PATENT DOCUMENT

Publication Number: US-9621230-B2
Application Number: US-201414195247-A
Country: US
Kind Code: B2

Title: Electronic device with near-field antennas

Abstract:
An electronic device may have multiple near-field communications antennas. Multiplexer circuitry may have a transceiver port that is coupled to a near-field communications transceiver, and multiple antenna ports coupled to respective near-field communications antennas. Non-near-field communications antennas may be used by non-near-field communications circuitry. The electronic device may have a housing with opposing first and second ends and a display. One of the near-field communications antennas and one of the non-near-field communications antenna may be formed from shared antenna structures at the first end. Another of the near-field communications antennas and another of the non-near-field communications antennas may be formed from shared antenna structures at the second end. An additional near field communications antenna may be overlapped by the display.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a first near-field communications loop antenna; 
 a second near-field communications loop antenna; 
 near-field communications circuitry that wirelessly communicates using the first and second near-field communications loop antennas; 
 an antenna ground; and 
 an inverted-F antenna resonating element, wherein the first near-field communications loop antenna includes a portion of the inverted-F antenna resonating element and a portion of the antenna ground. 
 
     
     
       2. The electronic device defined in  claim 1  further comprising:
 a first non-near-field communications antenna; 
 a second non-near-field communications antenna; and 
 non-near-field communications circuitry that wirelessly communicates using the first and second non-near-field communications antennas. 
 
     
     
       3. The electronic device defined in  claim 2 , wherein the first near-field communications loop antenna and the first non-near-field communications antenna are formed at least partly from the antenna ground. 
     
     
       4. The electronic device defined in  claim 2  further comprising a third near-field communications loop antenna. 
     
     
       5. The electronic device defined in  claim 4  wherein the non-near-field communications circuitry comprises a cellular telephone transceiver. 
     
     
       6. The electronic device defined in  claim 1 , further comprising:
 an additional inverted-F antenna resonating element, wherein the second near-field communications loop antenna includes a portion of the additional inverted-F antenna resonating element. 
 
     
     
       7. An electronic device, comprising:
 a first near-field communications loop antenna; 
 a second near-field communications loop antenna; 
 near-field communications circuitry that wirelessly communicates using the first and second near-field communications loop antennas 
 a first non-near-field communications antenna; 
 a second non-near-field communications antenna; 
 non-near-field communications circuitry that wirelessly communicates using the first and second non-near-field communications antennas; 
 an antenna ground for the first non-near-field communications antenna, wherein the first near-field communications loop antenna, the first non-near-field communications antenna, and the second near-field communications loop antenna and the second non-near-field communications antenna are formed at least partly from the antenna ground. 
 
     
     
       8. The electronic device defined in  claim 7  further comprising:
 a first inverted-F antenna resonating element; and 
 a second inverted-F antenna resonating element, wherein the first non-near-field communications antenna is formed from the first inverted-F antenna resonating element and the antenna ground, the second non-near-field communications antenna is formed from the second inverted-F antenna resonating element and the antenna ground, the first near-field communications loop antenna includes a portion of the first inverted-F antenna resonating element, and the second near-field communications loop antenna includes a portion of the second inverted-F antenna resonating element. 
 
     
     
       9. The electronic device defined in  claim 8  further comprising a third near-field communications loop antenna located between the first and second near-field communications antennas. 
     
     
       10. The electronic device defined in  claim 9  further comprising a display, wherein the display overlaps the third near-field communications loop antenna. 
     
     
       11. The electronic device defined in  claim 10  further comprising:
 control circuitry; and 
 multiplexer circuitry controlled by the control circuitry, wherein the multiplexer circuitry has a transceiver port coupled to the near-field communications circuitry, has a first antenna port coupled to the first near-field communications loop antenna, has a second antenna port coupled to the second near-field communications loop antenna, and has a third antenna port coupled to the third near-field communications loop antenna. 
 
     
     
       12. The electronic device defined in  claim 11  further comprising additional multiplexer circuitry coupled between the non-near-field communications circuitry and the first and second non-near-field communications antennas. 
     
     
       13. The electronic device defined in  claim 12  wherein the non-near-field communications circuitry comprises a cellular telephone transceiver. 
     
     
       14. An electronic device, comprising:
 a first near-field communications loop antenna; 
 a second near-field communications loop antenna; 
 near-field communications circuitry that wirelessly communicates using the first and second near-field communications loop antennas; and 
 peripheral conductive electronic device housing structures that form part of the first and second near-field communications loop antennas. 
 
     
     
       15. The electronic device defined in  claim 14 , further comprising:
 a first non-near-field communications antenna; 
 a second non-near-field communications antenna; and 
 non-near-field communications circuitry that wirelessly communicates using the first and second non-near-field communications antennas, wherein the peripheral conductive electronic device housing structures form part of the first and second non-near-field communications antennas. 
 
     
     
       16. Apparatus, comprising:
 a first near-field communications loop antenna; 
 a second near-field communications loop antenna; and 
 near-field communications circuitry; 
 multiplexer circuitry, wherein the multiplexer circuitry has a first antenna port coupled to the first near-field communications loop antenna, has a second antenna port coupled to the second near-field communications loop antenna, and has a transceiver port coupled to the near-field communications circuitry, and wherein the near-field communications circuitry wirelessly communicates using the first and second near-field communications loop antennas; 
 a conductive structure that forms at least part of the first near-field communications loop antenna and that forms at least part of the second near-field communications loop antenna, wherein the conductive structure forms an antenna ground; 
 non-near-field communications circuitry; 
 a first antenna resonating element arm, wherein the first antenna resonating element arm and the antenna ground form a first non-near-field communications antenna; and 
 a second antenna resonating element arm, wherein the second antenna resonating element arm and the antenna ground form a second non-near-field communications antenna and the non-near-field communications circuitry wirelessly communicates using the first and second non-near-field communications antennas. 
 
