PATENT DOCUMENT

Publication Number: US-10530042-B2
Application Number: US-201715699879-A
Country: US
Kind Code: B2

Title: Electronic device having shared antenna structures

Abstract:
An electronic device may be provided with wireless circuitry. The wireless circuitry may include multiple antennas and transceiver circuitry. The antennas may include antenna structures at opposing first and second ends of the electronic device. The antenna structures at a given end of the device may include antenna structures that are shared between multiple antennas. The electronic device may include a first antenna with an inverted-F antenna resonating element formed from portions of a peripheral conductive housing structure and may have an antenna ground that is separated from the antenna resonating element by a gap. A return path may bridge the gap. The electronic device may also include a second antenna that includes the antenna ground and an additional antenna resonating element. The antenna resonating element of the second antenna may be parasitically coupled to the return path of the inverted-F antenna at given frequencies.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 an antenna ground; 
 a first antenna that includes the antenna ground, a first antenna resonating element arm, a first antenna feed having a first positive antenna feed terminal coupled to the first antenna resonating element arm and a first ground antenna feed terminal coupled to the antenna ground, and a return path coupled between the first antenna resonating element arm and the antenna ground, wherein the first antenna is configured to convey radio-frequency signals in a first frequency band; and 
 a second antenna that includes the antenna ground, a second antenna resonating element arm, and a second antenna feed having a second positive antenna feed terminal coupled to the second antenna resonating element arm and a second ground antenna feed terminal coupled to the antenna ground, wherein the second antenna is configured to convey radio-frequency signals in a second frequency band that is different from the first frequency band and the second antenna resonating element arm is parasitically coupled to the return path of the first antenna at frequencies in a third frequency band that is different from the first and second frequency bands. 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the third frequency band is higher than the first frequency band and lower than the second frequency band. 
     
     
       3. The electronic device defined in  claim 2 , wherein the second frequency band comprises frequencies between 5150 MHz and 5850 MHz and the third frequency band comprises frequencies between 3400 MHz and 3700 MHz. 
     
     
       4. The electronic device defined in  claim 1 , further comprising:
 a housing having peripheral conductive housing structures, wherein a segment of the peripheral conductive housing structure forms the first antenna resonating element arm. 
 
     
     
       5. The electronic device defined in  claim 4 , further comprising:
 a third antenna resonating element arm formed from an additional segment of the peripheral conductive housing structures, wherein the segment of the peripheral conductive housing structures and the additional segment of the peripheral conductive housing structures extend from opposing sides of the first positive antenna feed terminal. 
 
     
     
       6. The electronic device defined in  claim 5 , wherein the first antenna feed is configured to convey radio-frequency signals in the first frequency band and the second antenna feed is configured to convey radio-frequency signals in the second and third frequency bands. 
     
     
       7. The electronic device defined in  claim 5 , wherein the return path of the first antenna comprises a conductive structure and an adjustable circuit coupled between the first antenna resonating element arm and the antenna ground. 
     
     
       8. The electronic device defined in  claim 7 , wherein the adjustable circuit comprises first and second inductors coupled in parallel between the conductive structure and a switch that selectively couples either the first inductor or the second inductor to the antenna ground. 
     
     
       9. The electronic device defined in  claim 8 , wherein the adjustable circuit further comprises a third inductor that is coupled between the conductive structure and the antenna ground in parallel with the first inductor, the second inductor, and the switch. 
     
     
       10. The electronic device defined in  claim 7 , wherein the adjustable circuit comprises a first inductor coupled between the conductive structure and a switch that selectively couples the first inductor to the antenna ground and the adjustable circuit further comprises a second inductor coupled between the conductive structure and the antenna ground in parallel with the first inductor and the switch. 
     
     
       11. The electronic device defined in  claim 4 , wherein the second antenna resonating element arm comprises metal traces on a plastic carrier. 
     
     
       12. An electronic device, comprising:
 a housing having a peripheral conductive structure; 
 an antenna ground; 
 a conductive path coupled between the peripheral conductive structure and the antenna ground; and 
 metal traces on a substrate, wherein the peripheral conductive structure is configured to convey wireless signals in a first radio-frequency communications band, the metal traces are configured to convey wireless signals in a second radio-frequency communications band, and a portion of the peripheral conductive structure, the conductive path, and a portion of the metal traces are configured to convey wireless signals in a third radio-frequency communications band. 
 
     
     
       13. The electronic device defined in  claim 12 , wherein the metal traces are parasitically coupled to the conductive path at frequencies in the third radio-frequency communications band. 
     
     
       14. The electronic device defined in  claim 12 , wherein the substrate comprises a plastic carrier and a portion of the conductive path is formed on the plastic carrier. 
     
     
       15. The electronic device defined in  claim 12 , wherein the substrate comprises a plastic carrier, the electronic device further comprising:
 at least one fastener that carries antenna signals and that mounts the plastic carrier to a printed circuit. 
 
     
     
       16. The electronic device defined in  claim 12 , wherein the conductive path comprises a conductive structure that is coupled to the peripheral conductive structure and an adjustable circuit that is coupled between the conductive structure and the antenna ground. 
     
