PATENT DOCUMENT

Publication Number: US-10673127-B2
Application Number: US-201916584106-A
Country: US
Kind Code: B2

Title: Electronic device wide band antennas

Abstract:
An electronic device such as a wristwatch may have a housing with metal sidewalls and a display having conductive display structures. The display structures may be separated from the sidewalls by a slot for an antenna that runs around the display module. A conductive interconnect may be coupled between the sidewalls and the display structures. A feed and tuning element may be coupled between the display structures and the sidewalls. A first length of the slot from the interconnect to the tuning element may radiate in a satellite band and a cellular band. A second length of the slot from the interconnect to the feed may radiate in a 2.4 GHz band. Harmonics of the second length may radiate in bands at and above 5.0 GHz. If desired clip and blade structures may form conductive paths for coupling antenna elements.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing having conductive housing walls; 
 conductive display structures in a display module separated from the conductive housing walls by a slot forming a slot antenna; 
 a clip structure mounted to the conductive display structures; and 
 a blade structure mounted to a substrate and configured to mate with the clip structure to form an electrical connection to the slot antenna for conveying radio-frequency signals using the slot antenna. 
 
     
     
       2. The electronic device defined in  claim 1 , further comprising:
 transceiver circuitry, wherein the clip structure serves as a positive antenna feed terminal for the slot antenna and the transceiver circuitry is operable to use the blade structure to convey the radio-frequency signals to the positive antenna feed terminal. 
 
     
     
       3. The electronic device defined in  claim 2 , wherein the substrate comprises a printed circuit substrate on which the blade structure mounted, the printed circuit substrate having conductive traces that couple the blade structure to the transceiver circuitry. 
     
     
       4. The electronic device defined in  claim 3 , wherein the clip structure is attached to a conductive base plate having a portion that overlaps the conductive display structures, the conductive base plate being attached to the conductive display structures at the portion of the conductive base plate. 
     
     
       5. The electronic device defined in  claim 4 , wherein the portion of the conductive base plate is soldered to the conductive display structures. 
     
     
       6. The electronic device defined in  claim 4 , wherein the conductive display structures comprise a touch sensor layer, a display panel layer, and a near-field communications antenna layer, the clip structure being electrically connected to a given one of the touch sensor layer, the display panel layer, and the near-field communications antenna layer. 
     
     
       7. The electronic device defined in  claim 1 , further comprising:
 an antenna ground for the slot antenna formed from the conductive housing walls, the blade structure being coupled to the antenna ground and forming a conductive path from the conductive display structures to the antenna ground. 
 
     
     
       8. The electronic device defined in  claim 7 , wherein the conductive path includes a conductive fastener configured to secure the substrate to the housing. 
     
     
       9. The electronic device defined in  claim 1 , wherein the blade structure is surrounded by a dielectric support structure that is mounted to the substrate. 
     
     
       10. The electronic device defined in  claim 9 , wherein the blade structure has an opening and extends along an axis perpendicular to a surface of the substrate to which the blade structure is mounted. 
     
     
       11. An electronic device, comprising:
 a housing having conductive walls; 
 a display module that includes conductive structures; 
 an antenna having a slot element with opposing edges defined by the conductive walls and the conductive structures, the slot element extending around first and second sides of the conductive structures; 
 an antenna feed coupled across the slot element; 
 a conductive interconnect structure coupled between the conductive walls and the first side of the conductive structures; and 
 a tuning element for the antenna coupled across the slot element at the second side of the conductive structures. 
 
     
     
       12. The electronic device defined in  claim 11 , wherein the slot element extends around a third side of the conductive structures and the antenna feed is across the slot element at the third side of the conductive structures. 
     
     
       13. The electronic device defined in  claim 11 , further comprising:
 a button mounted to the conductive walls, the tuning element being coupled across the slot element at a location between the button and the conductive interconnect structure. 
 
     
     
       14. The electronic device defined in  claim 11 , further comprising:
 a clip connected to the conductive structures that serves as a positive antenna feed terminal for the antenna feed. 
 
     
     
       15. The electronic device defined in  claim 11 , wherein tuning element comprises an inductor that is configured to tune a frequency response of the antenna for an ultra-wide band (UWB) frequency band, the electronic device further comprising:
 radio-frequency transceiver circuitry coupled to the antenna using a blade structure configured to mate with a clip and operable to convey radio-frequency signals in the UWB frequency band using the antenna. 
 
     
     
       16. A wristwatch, comprising:
 conductive housing sidewalls; 
 conductive display structures in a display module; 
 an antenna having a slot element with opposing edges defined by the conductive housing sidewalls and the conductive display structures; 
 a first set of clip and tab structures coupled to the conductive display structures forming a first electrical connection to the antenna; and 
 a second set of clip and tab structures coupled to the conductive display structures forming a second electrical connection to the antenna. 
 
     
     
       17. The wristwatch defined in  claim 16 , wherein the first set of clip and tab structures comprises a first clip structure mounted to the display module and a first tab structure mounted to a substrate surrounded by the conductive housing sidewalls. 
     
     
       18. The wristwatch defined in  claim 17 , wherein the second set of clip and tab structures comprises a second clip structure mounted to the display module and a second tab structure mounted to an additional substrate surrounded by the conductive housing sidewalls. 
     
     
       19. The wristwatch defined in  claim 17 , wherein the first set of clip and tab structures are configured to convey radio-frequency signals to an antenna feed for the antenna. 
     
     
       20. The wristwatch defined in  claim 17 , wherein the second set of clip and tab structures are configured to couple the conductive display structures to an antenna ground for the antenna.

