PATENT DOCUMENT

Publication Number: US-10879606-B2
Application Number: US-202016854774-A
Country: US
Kind Code: B2

Title: Electronic device slot antennas

Abstract:
An electronic device such as a wristwatch may have a housing with metal sidewalls and a display having conductive display structures. Printed circuits having corresponding ground traces may be coupled to the display for conveying data to and/or from the display. The conductive display structures may be separated from the metal sidewalls by a gap. A conductive interconnect may be coupled to the metal sidewalls and may extend across the gap to the conductive display structures. The conductive interconnect may be coupled to the ground traces on the printed circuits and/or may be shorted or capacitively coupled to the conductive display structures. When configured in this way, the metal sidewalls, the conductive display structures, and the conductive interconnect may define the edges of a slot antenna resonating element for a slot antenna.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 peripheral conductive housing structures; 
 a display mounted to the peripheral conductive housing structures, wherein the display comprises a display cover layer and a display module that emits image light through the display cover layer; 
 a conductive interconnect structure that electrically shorts a conductive structure in the display module to the peripheral conductive housing structure; 
 a slot that extends between at least two sides of the display module and the peripheral conductive housing structures, wherein the slot has edges defined by the conductive interconnect structure, the peripheral conductive housing structures, and the at least two sides of the display module; and 
 an antenna feed having a first feed terminal coupled to the peripheral conductive structures and a second feed terminal coupled to the display module, wherein the antenna feed is configured to feed antenna currents that flow along the display module, the conductive interconnect structure, and the peripheral conductive housing structures. 
 
     
     
       2. The electronic device defined in  claim 1 , further comprising a screw that secures the conductive interconnect structure to the peripheral conductive housing structures. 
     
     
       3. The electronic device defined in  claim 2 , further comprising an additional screw that secures the conductive interconnect structure to the peripheral conductive housing structures. 
     
     
       4. The electronic device defined in  claim 1 , wherein the conductive interconnect structure defines first and second opposing ends of the slot, the slot having a length extending from the first end to the second end that, and the length being selected to configure the slot to resonate in a frequency band. 
     
     
       5. The electronic device defined in  claim 4 , wherein the frequency band comprises a frequency between 1.5 GHz and 6.0 GHz. 
     
     
       6. The electronic device defined in  claim 4 , wherein the peripheral conductive housing structures comprise first, second, third and fourth sidewalls for the electronic device, the third sidewall opposes the first sidewall, the fourth sidewall opposes the second sidewall, and the second and fourth sidewalls extend from the first sidewall to the third sidewall, the slot comprising a first segment extending between the first sidewall and a first side of the at least two sides of the display module, and the slot comprising a second segment extending between the second sidewall and a second side of the at least two sides of the display module. 
     
     
       7. The electronic device defined in  claim 6 , wherein the slot further comprises a third segment extending between the third sidewall and a third side of the display module, the second segment extending from the first segment to the third segment. 
     
     
       8. The electronic device defined in  claim 7 , wherein the conductive interconnect structure electrically shorts the conductive structure in the display module to the fourth sidewall. 
     
     
       9. The electronic device defined in  claim 4 , wherein the conductive interconnect structure has a first branch that defines the first end of the slot and has a second branch that defines the second end of the slot. 
     
     
       10. An electronic device comprising:
 first, second, third, and fourth conductive sidewalls, wherein the third conductive sidewall opposes the first conductive sidewall, the fourth conductive sidewall opposes the second conductive sidewall, and the second and fourth conductive sidewalls extend from the first conductive sidewall to the third conductive sidewall; 
 a display having a display cover layer mounted to the first, second, third, and fourth conductive sidewalls, wherein the display comprises a display module configured to emit light through the display cover layer; 
 a slot having a first segment extending between the first conductive sidewall and a first edge of the display module, a second segment extending between the second conductive sidewall and a second edge of the display module, and a third segment extending between the third conductive sidewall and a third edge of the display module, wherein the second segment extends from the first segment to the third segment; 
 an antenna feed coupled across the slot and configured to convey antenna currents that flow along a perimeter of the slot; and 
 a conductive interconnect structure that couples the display module to the fourth conductive sidewall and that forms at least part of the perimeter of the slot. 
 
     
     
       11. The electronic device defined in  claim 10 , wherein the antenna feed is coupled to the second conductive sidewall and the second edge of the display module. 
     
     
       12. The electronic device defined in  claim 11 , further comprising a conductive fastening structure that attaches the conductive interconnect structure to the fourth conductive sidewall. 
     