     
       17. The electronic device defined in  claim 12 , further comprising:
 a first antenna feed having a first positive antenna feed terminal coupled to the peripheral conductive structure; and 
 a second antenna feed having a second positive antenna feed terminal coupled to the metal traces. 
 
     
     
       18. An electronic device, comprising:
 a housing having peripheral conductive housing structures; 
 a first antenna resonating element formed from a segment of the peripheral conductive housing structures and configured to resonate in a first frequency band; 
 an antenna ground; 
 a first antenna feed having a first positive antenna feed terminal coupled to the first antenna resonating element and a first ground antenna feed terminal coupled to the antenna ground; 
 a return path coupled between the first antenna resonating element and the antenna ground; 
 a second antenna resonating element; and 
 a second antenna feed having a second positive antenna feed terminal coupled to the second antenna resonating element and a second ground antenna feed terminal coupled to the antenna ground, wherein the second antenna resonating element is configured to resonate in a second frequency band that is higher than the first frequency band, and wherein a portion of the second antenna resonating element, at least a portion of the return path, and at least a portion of the first antenna resonating element are configured to resonate in a third frequency band that is higher than the first frequency band and lower than the second frequency band. 
 
     
     
       19. The electronic device defined in  claim 18 , wherein the second antenna resonating element arm is parasitically coupled to the return path at frequencies in the third frequency band. 
     
     
       20. The electronic device defined in  claim 19 , wherein the first frequency band comprises frequencies between 960 MHz and 1710 MHz, the second frequency band comprises frequencies between 5150 MHz and 5850 MHz, and the third frequency band comprises frequencies between 3400 MHz and  3700  MHz.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless communications circuitry. 
     Electronic devices often include wireless communications circuitry. For example, cellular telephones, computers, and other devices often contain antennas and wireless transceivers for supporting wireless communications. 
     It can be challenging to form electronic device antenna structures with desired attributes. In some wireless devices, antennas are bulky. In other devices, antennas are compact, but are sensitive to the position of the antennas relative to external objects. If care is not taken, antennas may become detuned, may emit wireless signals with a power that is more or less than desired, or may otherwise not perform as expected. 
     It would therefore be desirable to be able to provide improved wireless circuitry for electronic devices. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may include multiple antennas and transceiver circuitry. The antennas may include antenna structures at opposing first and second ends of the electronic device. The antenna structures at a given end of the device may include antenna structures that are shared between multiple antennas. 
     The electronic device may include an antenna with an inverted-F antenna resonating element formed from portions of a peripheral conductive electronic device housing structure and may have an antenna ground that is separated from the antenna resonating element by a gap. A short circuit path (return path) may bridge the gap. An antenna feed may be coupled across the gap in parallel with the short circuit path. The inverted-F antenna resonating element may be used to convey radio-frequency signals in a first frequency band. 
     The electronic device may include an additional antenna that includes the antenna ground and metal traces that form an antenna resonating element arm. The additional antenna may convey radio-frequency signals in a second frequency band that is different from the first frequency band. The antenna resonating element arm of the additional antenna may be parasitically coupled to the return path of the inverted-F antenna at frequencies in a third frequency band that is different from the first and second frequency bands. A portion of the peripheral conductive electronic device housing structure, a portion of the return path for the inverted-F antenna, and a portion of the antenna resonating element arm for the additional antenna may resonate in the third frequency band. 
    
    
     