Description:
This application is a continuation-in-part of patent application Ser. No. 15/991,498, filed May 29, 2018, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates to electronic devices, and more particularly, to antennas for electronic devices with wireless communications circuitry. 
     Electronic devices are often provided with wireless communications capabilities. 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. 
     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 such as a wristwatch may have a housing with metal portions such as metal sidewalls. A display may be mounted on a front face of the device. The display may include a display module with conductive display structures and a display cover layer that overlaps the display module. The conductive display structures may include portions of a touch sensor layer, portions of a display layer that displays images, portions of a near field communications antenna layer, a metal frame for the display module, a metal back plate for the display module, or other conductive structures. 
     The electronic device may include wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and an antenna such as a slot antenna. The conductive display structures may be separated from the metal sidewalls by a slot that runs laterally around the display module. The slot antenna may be fed using an antenna feed having a first feed terminal coupled to the conductive display structures and a second feed terminal coupled to the metal sidewalls. A conductive interconnect structure may be coupled to the metal sidewalls (e.g., using a conductive fastener) and may extend across the slot to the display module. The metal sidewalls, the conductive display structures, and the conductive interconnect structure may define the edges of a slot element for the slot antenna. A tuning element may be coupled between the conductive display structures and the conductive housing walls across the slot element. 
     A first length of the slot element extending from the conductive interconnect structure to the tuning element may be configured to radiate in a first frequency band such as a frequency band that includes a satellite navigation frequency band and a cellular telephone frequency band. A second length of the slot element extending from the conductive interconnect structure to the antenna feed may be configured to radiate in a second frequency band such as a 2.4 GHz wireless local area network frequency band. Harmonics of the second length of the slot element may be configured to radiate in a third frequency band such as a frequency band that includes a 5.0 wireless local area network frequency band and an ultra-wide band (UWB) frequency band between 5.0 GHz and 8.3 GHz. If desired, the tuning element may be omitted, and the antenna may be coupled to separate low band and high band impedance matching circuits. In this way, the antenna may operate with satisfactory antenna efficiency across a wide range of frequency bands including UWB frequency bands despite form factor limitations for the electronic device. 
     A clip structure may be soldered to conductive display structures in the display module and may form a positive antenna feed terminal of the slot antenna. A blade structure may be mounted to a substrate such as a printed circuit board and may mate with the clip structure to form a conductive path for conveying antenna signals to the positive antenna feed terminal. If desired, a separate set of clip and blade structures may form a short circuit path for the slot antenna and/or form a conductive path connecting to antenna tuning components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device in accordance with an embodiment. 
         FIG. 3  is a diagram of illustrative wireless circuitry in an electronic device in accordance with an embodiment. 
         FIG. 4  is a schematic diagram of an illustrative slot antenna in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative antenna formed using conductive display structures and conductive electronic device housing structures in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative electronic device having an antenna of the type shown in  FIG. 5  in accordance with an embodiment. 
         FIG. 7  is a top-down view of an illustrative antenna formed using conductive display structures that are grounded to conductive electronic device housing structures in accordance with an embodiment. 
         FIG. 8  is a circuit diagram of illustrative wireless circuitry having separate low band and high band matching circuits for performing wireless operations across multiple frequency bands in accordance with an embodiment. 
         FIG. 9  is a circuit diagram of illustrative wireless circuitry having shared matching circuitry for performing wireless operations across multiple frequency bands in accordance with an embodiment. 
         FIG. 10  is a top-down view an illustrative antenna formed using conductive display structures that are coupled to conductive electronic device housing structures using an antenna tuning component and conductive grounding structures in accordance with an embodiment. 
         FIG. 11  is a top-down view of an illustrative antenna tuning component formed on a flexible printed circuit for coupling conductive display structures to conductive electronic device housing structures in accordance with an embodiment. 
         FIG. 12  is a cross-sectional side view of an illustrative electronic device showing how a flexible printed circuit of the type shown in  FIG. 11  may be coupled to conductive electronic device housing structures in accordance with an embodiment. 
         FIG. 13  is a perspective view of an illustrative set of spring fingers that may be used to couple a positive antenna feed terminal to conductive display structures in accordance with an embodiment. 
         FIG. 14  is a graph of antenna performance (antenna efficiency) for illustrative antenna structures of the types shown in  FIGS. 5-13  in accordance with an embodiment. 
         FIG. 15  is a perspective view of an illustrative coupling mechanism for forming antenna connections in accordance with an embodiment. 
         FIG. 16  is a perspective side view of an illustrative electronic device with a front cover opened to show how coupling mechanisms of the type shown in  FIG. 15  may be provided on device components in accordance with an embodiment. 
         FIG. 17  is a top-down view of an illustrative antenna that is formed using conductive display structures coupled to conductive electronic device housing structures and that may include tuning components at various locations in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may be provided with wireless circuitry. The wireless circuitry may be used to support wireless communications in multiple wireless communications (frequency) bands. The wireless circuitry may include antennas. Antennas may be formed from electrical components such as displays, touch sensors, near-field communications antennas, wireless power coils, peripheral antenna resonating elements, conductive traces, and device housing structures, as examples. 
     Electronic device  10  may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a wristwatch (e.g., a smart watch). Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     In the example of  FIG. 1 , device  10  includes a display such as display  14 . Display  14  may be mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). Housing  12  may have metal sidewalls such as sidewalls  12 W or sidewalls formed from other materials. Examples of metal materials that may be used for forming sidewalls  12 W include stainless steel, aluminum, silver, gold, metal alloys, or any other desired conductive material. Sidewalls  12 W may sometimes be referred to herein as conductive sidewalls  12 W or conductive housing sidewalls  12 W. 
     Display  14  may be formed at (e.g., mounted on) the front side (face) of device  10 . Housing  12  may have a rear housing wall on the rear side (face) of device  10  such as rear housing wall  12 R that opposes the front face of device  10 . Conductive sidewalls  12 W may surround the periphery of device  10  (e.g., conductive sidewalls  12 W may extend around peripheral edges of device  10 ). Rear housing wall  12 R may be formed from conductive materials and/or dielectric materials. Examples of dielectric materials that may be used for forming rear housing wall  12 R include plastic, glass, sapphire, ceramic, wood, polymer, combinations of these materials, or any other desired dielectrics. 
     Rear housing wall  12 R and/or display  14  may extend across some or all of the length (e.g., parallel to the X-axis of  FIG. 1 ) and width (e.g., parallel to the Y-axis) of device  10 . Conductive sidewalls  12 W may extend across some or all of the height of device  10  (e.g., parallel to Z-axis). Conductive sidewalls  12 W and/or the rear housing wall  12 R 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 or dielectric 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 housing walls  12 R and/or  12 W from view of the user). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Display  14  may be protected using a display cover layer. The display cover layer may be formed from a transparent material such as glass, plastic, sapphire or other crystalline dielectric materials, ceramic, or other clear materials. The display cover layer may extend across substantially all of the length and width of device  10 , for example. 
     Device  10  may include buttons such as button  18 . There may be any suitable number of buttons in device  10  (e.g., a single button, more than one button, two or more buttons, five or more buttons, etc.). Buttons may be located in openings in housing  12  (e.g., openings in conductive sidewall  12 W or rear housing wall  12 R) or in an opening in display  14  (as examples). Buttons may be rotary buttons, sliding buttons, buttons that are actuated by pressing on a movable button member, etc. Button members for buttons such as button  18  may be formed from metal, glass, plastic, or other materials. Button  18  may sometimes be referred to as a crown in scenarios where device  10  is a wristwatch device. 
     Device  10  may, if desired, be coupled to a strap such as strap  16 . Strap  16  may be used to hold device  10  against a user&#39;s wrist (as an example). Strap  16  may sometimes be referred to herein as wrist strap  16 . In the example of  FIG. 1 , wrist strap  16  is connected to opposing sides  8  of device  10 . Conductive sidewalls  12 W on sides  8  of device  10  may include attachment structures for securing wrist strap  16  to housing  12  (e.g., lugs or other attachment mechanisms that configure housing  12  to receive wrist strap  16 ). Configurations that do not include straps may also be used for device  10 . 
     A schematic diagram showing illustrative components that may be used in device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include storage and processing circuitry such as control circuitry  28 . Control 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 control 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. 
     Control 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, control circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  28  include internet protocols, wireless local area network (WLAN) 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 or other wireless personal area network (WPAN) protocols, cellular telephone protocols, MIMO protocols, antenna diversity protocols, satellite navigation system protocols, millimeter wave communications protocols, IEEE 802.15.4 ultra-wideband communications protocols or other ultra-wideband communications protocols, etc. 
     Input-output circuitry  44  may include input-output devices  32 . Input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include user interface devices, data port devices, and other input-output components. For example, input-output devices  32  may include touch screens, displays without touch sensor capabilities, buttons, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, vibrators or other haptic feedback engines, digital data port devices, light sensors (e.g., infrared light sensors, visible light sensors, etc.), light-emitting diodes, motion sensors (accelerometers), capacitance sensors, proximity sensors, magnetic sensors, force sensors (e.g., force sensors coupled to a display to detect pressure applied to the display), etc. 
     Input-output circuitry  44  may include wireless circuitry  34  (sometimes referred to herein as wireless communications circuitry  34 ). Wireless circuitry  34  may include coil  50  and wireless power receiver  48  for receiving wirelessly transmitted power from a wireless power adapter. Wireless power receiver  48  may include, for example, rectifier circuitry and other circuitry for powering or charging a battery on device  10  using wireless power received by coil  50 . Coil  50  may, as an example, receive wireless power through rear housing wall  12 R ( FIG. 1 ) when mounted to a wireless power adapter. To support wireless communications, wireless 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 such as antennas  40 , transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless circuitry  34  may include radio-frequency transceiver circuitry  52  for handling various radio-frequency communications bands. For example, wireless circuitry  34  may include transceiver circuitry  36 ,  38 ,  42 ,  46 , and  54 . Transceiver circuitry  36  may be wireless local area network transceiver circuitry. Transceiver circuitry  36  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications or other WLAN bands and may handle the 2.4 GHz Bluetooth® communications band or other WPAN bands. Transceiver circuitry  36  may sometimes be referred to herein as WLAN transceiver circuitry  36 . 