     
       13. The electronic device defined in  claim 10 , further comprising:
 display module interface circuitry; and 
 a flexible printed circuit that couples the display module interface circuitry to the display module. 
 
     
     
       14. The electronic device defined in  claim 13 , wherein the conductive interconnect structure is shorted to a ground trace on the flexible printed circuit. 
     
     
       15. The electronic device defined in  claim 10 , wherein the conductive interconnect structure defines opposing first and second ends of the slot, the slot having a length from the first end to the second end that is selected to configure the slot to resonate in a frequency band. 
     
     
       16. The electronic device defined in  claim 15 , wherein the conductive interconnect structure is capacitively coupled to a conductive structure in the display module and forms a short circuit path to the fourth conductive sidewall at frequencies in the frequency band. 
     
     
       17. The electronic device defined in  claim 10 , wherein the conductive interconnect structure is shorted to a conductive structure in the display module. 
     
     
       18. An electronic device comprising:
 a display having a display cover layer and a display module configured to emit light through the display cover layer, wherein the display module has first, second, third, and fourth edges, the third edge opposes the first edge, and the fourth edge opposes the second edge; 
 peripheral conductive housing structures that run around the first, second, third, and fourth edges of the display module; 
 a slot having edges defined by the first, second, third, and fourth edges of the display module and the peripheral conductive housing structures; 
 an antenna feed coupled between the first edge and the peripheral conductive housing structures across the slot; and 
 a grounded conductive interconnect structure coupled between the third edge of the display module and the peripheral conductive housing structures across the slot. 
 
     
     
       19. The electronic device defined in  claim 18 , wherein the grounded conductive interconnect structure is configured to mitigate an electric field produced by the antenna feed at the third edge of the display module. 
     
     
       20. The electronic device defined in  claim 19 , further comprising:
 display module interface circuitry; and 
 a flexible printed circuit that couples the display module interface circuitry to the display module, wherein the grounded conductive interconnect structure is shorted to a ground trace on the flexible printed circuit.

Description:
This application is a continuation of patent application Ser. No. 15/698,481, filed on Sep. 7, 2017, 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. Printed circuits having corresponding ground traces may be coupled to the display module for conveying data to and/or from the display module (e.g., touch sensor data, near field communications data, image data, etc.). 
     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 gap that runs around the display module. The slot antenna may be fed using an antenna feed having a positive feed terminal coupled to the conductive display structures and a ground feed terminal coupled to the metal sidewalls. 
     A conductive interconnect may be coupled to the metal sidewalls (e.g., using a conductive fastener) and may extend across the gap to the display module. The conductive interconnect may be shorted to the conductive display structures in the display module or may be capacitively coupled to the conductive display structures in the display module. If desired, the conductive interconnect may be shorted to the ground traces on the printed circuits coupled to the display module (e.g., without being capacitively coupled or shorted to the conductive display structures). When configured in this way, the metal sidewalls, the conductive display structures, and the conductive interconnect may define the edges of a slot element (e.g., a slot antenna resonating element) for the slot antenna. The perimeter of the slot element (e.g., as defined by the metal sidewalls, the conductive display structures, and the conductive interconnect) may support coverage in one or more frequency bands. The presence of the grounded conductive interconnect may serve to define part of the slot element while mitigating excessively strong electric fields within the gap, thereby improving antenna efficiency relative to scenarios where the conductive interconnect is absent from the electronic device. 
    
    
     