     
     
       17. The apparatus defined in  claim 16  wherein the first near-field communications loop antenna includes at least part of the first antenna resonating element arm. 
     
     
       18. The apparatus defined in  claim 16  further comprising a third near-field communications loop antenna coupled to a third antenna port of the multiplexer circuitry. 
     
     
       19. The apparatus defined in  claim 16  further comprising an electronic device housing having opposing first and second ends, wherein the first antenna resonating element arm comprises an inverted-F antenna resonating element arm at the first end and the second antenna resonating element arm comprises an inverted-F antenna resonating element arm at the second end. 
     
     
       20. The apparatus defined in  claim 16  further comprising:
 a third near-field communications loop antenna; 
 an electronic device housing; 
 a first antenna window in the electronic device housing through which the first near field communications loop antenna operates; 
 a second antenna window in the electronic device housing through which the second near-field communications loop antenna operates; and 
 a display mounted in the electronic device housing and having a portion through which the third near-field communications loop antenna operates.

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 have near-field communications antennas. Multiplexer circuitry may be provided that has a transceiver port coupled to a near-field communications transceiver and that has multiple antenna ports coupled to respective near-field communications antennas. The electronic device may have non-near-field communications antennas that are used by a non-near-field communications transceiver. Multiplexing circuitry may be provided that has antenna ports coupled respectively to each of the non-near-field communications antennas and that has a transceiver port coupled to non-near-field communications transceiver. 
     The electronic device may have a housing with opposing first and second ends. A display may be mounted between the first and second ends. One of the near-field communications antennas and one of the non-near-field communications antenna may be formed from shared antenna structures at the first end. Another of the near-field communications antennas and another of the non-near-field communications antennas may be formed from shared antenna structures at the second end. Baluns may be used in coupling near-field communications transceiver circuitry to the near-field communications antennas. An additional near field communications antenna may be coupled to one of the antenna ports in the multiplexing circuitry for the near-field communications circuitry and may be overlapped by the display. 
    
    
     
