antenna  40  (e.g., to cover desired communications bands that extend over a range of frequencies larger than antenna  40  would cover without tuning). 
     Antennas  40  may include slot antenna structures, inverted-F antenna structures (e.g., planar and non-planar inverted-F antenna structures), loop antenna structures, combinations of these, or other antenna structures. 
     An illustrative inverted-F antenna structure is shown in  FIG. 4 . Inverted-F antenna structure  40  of  FIG. 4  has antenna resonating element  106  and antenna ground (ground plane)  104 . Antenna resonating element  106  may have a main resonating element arm such as arm  108 . The length of arm  108  may be selected so that antenna structure  140  resonates at desired operating frequencies. For example, the length of arm  108  (or a branch of arm  108 ) may be a quarter of a wavelength at a desired operating frequency for antenna  40 . Antenna structure  40  may also exhibit resonances at harmonic frequencies. If desired, slot antenna structures or other antenna structures may be incorporated into an inverted-F antenna such as antenna  40  of  FIG. 4  (e.g., to enhance antenna response in one or more communications bands). 
     Main resonating element arm  108  may be coupled to ground  104  by return path  110 . Antenna feed  112  may include positive antenna feed terminal  98  and ground antenna feed terminal  100  and may run parallel to return path  110  between arm  108  and ground  104 . If desired, inverted-F antenna structures such as illustrative antenna structure  40  of  FIG. 4  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.). If desired, antennas such as inverted-F antenna  40  of  FIG. 4  may have tunable components such as components  102  of  FIG. 3 . 
     A top interior view of an illustrative portion of device  10  that contains antennas is shown in  FIG. 5 . As shown in  FIG. 5 , device  10  may have peripheral conductive housing structures such as peripheral conductive housing structures  16 . Peripheral conductive housing structures  16  may be segmented by dielectric-filled gaps (e.g., plastic gaps)  18  such as gaps  18 - 1  and  18 - 2 . Antenna structures  40  may be used in forming a non-near-field antenna based on an inverted-F antenna design or antenna structures with other designs. Antenna structures  40  may include an inverted-F antenna resonating element arm such as arm  108  that is formed from the segment of peripheral conductive housing structures  16  extending between gaps  18 - 1  and  18 - 2 . 
     A dielectric-filled opening such as slot  101  may separate arm  108  from ground  104 . Air and/or other dielectric may fill slot  101  between arm  108  and ground structures  104 . If desired, slot  101  may be configured to form a slot antenna resonating element structure that contributes to the overall performance of the antenna. Antenna ground  104  may be formed from conductive housing structures, from electrical device components in device  10 , from printed circuit board traces, from strips of conductor such as strips of wire and metal foil, or other conductive structures. In one suitable arrangement ground  104  is formed from conductive portions of housing  12  (e.g., portions of a rear wall of housing  12  and portions of peripheral conductive housing structures  16  that are separated from arm  108  by peripheral gaps  18 ). Return path  110  for inverted-F antenna resonating element arm  108  may be coupled between arm peripheral conductive housing structures  16  and ground  104 . 
     To support near-field communications in device  10 , device  10  preferably includes a near-field communications antenna. Space can be conserved by using some or all of antenna structures  40  as both a cellular telephone antenna or other non-near-field communications antenna and as a near-field communications antenna. As an example, a near-field communications antenna for device  10  (e.g., an antenna that is used by near-field communications circuitry  120 ) may be formed using portions of antenna structures  40  of  FIG. 5  such as portions of resonating element  108  and ground  104 . By sharing conductive antenna structures between both near-field and non-near-field antennas, duplicative conductive structures can be minimized and antenna volume can be conserved within device  10 . 