       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 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 in accordance with an embodiment. 
         FIG. 6  is a top view of an illustrative wireless local area network and ultra-high band antenna in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of a wireless local area network and ultra-high band antenna of the type shown in  FIG. 6  in accordance with an embodiment. 
         FIG. 8  is a top perspective view of an illustrative electronic device with a carrier on which antenna structures of the type shown in  FIGS. 6 and 7  have been formed in accordance with an embodiment. 
         FIG. 9  is a top view of an illustrative carrier for a wireless local area network and ultra-high band antenna in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of an illustrative carrier of the type shown in  FIG. 9  in accordance with an embodiment. 
         FIGS. 11A-11C  are circuit diagrams of illustrative adjustable components that may be formed in a return path of antenna structures of the type shown in  FIGS. 5-8  in accordance with an embodiment. 
         FIG. 12  is a graph of antenna performance (antenna efficiency) as a function of frequency for a wireless local area network and ultra-high band antenna of the type shown in  FIGS. 5-10  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 one more antennas. The antennas of the wireless communications circuitry can 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. Conductive structures for the antennas 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 structures 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, 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 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. 
     As shown in  FIG. 3 , transceiver circuitry  90  in wireless circuitry  34  may be coupled to antenna structures  40  using paths such as path  92 . Wireless circuitry  34  may be coupled to control circuitry  28 . 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. 
     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. 
     Control circuitry  28  may use information from a proximity sensor (see, e.g., sensors  32  of  FIG. 2 ), wireless performance metric data such as received signal strength information, device orientation information from an orientation sensor, device motion data from an accelerometer or other motion detecting 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, and/or other information in determining when antenna(s)  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 structures  40  operate as desired. Adjustments to component  102  may also be made to extend the coverage of antenna structures  40  (e.g., to cover desired communications bands that extend over a range of frequencies larger than antenna structures  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 . As shown in  FIG. 4 , inverted-F antenna structure  40  (sometimes referred to herein as antenna  40  or inverted-F antenna  40 ) may include an inverted-F antenna resonating element such as antenna resonating element  106  and an antenna ground (ground plane) such as antenna ground  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  40  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). As an example, a slot antenna structure may be formed between arm  108  or other portions of resonating element  106  and ground  104 . In these scenarios, antenna  40  may include both slot antenna and inverted-F antenna structures and may sometimes be referred to as a hybrid inverted-F and slot antenna. 
     Arm  108  may be separated from ground  104  by a dielectric-filled opening such as dielectric gap  101 . Antenna ground  104  may be formed from housing structures such as a conductive support plate, printed circuit traces, metal portions of electronic components, or other conductive ground structures. Gap  101  may be formed by air, plastic, and/or other dielectric materials. 
     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.). Arm  108  may have other shapes and may follow any desired path if desired (e.g., paths having curved and/or straight segments). 
     If desired, antenna  40  may include one or more adjustable circuits (e.g., tunable components  102  of  FIG. 3 ) that are coupled to antenna resonating element structures  106  such as arm  108 . As shown in  FIG. 4 , for example, tunable components  102  such as adjustable inductor  114  may be coupled between antenna resonating element arm structures in antenna  40  such as arm  108  and antenna ground  104  (i.e., adjustable inductor  114  may bridge gap  101 ). Adjustable inductor  114  may exhibit an inductance value that is adjusted in response to control signals  116  provided to adjustable inductor  114  from control circuitry  28 . 
     A top interior view of an illustrative portion of device  10  that contains antennas  40  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 divided by dielectric-filled peripheral gaps (e.g., plastic gaps) such as gaps  18 . Antenna structures  40  may include antenna  40 F and antenna  40 W. Antenna  40 F (sometimes referred to as a cellular antenna) may include an inverted-F antenna resonating element arm  108  formed from a segment of peripheral conductive housing structures  16  extending between gaps  18 . Air and/or other dielectrics may fill slot  101  between arm  108  and ground structures  104 . If desired, opening  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 ). 
     Antenna  40 F may support a resonance in one or more desired frequency bands. The length of arm  108  may be selected to resonate in one or more desired frequency bands. For example, arm  108  may support a resonance in a cellular low band LB, midband MB, and high band HB. In order to handle wireless communications at other frequencies (e.g., frequencies in the 5 GHz wireless local area network band), an additional antenna such as antenna  40 W may be formed within region  206 . It also may be desirable to cover the ultra-high band UHB using the antenna structures of electronic device  10 . If desired, a portion of antenna  40 F and a portion of antenna  40 W may be used to cover communications in the ultra-high band (e.g., without the need for forming a separate antenna for covering the ultra-high band). 