     Wireless circuitry  34  may use cellular telephone transceiver circuitry  38  (sometimes referred to herein as cellular transceiver circuitry  38 ) for handling wireless communications in frequency ranges (communications bands) such as a low band (sometimes referred to herein as a cellular low band LB) from 600 to 960 MHz, a midband (sometimes referred to herein as a cellular midband MB) from 1400 MHz or 1700 MHz to 2170 or 2200 MHz, and a high band (sometimes referred to herein as a cellular high band HB) from 2200 or 2300 to 2700 MHz (e.g., a high band with a peak at 2400 MHz) or other communications bands between 600 MHz and 4000 MHz or other suitable frequencies (as examples). Cellular transceiver circuitry  38  may handle voice data and non-voice data. 
     Wireless circuitry  34  may include satellite navigation system circuitry such as Global Positioning System (GPS) receiver circuitry  42  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data (e.g., GLONASS signals at 1609 MHz). Satellite navigation system signals for receiver  42  are received from a constellation of satellites orbiting the earth. Wireless circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless circuitry  34  may include circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) transceiver circuitry  46  (e.g., an NFC transceiver operating at 13.56 MHz or another suitable frequency), etc. 
     In NFC links, wireless signals are typically conveyed over a few inches at most. In satellite navigation system links, cellular telephone links, and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. In WLAN and WPAN links at 2.4 and 5 GHz and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. 
     Ultra-wideband (UWB) transceiver circuitry  54  may support communications using the IEEE 802.15.4 protocol and/or other wireless communications protocols (e.g., ultra-wideband communications protocols). Ultra-wideband wireless signals may be based on an impulse radio signaling scheme that uses band-limited data pulses. Ultra-wideband signals may have any desired bandwidths such as bandwidths between 499 MHz and 1331 MHz, bandwidths greater than 500 MHz, etc. The presence of lower frequencies in the baseband may sometimes allow ultra-wideband signals to penetrate through objects such as walls. In an IEEE 802.15.4 system, a pair of electronic devices may exchange wireless time stamped messages. Time stamps in the messages may be analyzed to determine the time of flight of the messages and thereby determine the distance (range) between the devices and/or an angle between the devices (e.g., an angle of arrival of incoming radio-frequency signals). Transceiver circuitry  54  may operate (i.e., convey radio-frequency signals) in frequency bands such as an ultra-wideband frequency band between about 5 GHz and about 8.3 GHz (e.g., a 6.5 GHz frequency band, an 8 GHz frequency band, and/or at other suitable frequencies). 
     Wireless 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 slot antenna structures, loop antenna structures, patch antenna structures, stacked patch antenna structures, antenna structures having parasitic elements, inverted-F antenna structures, planar inverted-F antenna structures, helical antenna structures, monopole antennas, dipole antenna structures, Yagi (Yagi-Uda) antenna structures, surface integrated waveguide structures, hybrids of these designs, etc. If desired, one or more of antennas  40  may be cavity-backed antennas. 
     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 whereas another type of antenna is used in forming a remote wireless link antenna. If desired, space may be conserved within device  10  by using a single antenna to handle two or more different communications bands. For example, a single antenna  40  in device  10  may be used to handle communications in a WiFi® or Bluetooth® communication band at 2.4 GHz, a GPS communications band at 1575 MHz, a WiFi® communications band at 5.0 GHz, one or more cellular telephone communications bands such as a cellular midband between about 1700 MHz and 2200 MHz and a cellular high band between about 2200 and 2700 MHz, and UWB communications band between about 5 GHz and 8.3 GHz. If desired, a combination of antennas for covering multiple frequency bands and dedicated antennas for covering a single frequency band may be used. 
     It may be desirable to implement at least some of the antennas in device  10  using portions of electrical components that would otherwise not be used as antennas and that support additional device functions. As an example, it may be desirable to induce antenna currents in components such as display  14  ( FIG. 1 ), so that display  14  and/or other electrical components (e.g., a touch sensor, near-field communications loop antenna, conductive display assembly or housing, conductive shielding structures, etc.) can serve as part of an antenna for Wi-Fi, Bluetooth, GPS, cellular frequencies, UWB, and/or other frequencies without the need to incorporate separate bulky antenna structures in device  10 . 
       FIG. 3  is a diagram showing how transceiver circuitry  52  in wireless circuitry  34  may be coupled to antenna structures of a corresponding antenna  40  using signal paths such as signal path  60 . Wireless circuitry  34  may be coupled to control circuitry  28  over data and control path  56 . 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  40  with the ability to cover communications bands (frequencies) of interest, antenna  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  40  may be provided with adjustable circuits such as tunable components  58  to tune the antenna over communications bands of interest. Tunable components  58  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  64  that adjust inductance values, capacitance values, or other parameters associated with tunable components  58 , thereby tuning antenna  40  to cover desired communications bands. 
     Signal path  60  may include one or more radio-frequency transmission lines. As an example, signal path  60  of  FIG. 3  may be a transmission line having first and second conductive paths such as paths  66  and  68 , respectively. Path  66  may be a positive signal line (sometimes referred to herein as signal conductor  66 ) and path  68  may be a ground signal line (sometimes referred to herein as ground conductor  68 ). Lines  66  and  68  may form part of a coaxial cable, a stripline transmission line, a microstrip transmission line, an edge-coupled microstrip transmission line, an edge-coupled stripline transmission line, a waveguide structure, a transmission line formed from combinations of these structures, etc. Signal path  60  may sometimes be referred to herein as radio-frequency transmission line  60  or transmission line  60 . 
     Transmission lines in device  10  such as transmission line  60  may be integrated into rigid and/or flexible printed circuit boards if desired. In one suitable arrangement, transmission lines such as transmission line  60  may also include transmission line conductors (e.g., positive signal line  66  and ground signal line  68 ) integrated within multilayer laminated structures (e.g., layers of a conductive material such as copper and a dielectric material such as a resin that are laminated together without intervening adhesive). The multilayer laminated structures may, if desired, be folded or bent in multiple dimensions (e.g., two or three dimensions) and may maintain a bent or folded shape after bending (e.g., the multilayer laminated structures may be folded into a particular three-dimensional shape to route around other device components and may be rigid enough to hold its shape after folding without being held in place by stiffeners or other structures). All of the multiple layers of the laminated structures may be batch laminated together (e.g., in a single pressing process) without adhesive (e.g., as opposed to performing multiple pressing processes to laminate multiple layers together with adhesive). 
     A matching network formed from components such as inductors, resistors, and capacitors may be used in matching the impedance of antenna  40  to the impedance of transmission line  60 . 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. Matching network components may, for example, be interposed on transmission line  60 . The matching network components may be adjusted using control signals received from control circuitry  28  if desired. Components such as these may also be used in forming filter circuitry in antenna  40  (e.g., tunable components  58 ). 
     Transmission line  60  may be directly coupled to an antenna resonating element and ground for antenna  40  or may be coupled to near-field-coupled antenna feed structures that are used in indirectly feeding a resonating element for antenna  40 . As an example, antenna  40  may be a slot antenna, an inverted-F antenna, a loop antenna, a patch antenna, or other antenna having an antenna feed  62  with a positive antenna feed terminal such as terminal  70  and a ground antenna feed terminal such as terminal  72 . Positive signal line  66  may be coupled to positive antenna feed terminal  70  and ground signal line  68  may be coupled to ground antenna feed terminal  72 . 
     If desired, antenna  40  may include an antenna resonating element that is indirectly fed using near-field coupling. In a near-field coupling arrangement, transmission line  60  is coupled to a near-field-coupled antenna feed structure that is used to indirectly feed antenna structures such as the antenna resonating element. This example is merely illustrative and, in general, any desired antenna feeding arrangement may be used. 
     Antenna  40  may be formed using any desired antenna structures. In one suitable arrangement, antenna  40  may be formed using a slot antenna structure. An illustrative slot antenna structure that may be used for forming antenna  40  is shown in  FIG. 4 . As shown in  FIG. 4 , antenna  40  may include a conductive structure such as conductor  82  that has been provided with a dielectric opening such as dielectric opening  74 . Opening  74  may sometimes be referred to herein as slot  74 , slot antenna resonating element  74 , slot element  74 , or slot radiating element  74 . In the configuration of  FIG. 4 , slot  74  is a closed slot, because portions of conductor  82  completely surround and enclose slot  74 . Open slot antennas may also be formed in conductive materials such as conductor  82  (e.g., by forming an opening in the right-hand or left-hand end of conductor  82  so that slot  74  protrudes through conductor  82 ). 
     Antenna feed  62  for antenna  40  may be formed using positive antenna feed terminal  70  and ground antenna feed terminal  72 . In general, the frequency response of an antenna is related to the size and shapes of the conductive structures in the antenna. Slot antennas of the type shown in  FIG. 4  tend to exhibit response peaks when slot perimeter P is equal to the wavelength of operation of antenna  40  (e.g. where perimeter P is equal to two times length L plus two times width W). Antenna currents may flow between feed terminals  70  and  72  around perimeter P of slot  74 . As an example, where slot length L&gt;&gt;slot width W, the length of antenna  40  will tend to be about half of the length of other types of antennas such as inverted-F antennas configured to handle signals at the same frequency. Given equal antenna volumes, antenna  40  may therefore be able to handle signals at approximately twice the frequency of other antennas such as inverted-F antennas, for example. 
     Antenna feed  62  may be coupled across slot  74  at a location between opposing edges  76  and  78  of slot  74 . For example, antenna feed  62  may be located at a distance  80  from edge  76  of slot  74 . Distance  80  may be adjusted to match the impedance of antenna  40  to the impedance of transmission line  60  ( FIG. 3 ). For example, the antenna current flowing around slot  74  may experience an impedance of zero at edges  76  and  78  of slot  74  (e.g., a short circuit impedance) and an infinite (open circuit) impedance at the center of slot  74  (e.g., at a fundamental frequency of the slot). Antenna feed  62  may be located between the center of slot  74  and edge  76  at a location where the antenna current experiences an impedance that matches the impedance of transmission line  60 , for example (e.g., distance  80  may be between 0 and ¼ of the wavelength of operation of antenna  40 ). 