       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 top-down view an illustrative slot 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 slot antenna formed using conductive display structures and conductive electronic device housing structures in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative electronic device having a slot antenna of the type shown in  FIGS. 5 and 6  in accordance with an embodiment. 
         FIG. 8  is a perspective view of an illustrative conductive tab that may be used in coupling an antenna feed terminal to conductive display structures that are used in an antenna in accordance with an embodiment. 
         FIG. 9  is a perspective view of an illustrative set of spring fingers that may be used to couple a positive antenna feed terminal to the conductive tab of  FIG. 8  in accordance with an embodiment. 
         FIG. 10  is a rear perspective view of illustrative display structures that may be used in forming a part of a slot antenna and that may be shorted to conductive device housing structures in accordance with an embodiment. 
         FIG. 11  is a front perspective view of an illustrative electronic device having conductive display structures that are used in forming a part of a slot antenna and that are shorted to conductive device housing structures in accordance with an embodiment. 
         FIG. 12  is a perspective view of an illustrative electronic device having conductive interconnect structures that short display circuit boards to conductive device housing structures in accordance with an embodiment. 
         FIG. 13  is a graph of antenna performance (antenna efficiency) for illustrative antenna structures of the types shown in  FIGS. 5-12  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 include antennas. Antennas such as cellular telephone antennas and wireless local area network and satellite navigation system antennas may be formed from electrical components such as displays, touch sensors, near-field communications antennas, wireless power coils, peripheral antenna resonating elements, and device housing structures. 
     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. 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 sidewall structures 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. Housing  12  may, for example, have a substantially rectangular periphery (e.g., defined by four sidewall structures  12 W that meet at perpendicular or rounded corners), rounded shapes, or other shapes. 
     Display  14  may be formed at the front side (face) of device  10 . Housing  12  may have a rear housing wall such as rear wall  12 R that opposes front face of device  10 . Housing sidewalls  12 W may surround the periphery of device  10  (e.g., housing 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 . Housing sidewalls  12 W may extend across some or all of the height of device  10  (e.g., parallel to Z-axis). Housing sidewalls  12 W and/or the rear wall  12 R of housing  12  may form one or more exterior surfaces of device  10  (e.g., surfaces that are visible to a user of device  10 ) and/or may be implemented using internal structures that do not form exterior surfaces of device  10  (e.g., conductive 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 structures  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., in side wall  12 W or rear 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). In the example of  FIG. 1 , strap  16  is connected to opposing sides  8  of device  10 . Housing walls  12 W on sides  8  of device  10  may include attachment structures for securing strap  16  to housing  12  (e.g., lugs or other attachment mechanisms). 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 control circuitry such as storage and processing circuitry  28 . Storage and processing circuitry  28  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, MIMO protocols, antenna diversity 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, digital data port devices, light sensors, 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 . Wireless circuitry  34  may include coil  50  and wireless power receiver  48  for receiving wirelessly transmitted power from 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  90  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  36 ,  38 ,  42 , and  46 . Transceiver circuitry  36  may be wireless local area network transceiver circuitry that may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and that may handle the 2.4 GHz Bluetooth® communications band (or other wireless personal area network bands). Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in frequency ranges such as a low communications band from 700 to 960 MHz, a midband from 1400 MHz or 1500 MHz to 2170 or 2200 MHz (e.g., a midband with a peak at 1700 MHz), and a high band 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). Circuitry  38  may handle voice data and non-voice data. 
     Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) transceiver circuitry  46  (e.g., an NFC transceiver operating at 13.56 MHz or another suitable frequency), etc. 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. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless circuitry  34  may include 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, inverted-F antenna structures, planar inverted-F antenna structures, helical antenna structures, monopole antennas, dipole antenna structures, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna 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® or Bluetooth® communications band at 5.0 GHz, and one or more cellular telephone communications bands such as a cellular telephone midband between 1500 MHz and 2170 MHz. 
     It may therefore be desirable to implement 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 , 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 an antenna for Wi-Fi, Bluetooth, GPS, cellular frequencies, and/or other frequencies without the need to incorporate bulky antenna structures in device  10 . 