       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 diagram of a system in which antenna structures in an electronic device are being used to wirelessly communicate with external electrical equipment using near-field communications and non-near-field communications in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device with antenna structures in accordance with an embodiment. 
         FIG. 5  is a diagram of an electronic device having antenna structures that can be used to handle both non-near-field communications and near-field communications in accordance with an embodiment. 
         FIG. 6  is top view of an illustrative electronic device having upper antenna structures that may be shared between near-field and non-near-field communications, having lower antenna structures that may be shared between near-field and non-near-field communications, and having a near-field communications antenna that is interposed between the upper and lower antenna structures in accordance with an embodiment. 
         FIG. 7  is a diagram of an illustrative electronic device having multiplexed upper and lower non-near-field antennas and multiplexed upper, middle, and lower near-field antennas in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative electronic device such as a tablet computer with antenna structures in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with wireless circuitry. The wireless circuitry may include near-field communications circuitry. For example, a near-field communications transmitter-receiver (“transceiver”) may use a near-field communications antenna to transmit and receive near-field electromagnetic signals at a frequency such as 13.56 MHz. Near-field communications schemes involve near-field electromagnetic coupling between near-field antennas that are separated by a relatively small distance (e.g., 20 cm or less). The near-field communications antennas may be loop antennas. The wireless circuitry may also include cellular network transceiver circuitry, wireless local area network transceiver circuitry, satellite navigation system circuitry, or other non-near-field communications circuitry. The non-near-field communications circuitry can use an antenna to handle radio-frequency signals at frequencies of 700 MHz to 2700 MHz, 5 GHz, or other suitable frequencies. 
     To conserve space within an electronic device, a near-field communications antenna and a non-near-field communications antenna can be formed from shared antenna structures. For example, conductive electronic device housing structures, metal traces on printed circuits and other substrates, and other conductive structures in an electronic device may be configured to serve both as a non-near-field antenna and as a near-field antenna. Near-field and non-near-field antennas may also be implemented using separate antennas. 
       FIG. 1  is a perspective view of an illustrative electronic device of the type that may be provided with wireless communications circuitry having antenna structures for handling near-field communications and non-near-field communications. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands. The wireless communications circuitry may include antenna structures that include loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. 
     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 a peripheral conductive member or other conductive peripheral electronic device housing structures running around the periphery of an electronic device. The peripheral conductive housing structures may serve as a bezel for a planar structure such as a display and/or may form vertical sidewalls for the device. 
     If desired, antenna structures may be configured to handle both near-field communications (e.g., communications in a near-field communications band such as a 13.56 MHz band or other near-field communications band) and non-near-field communications (sometimes referred to as far field communications) such as cellular telephone communications, wireless local area network communications, and satellite navigation system communications. Near-field communications typically involve communication distances of less than about 20 cm and involve magnetic (electromagnetic) near-field coupling between near-field antennas such as loop antennas. Far field communications typically involved communication distances of multiple meters or miles. 
     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 cellular telephone, or a media player. Device  10  may also be a television, a set-top box, a desktop computer, a computer monitor into which a computer has been integrated, a television, a computer monitor, 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. 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, for example, be a touch screen that incorporates capacitive touch electrodes. Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. A display cover layer such as a cover glass layer or a layer of clear plastic may cover the surface of display  14 . Buttons such as button  19  may pass through openings in the display cover layer or other outer layer in display  14 . The cover glass may also have other openings such as an opening for speaker port  26 . 
     Housing  12  may include peripheral conductive housing structures  16  such as a metal member or other conductive member. Peripheral conductive housing structures  16  may run around the periphery of device  10  and display  14 . In configurations in which device  10  and display  14  have rectangular shapes, peripheral conductive housing structures  16  may have a rectangular ring shape (as an example). Peripheral conductive housing structures  16  or part of peripheral conductive housing 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 helps hold display  14  to device  10 ). Peripheral conductive housing structures  16  may also, if desired, form sidewall structures for device  10  (e.g., by forming a band with vertical sidewalls, by forming a band with rounded sidewalls, etc.). If desired, peripheral conductive housing structures  16  such as housing sidewalls may be formed as integral portions of a metal rear housing wall for device  10  (i.e., the rear surface and edges of housing  12  may be formed from a conductive material such as metal). 
     Peripheral conductive housing structures  16  may include a peripheral conductive member such as a peripheral metal member, a peripheral metal housing band, or other peripheral conductive housing member, may include a metal display bezel, may include metal housing sidewalls, or may include other peripheral conductive housing structures. Peripheral conductive housing structures  16  (e.g., a metal member) may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, three, or more than three separate structures may be used in forming a peripheral conductive housing member or metal sidewalls may be separated into one, two, three, or more than three sidewall segments. 
     It is not necessary for peripheral conductive housing structures  16  to have a uniform cross-section. For example, the top (front face) portion of peripheral conductive housing structures  16  may, if desired, have an inwardly protruding lip that helps hold display  14  in place. If desired, the bottom portion of peripheral conductive housing structures  16  may also have an enlarged lip (e.g., in the plane of the rear surface of device  10 ). In the example of  FIG. 1 , structures  16  have substantially straight vertical sidewalls. This is merely illustrative. Sidewalls in housing  12  may be curved or may have any other suitable shape. In some configurations (e.g., when structures  16  serve as a bezel for display  14 ), structures  16  may run around the lip of housing  12  (i.e., structures  16  may cover only the edge of housing  12  that surrounds display  14  and not the rear edge of housing  12  of the sidewalls of housing  12 ). 
     Display  14  may include conductive structures such as an array of capacitive touch sensor electrodes, conductive lines for addressing display pixel elements, driver circuits, etc. Housing  12  may include internal structures such as metal frame members, a planar sheet metal housing structure (sometimes referred to as a midplate) that spans the walls of housing  12  (i.e., a substantially rectangular member that is welded or otherwise connected between opposing sides of structures  16 ), printed circuit boards, and other internal conductive structures. These conductive structures may be located in the center of housing  12  under display  14  (as an example). 