     The example of  FIG. 4  is merely illustrative. In general, slot  74  may have any desired shape (e.g., where the perimeter P of slot  74  defines radiating characteristics of antenna  40 ). For example, slot  74  may have a meandering shape with different segments extending in different directions, may have straight and/or curved edges, etc. Conductor  82  may be formed from any desired conductive electronic device structures. For example, conductor  82  may include conductive traces on printed circuit boards or other substrates, sheet metal, metal foil, conductive structures associated with display  14  ( FIG. 1 ), conductive portions of housing  12  (e.g., conductive sidewalls  12 W of  FIG. 1 ), or other conductive structures within device  10 . In one suitable arrangement, different sides (edges) of slot  74  are defined by different conductive structures. For example, one side of slot  74  may be formed from conductive sidewalls  12 W whereas the other side of slot  74  is formed from conductive structures associated with display  14 . 
       FIG. 5  is a simplified cross-sectional side view of device  10  showing how antenna  40  may be formed from conductive structures associated with display  14  and conductive sidewalls  12 W. As shown in  FIG. 5 , antenna  40  may include conductive display structures  84  coupled to an antenna feed such as antenna feed  62 . Positive antenna feed terminal  70  of antenna feed  62  may be coupled to conductive display structures  84 . Ground antenna feed terminal  72  of antenna feed  62  may be coupled to ground (e.g., to conductive sidewalls  12 W of housing  12 ). 
     In this way, housing  12  and conductive display structures  84  may form conductor  82  of  FIG. 4  and may define the edges of slot  74  for antenna  40  (where the perimeter of slot  74  extends within the X-Y plane of  FIG. 5 ). As shown by  FIG. 5 , slot  74  may separate conductive display structures  84  from conductive sidewalls  12 W and may be bridged by antenna feed  62 . Slot  74  may surround one or more lateral sides of conductive display structures  84  (e.g., in the X-Y plane of  FIG. 5 ). 
     Housing  12  and conductive display structures  84  may define an interior cavity or volume  88  within device  10 . Additional device components may be mounted within volume  88 . Antenna feed  62  may be coupled to transceiver circuitry  52  by a transmission line such as a coaxial cable or a flexible printed circuit transmission line (e.g., transmission line  60  of  FIG. 3 ). 
     Conductive display structures  84  may, for example, include portions of display  14  ( FIG. 1 ) such as metal portions of a frame or assembly of display  14 , touch sensor electrodes within display  14 , portions of a near field communications antenna embedded within display  14 , ground plane structures within display  14 , a metal back plate for display  14 , or other conductive structures on or in display  14 . Conductive display structures  84  may sometimes be referred to herein as display module structures  84 . 
     Conductive display structures  84  may be coupled to ground (e.g., conductive sidewall  12 W) by conductive interconnect path  86  (e.g., across a portion of slot  74  extending between conductive display structures  84  and conductive sidewalls  12 W). Conductive interconnect path  86  may include conductive structures that are directly connected to conductive display structures  84 , may include conductive structures that are capacitively coupled to (but not in contact with) conductive display structures  84  (e.g., while still spanning part of slot  74  and electrically shorting conductive display structures  84  to housing  12 ), and/or may include conductive structures that are not coupled to conductive display structures  84  (e.g., while still spanning part of slot  74  and being held at a ground potential, thereby serving to electrically define the perimeter of slot  74  in the X-Y plane of  FIG. 5 ). In the example of  FIG. 5 , conductive housing  12  defines a rear wall of device  10  that opposes conductive display structures  84  (e.g., volume  88  may be partially defined by a rear wall of device  10 ). This is merely illustrative. If desired, some or all of the rear wall of device  10  may be formed from dielectric materials and volume  88  may be defined by other components such as one or more printed circuit boards within device  10 . 
     Antenna  40  may be used to transmit and receive radio-frequency signals in WLAN and/or WPAN bands at 2.4 GHz and 5.0 GHz, in cellular telephone bands between 1.7 GHz and 2.2 GHz and between 2.2 GHz and 2.7 GHz, in an ultra-wideband frequency band between about 5 GHz and 8.3 GHz, in satellite navigation bands at 1.5 GHz, and/or other desired frequency bands. The 2.4 GHz frequency band may include any desired WLAN and/or WPAN frequency bands at frequencies between 2.4 GHz and 2.5 GHz, for example. The 5.0 GHz frequency band may include any desired WLAN frequency bands at frequencies between 4.9 GHz and 5.9 GHz, for example. Additional antennas may also be provided in device  10  to handle these frequency bands and/or other frequency bands. The configuration for antenna  40  of  FIG. 5  is merely illustrative. 
       FIG. 6  is a cross-sectional side view of device  10  showing how antenna  40  and conductive interconnect path  86  of  FIG. 5  may be implemented within device  10 . As shown in  FIG. 6 , device  10  may have conductive sidewalls  12 W that extend from the rear face to the front face of device  10 . Housing  12  may include a dielectric rear housing wall such as dielectric rear housing wall  100 . Display  14  may be formed at the front face of device  10  whereas dielectric rear housing wall  100  is formed at the rear face of device  10 . Conductive sidewalls  12 W may be coupled to ground antenna feed terminal  72  of antenna feed  62 . Display  14  may include a display cover layer  98  and a display module  104  under display cover layer  98 . 
     Display module  104  may include conductive components that are used in forming conductive display structures  84  of antenna  40  ( FIG. 5 ). The conductive components in display module  104  may, for example, have planar shapes (e.g., planar rectangular shapes, planar circular shapes, etc.) and may be formed from metal and/or other conductive material that carries antenna currents. The thin planar shapes of these components and the stacked configuration of  FIG. 7  may, for example, capacitively couple these components to each other so that they may operate together at radio frequencies to form conductive display structures  84  of  FIG. 5  (e.g., to effectively/electrically form a single conductor). 
     The components that form conductive display structures  84  may include, for example, planar components on one or more layers  102  in display module  104  (e.g., a first layer  102 - 1 , a second layer  102 - 2 , a third layer  102 - 3 , or other desired layers). As one example, layer  102 - 1  may form a touch sensor for display  14 , layer  102 - 2  may form a display panel (sometimes referred to as a display, display layer, or pixel array) for display  14 , and layer  102 - 3  may form a near-field communications antenna for device  10  and/or other circuitry for supporting near-field communications (e.g., at 13.56 MHz). Layer  102 - 1  may include a capacitive touch sensor and may be formed from a polyimide substrate or other flexible polymer layer with transparent capacitive touch sensor electrodes (e.g., indium tin oxide electrodes), for example. Layer  102 - 2  may include an organic light-emitting diode display layer or other suitable display layer. Layer  102 - 3  may be formed from a flexible layer that includes a magnetic shielding material (e.g., a ferrite layer or other magnetic shielding layer) and that includes loops of metal traces. If desired, a conductive back plate, metal shielding cans or layers, and/or a conductive display frame may be formed under and/or around layer  102 - 3  and may provide structural support and/or a grounding reference for the components of display module  104 . Display module  104  may sometimes be referred to herein as display assembly  104 . 
     Conductive material in layers  102 - 1 ,  102 - 2 ,  102 - 3 , a conductive back plate for display  14 , conductive shielding layers, conductive shielding cans, and/or a conductive frame for display  14  may be used in forming conductive structures  84  defining edges of slot  74  for antenna  40 . This and/or other conductive material in display  40  used to form conductive display structures  84  may be coupled together using conductive traces, vertical conductive interconnects or other conductive interconnects, and/or via capacitive coupling, for example. 
     Antenna  40  may be fed using antenna feed  62 . Positive antenna feed terminal  70  of antenna feed  62  may be coupled to display module  104  and therefore conductive display structures  84  (e.g., to near-field communications layer  102 - 3 , display layer  102 - 2 , touch layer  102 - 1 , a metal back plate for display module  104 , and/or a metal display frame for display module  104 ). Ground antenna feed terminal  72  of antenna feed  62  may be coupled to an antenna ground in device  10  (e.g., conductive sidewall  12 W). 
     As shown in  FIG. 6 , device  10  may include printed circuit board structures such as printed circuit board  90 . Printed circuit board  90  may be a rigid printed circuit board, a flexible printed circuit board, or may include both flexible and rigid printed circuit board structures. Printed circuit board  90  may sometimes be referred to herein as main logic board  90  or logic board  90 . Electrical components such as transceiver circuitry  52 , display interface circuitry  92 , and other components may be mounted to logic board  90 . If desired, one or more additional antennas, coil  50  ( FIG. 2 ), and/or sensor circuitry or other input-output devices may be interposed between logic board  90  and dielectric rear housing wall  100  (e.g., for conveying wireless signals through dielectric rear housing wall  100 ). Antenna currents for antenna  40  may be conveyed through conductive sidewalls  12 W and display module  104  (i.e., conductive display structures  84  of  FIG. 5 ) around the perimeter of slot  74  (e.g., in the X-Y plane of  FIG. 7 ). Corresponding radio-frequency signals may be conveyed through display cover layer  98 , as shown by arrow  101 . 
     Display module  104  may include one or more display connectors such as connectors  96 . Connectors  96  may be coupled to one or more printed circuits  94 . Printed circuits  94  may include flexible printed circuits (sometimes referred to herein as display flexes  94 ), rigid printed circuit boards, or traces on other substrates if desired. Connectors  96  may convey signals between layers  102  of display module  104  and display interface circuitry  92  on logic board  90  via display flexes  94 . 
     As an example, display module  104  may include a first connector  96  that that conveys touch sensor signals from layer  102 - 1  to display interface circuitry  92  over a first display flex  94 , a second connector  96  that conveys display data (e.g., image data) from display interface circuitry  92  to display layer  102 - 2  over a second display flex  94  (e.g., layer  102 - 2  may emit light corresponding to the display data), and a third connector  96  that conveys near field communications signals to and/or from layer  102 - 3  over a third display flex  94 . Connectors  96  may include conductive contact pads, conductive pins, conductive springs, conductive adhesive, conductive clips, solder, welds, conductive wires, and/or any other desired conductive interconnect structures and/or fasteners for conveying data associated with display module  104  between display module  104  and circuitry on logic board  90  or elsewhere in device  10 . 
     Transceiver circuitry  52  may be coupled to antenna feed  62  of antenna  40  over radio-frequency transmission line  60  ( FIG. 3 ). Radio-frequency transmission line  60  may include conductive paths in flexible printed circuit  120  and dielectric support structure  118 . Dielectric support structure  118  may, for example, be formed from plastic or other dielectric materials, from a rigid printed circuit board, from a flexible printed circuit, etc. Conductive paths associated with radio-frequency transmission line  60  in flexible printed circuit  120  may be coupled to conductive paths associated with radio-frequency transmission line  60  in dielectric support structure  118  over radio-frequency connector  122 . 
     Ground signal line  68  in transmission line  60  ( FIG. 3 ) may be coupled to ground antenna feed terminal  72  over path  114  (e.g., ground traces in dielectric support structure  118  may be coupled to ground antenna feed terminal  72  over path  114 ). Path  114  may include conductive wire, conductive adhesive, conductive fasteners such as screws, conductive pins, conductive clips, conductive brackets, solder, welds, and/or any other desired conductive interconnect structures. Signal line  66  of transmission line  60  ( FIG. 3 ) may be coupled to positive antenna feed terminal  70  of antenna  40  over conductive clip  116  (e.g., signal traces in dielectric support structure  118  may be coupled to positive antenna feed terminal  70  over conductive clip  116 ). One or more components such as components  124  may be mounted to dielectric support structure  118  if desired. Components  124  may include amplifier circuitry, impedance matching circuitry, or any other desired components. 