       FIG. 3  is a diagram showing how transceiver circuitry  90  in wireless circuitry  34  may be coupled to antenna structures  40  using paths such as path  60 . Wireless circuitry  34  may be coupled to control circuitry  28 . Control circuitry  28  may be coupled to input-output devices  32 . Input-output devices  32  may supply output from device  10  and may receive input from sources that are external to device  10 . 
     To provide antenna structures  40  with the ability to cover communications frequencies of interest, antenna structures  40  may be provided with circuitry such as filter circuitry (e.g., one or more passive filters and/or one or more tunable filter circuits). Discrete components such as capacitors, inductors, and resistors may be incorporated into the filter circuitry. Capacitive structures, inductive structures, and resistive structures may also be formed from patterned metal structures (e.g., part of an antenna). If desired, antenna structures  40  may be provided with adjustable circuits such as tunable components  63  to tune antennas over communications bands of interest. Tunable components  63  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  63 , thereby tuning antenna structures  40  to cover desired communications bands. 
     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 and path  68  may be a ground signal line. Lines  66  and  68  may form parts of a coaxial cable, a stripline transmission line, and/or a microstrip transmission line (as examples). A matching network formed from components such as inductors, resistors, and capacitors may be used in matching the impedance of antenna structures  40  to the impedance of transmission line  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 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 structures  40 . 
     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 structures  40  may form 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 ground antenna feed terminal  72 . Positive transmission line conductor  66  may be coupled to positive antenna feed terminal  70  and ground transmission line conductor  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. 
     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 , slot antenna  40  may include a conductive structure such as structure  102  that has been provided with a dielectric opening such as dielectric opening  104 . Openings such as opening  104  of  FIG. 4  are sometimes referred to as slots, slot elements, or slot antenna resonating elements. In the configuration of  FIG. 4 , opening  104  is a closed slot, because portions of conductor  102  completely surround and enclose opening  104 . Open slot antennas may also be formed in conductive materials such as conductor  102  (e.g., by forming an opening in the right-hand or left-hand end of conductor  102  so that opening  104  protrudes through conductor  102 ). 
     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  104 . 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, slot antenna  40  will therefore be able to handle signals at approximately twice the frequency of other antennas such as inverted-F antennas, for example. 
     Feed  62  may be coupled across slot  104  at a location between opposing edges  114  and  116  of slot  104 . For example, feed  62  may be located at a distance  76  from side  114  of slot  104 . Distance  76  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  104  may experience an impedance of zero at edges  114  and  116  of slot  104  (e.g., a short circuit impedance) and an infinite (open circuit) impedance at the center of slot  104  (e.g., at a fundamental frequency of the slot). Location  76  may be located between the center of slot  104  and edge  114  at a location where the antenna current experiences an impedance that matches the impedance of transmission line  60 , for example (e.g., distance  76  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  104  may have any desired shape (e.g., where the perimeter P of slot  104  defines resonant characteristics of antenna  40 ). For example, slot  104  may have a meandering shape with different segments extending in different directions, may have straight and/or curved edges, etc. Conductive structures  102  may be formed from any desired conductive electronic device structures. For example, conductive structures  102  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 walls  12 W of  FIG. 1 ), or other conductive structures within device  10 . In one suitable arrangement, different sides (edges) of slot  104  may be defined by different conductive structures. 
       FIG. 5  is a top-down view showing how slot  104  may follow a meandering path and may have edges defined by different conductive electronic device structures. As shown in  FIG. 5 , slot  104  may have a first set of edges (e.g., outer edges  114 ,  121 ,  123 ,  125 , and  116 ) defined by conductive housing structures  12  and a second set of edges (e.g., inner edges  118 ,  120 , and  122 ) defined by conductive structures  110 . Conductive structures  110  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 structures  110  may sometimes be referred to herein as conductive display structures  110  or conductive display module structures  110 . Conductive housing structures  12  may, for example, include conductive walls  12 W located on different sides of device  10  ( FIG. 1 ). 