     Ground  104  may serve as antenna ground for one or more antennas. For example, antenna  40 F may include a ground plane formed from ground  104 . Antenna  40 W (sometimes referred to as a wireless local area network and ultra-high band antenna) may include a resonating element in region  206  and ground  104 . Inverted-F antenna  40 F may be fed using antenna feed  112  having a first terminal  98  coupled to peripheral housing structure  16  and a second terminal  100  coupled to ground  104  (e.g., across slot  101 ). Positive transmission line conductor  94  and ground transmission line conductor  96  may form transmission line  92  that is coupled between cellular transceiver circuitry  38  and antenna feed  112 . Cellular transceiver circuitry  38  (i.e., remote wireless transceiver circuitry  38  as shown in  FIG. 2 ) may handle 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, and an ultra-high band from 3400 to 3700 MHz. Cellular transceiver circuitry  38  may use transmission line  92  and feed  112  to handle low band, low-midband, midband, and/or high band communications (e.g., radio-frequency signals in the low band, low-midband, midband, and/or high band may be conveyed by antenna  40 F over feed  112 ). 
     Wireless local area network and ultra-high band antenna  40 W in region  206  may include an inverted-F antenna resonating element or other suitable antenna resonating element. The wireless local area network and ultra-high band antenna may convey radio-frequency signals in a wireless local area network communications band (e.g., from 5150-5850 MHz). The radio-frequency signals in the wireless local area network band may be conveyed to and from antenna  40 W over a dedicated antenna feed such as feed  220 . Feed  220  may include a positive antenna feed terminal  208  and ground antenna feed terminal  210 . Ground antenna feed terminal  210  may be coupled to ground  104  (i.e., ground  104  may serve as an antenna ground for wireless local area network and ultra-high band antenna  40 W as well as an antenna ground for antenna  40 F). Positive antenna feed terminal  208  may be coupled to the antenna resonating element of wireless local area network and ultra-high band antenna  40 W within region  206 . 
     Feed  220  of the wireless local area network and ultra-high band antenna  40 W may convey radio-frequency signals over positive signal conductor  222  and ground signal conductor  224  of signal path  226 . Signal path  226  may be coaxial cable, a stripline transmission line, a microstrip transmission line, or other radio-frequency transmission line structure (as examples). 
     In order to optimize space consumption within device  10 , antenna  40 W may support resonances in multiple frequency bands. For example, antenna  40 W may support communications in a wireless local area network band at 5 GHz (e.g., a band between approximately 5150-5850 MHz). Antenna  40 W may additionally support communications in an ultra-high cellular band (e.g., at frequencies between 3400 and 3700 MHz). In order to convey radio-frequencies in the ultra-high band, feed  220  may be coupled to a port of cellular transceiver circuitry  38 . 
     In order to isolate the signals conveyed by wireless local area network transceiver circuitry  36  from the signals conveyed by cellular telephone transceiver circuitry  38 , diplexer  230  may be interposed on transmission line  226 . For example, diplexer  230  may have a first port coupled to feed  220 , a second port coupled to transceiver  36 , and a third port coupled to transceiver  38 . Diplexer  230  may receive radio-frequency signals from both wireless local area network transceiver circuitry  36  and cellular transceiver circuitry  38  and may combine the signals before conveying the combined signals to feed  220 . Similarly, diplexer  230  may receive radio-frequency signals from feed  220  and may filter the signals by frequency so that the signals at wireless local area network frequencies (e.g., between 5150-5850 MHz) are conveyed to transceiver  36  and the signals at cellular telephone frequencies (e.g., in the ultra-high band) are conveyed to transceiver  38 . In this way, antenna  40 W may support communications over both wireless local area network and cellular telephone frequencies using the same feed  220  while isolating transceiver  36  from transceiver  38 . Diplexer  230  may, for example, include one or more low-pass filters, band-pass filters, band stop filters, and/or high-pass filters. In one suitable example, wireless local area network transceiver circuitry  36  may be coupled to a high-pass filter within diplexer  230  whereas cellular transceiver  38  is coupled to a low-pass filter in diplexer  230 . Other arrangements may be used if desired. 
     Return path  110  of inverted-F antenna  40 F may be coupled between arm  108  (at node  202 ) and ground  104  (at node  204 ). Return path  110  may, for example, include a conductive element  232  and an inductive component such as inductor  234 . Return path  110  (e.g., including both conductive element  232  and inductor  234 ) may serve as the return path for antenna  40 F (e.g., cellular telephone signals that are conveyed over resonating element arm  108  of antenna  40 F via feed  112  may be shorted to ground  104  over return path  110 ). At the same time, conductive element  232  of return path  110  may be parasitically coupled (e.g., via near field electromagnetic coupling) to conductive elements within wireless local area network and ultra-high band antenna  40 W formed in region  206  (e.g., to a portion of the antenna resonating element of antenna  40 W). This parasitic coupling may serve to improve the overall antenna efficiency within the ultra-high band for wireless communications circuitry  34 . If desired, the antenna resonating element within region  206  of antenna  40 W may be formed over a portion of slot  101  (e.g., the portion of ground  104  under region  206  may be removed) to enhance the antenna efficiency of antenna  40 W relative to scenarios where ground plane  104  extends under all of region  206 . 