     As shown in  FIG. 5 , a near-field communications antenna for device  10  may be formed from antenna structures  40  such as portions of inverted-F antenna resonating element arm  108 , return path  110 , and ground  104 . The non-near-field communications antenna formed from antenna structures  40  may be fed using an antenna feed such as feed  112 . Positive antenna feed terminal  98  of feed  112  may be coupled to peripheral conductive structures  16  whereas ground feed terminal  100  is coupled to ground  104 . Positive transmission line conductor  94  and ground transmission line conductor  96  of transmission line  92  may be coupled between transceiver circuitry  90  and antenna feed  112 . Transceiver circuitry  90  may handle wireless communications in frequency bands such as a low communications band from 700 to 960 MHz, a low-midband from 960 to 1710 MHz, a midband from 1710 to 2170 MHz, a high band from 2300 to 2700 MHz, an ultra-high band from 3400 to 3700 MHz, 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications, and/or a 1575 MHz band for GPS signals. 
     The non-near-field communications inverted-F antenna formed from structures  40  may have a return path such as return path  110  coupled between arm  108  (at terminal  202 ) and ground  104  (at terminals  204 - 1  and  204 - 2 ). Return path  110  may include one or more inductors such as inductors  206  and  208 . If desired, inductors  206  and  208  may be coupled in parallel between terminal  202  on peripheral conductive housing structure  16  and different locations on ground  104 . For example, inductor  206  may be coupled between terminal  202  and ground terminal  204 - 1 , whereas inductor  208  is coupled between terminal  202  and ground terminal  204 - 2 . Inductors  206  and  208  may be fixed inductors or may be adjustable inductors. For example, each inductor may be coupled to a switch that selectively opens to disconnect the inductor between terminal  202  and ground  104 . 
     In this way, return path  110  may be split between a single point  202  on peripheral conductive housing structures  16  and multiple points on ground  104 . Because return path  110  is split between two paths that are coupled in parallel between terminal  202  and ground  104 , return path  110  may sometimes be referred to herein as a split short path or a split return path. The split short path may, for example, improve antenna efficiency for the non-near-field communications antenna formed from structures  40  relative to scenarios where the return path is implemented using a single conductive path between terminal  202  and ground  104 . For example, if return path  110  only included inductor  206 , antenna structures  40  may have a relatively high antenna efficiency in a first portion of the midband MB (e.g., between 1710 MHz and 1940 MHz). If return path  110  only included inductor  208 , antenna structures  40  may have a relatively high antenna efficiency in a second portion of the midband MB (e.g., between 1940 MHz and 2170 MHz). However, when return path  110  is a split return path that includes both inductor  206  and  208 , antenna structures  40  may have a relatively high antenna efficiency across the entire midband MB (e.g., between 1710 MHz and 2170 MHz). 
     Ground plane  104  may have any desired shape within device  10 . For example, ground plane  104  may align with gap  18 - 1  in peripheral conductive hosing structures  16  (e.g., the lower edge of gap  18 - 1  may be aligned with the edge of ground plane  104  defining slot  101  adjacent to gap  18 - 1  such that the lower edge of gap  18 - 1  is approximately collinear with the edge of ground plane  104  at the interface between ground plane  104  and the portion of peripheral conductive structures  16  adjacent to gap  18 - 1 ). This example is merely illustrative and, in another suitable arrangement, ground plane  104  may have an additional vertical slot adjacent to gap  18 - 1  that extends below gap  18 - 1  (e.g., along the Y-axis of  FIG. 5 ). 
     If desired, ground plane  104  may include a vertical slot  162  adjacent to gap  18 - 2  that extends beyond the lower edge (e.g., lower edge  210 ) of gap  18 - 2  (e.g., in the direction of the Y-axis of  FIG. 5 ). Slot  162  may, for example, have two edges that are defined by ground  104  and one edge that is defined by peripheral conductive structures  16 . Slot  162  may have an open end defined by an open end of slot  101  at gap  18 - 2 . Slot  162  may have a width  176  that separates ground  104  from the portion of peripheral conductive structures  16  below slot  18 - 2  (e.g., in the direction of the X-axis of  FIG. 5 ). Because the portion of peripheral conductive structures  16  below gap  18 - 2  is shorted to ground  104  (and thus forms part of the antenna ground for antenna structures  40 ), slot  162  may effectively form an open slot having three sides defined by the antenna ground for antenna structures  40 . Slot  162  may have any desired width (e.g., about 2 mm, less than 4 mm, less than 3 mm, less than 2 mm, less than 1 mm, more than 0.5 mm, more than 1.5 mm, more than 2.5 mm, 1-3 mm, etc.). Slot  162  may have an elongated length  178  (e.g., perpendicular to width  176 ). Slot  162  may have any desired length (e.g., 10-15 mm, more than 5 mm, more than 10 mm, more than 15 mm, more than 30 mm, less than 30 mm, less than 20 mm, less than 15 mm, less than 10 mm, between 5 and 20 mm, etc.). 