     In the example of  FIG. 5 , slot  104  follows a meandering path and has a first segment  77  between edge  121  of housing  12  and edge  118  of conductive display structures  110 , a second segment  79  between edge  123  of housing  12  and edge  120  of conductive display structures  110 , and a third segment  81  between edge  125  of housing  12  and edge  122  of conductive display structures  110 . Segments  77  and  81  may extend along parallel longitudinal axes. Segment  79  may extend between ends of segments  77  and  81  (e.g., along a longitudinal axis perpendicular to the longitudinal axes of segments  77  and  81 ). In this way, slot  104  may be an elongated slot that extends between conductive display structures  110  and conductive housing structures  12  (e.g., around two, three, or more than three sides of display structures  110 ). 
     Antenna feed  62  may have a ground feed terminal  72  coupled to housing  12  and a positive feed terminal  70  coupled to conductive display structures  110 . Positive feed terminal  70  may be coupled to edge  118 , edge  120 , or edge  122  of conductive display structures  110 , for example. In the example of  FIG. 5 , feed terminal  70  is coupled to edge  120  of structures  110 . Feed  62  may be coupled across slot  104  at distance  76  from edge  114  of slot  104 . When configured in this way, slot  104  may have length L defined by the cumulative lengths of segments  77 ,  79 , and  81 . The perimeter of slot  104  may be defined by the sum of the lengths of edges  121 ,  123 ,  125 ,  116 ,  122 ,  120 ,  118 , and  114 . 
     Antenna feed  62  may convey antenna currents around the perimeter of slot  104  (e.g., over conductive housing structures  12  and conductive display structures  110 . 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. The lengths of edges  121 ,  123 ,  125 ,  116 ,  122 ,  120 , and  118  may be selected so that length L is approximately equal to one-half of the wavelength of operation of antenna  40 , for example (e.g., an effective wavelength of operation of antenna  40  given dielectric loading conditions at slot  104 ). 
     One or more conductive interconnect paths  112  (e.g., first conductive interconnect path  112 - 1  and second conductive interconnect path  112 - 2 ) may define portions of the edges of slot  104  and may serve to effectively define the length L of slot  104 . Conductive paths  112  may be held at a ground potential and/or may short conductive display structures  110  to housing  12 . When configured in this way, antenna currents conveyed by feed  62  may experience a short circuit impedance perpendicular to edges  114  and  116 , thereby serving to define a part of the perimeter of slot  104 . 
     If desired, the location of conductive paths  112 - 1  and  112 - 2  may be adjusted (e.g., as shown by arrows  124 ) to extend the length L of slot  104  (e.g., so that slot  104  resonates at desired frequencies). In one suitable arrangement, length L is selected so that slot  104  covers a first frequency band (e.g., a first frequency band from 1.5 GHz to 2.4 GHz that covers WLAN, WPAN, satellite navigation communications, and/or a cellular midband frequencies) and a second frequency band defined by a harmonic mode of slot  104  (e.g., a second frequency band from 5.0 GHz to 6.0 GHz that covers WLAN communications frequencies). Conductive paths  112  may be directly connected to display structures  110 , may be indirectly coupled to display structures  110  via capacitive coupling, or may be separated from display structures  110  (e.g., paths  112  need not be in contact with display structures  110  to electrically define part of the perimeter of slot  104 ). 
     In scenarios where interconnect paths  112  are absent from device  10 , excessively strong electric fields may be generated between display structures  110  and housing  12  at the side of device  10  opposing feed  62 . The presence of these fields may limit the overall antenna efficiency of antenna  40 . However, the presence of interconnect paths  112  may effectively form a short circuit between structures  110  and housing  12 . This may, for example, configure housing  12  and conductive display structures  110  to electrically behave as a single metal body, mitigating the excessive electric field at the side of device  10  opposing feed  62  and serving to increase antenna efficiency relative to scenarios where interconnect paths  112  are absent from device  10 . The presence of interconnect paths  112  may allow for the width W of slot  104  and the thickness of device  10  to be reduced given equal antenna efficiencies relative to scenarios where interconnect paths  112  are not formed within device  10 , for example. 
     Conductive interconnect paths  112  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  104  and/or effectively forming an electrical short circuit path between display structures  110  and housing  12 . 
     In the example of  FIG. 5 , two conductive interconnect paths  112  are formed in device  10 . This is merely illustrative. If desired, one, two, or more than two paths  112  may be used. Housing  12  and conductive display structures  110  may define width W of slot  104 . Slot  104  may have a uniform width along length L or may have different widths along length L if desired. 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  104  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.). If desired, one or more antenna tuning components (e.g., components  63  of  FIG. 3 ) may be coupled across slot  104  or between two locations on one or more sides of slot  104  for adjusting the frequency response of slot  104  and thus antenna  40 . 