     If desired, tunable components such as adjustable component  114  may bridge slot  101  at a first location along slot  101  (e.g., component  114  may be coupled between terminal  126  on ground plane  104  and terminal  128  on peripheral conductive structures  16 ). Component  114  may include switches coupled to fixed components such as inductors for providing adjustable amounts of inductance or an open circuit between ground  104  and peripheral conductive structures  16 . Component  114  may also include fixed components that are not coupled to switches or a combination of components that are coupled to switches and components that are not coupled to switches. These examples are merely illustrative and, in general, component  114  may include other elements such as adjustable return path switches, switches coupled to capacitors, or any other desired components. If desired, adjustable component  114  may include one or more inductors coupled to a radio-frequency switching circuit. In one illustrative example, adjustable component  114  may include two inductors coupled in parallel between terminals  126  and  128 . A radio-frequency switching circuit may selectively couple the inductors between terminals  126  and  128  to tune the antenna. Additional adjustable components may be included at any desired location within electronic device  10  (i.e., between resonating element  108  and ground  104 , across gap  18 , etc.) to tune antenna  40 F. The example of  FIG. 5  is merely illustrative. 
       FIG. 6  is a top view of wireless local area network and ultra-high band antenna  40 W (e.g., within region  206  of  FIG. 5 ). As shown in  FIG. 6 , antenna  40 W may include an antenna resonating element such as antenna resonating element  236  and ground  104 . Antenna resonating element  236  may, for example, include conductive traces on one or more dielectric substrates. A first portion  236 - 1  of resonating element  236  may be coupled to positive antenna feed terminal  208 . A second portion  236 - 2  of resonating element  236  may be coupled to ground antenna feed terminal  210 . The first and second portions of resonating element  236  may be coupled to a third portion  236 - 3  of resonating element  236  that is substantially perpendicular to the first and second portions. The third portion of resonating element  236  may be coupled to a fourth portion  236 - 4  of resonating element  236  that is substantially perpendicular to the third portion and substantially parallel to the first and second portions. Fourth portion  236 - 4  of resonating element  236  may be coupled to a fifth portion  236 - 5  of resonating element  236  that is substantially perpendicular to the fourth portion and substantially parallel to the third portion. In the example of  FIG. 6 , antenna  40 W is an inverted-F antenna structure (with a return path formed by segment  236 - 2  and a portion of segment  236 - 3 ). This example for the arrangement of resonating element  236  is merely illustrative, and other arrangements for resonating element  236  may be used if desired. The segments of resonating element  236  may follow any desired paths and have any desired shapes. 
     The metal traces that form antenna resonating element  236  may be formed on any desired substrate. In some cases, antenna resonating element  236  may be formed from traces on a dielectric support structure such as a plastic carrier. The plastic carrier may be formed on an underlying printed circuit such as printed circuit  238 . Printed circuit  238  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). 
     The length of portions  236 - 1 ,  236 - 2 ,  236 - 3 ,  236 - 4 , and  236 - 5  of antenna resonating element  236  may be selected so that the antenna resonating element resonates at desired frequencies. For example, the sum of the lengths of portions  236 - 3 ,  236 - 4 , and  236 - 5  may be selected to be approximately equal to one quarter of a wavelength of operation of antenna  40 W (e.g., a wavelength corresponding to a wireless local area network frequency between 5150 and 5850 MHz). Antenna feed  220  may convey radio-frequency wireless local area network signals in a wireless local area network band such as a band between 5150 and 5850 MHz (e.g., using transceiver  36 ). Antenna currents  240  corresponding to the wireless local area network signals at these frequencies may flow over antenna resonating element  236  (e.g., the length of the different portions of resonating element  236  may be selected to support resonance at these frequencies). Ultra-high band signals may also flow over feed  220  (e.g., via transceiver  38  and transmission line  226 ). In the ultra-high band (e.g., 3400-3700 MHz), antenna resonating element  236  may be parasitically coupled to conductive element  232  of return path  110  of antenna  40 F. Corresponding ultra-high band antenna currents  242  may be present on antenna resonating element  236 , conductive element  232 , and peripheral conductive housing structure  16 . 
     As previously discussed, for antenna  40 F, conductive element  232  and inductor  234  serve as a return path between terminal  202  on peripheral conductive structure  16  and terminal  204  on ground  104 . However, when ultra-high band signals are conveyed to feed  220 , antenna currents  242  are induced on conductive element  232  (sometimes referred to as a parasitic element) via near field electromagnetic coupling and continue to flow along the corresponding path  242 . In this way, path  242  supports a resonance in the ultra-high band (i.e., antenna currents flow over antenna resonating element  236 , conductive element  232 , and peripheral conductive housing structure  16  at the ultra-high band frequencies). The length of the antenna resonating element  236 , conductive element  232 , and peripheral conductive housing structure  16  that form path  242  may be selected to support this resonance (e.g., the sum of the lengths of antenna resonating element  236 , conductive element  232 , and peripheral conductive housing structure  16  that form path  242  may be selected to be approximately equal to one quarter of a wavelength of the ultra-high band signals). Because conductive element  232  carries induced ultra-high band antenna currents from feed  220  (despite not being directly fed by feed  220 ), conductive element  232  may sometimes be referred to as an indirectly-fed antenna element (at least at ultra-high band frequencies). 