     If desired, a conductive tab or blade such as conductive tab  112  may be coupled to the conductive structures of display module  104  (e.g., conductive structures in layers  102 , a conductive back plate, a conductive frame, conductive shielding cans or layers, and/or other conductive display structures  84  in display module  104 ). Clip  116  may mate with tab  112  to form an electrical connection between transmission line  60  and positive antenna feed terminal  70  (e.g., positive antenna feed terminal  70  may be located on tab  112  when clip  116  is attached to tab  112 ). Clip  116  may, for example, be a tulip clip or other clip that has prongs or other structures that exerts pressure towards tab  112 , thereby ensuring that a robust and reliable electrical connection is held between tab  112  and clip  116  over time. 
     When configured in this way, antenna currents may be conveyed over antenna feed  62  and may begin to flow around the perimeter of slot  74  (e.g., in the X-Y plane of  FIG. 6 ). In order to help define the lateral (elongated) length L of slot  74 , conductive interconnect paths such as conductive interconnect path  86  of  FIG. 5  may span gap  113  between a given side of display module  104  and an adjacent conductive sidewall  12 W. In the example of  FIG. 6 , conductive interconnect path  86  of  FIG. 5  is implemented using conductive interconnect structures  106 . Conductive interconnect structures  106  may sometimes be referred to herein as conductive grounding structures  106  or grounding structures  106 . 
     In one suitable arrangement, conductive interconnect structures  106  may be shorted to (e.g., in direct contact with) the conductive material in display module  104 , as shown by dashed lines  108 . For example, conductive interconnect structures  106  may be shorted to conductive material within layer  102 - 1 , layer  102 - 2 , or layer  102 - 3 , a conductive frame of display module  104 , a conductive back plate of display module  104 , shielding structures in display module  104 , and/or other conductive material in display module  104  that are used to form conductive display structures  84  of antenna  40 . 
     If desired, conductive adhesive or conductive fastening structures such as pins, solder, welds, springs, screws, clips, brackets, and/or other fastening structures may be used to ensure that conductive interconnect structures  106  are held in contact with conductive material in display module  104 . Conductive interconnect structures  106  may extend across gap  113  and may be shorted to conductive sidewall  12 W. Conductive interconnect structures  106  may be held into contact with conductive sidewall  12 W using conductive adhesive, pins, springs, screws, clips, brackets, solder, welds, and/or other structures if desired. In the example of  FIG. 6 , a conductive screw  110  fastens conductive interconnect structures  106  to conductive sidewall  12 W and serves to electrically short conductive interconnect structures  106  and thus conductive display structures  84  to conductive sidewall  12 W. 
     When configured in this way, conductive interconnect structures  106  may define a portion of the perimeter of slot  74  in antenna  40  (e.g., in the X-Y plane of  FIG. 6 ), thereby partially defining length L of slot  74  ( FIG. 4 ). In addition, conductive interconnect structures  106  (e.g., conductive interconnect path  86  as shown in  FIG. 5 ) may form a short circuit path between conductive material in display module  104  and conductive sidewall  12 W (e.g., antenna currents for antenna  40  may flow over conductive interconnect structures  106  between display module  104  and conductive sidewall  12 W). Shorting display module  104  to conductive sidewall  12 W across gap  113  may serve to mitigate excessively strong electric fields that would otherwise be present in the vicinity of gap  113  due to the location of antenna feed  62  on a different side of display module  104 . This may serve to optimize antenna efficiency relative to scenarios where display module  104  is completely isolated from conductive sidewalls  12 W, for example. 
     This example is merely illustrative. Conductive interconnect structures  106  need not directly contact display module  104 . In another suitable arrangement, conductive interconnect structures  106  may span gap  113  without directly contacting display module  104  (e.g., as shown in  FIG. 6 ). In this scenario, conductive interconnect structures  106  may be electrically shorted to one or more display flexes  94  (e.g., to ground conductors or other conductive material in display flexes  94 ). For example, conductive interconnect structures  106  may be electrically shorted to display flexes  94  using conductive adhesive or conductive fastening structures such as pins, solder, welds, springs, screws, clips, brackets, and/or other structures that ensure that conductive interconnect structures  106  are held in contact with display flexes  94 . 
     If desired, conductive interconnect structures  106  may be located sufficiently close to the conductive material in display module  104  so as to effectively short conductive display structures  84  to ground (e.g., at radio-frequencies handled by antenna feed  62 ). For example, conductive interconnect structures  106  may be capacitively coupled to conductive display structures  84  in display module  104  and antenna currents associated with antenna  40  may flow between display module  104  and conductive sidewall  12 W over conductive interconnect structures  106  (e.g., via capacitive coupling). Conductive interconnect structures  106  need not be shorted to display flexes  94  in this scenario, if desired. Conductive interconnect structures  106  may directly contact one, both, or neither of display module  104  and display flexes  94 . Conductive interconnect structures  106  may be capacitively coupled to one, both, or neither of display module  104  and display flexes  94 . 
     In another suitable arrangement, conductive interconnect structures  106  may be located far enough away from display module  104  so that conductive interconnect structures  106  are not capacitively coupled to the conductive material in display module  104 . In this scenario, because conductive interconnect structures  106  are held at a ground potential (e.g., because conductive interconnect structures  106  short ground structures in display flexes  94  to the grounded conductive sidewall  12 W), conductive interconnect structures  106  may still electrically define edges of slot  74  despite not actually being in contact with or capacitively coupled to conductive display structures  84  in display module  104 , thereby helping to define length L of slot  74  ( FIG. 4 ). 
     The example of  FIG. 6  is merely illustrative. In general, conductive sidewalls  12 W, cover layer  98 , and dielectric rear housing wall  100  may have any desired shapes. Additional components may be formed within volume  88  if desired. A substrate or other support structure may be interposed between logic board  90  and display flexes  94  if desired (e.g., to hold display flexes  94  in place). Other arrangements may be used if desired. If desired, flexible printed circuit  120  may be coupled to antenna feed  62  without dielectric support structure  118  or flexible printed circuit  120  may be omitted (e.g., dielectric support structure  118  may be coupled directly to transceiver circuitry  52 ). Other transmission line and feeding structures may be used if desired. 
       FIG. 7  is a top-down view showing how slot  74  of antenna  40  may follow a meandering path around display module  104  and may have edges defined by display module  104 , conductive sidewalls  12 W, and conductive interconnect structures  106 . The plane of the page in  FIG. 7  may, for example, lie in the X-Y plane of  FIGS. 5 and 6 . In the example of  FIG. 7 , display cover layer  98  of  FIG. 6  is not shown for the sake of clarity. 
     As shown in  FIG. 7 , slot  74  of antenna  40  may follow a meandering path and may have edges defined by different conductive electronic device structures. For example, slot  74  may have a first set of edges (e.g., outer edges) defined by conductive sidewalls  12 W and a second set of edges (e.g., inner edges) defined by conductive structures such as conductive display structures  84 . Conductive display structures  84  may, for example, include conductive portions of display module  104  ( FIG. 6 ) such as metal portions of a frame or assembly of display  14 , touch sensor electrodes within layer  102 - 1 , pixel circuitry within layer  102 - 2 , portions of a near field communications antenna embedded within layer  102 - 3 , ground plane structures within display  14 , a metal back plate for display  14 , or other conductive structures on or in display  14 . 
     In the example of  FIG. 7 , slot  74  follows a meandering path and has a first segment  126  extending between edge the left conductive sidewall  12 W and conductive display structures  84 , a second segment  128  extending between the top conductive sidewall  12 W and conductive display structures  84 , and a third segment  130  extending between the right conductive sidewall  12 W and conductive display structures  84 . Segments  126  and  130  may extend along parallel longitudinal axes. Segment  128  may extend between ends of segments  126  and  130  (e.g., perpendicular to the longitudinal axes of segments  126  and  130 ). In this way, slot  74  may be an elongated slot that extends between conductive display structures  84  and multiple conductive sidewalls  12 W (e.g., to maximize the length of slot  74  for covering relatively low frequency bands such as satellite navigation communications bands and low band cellular telephone communications bands). 
     Antenna  40  may be fed using antenna feed  62  coupled across width W of slot  74 . In the example of  FIG. 7 , antenna feed  62  is coupled across segment  128  of slot  74 . This is merely illustrative and, in general, antenna feed  62  may be coupled across any desired portion of slot  74 . Ground antenna feed terminal  72  of antenna feed  62  may be coupled to a given conductive sidewall  12 W and positive antenna feed terminal  70  of antenna feed  62  may be coupled to conductive display structures  84 . This is merely illustrative and, if desired, ground antenna feed terminal  72  may be coupled to conductive display structures  84  and positive antenna feed terminal  70  may be coupled to conductive sidewall  12 W. 
     When configured in this way, slot  74  may have length L defined by the cumulative lengths of segments  126 ,  128 , and  130 . The perimeter of slot  74  may be defined by the sum of the lengths of the edges of these segments. Antenna  40  may, for example, exhibit response peaks when the perimeter of slot  74  is approximately equal to the effective wavelength of operation of the antenna (e.g., the wavelength after accounting for dielectric effects associated with the materials in device  10 ). Antenna feed  62  may convey antenna currents around the perimeter of slot  74  (e.g., over conductive sidewalls  12 W and conductive display structures  84 ). The antenna currents may generate corresponding wireless signals that are transmitted by antenna  40  or may be generated in response to corresponding wireless signals received by antenna  40  from external equipment. 
     Conductive interconnect structures  106  may define opposing edges  76  and  78  of slot  74  and may serve to effectively define the length L of slot  74 . Conductive interconnect structures may be held at a ground potential and/or may short conductive display structures  84  to conductive sidewall  12 W. When configured in this way, antenna currents conveyed by antenna feed  62  may experience a short circuit impedance at ends  76  and  78  of slot  74  (over conductive interconnect structures  106 ). 
     If desired, the location and width of conductive interconnect structures  106  may be adjusted (e.g., as shown by arrows  131 ) to extend or contract the length L of slot  74  (e.g., so that slot  74  radiates at desired frequencies). In one suitable arrangement, antenna  40  may be provided with suitable impedance matching circuitry and a selected length L so that slot  74  radiates in a first frequency band (e.g., a first frequency band from 1.5 GHz to 2.2 GHz that covers WLAN, WPAN, satellite navigation, cellular midband, and/or some cellular high band frequencies), a second frequency band (e.g., a second frequency band from 2.2 GHz to 3.0 GHz that covers WLAN/WPAN frequencies), and a third frequency band (e.g., a third frequency band from 5.0 to 8.0 GHz that covers WLAN frequencies and UWB frequencies). One or more of these frequency bands may be covered by harmonic modes of slot  74  if desired. Conductive interconnect structures  106  may be directly connected to conductive display structures  84  (e.g., as shown by dashed lines  108  of  FIG. 6 ), may be indirectly coupled to conductive display structures  106  via capacitive coupling, or may be separated from conductive display structures  106  (e.g., conductive interconnect structures  106  need not be in contact with conductive display structures  84  to electrically define part of the perimeter of slot  74 ). 