     In regions  22  and  20 , openings (gaps) may be formed within the conductive structures of device  10  (e.g., between peripheral conductive housing structures  16  or other conductive structures at the upper and lower edges of device  10  and opposing conductive structures that may form an antenna ground such as conductive housing structures, a conductive ground plane associated with a printed circuit board, and conductive electrical components in device  10 ). These openings may be filled with air, plastic, and other dielectrics. Conductive housing structures and other conductive structures in device  10  may serve as a ground plane for 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 arm from the ground plane, or may otherwise serve as part of antenna structures formed in regions  20  and  22 . If desired, one or more near-field communications antennas or other antennas may be located under display  14  between 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, 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 such locations. 
     Portions of peripheral conductive housing structures  16  may be provided with 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 may be filled with dielectric such as polymer, ceramic, glass, air, other dielectric materials, or combinations of these materials. Gaps  18  may divide peripheral conductive housing structures  16  into one or more peripheral conductive housing structure (member) segments. There may be, for example, two segments of a peripheral conductive housing member or other peripheral conductive housing structures  16  (e.g., in an arrangement with two gaps), three segments (e.g., in an arrangement with three gaps), four segments (e.g., in an arrangement with four gaps, etc.). The segments of the peripheral conductive housing member or other peripheral conductive housing structures that are formed in this way may form parts of antennas in device  10 . 
     If desired, device  10  may have upper and lower antennas and a middle (central) antenna that is located between the upper and 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 middle antenna may be located between regions  20  and  22  and may overlapped by display  14 . 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. 
     If desired, antenna structures may be shared between near-field and non-near-field communications. As an example, antenna structures in region  22  may be configured to serve both as a non-near-field antenna such as an inverted-F antenna that handles non-near-field communications and as a near-field antenna such as a loop antenna that handles near-field communications. The antenna structures in region  20  may be configured to serve both as a non-near-field antenna such as an inverted-F antenna that handles non-near-field communications and as a near-field antenna such as a loop antenna that handles near-field communications. The antenna structures in the region between regions  20  and  22  may be configured to serve as a near-field antenna such as a loop antenna that handles near-field communications without handling non-near-field communications (as an example). 
     Antennas in device  10  may be used to support any communications bands of interest. For example, device  10  may use non-near-field antennas to handle non-near-field-communications such as local area network communications, voice and data cellular telephone communications, global positioning system (GPS) communications or other satellite navigation system communications, Bluetooth® communications, etc. Device  10  may use near-field communications antennas to handle near-field communications (e.g., communications at 13.56 MHz). 
     A schematic diagram of an illustrative configuration that may be used for electronic device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , electronic 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 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, 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, near-field communications protocols, etc. 
     Circuitry  28  may be configured to implement control algorithms that control the use of antennas in device  10 . For example, circuitry  28  may perform signal quality monitoring operations, sensor monitoring operations, and other data gathering operations and may, in response to the gathered data and information on which communications bands are to be used in device  10 , control which antenna structures within device  10  are being used to receive and process data and/or may adjust one or more switches, tunable elements, or other adjustable circuits in device  10  to adjust antenna performance. As an example, circuitry  28  may control which of two or more antennas is being used to receive or transmit near-field or non-near-field wireless signals, which antenna is being used to handle incoming radio-frequency signals, may control which of two or more antennas is being used to transmit radio-frequency signals, may control the process of routing incoming data streams over two or more antennas in device  10  in parallel, may tune an antenna to cover a desired communications band, may perform time-division multiplexing operations to share antenna structures between near-field and non-near-field communications circuitry, to share a non-near-field communications transceiver between multiple non-near-field antennas, to share a near-field communications transceiver between multiple near-field antennas, etc. 
     In performing these control operations, circuitry  28  may open and close switches (e.g., switches associated with one or more multiplexers or other switching circuitry), may turn on and off receivers and transmitters, may adjust impedance matching circuits, may configure switches in front-end-module (FEM) radio-frequency circuits that are interposed between radio-frequency transceiver circuitry and antenna structures (e.g., filtering and switching circuits used for impedance matching and signal routing), may adjust switches, tunable circuits, and other adjustable circuit elements that are formed as part of an antenna or that are coupled to an antenna or a signal path associated with an antenna, and may otherwise control and adjust the components of device  10 . 
     Input-output circuitry  30  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 circuitry  30  may include input-output devices  32 . Input-output devices  32  may include touch screens, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  32  and may receive status information and other output from device  10  using the output resources of input-output devices  32 . The sensors in input-output circuitry  30  may gather information about the operating environment of device  10  and/or user input and may include sensors such as a touch sensor, an accelerometer, a compass, a proximity sensor, an ambient light sensor, and other sensors. Sensor data may be used in controlling antenna operation (e.g., in switching between antennas, tuning antennas, etc.). 
     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, 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 satellite navigation system receiver circuitry such as Global Positioning System (GPS) receiver circuitry  35  (e.g., for receiving satellite positioning signals at 1575 MHz) or satellite navigation system receiver circuitry associated with other satellite navigation systems. 
     Wireless local area network transceiver circuitry  36  in wireless communications circuitry  34  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 cellular telephone bands such as bands in frequency ranges of about 700 MHz to about 2700 MHz or bands at higher or lower frequencies. 
     Wireless communications circuitry  34  may include near-field communications circuitry  42 . Near-field communications circuitry  42  may handle near-field communications at frequencies such as the near-field communications frequency of 13.56 MHz or other near-field communications frequencies of interest. 