     Conductive element  232  may be separated from antenna resonating element  236  by a distance  244  (e.g., in the direction of the Y-axis of  FIG. 6 ). Gap  18  may have a width  243 . Conductive element  232  may have a portion with a length  245 . As previously discussed, at least a portion of ground plane  104  may be removed to help improve performance of the wireless local area network and ultra-high band antenna. The removed portion of ground plane  104  may sometimes be referred to as a cutout. The cutout may have a width  247 . Width  243  may be between 1 and 3 millimeters, between 1 and 5 millimeters, greater than 0.5 millimeters, greater than 1 millimeter, less than 4 millimeters, or any other desired width. Distance  244  may be between 0.5 and 3 millimeters, less than 2 millimeters, greater than 0.5 millimeters, or any other desired distance. Length  245  may be between 2 and 8 millimeters, between 4 and 6 millimeters, between 5 and 6 millimeters, greater than 3 millimeters, less than 10 millimeters, or any other desired length. Width  247  may be between 2 and 15 millimeters, between 8 and 12 millimeters, between 5 and 15 millimeters, greater than 2 millimeters, greater than 5 millimeters, greater than 8 millimeters, less than 10 millimeters, less than 15 millimeters, or any other desired width. Widths  243  and  247 , distance  244 , and length  245  may be adjusted to improve the antenna performance (antenna efficiency) and ensure the antenna resonates in desired frequency bands. 
     Conductive element  232  may be formed from metal traces on a dielectric substrate (i.e., on the same dielectric substrate as antenna resonating element  236  or on a different dielectric substrate as antenna resonating element  236 ), one or more additional conductive structures (i.e., clips, springs, brackets, pins, screws, etc.), or a combination of metal traces and additional conductive structures. 
       FIG. 7  is a cross-sectional side view of wireless local area network and ultra-high band antenna  40 W (e.g., as taken in the Y-Z plane of  FIG. 6 ). As shown in  FIG. 7 , antenna resonating element  236  may be formed on a dielectric support structure such as carrier  246 . Carrier  246  may be formed from molded plastic or other dielectric materials. In one suitable arrangement, carrier  246  may be formed from plastic and may sometimes be referred to herein as plastic carrier  246 . Portions of carrier  246  may form a dielectric block that serves as a riser for resonating element  236 . Carrier  246  may raise antenna resonating element  236  upwards away from underlying conductive structures such as ground  104 , thereby enhancing antenna bandwidth. Metal traces on carrier  246  such as the metal traces that form antenna resonating element  236  may be formed from laser patterned metal (e.g., metal plated onto carrier  246  following selective laser activation of desired antenna trace areas by laser exposure using laser direct structuring techniques), may be formed from metal foil that has been incorporated into carrier  246  using insert molding techniques, and/or may include other metal structures embedded within or formed on surfaces of carrier  246 . 
     Carrier  246  may be formed on printed circuit  238 . As previously discussed, printed circuit  238  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  238  may, for example, form a main logic board or motherboard for electronic device  10 . 
     As shown in  FIG. 7 , housing  12  may include dielectric housing portions such as dielectric layer  12 - 1  and conductive housing portions such as conductive layer  12 - 2  (sometimes referred to herein as conductive housing wall  12 - 2 ). If desired, dielectric layer  12 - 1  may by formed under layer  12 - 2  such that layer  12 - 1  forms an exterior surface of device  10  (e.g., thereby protecting layer  12 - 2  from wear and/or hiding layer  12 - 2  from view of a user). Carrier  246  and printed circuit  238  may be formed over conductive housing portion  12 - 2  and dielectric housing portion  12 - 1 . Conductive housing portion  12 - 2  may form a portion of ground  104 . As examples, conductive housing portion  12 - 2  may be a conductive support plate or wall (e.g., a conductive back plate or rear housing wall) for device  10 . Conductive housing portion  12 - 2  may, if desired, extend across the width of device  10  (e.g., between two opposing sidewalls formed by peripheral housing structures  16 ). If desired, conductive housing portion  12 - 2  and the opposing sidewalls of device  10  may be formed from a single integral piece of metal or portion  12 - 2  may otherwise be shorted to the opposing sidewalls of device  10 . Dielectric layer  12 - 1  may be a thin glass, sapphire, ceramic, or sapphire layer or other dielectric coating, as examples. In another suitable arrangement, layer  12 - 1  may be omitted if desired. 
     Display cover layer  248  may cover carrier  246  and printed circuit  238 . Display cover layer  248  may be a layer of clear glass or plastic that covers the surface of an underlying display module for display  14  of  FIG. 1 . Alternatively, display cover layer  248  may be the outermost layer of the display module (i.e., layer  248  may be a color filter layer, thin-film transistor layer, or other display layer). 