     In scenarios where conductive interconnect structures  106  are absent from device  10 , excessively strong electric fields may be generated between conductive display structures  84  and the conductive sidewall  12 W at the side of device  10  opposite to antenna feed  62 . These fields may limit the overall antenna efficiency of antenna  40 . However, the presence of conductive interconnect structures  106  may effectively form a short circuit between conductive display structures  84  and conductive sidewall  12 W. This may, for example, configure housing  12  and conductive display structures  84  to electrically behave as a single metal body, mitigating excessive electric fields at the side of device  10  opposing antenna feed  62 . In this way, antenna  40  may operate with greater antenna efficiency relative to scenarios where conductive interconnect structures  106  are absent from device  10 . The presence of conductive interconnect structures  106  may allow for the width W of slot  74  and the thickness of device  10  to be reduced given equal antenna efficiencies relative to scenarios where conductive interconnect structures  106  are not formed within device  10 , for example. 
     Conductive interconnect structures  106  may include any desired conductive structures such as conductive adhesive (e.g., conductive tape), conductive fasteners (e.g., conductive screws or clips such as blade clips), conductive pins, solder, welds, conductive traces on flexible printed circuits, metal foil, stamped sheet metal, integral device housing structures, conductive brackets, conductive springs, and/or any other desired structures for defining the perimeter of slot  74  and/or effectively forming an electrical short circuit path between conductive display structures  84  and housing  12 . 
     As shown in  FIG. 7 , multiple display flexes  94  may be formed under conductive display structures  84  (e.g., a first display flex  94 - 1 , a second display flex  94 - 2 , and a third display flex  94 - 3 ). Display flex  94 - 3  may be electrically coupled to layer  102 - 3  ( FIG. 6 ), display flex  94 - 2  may be electrically coupled to layer  102 - 2 , and display flex  94 - 1  may be electrically coupled to layer  102 - 1 . The ends of display flexes  94  closest to antenna feed  62  may be coupled to conductive display structures  84 , for example. The opposing ends of display flexes  94  may be coupled to display interface circuitry  92  ( FIG. 6 ). Display flex  94 - 3  may convey near field communications signals between layer  102 - 3  and other communications circuitry on logic board  90 . Display flex  94 - 2  may convey image data between layer  102 - 2  and display circuitry on logic board  90 . Display flex  94 - 1  may convey touch sensor data between layer  102 - 1  and control circuitry on logic board  90 . Conductive interconnect structures  106  may electrically short grounded portions of display flexes  94 - 1 ,  94 - 2 , and  94 - 3  to conductive sidewalls  12 W if desired. 
     The example of  FIG. 7  is merely illustrative. Slot  74  may have a uniform width W along length L or may have different widths along length L. If desired, width W may be adjusted to tweak the bandwidth of antenna  40 . As an example, width W may be between 0.5 mm and 1.0 mm. Slot  74  may have other shapes if desired (e.g., shapes with more than three segments extending along respective longitudinal axes, fewer than three segments, curved edges, etc.). 
     Impedance matching circuitry may be coupled to antenna  40  to optimize antenna efficiency for antenna  40  across multiple different frequency bands of interest. In practice, it can be difficult to provide impedance matching circuitry with satisfactory bandwidth for impedance matching in the UWB band from 5.0 GHz to 8.3 GHz in addition to WLAN, WPAN, GPS, and cellular bands at lower frequencies.  FIG. 8  is a circuit diagram showing how antenna  40  may be provided with impedance matching circuitry that supports communications across these frequencies. 
     As shown in  FIG. 8 , transceiver circuitry  52  may be coupled to antenna  40  through filter circuitry such as diplexer circuitry  134  and impedance matching circuitry such as high band impedance matching circuitry  140  and low band impedance matching circuitry  142 . Low band impedance matching circuitry  142  and high band impedance matching circuitry  140  may be coupled in parallel between transceiver circuitry  52  and diplexer circuitry  134 , for example. During wireless operations, transceiver circuitry  52  may receive data for transmission over data path  132  (e.g., baseband data received from baseband circuitry or control circuitry  28  of  FIG. 2 ). Transceiver circuitry  52  may up-convert the data and may transmit the data over antenna  40 . Similarly, antenna  40  may receive radio-frequency signals and may convey the radio-frequency signals to transceiver circuitry  52 . Transceiver circuitry  52  may down-convert the received radio-frequency signals to baseband frequencies and may output the down-converted signals on data path  132 . 
     Diplexer circuitry  134  may separate radio-frequency signals at relatively low frequencies such as frequencies in the cellular midband, the cellular high band, the GPS band, and 2.4 GHz WLAN/WPAN bands from radio-frequency signals at relatively high frequencies such as frequencies in the 5.0 GHz WLAN band and the UWB band. As one example, diplexer circuitry  134  may include a high pass filter  136  and a low pass filter  138 . High pass filter  136  may block radio-frequency signals in the cellular midband, the cellular high band, the GPS frequency band, and the 2.4 GHZ WLAN/WPAN frequency bands while passing radio-frequency signals in the 5.0 GHZ WLAN band and the UWB band. Low pass filter  138  may pass radio-frequency signals in the cellular midband, the cellular high band, the GPS frequency band, and the 2.4 GHZ WLAN/WPAN frequency bands while blocking radio-frequency signals in the 5.0 GHZ WLAN band and the UWB band. 
     High band impedance matching circuitry  140  may perform impedance matching for antenna  40  at relatively high frequencies such as frequencies in the 5.0 GHz WLAN band and/or the UWB band. In the example of  FIG. 8 , high band impedance matching circuitry  140  includes a capacitor  148  coupled in series between transceiver circuitry  52  and high pass filter  136 , a first inductor  146  coupled between a first side of capacitor  148  and ground  144 , and a second inductor  150  coupled between a second side of capacitor  148  and ground  144 . This is merely illustrative and, in general, high band impedance matching circuitry  140  may include any desired resistive, capacitive, and/or inductive components arranged in any desired manner. 
     Low band impedance matching circuitry  142  may perform impedance matching for antenna  40  at relatively low frequencies such as frequencies in the cellular midband, the cellular high band, the GPS frequency band, and/or 2.4 GHz WLAN/WPAN frequency bands. In the example of  FIG. 8 , low band impedance matching circuitry  142  includes a first inductor  156  coupled in series between transceiver circuitry  52  and low pass filter  138 , a capacitor  154  coupled between a first side of first inductor  156  and ground  144 , and a second inductor  152  coupled between the first side of first inductor  156  and ground  144 . This is merely illustrative and, in general, low band impedance matching circuitry  142  may include any desired resistive, capacitive, and/or inductive components arranged in any desired manner. 
     Separately matching antenna  40  for relatively low and relatively high frequencies using low band impedance matching circuitry  142  and high band impedance matching circuitry  140  in this way may extend the range of frequencies over which antenna  40  can be satisfactorily matched to transceiver circuitry  52  (and transmission line  60  of  FIG. 3 ). This may effectively extend the bandwidth of the impedance matching circuitry for antenna  40  to include frequencies from the GPS frequency band through the UWB frequency band, thereby ensuring that antenna  40  operates with satisfactory antenna efficiency across each frequency band of interest. 
     The example of  FIG. 8  is merely illustrative. In another suitable arrangement, the same matching circuitry may be used for covering each frequency band of interest for antenna  40 .  FIG. 9  is a circuit diagram showing how the same matching circuitry may be used for covering each frequency band of interest for antenna  40 . 
     As shown in  FIG. 9 , wireless circuitry  34  may include multiplexing circuitry  158  and matching circuitry  160  coupled between transceiver circuitry  52  and antenna  40 . Matching circuitry  160  may include components for impedance matching antenna  40  from relatively low frequencies such as frequencies in the GPS frequency band to relatively high frequencies such as frequencies in the UWB frequency band. Multiplexing circuitry  158  may include switching circuitry, filter circuitry, or other desired multiplexing circuitry for multiplexing radio-frequency signals at relatively low frequencies with radio-frequency signals at relatively high frequencies onto antenna  40 . If desired, transceiver circuitry  52  and multiplexing circuitry  158  may be formed on a shared (common) integrated circuit, printed circuit board, substrate, or package. 
     In this scenario, antenna  40  may be provided with tuning components (e.g., tunable components  58  of  FIG. 3 ) to recover satisfactory antenna efficiency across all the frequency bands of operation for antenna  40  (e.g., frequencies from the GPS frequency band through the UWB frequency band).  FIG. 10  is a top-down view showing how antenna  40  may be provided with tuning components for covering these frequencies of operation. The plane of the page in  FIG. 10  may, for example, lie in the X-Y plane of  FIGS. 5 and 6 . In the example of  FIG. 10 , display cover layer  98  of  FIG. 6  is not shown for the sake of clarity. 
     As shown in  FIG. 10 , conductive interconnect structures  106  may couple conductive display structures  84  to conductive sidewalls  12 W across segment  130  of slot  74 . When configured in this way, slot  74  has a fourth segment  162  at the side of conductive display structures  84  opposite to segment  128  of slot  74 . This may extend the physical length of slot  74  to include segments  162 ,  126 ,  128 , and a portion of segment  130 . In this scenario, display flexes  94 - 1 ,  94 - 2 , and  94 - 3  may follow curved paths from the side of conductive display structures  84  adjacent to segment  128  of slot  74  to the location of conductive interconnect structures  106  (e.g., so that display flexes  94  are still shorted to conductive sidewall  12 W through conductive interconnect structures  106 ). 
     An antenna tuning component such as tuning component  164  may be coupled across the width of slot  74 . Tuning component  164  may have a first terminal  176  coupled to conductive display structures  84  at a location along slot  74  that is interposed between positive antenna feed terminal  70  and conductive interconnect structures  106 . Terminal  176  may be separated from conductive interconnect structures  106  along the edge of slot  74  by distance  172 . Terminal  176  may be separated from positive antenna feed terminal  70  along the edge of slot  74  by distance  170 . Tuning component  164  may have a second terminal  174  that is coupled to conductive sidewalls  12 W. Button (crown)  18  of device  10  may be coupled to conductive sidewalls  12 W at a location between tuning component  164  and conductive interconnect structures  106 . Button  18  may include conductive button assembly structures  168  that lie within segment  130  of slot  74  (e.g., conductive button assembly structures  168  may define part of the edge of slot  74 ). 
     Tuning component  164  may include any desired fixed or adjustable inductive, resistive, and/or capacitive components arranged in any desired manner between terminals  176  and  174 . Tuning component  164  may include an actively adjustable (tunable) component such as an adjustable inductor having an inductance that is dynamically adjusted by control circuitry  28  ( FIG. 2 ) if desired. In this scenario, control circuitry  28  may adjust the inductance of tuning component  164  in real time to tune the frequency response of antenna  40 . 
     Antenna  40  of  FIG. 10  may have a first radiative mode associated with the length  165  of slot  74  extending from edge  76  to tuning component  164 . Length  165  may be sufficiently long to cover communications at relatively low frequencies such as frequencies in the GPS frequency band, the cellular midband, and the cellular high band (e.g., length  165  may be selected to support satisfactory antenna efficiency at these frequencies). Tuning component  164  may appear as a short circuit path across the width of slot  74  for antenna current conveyed by antenna feed  62  at these relatively low frequencies (thereby effectively defining an edge of slot  74  that opposes edge  76 ). 