     Circuitry  44  such as satellite navigation system receiver circuitry  35 , wireless local area network transceiver circuitry  36 , and cellular telephone transceiver circuitry  38  that does not involve near-field communications may sometimes be referred to as non-near-field communications circuitry or far field communications circuitry. 
     Antenna structures  40  may be shared by non-near-field communications circuitry  44  and near-field communications circuitry  42  and/or may include one or more separate near-field and non-near-field antennas. 
     If desired, communications circuitry  34  may include circuitry for other short-range and long-range wireless links. For example, wireless communications circuitry  34  may include wireless circuitry for receiving radio and television signals, paging circuits, etc. In near-field communications, wireless signals are typically conveyed over distances of less than 20 cm. 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 communications circuitry  34  may include antenna structures  40 . Antenna structures  40  may include one or more antennas. Antennas structures  40  may be formed using any suitable antenna types. For example, antenna structures  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, closed and open slot antenna structures, planar inverted-F antenna structures, helical antenna structures, strip antennas, monopoles, dipoles, 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. 
     To accommodate near-field communications within the potentially tight confines of device housing  12 , antenna structures  40  may be shared between non-near-field communications circuitry  44  and near-field communications circuitry  42 . When, for example, it is desired to transmit and receive cellular telephone signals or other non-near-field communications, antenna structures  40  may be used by cellular telephone transceiver circuitry  38  or other non-near-field transceiver circuitry  44 . When it is desired to transmit and receive near-field communications signals, antenna structures  40  may be used by near-field communications circuitry  42 . Separate near-field communications antennas and non-near-field communications antennas may also be used in device  10 , if desired. 
       FIG. 3  is a schematic diagram showing how antenna structures  40  in device  10  may be used by near-field communications circuitry  42  and non-near-field communications circuitry  44 . As shown in  FIG. 3 , electronic device  10  includes control circuitry  28  and input-output devices  32 . Control circuitry  28  may use input-output devices  32  to provide output to a user and to receive input. Control circuitry  28  may use wireless transceiver circuitry  50  and antenna structures  40  to communicate with external equipment over one or more wireless communications bands including bands for non-near-field communications and near-field communications. Antenna structures  40  may include one or more near-field-communications antennas, one or more non-near-field communications antennas, one or more antenna arrays or other sets of multiple antennas such as a near-field antenna array having multiple near-field antennas and/or a non-near-field antenna array having multiple non-near-field antennas, etc. If desired, some of antenna structures  40  may be shared between near-field and non-near-field communications. Antenna structures  40  may also contain near-field antennas that do not handle any non-near-field antennas (i.e., antennas that are exclusively used for handling near-field communications) and/or non-near-field antennas that do not handle any near-field communications (i.e., antennas that are exclusively used for handling non-near-field communications). 
     Near-field communications circuitry  42  and non-near-field communications circuitry  44  may be coupled to antenna structures  40 . Near-field communications circuitry  42  (e.g., a near-field communications transceiver) may use antenna structures  40  to communicate with external near-field communications equipment  58  over near-field communications link  64 . Non-near-field communications circuitry such as radio-frequency transceiver circuitry  44  may use antenna structures  40  to communicate with a cellular telephone network, a wireless local area network, or other far field (non-near-field) wireless network equipment  54  over non-near-field communications wireless link  56 . 
     External equipment such as external equipment  58  may communicate with near-field communications circuitry  42  via magnetic induction. Equipment  58  may include a loop antenna such as loop antenna  62  that is controlled by control circuitry  60 . Loop antenna  62  and one or more loop antennas in antenna structures  40  may be electromagnetically coupled to support near-field wireless communications when loop antenna  62  and the loop antenna(s) in structures  40  are within an appropriately close distance of each other such as 20 cm or less, as indicated by near-field communications signals  64  of  FIG. 3 . 
     Device  10  may use near-field communications circuitry  42  and antenna structures  40  (e.g., the near-field communications loop antenna(s) of antenna structures  40 ) to communicate with external near-field communications equipment  58  using passive or active communications. In passive communications, device  10  may use near-field communications circuitry  42  and antenna structures  40  to modulate electromagnetic signals  64  from equipment  58 . In active communications, near-field communications circuitry  42  and antenna structures  40  may transmit radio-frequency electromagnetic signals  64  to external equipment  58 . 
     To provide antenna structures  40  with the ability to cover communications frequencies of interest, antenna structures  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 structures  40  may be provided with adjustable circuits such as tunable circuitry  52 . Tunable circuitry  52  may be controlled by control signals from control circuitry  28 . For example, control circuitry  28  may supply control signals to tunable circuitry  52  via control path  66  during operation of device  10  whenever it is desired to tune antenna structures  40  to cover a desired communications band (e.g., a desired non-near-field communications band). Paths  68  may be used to convey data between control circuitry  28  and transceiver circuitry  50 . 
     Passive filter circuitry in antenna structures  40  may help antenna structures  40  exhibit antenna resonances in communications bands of interest (e.g., passive filter circuitry in antenna structures  40  may short together different portions of antenna structures  40  and/or may form open circuits or pathways of other impedances between different portions of antenna structures  40  to ensure that desired antenna resonances are produced). 
     Transceiver circuitry  50  may be coupled to antenna structures  40  by signal paths such as signal paths  70  and  72 . Signal paths  70  and  72  may include transmission lines, portions of conductive housing structures, ground plane structures, traces on printed circuits, or other conductive paths. If desired, circuitry such as switching circuitry or passive combiner circuitry may be interposed in paths such as paths  70  and  72  to allow transceivers to be shared among multiple antennas. 
     Impedance matching circuitry formed from components such as inductors, resistors, and capacitors may be used in matching the impedance of antenna structures  40  to the impedance of transmission line structures coupled to antenna structures  40 . Filter circuitry may also be provided in the transmission line structures and/or antenna structures  40 . 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 passive filter circuitry in antenna structures  40  and tunable circuitry  52  in antenna structures  40 . 