     As shown in  FIG. 7 , positive antenna feed terminal  208  of antenna  40 W may be coupled to an additional terminal  250  on printed circuit  238 . Terminals  208  and  250  may be electrically connected using any desired conductive interconnect structures (e.g., springs, screws, clips, brackets, pins, conductive vias, solder, welds, conductive adhesive, etc.). Ground antenna feed terminal  210  may be coupled to terminal  252  on printed circuit  238 . Terminal  252  in printed circuit  238  may be coupled to terminal  254  on ground  104  (e.g., on conductive layer  12 - 2 ). Terminals  210 ,  252 , and  254  may be electrically connected by one or more conductive structures (e.g., springs, screws, clips, brackets, pins, conductive vias, solder, welds, conductive adhesive, etc.). In one suitable arrangement, a first screw may be used to couple terminal  208  to terminal  250  and a second screw may be used to couple terminal  210  to both terminals  252 , and  254 . Printed circuit  238  and carrier  246  may include one or more openings (e.g., threaded holes) or other engagement structures to accommodate screws or other fasteners. Fasteners used to form conductive paths between carrier  246 , printed circuit  238 , and conductive layer  12 - 2  may, for example, be used to mechanically secure carrier  246 , printed circuit  238 , and layer  12 - 2  together. Printed circuit  238  may include transmission line structures for conveying radio-frequency signals between feed terminals  208  and  210  and transceivers  36  and  38  (e.g., structures for transmission line  92  and/or  226  of  FIG. 5 ). 
     Conductive element  232  may be coupled between terminal  202  on peripheral conductive housing structure  16  and terminal  256  in printed circuit  238 . Inductor  234  may be coupled between terminals  256  and  258  (e.g., inductor  234  may be mounted to printed circuit  238 ). Terminal  258  in printed circuit  238  may be coupled to ground terminal  204  on ground  104  (e.g., layer  12 - 2 ). Conductive element  232  may be implemented using any desired conductive structures to short terminal  202  to terminal  256 . For example, conductive element  232  may include a shorting pin, metal strip, an integral portion of housing  16 , conductive wire, a conductive screw, a conductive spring, or other structures. If desired, a portion of conductive element  232  may be formed from conductive traces on printed circuit  238 . Inductor  234  may be a fixed component on printed circuit  238  (e.g., a surface-mount technology component) or may be formed from a distributed inductance on printed circuit  238 . A conductive interconnect structure may electrically connect terminal to  258  to terminal  204 . For example, a screw or other fastener may be used to electrically connect terminals  258  and  204 . 
       FIG. 8  is an interior top perspective view of electronic device  10 . As shown in  FIG. 8 , conductive housing wall  12 - 2  may form antenna ground  104  and may extend between opposing sides of peripheral conductive structures  16 . Opening  101  may separate arm  108  of antenna  40 F from ground  104 . Antenna feed  112  for antenna  40 F may include positive antenna feed terminal  98  and ground antenna feed terminal  100  coupled to opposing sides of opening  101 . Antenna structures for antenna  40 W such as the metal traces of antenna resonating element  236  may be formed on carrier  246 . 
     Conductive fasteners such as screws  260 ,  262 , and  264  may be used to mount carrier  246  and printed circuit  238  within the housing of device  10  and may be used to carry antenna signals. 
     For example, screw  260  may form an electrical contact between terminal  210  of resonating element  236 , terminal  252  on printed circuit  238 , and terminal  254  on ground  104 . Screw  260  may pass through an opening in carrier  246  (at terminal  210 ) and an opening in printed circuit  238  (at terminal  252 ) and may screw into a threaded opening in ground  104  (at terminal  254 ). Screw  260  may serve to short ground antenna feed terminal  210  to ground  104  and to transmission line structures in printed circuit  238 . 
     Screw  262  may form an electrical contact between terminal  208  of resonating element  236  and terminal  250  on printed circuit  238 . Screw  262  may pass through an opening in carrier  246  (at terminal  208 ) and may screw into a threaded opening in printed circuit  238  (at terminal  250 ). Screw  262  may serve to couple feed terminal  208  to transmission line structures on printed circuit  238 . 
     Screw  264  may form an electrical contact between terminal  258  on printed circuit  238  and terminal  204  on ground  104 . Screw  264  may pass through an opening in printed circuit  238  (at terminal  258 ) and may screw into a threaded opening in ground  104  (at terminal  204 ). Screw  264  may serve to short antenna signals conveyed by antenna feed  112  to ground  104  through structure  232  and inductor  234 . 
     The example of  FIG. 8  is merely illustrative. In general, any desired conductive interconnect structures may be used to electrically connect terminals within electronic device  10 . In the example of  FIG. 8 , plastic carrier  246  is used to support an antenna resonating element that is used to convey both wireless local area network and ultra-high band signals. If desired, plastic carrier  246  may carry antenna traces for a single antenna, may carry antenna traces for two different antennas, may carry antenna traces for two or more different antennas, may carry antenna traces for three or more different antennas, etc. 
     In the example of  FIGS. 7 and 8 , antenna resonating element  236  is formed on carrier  246  and conductive element  232  is not formed on carrier  246 . However, this is merely illustrative. If desired, carrier  246  may carry antenna resonating element  236  and metal traces that form at least a portion of conductive element  232 . 
       FIG. 9  is a top view of an illustrative carrier with both metal traces for antenna resonating element  236  and metal traces that form at least a portion of conductive element  232 . As shown in  FIG. 9 , carrier  246  may have a first portion  246 - 1  with a first height and a second portion  246 - 2  with a second height that is greater than the first height (e.g., in the Z-dimension of  FIG. 9 ). Antenna resonating element  236  may be coupled to positive antenna feed terminal  208  and ground antenna feed terminal  210 . Conductive element  232  may be coupled between terminals  202  and  256 . 