     Electronic device  10  may be characterized by longitudinal axis  282 . Length  178  may extend parallel to longitudinal axis  282  (and the Y-axis). Portions of slot  162  may contribute slot antenna resonances to antenna  40  in one or more frequency bands if desired. For example, the length and width of slot  162  may be selected so that antenna  40  resonates at desired operating frequencies. If desired, the overall length of slots  101  and  162  may be selected so that antenna  40  resonates at desired operating frequencies. 
     In order to support near-field communications using antenna structures  40 , near-field communications circuitry  120  (NFC TX/RX) may transmit and receive near-field communications signals (e.g., signals in a near-field communications band such as a 13.56 MHz near-field communications band). Near-field communications transceiver circuitry  120  may be coupled to antenna structures  40  using a conductive path such as path  132 . Path  132  may, for example, be a single-ended transmission line signal path for conveying single-ended near-field communications signals. In this scenario, near-field communications transceiver circuitry  120  may include balun circuitry or other circuitry for converting the single-ended signals into differential signals and for converting differential signals into the single-ended signals. As shown in  FIG. 5 , node  214  on path  132  may be shorted to ground  104  through a capacitive circuit such as capacitor  218 . Node  214  may also be coupled to terminal  212  on peripheral conductive housing structures  16  via an inductive circuit such as inductor  220 . Inductor  220  may have a selected inductance and capacitor  218  may have a selected capacitance to ensure that antenna structures  40  operate with satisfactory antenna efficiency while conveying both near-field and non-near-field signals. 
     For example, the inductance of inductor  220  may be selected to ensure that resonating element arm  108  is impedance matched to transmission line  92  at non-near-field communications frequencies (e.g., cellular telephone frequencies). As an example, inductor  220  may have an inductance of approximately 10 nH, between 8 nH and 12 nH, between 5 nH and 15 nH, or other inductances. 
     In order to perform such impedance matching, inductor  220  is coupled between terminal  212  and ground  104 . In scenarios where antenna structures  40  are only used for conveying non-near-field communications, the non-near-field communications antenna formed from structures  40  may exhibit optimal performance at cellular telephone frequencies if inductor  220  is shorted directly to ground plane  104  at node  214 . However, when antenna structures  40  are also used to support near-field communications, shorting inductor  220  to ground  104  at node  214  would short out near-field communications signals from transceiver  120  to ground  104  before the corresponding antenna currents could pass to peripheral conductive housing structures  16 , thereby preventing structures  40  from wirelessly conveying the near-field signals with satisfactory efficiency. 
     In order to allow inductor  220  to perform satisfactory impedance matching at non-near-field communications frequencies for the non-near-field communications antenna formed from structures  40  while still allowing structures  40  to support near-field communications, capacitor  218  may short terminal  214  to antenna ground  104  at ground terminal  216  (e.g., inductor  220  may be shorted to ground  104  through node  214  and capacitor  218 ). Capacitor  218  may have a relatively large capacitance that is selected to block relatively low frequency signals such as near-field communications signals conveyed by transceiver  120  from passing from node  214  to ground point  216  while also allowing relatively high frequency signals such as non-near-field communications signals conveyed by transceiver  90  to pass from node  214  to ground  216 . In other words, capacitor  218  may serve as a filter that forms an open circuit between node  214  and terminal  216  at near-field communications frequencies and that forms a short circuit between node  214  and terminal  216  at non-near-field communications frequencies (e.g., frequencies greater than 100 MHz, greater than 20 MHz, greater than 13.56 MHz, etc.). As examples, capacitor  218  may have a capacitance of approximately 50 pF, between 30 and 100 pF, greater than 10 pF, less than 100 pF, greater than 30 pF, greater than 50 pF, or other desired capacitances. 