     Tuning component  164  may appear as a tuning inductance (e.g., in scenarios where tuning component  164  includes an inductor) for antenna current conveyed by antenna feed  62  at relatively high frequencies such as frequencies in 2.4 GHz WLAN/WPAN frequency band. At these relatively high frequencies, antenna  40  may exhibit a second radiative mode associated with the length  163  of slot  74  extending from antenna feed  62  to edge  76  (e.g., length  163  may be selected to support satisfactory antenna efficiency at these frequencies). One or more harmonic modes associated with length  163  of slot  74  may allow antenna  40  to cover even higher frequencies such as frequencies in the 5.0 GHz WLAN frequency band and the UWB frequency band. The location of antenna feed  62  (e.g., distance  170 ), the location of tuning component  164  (e.g., distance  172 ), and the impedance (e.g., inductance) of tuning component  164  may be selected to tweak the frequency response of antenna  40  to provide coverage in any desired frequency bands with satisfactory antenna efficiency. 
     In the absence of tuning component  164 , antenna  40  may be limited to covering relatively low frequencies such as frequencies in the GPS frequency band, the cellular midband, and the cellular high band. By forming tuning component  164  within antenna  40 , antenna  40  may continue to operate at these relatively low frequencies (e.g., from a fundamental mode associated with length  165 ) while also supporting communications in the 2.4 GHz WLAN/WPAN band (e.g., from a fundamental mode associated with length  163 ) and in the 5.0 GHz WLAN and UWB bands (e.g., from one or more harmonic modes associated with length  163 ). In this way, antenna  40  may operate with satisfactory antenna efficiency across each of these frequency bands while using the same matching circuitry  160  ( FIG. 9 ) for each band. This may, for example, reduce the area and manufacturing cost required to form separate matching circuits such as low band impedance matching circuitry  142  and high band impedance matching circuitry  140  of  FIG. 8 . 
     The example of  FIG. 10  is merely illustrative. In general, tuning component  164  may be coupled across any desired segment of slot  74 . Button  18  may be mounted to any desired conductive sidewall  12 W. Antenna feed  62  may be coupled across any desired segment of slot  74 . Additional conductive interconnect structures  106  may be coupled across slot  74  if desired. While device  10  is shown having a rectangular outline in  FIG. 10 , device  10  may have any desired shape. Slot  74  may have additional segments or may follow other desired paths. Any desired number of display flexes  94  may be coupled to conductive interconnect structures  106 . One or more parasitic antenna resonating elements may be mounted over or otherwise electromagnetically coupled to slot  74  for adjusting the frequency response and bandwidth of antenna  40 . 
       FIG. 11  is a top-down view showing how tuning component  164  may be mounted to a substrate. As shown in  FIG. 11 , tuning component  164  may be mounted to a substrate such as substrate  178 . Substrate  178  may be a plastic substrate, a ceramic substrate, a glass substrate, a rigid printed circuit board substrate, a flexible printed circuit substrate, or any other desired substrate. Tuning component  164  may be coupled to terminal  176  via conductive traces  180  on substrate  178 . Tuning component  164  may be coupled to terminal  174  via conductive traces  180  on substrate  178 . Substrate  178  may have a shape that allows substrate  178  to conform to the shape of other components in device  10  and/or to allow substrate  178  to bend along any desired axes for coupling tuning component  164  across slot  74 . The example of  FIG. 11  is merely illustrative. In general, any desired number of tuning components may be mounted to flexible printed circuit substrate  178  and coupled in any desired manner between terminals  176  and  174 . 
       FIG. 12  is a cross-sectional side view of device  10  showing how tuning component  164  may be coupled to housing  12  (e.g., as taken in the direction of arrow  167  of  FIG. 10 ). As shown in  FIG. 12 , terminal  174  of tuning component  164  ( FIGS. 10 and 11 ) may be coupled to surface  182  of conductive sidewall using conductive fastener  184 . Conductive fastener  184  may include a conductive pin, a conductive screw, welds, solder, conductive adhesive, and/or a conductive spring, as examples. Conductive fastener  184  may mechanically hold the end of substrate  178  in place on surface  182  of conductive sidewall  12 W and may serve to short conductive traces  180  on substrate  178  ( FIG. 11 ) to conductive sidewall  12 W. Surface  182  may be a ledge structure (e.g., display cover layer  98  may be mounted to surface  182 ), a conductive bracket, a conductive frame, or any other desired portion of conductive sidewall  12 W. 
     In another suitable arrangement, terminal  174  of tuning component  164  may be coupled to surface  192  using conductive fastener  186 . Surface  192  may be a ledge on conductive sidewall  12 W, an integral portion of conductive sidewall  12 W that forms a part of the rear wall of device  10 , a conductive frame, a conductive bracket, conductive traces on a printed circuit board or other substrate, or any other desired conductive structures that are coupled to ground. Conductive fastener  186  may include a conductive pin, a conductive screw, welds, solder, conductive adhesive, and/or a conductive spring, as examples. Conductive fastener  186  may mechanically hold the end of substrate  178  in place on surface  192  and may serve to short conductive traces  180  on substrate  178  ( FIG. 11 ) to conductive sidewall  12 W. If desired, conductive fastener  186  may also hold other components such as components  188  in place on surface  192 . Components  188  may include a vibrator assembly, speaker assembly, button assembly, sensor assembly, or any other desired components in device  10 . In this scenario, terminal  174  of tuning component  164  is mounted within cavity  190  between conductive button assembly structures  168  and conductive sidewall  12 W. This example is merely illustrative and, in general, tuning component  164  may be coupled to any desired portion of housing  12 . The opposing end of tuning component  164  (e.g., terminal  176  of  FIG. 10 ) may be coupled to conductive display structures  84 . 
     Tabs, clips, or other protruding portions of display module  104  such as tab  112  may serve as positive antenna feed terminal  70  for antenna  40  ( FIG. 6 ). Tab  112  may be received between flexible spring fingers such as metal prongs in clip  116 . A perspective view of clip  116  in an illustrative configuration is shown in  FIG. 13 . As shown in  FIG. 13 , clip  116  may be mounted on a plastic support structure  194  or other suitable support structures. Plastic support structure  194  may be mounted to dielectric support structure  118 . Metal traces such as metal traces  200  on dielectric support structure  118  may route positive antenna feed signals to clip  116 . Clip  116  may include prongs  116 P that mechanically hold tab  112  ( FIG. 6 ) in place and that electrically couple metal traces  200  on dielectric support structure  118  to positive antenna feed terminal  70 . If desired, impedance matching circuitry and other circuitry may be mounted on dielectric support structure  118 . 
     In some scenarios, conductive structures such as conductive structures  196  are formed on or through plastic support structure  194  to couple traces  200  to clip  116 . In practice, conductive structures  196  may introduce too great of an inductance to support satisfactory communications across each of the frequency bands of interest. If desired, clip  116  may be coupled to conductive traces  200  via metal wire  198 . Metal wire  198  may exhibit less inductance than conductive structures  196 . This may, for example, allow for improved antenna efficiency across each of the frequency bands of interest relative to scenarios where conductive structures  196  are used. Metal wire  198  may be coupled to conductive traces  200  using solder or any other desired conductive fastening structures. The example of  FIG. 9  is merely illustrative and, if desired, other conductive fastening mechanisms may be used to secure transmission line  60  to positive antenna feed terminal  70  ( FIG. 3 ). 
       FIG. 14  is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency for antenna  40 . As shown in  FIG. 14 , curve  202  plots the antenna efficiency of antenna  40  in the absence of tunable component  164  ( FIG. 10 ) and in the absence of separate low and high band impedance matching circuits ( FIG. 8 ). As shown by curve  202 , the length of slot  74  supports an efficiency peak at relatively low frequencies such as frequencies in the GPS band at 1.5 GHz, the cellular midband from 1.4 GHz to 2.2 GHz, and the cellular high band at 2.2 GHz. However, in this scenario, antenna  40  may exhibit relatively low (e.g., insufficient) antenna efficiency in the 2.4 GHz WLAN/WPAN band, the 5.0 GHz WLAN band, cellular bands at frequencies greater than 2.4 GHz, and the UWB band from 5.0 GHz to 8.3 GHz. 
     Curve  204  plots the antenna efficiency of antenna  40  in scenarios where tuning component  164  ( FIG. 10 ) and matching circuitry  160  ( FIG. 9 ) are present, as well as in scenarios where low band impedance matching circuitry  142  and high band impedance matching circuitry  140  ( FIG. 8 ) are coupled to antenna  40  of  FIG. 7  (e.g., in the absence of tuning component  164 ). As shown by curve  204 , length  165  of slot  74  ( FIG. 10 ) supports an efficiency peak at relatively low frequencies such as frequencies in the GPS band at 1.5 GHz, the cellular midband from 1.4 GHz to 2.2 GHz, and the cellular high band at 2.2 GHz. At the same time, length  163  of slot  74  ( FIG. 10 ) supports an efficiency peak at higher frequencies such as frequencies in the 2.4 GHz WLAN/WPAN band and cellular bands above 2.4 GHz. Harmonic modes of length  163  support efficiency peaks at higher frequencies such as frequencies in the 5.0 GHz WLAN frequency band and the UWB band from 5.0 GHz to 8.3 GHz. In this way, antenna  40  may exhibit satisfactory antenna efficiency across each of these bands despite the constrained form factor of device  10 . The example of  FIG. 14  is merely illustrative. In general, efficiency curve  204  may have other shapes. Curve  204  (i.e., antenna  40 ) may exhibit efficiency peaks in any desired number of frequency bands and across any desired frequencies. 
     Referring back to  FIG. 6 , an electrical connection from radio-frequency transmission line signal path  66  to positive antenna feed terminal  70  may include conductive clip  116 . Clip  116  may be formed on plastic support structure  194  ( FIG. 13 ) and may mate with tab  112  coupled to conductive structures of display module  104  to provide an electrical connection between radio-frequency transmission line signal path  66  and positive antenna feed terminal  70 . In some scenarios, the electrical connection using clip  116  to tab  112  may introduce undesirable inductance in feeding antenna  40 . As examples, conductive path  198  in  FIG. 13  may be a long and meandering path to form a secure and reliable connection to clip  116 , clip  116  and tab  112  may have a minimum height requirement (along Z-axis) for a secure electrical connection, etc. The long and meandering path, the extended height along the Z-axis, or other factors that increase the effective length of the connection to positive antenna feed terminal  70  may introduce an inductance along transmission line signal path  55  that can undesirably filter out high frequency signals (e.g., serving as a low-pass filter). It may therefore be desirable to provide a path with reduced inductance (relative to the scenarios mentioned above) for conveying radio-frequency signals. 
       FIG. 15  is a perspective view showing one illustrative coupling mechanism that may be provided in device  10  for establishing a conductive path to antenna elements (e.g., antenna feed) with reduced (minimized) inductance for conveying radio-frequency signals. As shown in  FIG. 15 , a bottom portion  208  of the coupling mechanism may include a blade structure such as blade structure  210 . Blade structure  210  may sometimes be referred to herein as blade  210 , tab  210 , flap  210 , conductive structure  210 , or structure  210 . Blade structure  210  may be formed from conductive material such as metal or other conductive materials. Support structure  220  may surround a base portion of blade structure  210 . Support structure  220  may be formed from a dielectric material, a non-dielectric material, a conductive material, a combination of these materials, or any other suitable materials. 
     In the example of  FIG. 15 , blade structure  210  may extend substantially perpendicular to the surface to which it is mounted (e.g., may extend along the Z-axis along a height of device  10  ( FIG. 1 )). This is merely illustrative. If desired, blade structure  210  may include one or more bends, may extend at any suitable angle from surface to which it is mounted, or may have any suitable configuration. Blade structure  210  may also include an opening  211  (sometimes referred to herein as hole  211 ) that reduces the surface area of blade structure  210  to reduce undesired capacitive characteristics of the coupling mechanism and/or to impart other electrical or manufacturing advantages. In another suitable arrangement, opening  211  may be omitted. 