       FIG. 10  is cross-sectional side view taken along line  266  of  FIG. 9 . As shown in  FIG. 10 , carrier portion  246 - 1  has a first height  268  whereas carrier portion  246 - 2  has a second height  270 . Height  270  may be greater than height  268 . Conductive element  232  may be formed at least partially from metal traces on portion  246 - 1  of carrier  246 . Metal traces on portion  246 - 1  of carrier may be coupled to additional conductive structures (e.g., springs, screws, clips, brackets, pins, conductive vias, solder, welds, conductive adhesive, etc.) that form additional portions of conductive element  232 . Antenna resonating element  236  may be formed on carrier portion  246 - 2 . The example of  FIGS. 9 and 10  are merely illustrative. If desired, height  270  may be less than height  268 . Traces  232  and/or  236  may be embedded within the material of carrier  246  if desired. 
     In the example of  FIGS. 6-8 , inductor  234  is depicted as a single fixed inductor. However, this is merely illustrative.  FIGS. 11A-11C  are circuit diagrams showing other possible arrangements for implementing return path  110  of antenna  40 F. 
     As shown in  FIG. 11A , adjustable component  272  may be interposed between terminals  256  and  258  (e.g., within return path  110  of antenna  40 F). Adjustable component  272  may include multiple inductors such as inductors  274 ,  276 , and  278 . Inductors  276  and  278  may be coupled to radio-frequency switching circuit  280 . Switching circuit  280  may be a single-pole double-throw switch, for example. When switch  280  is in a first state, inductor  276  may be coupled between terminals  256  and  258 . When switch  280  is in a second state, inductor  278  may be coupled between terminals  256  and  258 . In a third state, switch  280  may be open and neither inductor  276  nor inductor  278  is coupled between terminals  256  and  258 . The state of switch  280  may be changed to tune antenna  40 F to resonate in particular frequencies. Inductor  274  may be a fixed inductor that is not coupled to switch  280 . Inductor  274  may be referred to as a bypass inductor. Inductor  274  may always be coupled between terminals  256  and  258 . Inductors  274 ,  276 , and  278  may have any desired inductance values. The inductance values of inductors  274 ,  276 , and  278  may be different or may be the same. 
     In the example of  FIG. 11B , adjustable component  282  may be interposed between terminals  256  and  258 . Adjustable component  282  may include inductors  284  and  286 . Inductors  284  and  286  may be coupled to radio-frequency switching circuit  285 . Switching circuit  285  may be a single-pole double-throw switch, for example. When switch  285  is in a first state, inductor  284  may be coupled between terminals  256  and  258 . When switch  285  is in a second state, inductor  286  may be coupled between terminals  256  and  258 . The state of switch  285  may be changed to tune antenna  40 F to resonate in particular frequencies. Inductors  284  and  286  may have any desired inductance values. The inductance values of inductors  284  and  286  may be different or may be the same. 
     In the example of  FIG. 11C , adjustable component  288  may be interposed between terminals  256  and  258 . Adjustable component  288  may include inductors  290  and  292 . Inductors  290  and  292  may be coupled to radio-frequency switching circuit  294 . Switching circuit  294  may be a single-pole single-throw switch, for example. When switch  294  is in a first state, inductor  292  may be coupled between terminals  256  and  258 . When switch  294  is in a second state, switch  294  may be open and inductor  292  is not coupled between terminals  256  and  258 . The state of switch  294  may be changed to tune antenna  40 F to resonate in particular frequencies. Inductor  290  may be a fixed inductor that is not coupled to switch  294 . Inductor  290  may be referred to as a bypass inductor. Inductor  290  may always be coupled between terminals  256  and  258 . Inductors  290  and  292  may have any desired inductance values. The inductance values of inductors  290  and  292  may be different or may be the same. 
     The examples of  FIGS. 11A-11C  are merely illustrative. In general, any desired components may be connected between terminals  256  and  258  in the return path (i.e., inductors, capacitors, resistors, etc.) of antenna  40 F. 
       FIG. 12  is a graph of antenna efficiency as a function of frequency for an illustrative wireless local area network and ultra-high band antenna of the type shown in  FIGS. 6-10 . As shown in  FIG. 12 , antenna  40 W may exhibit resonances in an ultra-high band UHB (e.g., 3400-3600 MHz) and a 5 GHz wireless local area network band (e.g., 5150-5850 MHz). This example is merely illustrative and, if desired, antenna  40  may exhibit resonances in a subset of these bands and/or in additional bands. 
     Ultra-high band (UHB) may extend from 3400 MHz to 3600 MHz or other suitable frequency range. As shown in  FIG. 12 , antenna  40 W may have an antenna efficiency characterized by curve  302  in ultra-high band UHB. The response of antenna  40 W may be associated with antenna currents flowing over path  242  of  FIG. 6 , for example. The 5 GHz wireless local area network band may extend from 5150 to 5850 MHz or other suitable frequency range. As shown in  FIG. 12 , antenna  40 W may have an antenna efficiency characterized by curve  304  in the 5 GHz wireless local area network band. The response of antenna  40 W may be associated with antenna currents flowing over path  240  of  FIG. 6 , for example. In this way, antennas  40 W and  40 F may collectively cover multiple cellular telephone bands such as a low band, midband, high band, and ultra-high band, as well as a wireless local area network band with satisfactory antenna efficiency and without requiring the use of a separate antenna within device  10  for handling the ultra-high band. This may, for example, optimize the space required within device  10  to form the antenna structures required for covering each of these bands. 
     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: 20170908
Publication Date: 20200107
Grant Date: 20200107
Priority Date: 20170908
Inventors: AVSER, BILGEHAN
ATMATZAKIS, GEORGIOS
XU, HAO
PASCOLINI, MATTIA
YARGA, SALIH
GAO, XU
HAN, XU
ZHOU, YIJUN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/328", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/328", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q5/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/328", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 65632158