     A transmission line may be coupled between transceiver  44  and antenna feed structures associated with antenna structures  40 . As an example, antenna structures  40  may form one or more non-near-field communications antennas such as one or more inverted-F antennas each having an antenna feed with a positive antenna feed terminal and a ground antenna feed terminal. For each antenna, a positive transmission line conductor may be coupled to the positive antenna feed terminal and a ground transmission line conductor may be coupled to the ground antenna feed terminal. Other types of antenna feed arrangements may be used to couple non-near-field communications transceiver  44  to non-near-field antennas in antenna structures  40  if desired. 
     Near-field communications circuitry  42  may be coupled to near-field communications antennas using switching circuitry or passive signal combining circuitry. This allows a near-field communications transceiver integrated circuit to be shared between multiple antennas. If desired, a balun may be interposed between near-field communications circuitry  42  and a near-field communications antenna in antenna structures  40 . Near-field communications circuitry  42  may have a differential output. The balun may convert differential output (signals referenced to each other) from circuitry  42  to single-ended signals (signals referenced to ground) for feeding the near-field communications antenna formed from antenna structures  40 . 
     Tunable circuitry  52  may be formed from one or more tunable circuits such as circuits based on capacitors, resistors, inductors, and switches. Tunable circuitry  52  and filter circuitry in antenna structures  40  may be implemented using discrete components mounted to a printed circuit such as a rigid printed circuit board (e.g., a printed circuit board formed from glass-filled epoxy) or a flexible printed circuit formed from a sheet of polyimide or a layer of other flexible polymer, a plastic carrier, a glass carrier, a ceramic carrier, or other dielectric substrate. During operation of device  10 , control circuitry  28  may issue commands on path  66  to adjust switches, variable components, and other adjustable circuitry in tunable circuitry  52 , thereby tuning antenna structures  40 . If desired, tunable circuitry  52  may include one or more inductors. A switch circuit may be used to selectively switch a desired number of the inductors into use. By varying the inductance of tunable circuitry  52  in this way, antenna structures  40  can be tuned to cover desired communications bands. Tunable circuitry  52  may also include one or more capacitors that are selectively switched into use with a switching circuit to tune antenna structures  40 . Capacitance adjustments and inductance adjustments may be made using a tunable circuit with adjustable capacitors and inductors and/or separately adjustable capacitor circuits and inductor circuits may be used in tuning antenna structures  40 . 
     A cross-sectional side view of an illustrative electronic device such as electronic device  10  of  FIG. 1  taken lengthwise and viewed from the right-hand side of device  10  is shown in  FIG. 4 . As shown in  FIG. 4 , display  14  may include a display module such as display module  202  mounted under display cover layer  200 . Display module  202  contains an array of display pixels that display images for a user. The size of the array of display pixels defines the active area of display  14 . Display cover layer  200  may be a layer of clear glass or plastic. Display module  202  may be based on liquid crystal display components, may be an array of organic light-emitting diodes, or may be based on other suitable display technology. If desired, a touch sensor may be incorporated into module  202  or other portion of display  14 . 
     Housing  12  may contain dielectric structures and/or conductive structures. For example, housing  12  may, if desired, include peripheral conductive housing structures such as peripheral structures  16  of  FIG. 1 . Rear surface  210  of housing  12  may be formed from metal or dielectric. With one suitable arrangement, some or all of rear surface  210  is formed from dielectric so that a near-field communications antenna such as a near-field communications loop antenna may be formed from antenna structures  40 C such as one or more loops of metal lines  208  that are overlapped by display  14 . Antenna structures  40 C may, if desired, be formed from metal traces on the inside surface of a plastic housing structure, on a printed circuit, on a plastic carrier mounted within device  10 , or on other dielectric substrates. If desired, a ferromagnetic shielding layer may be interposed between near-field communications antenna  40 C and internal device components in device  10  such as components  206  on printed circuit  204 . The ferromagnetic shielding layer may prevent near-field communications signals from inducing eddy currents in the conductive structures of device  10  such as printed circuit  204  and components  206 , thereby ensuring that near-field communications performance is satisfactory. 
     Device  10  may have antenna structures  40 A in region  22  and antenna structures  40 B in region  20 . Antenna structures  40 A may be used to form a near-field communications antenna for handling wireless near-field communications signals and may be used to form a non-near-field communications antenna for handling wireless non-near-field communications signals (e.g., antenna structures  40 A may be shared between circuitry  44  and circuitry  42 ). Antenna structures  40 B may also be used to form a near-field communications antenna for handling wireless near-field communications signals and may be used to form a non-near-field communications antenna for handling wireless non-near-field communications signals (e.g., antenna structures  40 B may be shared between circuitry  44  and circuitry  42 ). Antenna structures  40 C may serve exclusively as a near-field communications antenna (as an example). Particularly when near-field communications antennas are implemented in regions  20  and  22  and are not blocked by the presence of overlapping structures such as display  14 , near-field communications signals may be transmitted and/or received from both the front surface and the opposing rear surface of device  10 . This allows a user of device  10  to use a near-field antenna in structures  40 A (or in structures  40 B) when either the front (display) surface of device  10  or the opposing rear surface  210  of device  10  faces or is otherwise in the vicinity of external loop antenna  62 . 
     Antenna structures  40 A and  40 B may be used in forming non-near-field antennas based on inverted-F antenna designs or antenna structures with other designs. An illustrative configuration for electronic device  10  that incorporates inverted-F antenna structures  40  for use as structures  40 A in region  22  and/or as structures  40 B in region  20  is shown in  FIG. 5 . 
     As shown in  FIG. 5 , antenna structures  40  may include inverted-F antenna resonating element  76  and a conductive structure such as antenna ground  88 . Antenna ground  88  may be formed from ground traces on a flexible printed circuit, ground traces on a rigid printed circuit board, metal traces on other dielectric carriers, portions of an electronic device housing such as a metal midplate structure or internal frame structures, conductive structures such as metal portions of electrical components in device  10 , or other conductive structures. Inverted-F antenna resonating element  76  may be formed from a segment of peripheral conductive housing structures  16  (e.g., a segment of a metal band or other metal member that surrounds display  14 , etc.), other metal housing structures, metal portions of electronic components in device  10 , metal traces on printed circuit substrates (e.g., metal traces on a flexible printed circuit having a flexible dielectric substrate or on a rigid printed circuit board), plastic carriers, or other dielectric substrates, or other conductive structures. 