     When configured in this way, non-near-field communications antenna signals (antenna currents) such as cellular telephone signals conveyed by feed  112  may follow path  224  from resonating element  108  through inductor  220  and capacitor  218  to ground (through ground terminal  216 ). At the same time, near-field communication antenna signals (antenna currents) may flow over path  222  through inductor  220 , peripheral conductive housing structure  16 , return path  110  (e.g., inductor  208 ), and ground  104  (e.g., a loop path that forms a loop antenna resonating element for a near-field communications loop antenna formed from antenna structures  40 ). Antenna structures  40  may, if desired, concurrently or simultaneously convey near-field communications signals and non-near-field communications signals with satisfactory efficiency. 
     In the example of  FIG. 5 , near-field communications antenna signals are depicted as following path  222  through inductor  208  of return path  110 . However, this example is merely illustrative. As previously discussed, return path  110  may be split into two inductors coupled in parallel between terminal  202  and ground  104 . Path  222  may therefore pass through inductor  208 , inductor  206 , or both inductors  206  and  208 . Extending the loop antenna resonating element across the width of device  10  in this way may, for example, allow device  10  to be relatively immune to device positioning when communicating with external near-field communications circuitry such as an RFID reader. The example of  FIG. 5  is merely illustrative. If desired, inductor  220  and/or capacitor  218  may be replaced with any desired filter circuitry (e.g., filter circuitry including inductive, capacitive, and/or resistive components arranged in any desired manner). The filter circuitry may include, for example, high pass filter circuitry, low pass filter circuitry, band pass filter circuitry, notch filter circuitry, etc. 
       FIG. 6  is a top view of path  132  for conveying near-field communications signals using antenna structures  40 . As shown in  FIG. 6 , electronic device  10  may include a flexible printed circuit such as flexible printed circuit board  226 . Flexible printed circuit board  226  may be a printed circuit formed from sheets of polyimide or other flexible polymer layers. Flexible printed circuit board  226  may include patterned metal traces for carrying signals between components on the flexible printed circuit board. Inductor  220  and capacitor  218  may be fixed components mounted on flexible printed circuit  226  (e.g., surface mount technology components). In another suitable arrangement, inductor  220  may be formed from a distributed inductance and/or capacitor  218  may be formed from a distributed capacitance on printed circuit  226 . 
     Flexible printed circuit  226  may include a positive antenna feed terminal  230  and a ground antenna feed terminal  232  for the near-field communications antenna. Feed terminals  232  and  230  may, if desired, be coupled to path  132  through a differential-to-single ended converter such as a balun (not shown) that converts differential signals appearing across differential terminals  232  and  230  to single-ended loop current signals that flow over path  132  and loop path  222  of  FIG. 5 . Path  132  may be formed from metal traces on the printed circuit coupled to transceiver circuitry  120  (e.g., feed terminal  230  or a balun having differential terminals coupled to terminals  230  and  232  and a single ended terminal coupled to path  132 ). Path  132  may be coupled to node  214 . Inductor  220  may be coupled between node  214  and terminal  234  on flexible printed circuit  226 . Terminal  234  on the flexible printed circuit may then be coupled to terminal  212  on peripheral conductive housing structure  16 . Terminals  212  and  234  may be coupled using any desired conductive structure (e.g., a bracket, clip, spring, pin, screw, solder, weld, conductive adhesive, etc.). If desired, the structure that electrically connects the flexible printed circuit to the peripheral conductive housing structure may also mechanically secure the flexible printed circuit to the peripheral conductive housing structure or another structure within the electronic device. 