     Blade structure  210  and support structure  200  may be disposed on (e.g., mounted to the surface of) an underlying substrate such as substrate  212  (only a portion of which is shown in  FIG. 15 ). Substrate  212  may be a flexible or rigid printed circuit (substrate) such as flexible printed circuit  120  in  FIG. 6  or logic board  90  in  FIG. 6 , may be a dielectric support structure such as dielectric support  118  in  FIG. 6 , may be a retaining member for device components, may be a device housing structure, may serve the functions of a combination of these structures, or may be any other suitable substrate structure. 
     Substrate  212  may include conductive paths  214  and  216  formed from conductive lines or conductive traces embedded within substrate  212  and/or formed on top of substrate  212  (e.g., on an exterior surface of substrate  212 ). A corresponding conductive path such as one of paths  214  and  216  may be coupled to blade structure  210  to provide appropriate electrical connections to blade  210  depending on the function of the coupling mechanism (e.g., as a positive antenna signal path, as an antenna ground short circuit path, etc.). 
     As an example, path  214  may form at least a portion of transmission line structures (e.g., radio-frequency transmission line  60  in  FIG. 3 ). Transceiver circuitry (e.g., transceiver circuitry  52  in  FIG. 3 ) may be coupled to blade structure  210  using path  214  and optionally using other structures (e.g., wires or cables) that form transmission line structures. In this manner, blade structure  210  may be configured to convey radio-frequency signals to an antenna feed terminal such as positive antenna feed terminal  70  ( FIG. 3 ). 
     As another example, path  216  may be coupled to a conductive fastener such as screw  218  that mounts or secures substrate  212  to other device structures such as a housing member. Screw  218  may electrically connect path  214  and blade structure  210  to an antenna ground such as an antenna ground on a printed circuit (e.g., printed circuit  120  or board  90  in  FIG. 6 ), and/or a conductive housing member (e.g., conductive housing sidewalls  12 W). In this manner, blade structure  210  may be configured to couple and electrically short antenna elements to an antenna ground using a conductive structure such as screw  218 . These examples are merely illustrative. If desired, path  214  may be used to as an antenna ground short circuit path, path  216  may be used convey radio-frequency signals through a conductive fastener, or any other suitable conductive path may be made to electrically connect to blade structure  210 . If desired, the conductive path may include wires, conductive traces, conductive fasteners, conductive adhesive, conductive elements for device components, conductive housing members, or any other suitable elements. 
     The coupling mechanism in  FIG. 15  may include a top portion  206  that includes conductive clip  230  (sometimes referred to as clip structure  230 ). Clip  230  may mate with blade structure  210  to form an electrical connection. As examples, clip  230  may be a tulip clip or another type of clip that has prongs or other structures that exert pressure towards blade structure  210 . This may ensure that a robust and reliable electrical connection is held between clip  230  and blade structure  210 . In the example of  FIG. 15 , clip  230  may include flexible spring fingers such as metal prongs  230 P that exert pressure toward blade structure  210  when blade structure  210  is inserted into opening  232  between prongs  230 P. 
     Clip  230  may be mounted to a conductive layer such as base plate  234  (sometimes referred to herein as metal sheet  234 ). Clip  230  may be electrically and mechanically coupled to base plate  234 . As examples, clip  230  may be coupled to base plate  234  using solder, welds, conductive fasteners, conductive adhesive, or any other conductive attachment structures. Base plate  234  may have at least portion  236  that overlaps conductive portion  238  of substrate  240  (only a portion of which is shown in  FIG. 15 ). In the example of  FIG. 15 , portion  236  may be soldered to portion  238  to form an electrical connection between clip  230  and conductive structures on substrate  240 . This is merely illustrative. If desired, electrical connection between clip  230  and the conductive structures on substrate  240  may be formed using any other suitable structures. 
     Substrate  240  may be a portion of a display module such as display module  104  in  FIG. 6 . As examples, substrate  240  may be a portion of a touch sensor layer for a display module, a display panel layer for a display module, a near-field communications antenna layer for a display module, a conductive back plate for a display module, conductive shielding layers for a display module, conductive shielding cans for a display module, and/or a conductive frame for a display module. 
       FIG. 16  shows locations at which one or more sets of the coupling mechanism in  FIG. 15  (e.g., pairs of the clip-blade structures such as clip  230  and blade structure  210  in  FIG. 15 ) may be implemented in device  10 . In  FIG. 16 , front cover of device  10  (e.g., display cover layer  98 ) is shown to be in an open or unmounted state with respect to sidewalls  12 W to more clearly show the locations of the clip-blade pairs. Top portion  206  in  FIG. 15  having clip  230  may be placed at one or more locations  250 - 1 ,  250 - 2 ,  250 - 3 , and  250 - 4  at display module  104 . Bottom portion  208  in  FIG. 15  having blade structure  210  may be placed at one or more corresponding locations  252 - 1 ,  252 - 2 ,  252 - 3 , and  252 - 4  at logic board  90 . More specifically, if clip  230  is placed at location  250 - 1 , a corresponding blade structure  210  may be placed at location  252 - 1 . This may similarly apply for any other location pairs (e.g., locations  250 - 2  and  252 - 2 , locations  250 - 3  and  252 - 3 , locations  250 - 4  and  252 - 4 , etc.). Any suitable number of clips  230  and blade structures  210  may be placed at locations in  FIG. 16  or at any other suitable locations in device  10 . 
     As an example, device  10  may include two sets (pairs) of clips  230  and blade structures  210 , a first set (pair) formed at locations  250 - 3  and  252 - 3  and a second set (pair) formed at locations  250 - 4  and  252 - 4 . Configured in this manner, the first set of clip  230  and blade structure  210  may provide feeding at antenna feed  62  in  FIG. 10 . In particular, clip  230  at location  250 - 3  may form a positive antenna feed terminal such as positive antenna feed terminal  70  in  FIG. 10 , and blade structure  210  may convey positive antenna signals to clip  230  from transceiver circuitry and/or other transmission line structure. The second set of clip  230  and blade structure  210  may be used to implement other antenna components such as antenna ground short circuit paths, conductive paths that define edges of slot  74  in  FIG. 10 , connections to and from antenna tuning components (e.g., tuning component  164  in  FIG. 10 ), and/or antenna tuning components themselves. This example is merely illustrative. If desired, sets of clips  230  and blade structure  210  may be disposed at other locations. 
       FIG. 16  shows locations  250  relative to display module  104 . If desired, clips  230  (and corresponding base plates  234  in  FIG. 15 ) may be attached to conductive display structures of display module  104  or other structures outside of display module  104  (e.g., retaining members, shielding members, connective printed circuits etc.). Similarly,  FIG. 16  shows locations  252  relative to logic board  90 . If desired, blade structures  210  (and corresponding support structures  220  in  FIG. 15 ) may be attached to structures of logic board  90  such as components mounted on logic board  90  or other structures separate from logic board  90  (e.g., retaining members, shielding members, connective printed circuits, etc.). 
     By providing blade structure  210  as a portion of the coupling mechanism described in  FIGS. 15 and 16 , the coupling mechanism may provide conductive paths with reduced inductances, which are especially beneficial when the conductive paths are used to convey high-frequency antenna signals. Additionally, by introducing clip  230  and base plate  234  separately from (e.g., not as an integral portion with) substrate  240  in  FIG. 15 , clip  230  and base  234  may be more precisely attached to substrate  240  after substrate  240  is manufactured, thereby simplifying the manufacturing process and increasing alignment with blade structure  210 . 
     In some scenarios (e.g., to accommodate for device components, to increase isolation between components, etc.), it may be desirable to provide tuning components such as tuning component  164  in a configuration where conductive interconnect structures  106  are provided across portion  162  of slot  74  ( FIG. 10 ) instead of across portion  130  of slot  74  ( FIG. 7 ).  FIG. 17  shows a configuration for antenna  40  having conductive interconnect structure  106  formed across portion  162  of slot  74  and having tuning component  260 . 
     As shown in  FIG. 17 , tuning component  260  may be coupled across the width of slot  74 . Tuning component  260  may have a first terminal  262  coupled to conductive display structures  84  at a location along slot  74  that is interposed between positive antenna feed terminal  70  and conductive interconnect structures  106 . Terminal  262  may be separated from conductive interconnect structures  106  along the edge of slot  74  by distance  266 . Terminal  262  may be separated from positive antenna feed terminal  70  along the edge of slot  74  by distance  268 . Tuning component  260  may have a second terminal  264  that is coupled to conductive sidewalls  12 W at a location along slot  74  that is interposed between ground antenna feed terminal  72  and conductive interconnect structures  106 . 
     Tuning component  260  may include any desired fixed or adjustable inductive, resistive, and/or capacitive components arranged in any desired manner between terminals  262  and  264 . Tuning component  260  may include an actively adjustable (tunable) component such as an adjustable inductor having an inductance that is dynamically adjusted by control circuitry  28  ( FIG. 2 ) if desired. In this scenario, control circuitry  28  may adjust the inductance of tuning component  260  in real time to tune the frequency response of antenna  40 . 
     Tuning component  260  may appear as a short circuit path across the width of slot  74  for antenna current conveyed by antenna feed  62  at relatively low frequencies such as frequencies in the GPS frequency band, the cellular midband, and the cellular high band (thereby effectively defining an edge of slot  74  at tuning component  164 ). At these relatively low frequencies, antenna  40  (e.g., a first portion of slot  74 ) may exhibit a first radiative mode. Tuning component  260  may appear as a tuning inductance (e.g., in scenarios where tuning component  260  includes an inductor) for antenna current conveyed by antenna feed  62  at relatively high frequencies such as frequencies in 2.4 GHz WLAN/WPAN frequency band. At these relatively high frequencies, antenna  40  (e.g., a second portion of slot  74 ) may exhibit a second radiative mode. One or more harmonic modes associated a portion of slot  74  (e.g., the second portion of slot  74 ) may allow antenna  40  to cover even higher frequencies such as frequencies in the 5.0 GHz WLAN frequency band and the UWB frequency band. The location of antenna feed  62  (e.g., distance  268 ), the location of tuning component  260  (e.g., distance  266 ), and the impedance (e.g., inductance) of tuning component  260  may be selected to tweak the frequency response of antenna  40  to provide coverage in any desired frequency bands with satisfactory antenna efficiency. 
     The configuration of antenna  40  in  FIG. 17  using tuning component  260  is merely illustrative. If desired, feed  62 , tuning component  260 , and conductive interconnection structures  106  may be formed across any portion of slot  74  (e.g., across any one or more segments  126 ,  128 ,  130 , and  162 ). As an example, antenna  40  may include tuning component  270  coupled across segment  130  is mounted instead of tuning component  260  coupled across segment  126 . Segment  130  may be parallel to a sidewall  12 W to which button  18  is mounted as shown  FIG. 10 , but not explicitly shown in  FIG. 17 . In this configuration, tuning component  270  (or tuning component  260 ) may be interposed between button  18  (e.g., including the corresponding button assembly for button  18 ) and conductive interconnect structures  106 . Other placements or configurations for antenna elements such as antenna tuning components in antenna  40  may be used if desired. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20190926
Publication Date: 20200602
Grant Date: 20200602
Priority Date: 20180529
Inventors: Ruaro, Andrea
DA COSTA BRAS LIMA, EDUARDO JORGE
Martinis, Mario
PAPANTONIS, DIMITRIOS
NATH, JAYESH
PASCOLINI, MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/342", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/335", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 69229349