       FIG. 6  is a simplified cross-sectional side view of device  10  showing how antenna  40  may be formed from conductive display structures  110  and housing  12  (e.g., as taken along dashed line AA′ of  FIG. 5 ). As shown in  FIG. 6 , antenna  40  may include conductive display structures  110  coupled to an antenna feed such as feed  62 . Feed  62  may have a positive antenna feed terminal such as positive antenna feed terminal  70  and a ground antenna feed terminal such as ground antenna feed terminal  72 . Positive antenna feed terminal  70  may be coupled to conductive display structures  110 . Ground antenna feed terminal  72  may be coupled to ground (e.g., to metal sidewalls  12 W of housing  12  and other conductive structures around element  110  such as printed circuit structures). Housing  12  and conductive display structures  110  may define an interior cavity or volume  130 . Additional device components may be mounted within volume  130  if desired. Feed  62  may be coupled to transceiver circuitry  90  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  110  may be coupled to ground (e.g., housing wall  12 W) by interconnect path  112  (e.g., across gap  113  at the side of structures  110  opposing feed  62 ). Interconnect path  112  may include conductive structures that are directly connected to display structures  110 , may include conductive structures that are capacitively coupled to (but not in contact with) display structures  110  (e.g., while still spanning gap  113  and electrically shorting display structures  110  to housing  12 ), and/or may include conductive structures that are not coupled to display structures  110  (e.g., while still spanning gap  113  and being held at a ground potential, thereby serving to electrically define the perimeter of slot  104  in the X-Y plane of  FIG. 6 ). In the example of  FIG. 6 , conductive housing  12  defines a rear wall of device  10  that opposes conductive structures  110  (e.g., volume  130  may be 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  130  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, in satellite navigation bands at 1.5 GHz, and/or other desired frequency bands. 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. 6  is merely illustrative. 
       FIG. 7  is a cross-sectional side view of illustrative device  10  showing how conductive paths  112  may be implemented within antenna  40  (e.g., as taken along line AA′ of  FIG. 5 ). As shown in  FIG. 7 , device  10  may have conductive housing sidewall structures  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 housing wall  48 . Display  14  may be formed at the front face of device  10  whereas dielectric rear housing wall  148  is formed at the rear face of device  10 . Metal housing sidewalls  12 W may be coupled to ground feed terminal  72  of antenna  40 . Display  14  may include a display cover layer  146  and a display module  140  under cover layer  146 . 
     Display module  140  may include conductive components that are used in forming conductive display structures  110  of slot antenna  40  ( FIGS. 5 and 6 ). The conductive components in display module  140  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  110  of  FIGS. 5 and 6  (e.g., to effectively/electrically form a single conductor). 
     The components that form conductive display structures  110  may include, for example, planar components on one or more layers  142  (e.g., a first layer  142 - 1 , a second layer  142 - 2 , a third layer  142 - 3 , or other desired layers). As one example, layer  142 - 1  may form a touch sensor for display  14 , layer  142 - 2  may form a display panel (sometimes referred to as a display, display layer, or pixel array) for display  14 , and layer  142 - 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). Touch sensor  142 - 1  may be 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. Display panel  142 - 2  may be an organic light-emitting diode display layer or other suitable display layer. Near-field communications layer  142 - 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  142 - 3  and may provide structural support and/or a grounding reference for the components of module  140 . Module  140  may sometimes be referred to herein as display assembly  140 . 
     Conductive material in layers  142 - 1 ,  142 - 2 ,  142 - 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  110  defining slot elements  104  (e.g., slot antenna resonating elements) of slot antenna  40 . This and/or other conductive material in display  14  used to form conductive display structures  110  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 . Feed  62  may have a positive terminal such as terminal  70  that is coupled to display module  140  and therefore conductive display structures  110  (e.g., to near-field communications layer  142 - 3 , display layer  142 - 2 , touch layer  142 - 1 , a metal back plate for module  140 , and/or a metal display frame for module  140 ). Feed  62  may have a ground terminal such as terminal  72  that is coupled to an antenna ground in device  10  (e.g., metal housing wall  12 W). 
     As shown in  FIG. 7 , device  10  may include printed circuit board structures such as printed circuit board  163 . Printed circuit board  163  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  163  may sometimes be referred to herein as main logic board  163 . Electrical components such as transceiver circuitry  90 , interface circuitry such as display interface circuitry  158 , and other components may be mounted to main logic board  163 . 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  163  and dielectric rear housing wall  148  (e.g., for conveying wireless signals through wall  148 ). Antenna currents for slot antenna  40  may be conveyed around the perimeter of slot  104  (e.g., in the X-Y plane of  FIG. 7 ) and corresponding radio-frequency signals may be conveyed through display cover layer  146 , as shown by arrow  144 . 
     Display module  140  may include one or more connectors  154 . Connectors  154  may be coupled to one or more printed circuits  156 . Printed circuits  156  may include flexible printed circuits (sometimes referred to herein as display flexes  156 ), rigid printed circuit boards, or traces on other substrates if desired. Connectors  154  may convey signals between layers  142  of display module  140  and display interface circuitry  158  on logic board  163  over display flexes  156 . 