     Antenna resonating element  76  may include main antenna resonating element arm  78  (e.g., a segment of peripheral conductive housing structures  16  that extends between respective peripheral conductive housing structure gaps such as gaps  18 - 1  and  18 - 2  or an arm formed from metal traces on a printed circuit or other dielectric substrate). Main antenna resonating element arm  78  may have one or more branches. For example, arm  78  may have a low band arm LB for producing a low communications band resonance and a high band arm HB for producing a high communications band resonance. Tip portion  94  of high band branch HB may be separated by gap  18 - 2  from ground plane  88  and may have an associated capacitance C2. Tip portion  92  of low band branch LB may be separated by gap  18 - 1  from ground plane  88  and may have associated capacitance C1. The size and shapes of the metal structures adjoining gaps  18 - 1  and  18 - 2  may be configured to adjust the values of C1 and C2 and thereby adjust antenna performance. If desired, optional inductors may span gaps  18 - 1  and  18 - 2  (e.g., to adjust antenna frequency response and/or provide a current path for forming a near-field communications loop antenna). 
     Arm  78  may be separated from ground plane  88  by a dielectric-filled opening such as gap  90 . Gap  90  may contain plastic, glass, ceramic, air, or other dielectric materials. Non-near-field communications antenna return path  80  in the non-near-field communications antenna of antenna structures  40  may bridge gap  90 . Non-near-field communications antenna feed path  82  may bridge gap  90  in parallel with return path  80 . Antenna feed terminals such as positive antenna feed terminal  84  and ground antenna feed terminal  86  may form a non-near-field communications antenna feed within antenna feed path  82 . The conductive structures of antenna return path  80  and antenna feed path  82  may be formed from metal traces on printed circuits, metal traces on plastic carriers, conductive housing structures, or other conductive structures in device  10 . 
     Impedance matching circuitry, filter circuitry, and tuning circuitry  52  of  FIG. 3  may be interposed in paths that bridge gap  90  such as path  80 , feed path  82 , or one or more parallel tuning paths, may bridge gaps such as gaps  18 - 1  and  18 - 2  at the tips of main antenna resonating element arm  78  of antenna resonating element  76 , may be formed in other portions of antenna resonating element  76  and/or may be incorporated into ground structures such as antenna ground  88 . 
     To support near-field communications in device  10 , device  10  preferably includes near-field communications antennas. Space can be conserved by using some or all of antenna structures  40 A (and  40 B) to form a non-near-field communications antenna such as a cellular telephone antenna and to form 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  42  of  FIG. 2  to support communications with external equipment  58  over link  64 ) may be formed using portions of the antenna structures of  FIG. 5  such as portions of antenna resonating element  76  and antenna ground  88  (and other conductive structures that form a loop antenna). By sharing conductive antenna structures between both near-field and non-near-field antennas and by sharing some or all of dielectric opening  90  between both near-field and non-near-field antennas, duplicative conductive structures can be minimized and antenna volume can be conserved within device  10 . Antenna structures such as antenna structures  40  of  FIG. 5  may be used in forming antenna structures  40 A at one end of device  10  and antenna structures such as antenna structures  40  of  FIG. 5  may be used in forming antenna structures  40 B at an opposing end of device  10  (as an example). With this type of configuration, structures  40 A form a near-field communications antenna and a non-near field communications antenna and structures  40 B form a near-field communications antenna and a non-near-field communications antenna. 
     Baluns such as balun  108  may be used in coupling near-field communications circuitry  42  to antenna structures  40 . In general, balun  108  may be used to couple communications circuitry  42  to any suitable portion of antenna structures  40  (e.g., an antenna feed path, an antenna return path, portions of arm  78 , a separate conductive line that is connected to a return path or other conductive structure in structures  40 , etc.). In the illustrative configuration of  FIG. 5 , balun  108  is coupled to arm  78  of structures  40  using a path containing inductor  132 . This is merely illustrative. A balun such as balun  108  may be used to couple near-field communications circuitry  42  to any suitable portion of antenna structures  40  if desired. 
     As shown in the example of  FIG. 5 , antenna structures  40  include antenna resonating element  76  and antenna ground  88 . Antenna resonating element arm  78  of antenna resonating element  76  is separated from antenna ground  88  by gap  90 . Non-near-field communications antenna return path  80  spans gap  90  in parallel with antenna feed path  82 . Positive antenna feed terminal  84  and ground antenna feed terminal  86  form a non-near-field communications antenna feed that is coupled to non-near-field communications circuitry  44  (e.g., a non-near-field communications transceiver such as a cellular telephone transceiver, wireless local area network transceiver, etc.). Ground antenna feed terminal  86  is coupled to antenna ground  88 . 
     When it is desired to transmit and/or receive non-near-field communications signals with antenna structures  40 , antenna resonating element arm  78 , antenna return path  80 , antenna feed path  82 , and antenna ground  88  (and, if desired, other structures) serve as a non-near-field communications antenna (i.e., an inverted-F antenna) that is used by non-near-field communications circuitry  44 . 
     Near-field communications circuitry  42  (e.g., a near-field communications transceiver operating at 13.56 MHz or other suitable near-field communications frequency) may be coupled to antenna structures  40  using balun  108 . Near-field communications circuitry  42  may have a ground terminal that is coupled to antenna ground  88 . Near-field communications circuitry  42  may also have a pair of differential signal terminals (sometimes referred to as +V and −V terminals) for handling differential near-field communications signals. The differential signal terminals of near-field communications circuitry  42  may be coupled to respective terminals  116  and  118  of balun  108 . 
     Balun  108  may contain coupled inductors  114  and  112 . Inductors  114  and  112  may be coupled by near-field electromagnetic coupling (i.e., inductors  114  and  112  form a transformer and are magnetically coupled). Inductor  114  may have a terminal such as terminal  116  that is coupled to the +V terminal of near-field communications circuit  42  and may have a terminal such as terminal  118  that is coupled to the −V terminal of near-field communications circuit  42 . Inductor  112  may have a terminal such as terminal  110  that is coupled to antenna ground  88 . Inductor  112  may also have an opposing terminal coupled to node  128 . Capacitor  136  or other circuitry for tuning the response of antenna structures  40  may be coupled between node  128  and terminal  130 . Terminal  130  may be connected to antenna ground  88 . Inductor  132  or other circuitry for tuning the response of antenna structures  40  may be coupled between node  128  and node  134  on antenna resonating element arm  78 . Antenna resonating element arm  78  may be formed from a segment of peripheral conductive housing structures  16  or from metal traces on a printed circuit or other support structure. When operated in a near-field communications mode using near-field communications circuitry  42 , antenna structures  40  of  FIG. 5  form a loop antenna that handles near-field communications signals such as loop current  124 . The loop antenna is formed from a loop-shaped signal path that includes balun inductor  112 , inductor  132 , the segment of arm  78  between node  134  and return path  80 ), return path  80 , and antenna ground  88 . In other configurations, the loop antenna may be formed from different loop-shaped paths through antenna structures  40 . The configuration of  FIG. 5  is merely illustrative. 