     Capacitor  218  may be coupled between terminal  214  and ground terminal  216 . Ground terminal  216  may be formed from any desired conductive structure that is coupled to ground plane  104 . In some cases, the structure that electrically connects the terminal  216  to ground may also mechanically secure the flexible printed circuit (e.g., to a conductive support plate that forms at least a portion of ground plane  104 ). Ground terminal  216  may be formed by a fastener such as a screw or may be formed by any other desired type of conductive structure (e.g., a bracket, clip, spring, pin, screw, solder, weld, conductive adhesive, etc.). If desired, conductive structures may also short ground terminal  216  to grounded conductive structures in display  14  (e.g., a conductive display frame or display plate). 
     Flexible printed circuit board  226  may be coupled to an additional printed circuit (e.g., printed circuit  228 ). Printed circuit  228  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., a flexible printed circuit formed from a sheet of polyimide or other flexible polymer layer). Printed circuit  228  may be the motherboard or main logic board for electronic device  10 , for example. Flexible printed circuit board  226  may be connected to printed circuit board  228  at positive antenna feed terminal  230  and/or ground antenna feed terminal  232 . Printed circuit board  228  may be mounted above or below flexible printed circuit  226 . 
       FIG. 7  is a cross-sectional side view taken along line  235  in  FIG. 6 .  FIG. 7  shows one example of how ground plane  104 , flexible printed circuit  226 , and printed circuit board  228  may be connected. As shown in  FIG. 7 , a conductive screw boss  236  may be formed on ground plane  104 . If desired, screw boss  236  may be formed integrally with conductive housing structures (e.g., internal and/or external structures, support plate structures that form a rear housing wall, etc.) that form portions of ground plane  104 . Screw boss  236  may be conductive and may short ground plane  104  to flexible printed circuit  226  and printed circuit board  228 . In one illustrative embodiment, conductive screw boss  236  may be shorted to a ground antenna feed terminal (i.e., ground antenna feed terminal  232  in  FIG. 6 ) in flexible printed circuit  226 . A screw such as screw  238  may be screwed into screw boss  236 . Screw  238  may apply a bias force in direction  244  to secure printed circuit board  228  and flexible printed circuit  226  to ground plane  104 . Printed circuit board  228  and flexible printed circuit  226  may have openings to receive screw  238 , screw boss  236 , or a combination of screw  238  and screw boss  236 . 
     The bias force applied by screw  238  may also press feed pads  242  on printed circuit board  228  into feed pads  240  on flexible printed circuit  226 . Feed pads  240  and  242  may be conductive feed pads formed on the surface of flexible printed circuit  226  and printed circuit board  228  respectively. Printed circuit board  228  may send antenna feed signals to flexible printed circuit board  226  through feed pads  240  and  242 . Feed pads  240  on flexible printed circuit  226  may be considered to form the positive antenna feed terminal (e.g., positive antenna feed terminal  230  in  FIG. 6  or the single ended output of a balun coupled to the differential feed terminals of transceiver  120 ) for the near-field communications antenna. Feed pads  240  and  242  may have an annular shape such that the feed pads surround screw boss  236 . Alternatively, feed pads  240  and  242  may have any other desired shape. 
     The example of  FIG. 7  where flexible printed circuit  226  is formed underneath printed circuit board  228  is merely illustrative. If desired, printed circuit board  228  may be formed underneath flexible printed circuit  226 . Additionally, in the example of  FIG. 7 , screw  238  is not used to electrically connect any components within the electronic device. Therefore, screw  238  does not need to be conductive (i.e., screw  238  could be a dielectric material such as plastic). However, in other embodiments, screw  238  may be formed from a conductive material and may electrically connect components together. For example, screw  238  may electrically connect printed circuit board  228 , flexible printed circuit  226 , and/or ground plane  104 . In embodiments where screw  238  electrically connects components, some or all of screw boss  236  may be formed from a dielectric material if desired. 
     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: 20170911
Publication Date: 20190416
Grant Date: 20190416
Priority Date: 20170911
Inventors: ZHOU, YIJUN
WANG, Yiren
EDWARDS, JENNIFER M.
XU, HAO
PASCOLINI, MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/328", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/241", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q13/103", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B1/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/0053", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q23/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/328", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/242", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2258", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/103", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/328", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/241", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 65441451