     As an example, display module  140  may include a first connector  154  that conveys near field communications signals to and/or from layer  142 - 1  over a first flex circuit  156 , a second connector  154  that conveys display data (e.g., image data) from display interface  158  to display layer  142 - 2  over a second flex circuit  156  (e.g., layer  142 - 2  may emit light corresponding to the display data), and a third connector  154  may convey touch sensor signals from layer  142 - 1  to interface circuitry  158  over a third flex circuit  156 . Connectors  154  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  140  between display module  140  and circuitry on logic board  163  or elsewhere in device  10 . 
     Radio-frequency transceiver  90  may be coupled to feed  62  of antenna  40  over radio-frequency transmission line  60  ( FIG. 4 ). Radio-frequency transmission line  60  may include conductive paths in flexible printed circuit  160  and dielectric support structure  162 . Dielectric support structure may, for example, be formed from plastic or other dielectric materials. The conductive paths associated with radio-frequency transmission line  60  in printed circuit  160  may be coupled to the conductive paths associated with radio-frequency transmission line  60  in printed circuit  160  over radio-frequency connector  164 . 
     Ground conductor  68  in transmission line  60  ( FIG. 4 ) may be coupled to ground feed terminal  72  over path  168  (e.g., ground traces in substrate  162  may be coupled to terminal  72  over path  168 ). Path  168  may include a 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 conductor  66  of transmission line  60  ( FIG. 4 ) may be coupled to feed terminal  70  of antenna  40  over conductive clip  152  (e.g., signal traces in substrate  162  may be coupled to terminal  70  over conductive clip  152 ). 
     If desired, a conductive tab or blade such as conductive tab  150  may be coupled to the conductive structures of display module  140  (e.g., conductive structures in layers  142 , a conductive back plate, a conductive frame, conductive shielding cans or layers, and/or other conductive structures in module  140 ). Clip  152  may mate with tab  150  to form an electrical connection between transmission line  60  and feed terminal  70  (e.g., feed terminal  70  may be located on tab  150  when clip  152  is attached to tab  150 ). Clip  152  may, for example, be a tulip clip or other clip that has prongs or other structures that exerts pressure towards tab  150 , thereby ensuring that a robust and reliable electrical connection is held between tab  150  and clip  152  over time. 
     When configured in this way, antenna currents may be conveyed over feed  62  and may begin to flow around the perimeter of slot  104  (e.g., in the X-Y plane of  FIG. 7 ). In order to define the lateral length L of slot  104 , conductive interconnect paths  112  may span gap  113  between a given side of module  140  and an adjacent sidewall  12 W. In the example of  FIG. 7 , conductive interconnect paths  112  are implemented using conductive interconnect structures  172  and/or conductive interconnect structures  174 . 
     As shown in  FIG. 7 , conductive interconnect structure  172  may be shorted to (e.g., in direct contact with) the conductive material in module  140  (e.g., conductive material within layer  142 - 1 , layer  142 - 2 , or layer  142 - 3 , a conductive frame of module  140 , a conductive back plate of module  140 , shielding structures in module  140 , and/or other conductive material in module  140  that are used to form conductive display structures  110  of antenna  40 ). For example, conductive adhesive or conductive fastening structures such as pins, springs, screws, clips, brackets, and/or other fastening structures may be used to ensure that interconnect  172  is held in contact with conductive material in display module  140 . Interconnect  172  may extend across gap  113  and may be shorted to housing wall  12 W. Interconnect  172  may be held into contact with housing wall  12 W using conductive adhesive, pins, springs, screws, clips, brackets, and/or other structures if desired. In the example of  FIG. 7 , a conductive screw  170  fastens interconnect  172  to wall  12 W and serves to electrically short interconnect  172  and conductive display structures  110  to wall  12 W. 
     When configured in this way, conductive interconnect  172  may define a portion of the perimeter of slot  104  in antenna  40  (e.g., in the X-Y plane of  FIG. 7  and as shown in  FIG. 5 ), thereby partially defining length L of slot  104 . In addition, interconnect  172  may form a short circuit between conductive material in module  140  (e.g., conductive structures  110  as shown in  FIGS. 5 and 6 ) and housing sidewall  12 W (e.g., antenna currents for antenna  40  may flow over interconnect  172  between module  140  and housing wall  12 W). By shorting module  140  to wall  12 W across gap  113 , any excessively strong electric fields in region  113  may be mitigated, thereby optimizing antenna efficiency relative to scenarios where module  140  is completely isolated from walls  12 W. 
     This example is merely illustrative. Interconnect paths  112  need not directly contact display module  140 . In another suitable arrangement, interconnect paths  112  may span gap  113  without directly contacting display module  140  (e.g., as shown by conductive interconnect structures  174 ). In this scenario, interconnect structures  174  may be electrically shorted to one or more display flexes  156  (e.g., to ground conductors or other conductive material in display flexes  156 ). For example, interconnect structures  174  may be electrically shorted to display flexes  156  using conductive adhesive or conductive fastening structures such as pins, springs, screws, clips, brackets, and/or other structures that ensure that interconnect structures  174  are held in contact with display flexes  174 . Interconnect  174  may extend across gap  113  and may be shorted to housing wall  12 W using screw  170  or other fastening structures. 