       FIG. 6  is a front view of device  10  showing how antenna structures  40 A may be located at upper end region  22  of device  10  and how antenna structures  40 B may be located at lower end region  20  of device  10 . Antenna structures  40 C may form a near-field communications loop antenna in a middle region of device  10  between regions  20  and  22 . The loop antenna of structures  40 C may be formed from one or more turns of metal signal lines  208 . The near-field communications antenna of structures  40 C may have near-field communications feed terminals such as terminals  116 C and  118 C. Terminals  116 C and  118 C may be coupled to near-field communications transceiver  42  without an intervening balun (as an example). Balun  108 A may have near-field communications terminals  116 A and  118 A for coupling near-field communications transceiver  42  to antenna structures  40 A. Balun  108 B may have near-field communications terminals  116 B and  118 B for coupling near-field communications transceiver  42  to antenna structures  40 B. Baluns  108 A and  108 B may be coupled to structures  40 A and  40 B as described in connection with  FIG. 5  or using other coupling arrangements. 
     Antenna structures  40 A and  40 B may support both near-field and non-near-field communications. Non-near-field antenna terminals (feed terminals)  84 A and  86 A may be used to couple non-near-field communications circuitry  44  to antenna structures  40 A. Non-near-field antenna terminals (feed terminals)  84 B and  86 B may be used to couple non-near-field communications circuitry  44  to antenna structures  40 B. 
     The near-field communications loop antenna in structures  40 A, the near-field communications loop antenna in structures  40 C, and the near-field communications loop antenna in structures  40 B may form a set (e.g., an array) of three-antenna near-field communications antennas. As shown in  FIG. 7 , multiplexing circuitry  300  may be used to couple near-field communications circuitry to each of these three near-field communications antennas. In particular, multiplexing circuitry  300  may have a transceiver port that is coupled to differential signal terminals (+V) and (−V) in near-field communications circuitry  42  and may have three antenna ports that are coupled respectively to near-field communications terminals  116 A and  118 A for the near-field communications loop antenna in structures  40 A, near-field communications terminals  116 C and  118 C for near-field communications loop antenna of structures  40 C, and near-field communications terminals  116 B and  118 B for the near-field communications loop antenna in structures  40 B. Path  304  may be used to convey near-field communications data between control circuitry  28  and near-field communications circuitry  42 . Multiplexer circuitry  300  may be based on a passive signal combining circuit that couples circuitry  42  to the three near-field communications antennas of  FIG. 7  in parallel or may be active switching circuitry that switches circuitry  42  to a selected one of the near-field communications antennas. With an active switching arrangement, control signals from control circuitry  28  (e.g., control signals that are conveyed to multiplexing circuitry  300  over path  302  from a baseband processor integrated circuit in control circuitry  28 ) may be used in controlling multiplexer  300  (e.g., to cycle through each of the near-field communications loop antennas in a predetermined sequence and/or to select a particular near-field communications loop antenna to switch into use based on sensor data, received signal strength information, or other real time information). 
     In addition to near-field communications antenna multiplexing circuitry such as multiplexing circuitry  300 , device  10  may, if desired, include non-near-field communications antenna multiplexing circuitry such as multiplexing circuitry  306 . Multiplexing circuitry  306  may be used to implement a non-near-field communications antenna diversity scheme in which an optimal antenna from a set (e.g., an array) of antennas is switched into use in real time based on sensor data, received signals strength information, or other real time information. As shown in  FIG. 7 , multiplexing circuitry  306  may be controlled by control signals from control circuitry  28  (e.g., a baseband processor) that are conveyed to multiplexing circuitry  306  from control circuitry  28  over path  308 . Path  310  may be used to route non-near-field communications data between control circuitry  28  and non-near-field communications transceiver  44 . Multiplexing circuitry  306  may have a transceiver port that is coupled to non-near-field communications transceiver  44  and may have a pair of non-near-field communications antenna ports coupled respectively to terminals  84 A and  86 A of the non-near-field communications antenna of structures  40 A and terminals  84 B and  86 B of the non-near-field communications antenna of structures  40 B. Configurations for device  10  that have more than three or fewer than three near-field communications loop antennas and/or that have more than two or fewer than two non-near-field communications antennas may also be used. The arrangement of  FIG. 7  is merely illustrative. 
     Use of the multiple near-field antennas of  FIG. 7  allows a user of device  10  to perform near-field communications operations while holding device  10  in numerous different orientations relative to antenna  62 . Use of the multiple non-near-field antennas of  FIG. 7  helps prevent the non-near-field antennas of device  10  from becoming blocked by the body of the user of device  10  or other external object. 
     If desired, device  10  may be a portable electronic device such as a tablet computer.  FIG. 8  is a cross-sectional side view of an illustrative electronic device such as a tablet computer. As shown in  FIG. 8 , device  10  may have a display such as display  14  mounted on a front side of housing  12 . Housing  12  may have a planar rear wall that forms an opposing rear side of housing  12 . Housing  12  may be formed from a dielectric such as plastic or other suitable material. If desired, housing  12  may be formed from a metal such as aluminum. Dielectric windows may be formed in a metal housing. As shown in  FIG. 8 , for example, plastic antenna window  301  may be used to cover antenna structures  40 A. Antenna structures  40 A may include a satellite navigation antenna, one or more cellular telephone and wireless local area network antennas, and a near-field communications loop antenna and may operate through window  301  (as an example). Antenna structures  40 C may be formed over dielectric window  303 , so that antenna structures  40 C may operate through window  303 . Window  303  may be formed from plastic or other suitable material and may have the shape of a logo or other suitable shape (i.e., window  303  may be a logo-shaped antenna window). Antenna structures  40 C may include a wireless local area network antenna and/or a near-field communications loop antenna (as an example). A near-field communications loop antenna and/or a non-near-field communications antenna may also be mounted under an inactive border portion of display  14  (see, e.g., antenna structures  40 B) and may operate through the display. Display  14  may have a dielectric cover layer such as a glass cover layer. Antenna structures  40 B (e.g., a near-field communications antenna) may operate through the glass cover layer. If desired, antenna windows such as antenna window  301  of  FIG. 8  may also be formed at opposing ends of device housing  12 . The configuration of  FIG. 8  is merely illustrative. 
     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: 20140303
Publication Date: 20170411
Grant Date: 20170411
Priority Date: 20140303
Inventors: OUYANG YUEHUI
HAKIM JOSEPH
DARNELL DEAN F.
PASCOLINI MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/0421", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q5/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/06", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/0081", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/35", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/06", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/26", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B5/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B5/48", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 52435010