     If desired, conductive interconnect structures  174  may be located sufficiently close to the conductive material in display module  140  so as to effectively short conductive display structures  110  to ground (e.g., at radio-frequencies handled by feed  62 ). For example, interconnect structures  174  may be capacitively coupled to conductive display structures  110  in display module  140  and antenna currents associated with antenna  40  may flow between display module  140  and housing wall  12 W over interconnect  174  (e.g., via capacitive coupling). Conductive interconnect structures  174  need not be shorted to display flexes  156  in this scenario, if desired. 
     In another suitable arrangement, conductive interconnect structures  174  may be located far enough away from display module  140  so that interconnect structures  174  are not capacitively coupled to the conductive material in display module  140 . In this scenario, because interconnect structure  174  is held at a ground potential (e.g., because interconnect structure  174  shorts ground structures in display flexes  156  to grounded housing wall  12 W), interconnect structure  174  may electrically define edges of slot  104  despite not actually being in contact with or capacitively coupled to conductive display structures  110  in module  140 , thereby defining length L of slot  104  (e.g., in the X-Y plane as shown in  FIG. 5 ). 
     The example of  FIG. 7  is merely illustrative. In general, housing sidewalls  12 W, cover layer  146 , and rear housing wall  148  may have any desired shapes. Additional components may be formed within volume  130  if desired. A substrate or other support structure may be interposed between logic board  163  and display flexes  156  if desired (e.g., to hold flexes  156  in place). Other arrangements may be used if desired. If desired, flexible printed circuit  160  may be coupled to feed  62  without plastic support  162  or flexible printed circuit  160  may be omitted (e.g., support  162  may be coupled directly to transceiver  90 ). Other transmission line and feeding structures may be used if desired. 
     Tabs, clips, or other protruding portions of display module  140  such as tab  150  may serve as antenna feed terminal  70 . Tab  150  may be received between flexible spring fingers such as metal prongs in clip  152 . A rear perspective view of module  140  in an illustrative configuration in which tab  150  has been formed from a strip of metal is shown in  FIG. 8 . As shown in  FIG. 8 , display module  140  may include conductive structures  110  such as conductive structures in layers  142 , a metal frame for module  140 , a metal back plate for module, shielding structures, or other conductive structures. Tab  150  may be coupled to conductive structures  110 . For example, tab  150  may be formed from an integral protrusion of conductive structures  110  or may be coupled to structures  110  using conductive adhesive, conductive screws, welds, solder, or other conductive fasteners. If desired, tab  150  may have a coating such as coating  172  (e.g., gold, nickel, or other metals) to facilitate satisfactory ohmic contact between tab  150  and the prongs of clip  152  ( FIG. 7 ) when the coated surface of portion  172  is received between the prongs of clip  152 . 
     A perspective view of clip  152  in an illustrative configuration in which clip  152  is secured using fasteners such as screws  174  is shown in  FIG. 9 . As shown in  FIG. 9 , clip  152  may be mounted on a plastic support structure  162  ( FIG. 7 ) or other suitable support structures. Metal traces on structure  162  may route positive antenna feed signals to clip  152 . Clip  152  may include prongs  152 P that mechanically hold tab  150  in place and that electrically couple the metal traces on structure  162  to feed terminal  70 . If desired, impedance matching circuitry and other circuitry may be mounted on support structure  162 . The example of  FIG. 9  is merely illustrative and, if desired, other conductive fastening mechanisms may be used to secure transmission line  60  to feed terminal  70 . 
     A rear perspective view of illustrative electrical components that may be stacked under display cover layer  146  and that may form antenna conductor  110  of antenna  40  is shown in  FIG. 10 . As shown in  FIG. 10 , display module  140  may include touch sensor layer  142 - 1 , display layer  142 - 2 , and near-field communications antenna layer  142 - 3 . Layer  142 - 1 , layer  142 - 2 , and layer  142 - 3  are stacked next to each other and may therefore be capacitively coupled to each other, if desired. This may, for example, allow layers  142  to operate together as conductive display structures  110  of antenna  40  at radio frequencies (e.g., at WLAN, WPAN, satellite navigation, and cellular telephone frequencies). 
     Layer  142 - 1 , layer  142 - 2 , and layer  142 - 3  may be interconnected with other components in device  10  such as display module interface circuitry  158  ( FIG. 7 ) using connectors  154  (e.g., a first connector  154 - 1  coupled to layer  142 - 1 , a second connector  154 - 2  coupled to layer  142 - 2 , and a third connector  152 - 3  coupled to layer  142 - 3 ). Connectors  154  may be mounted on the underside of layer  142 - 3 , on tail  142 - 2 T of layer  142 - 2 , on tail  142 - 1 T of layer  142 - 1 , and/or on other suitable structures. Layers  142  need not have tails if desired. 
     Components  212  may be mounted to layer  142 - 1 ,  142 - 2 , and/or  142 - 3 . Components  212  may, for example, include near-field communications circuitry, touch sensor processing circuitry, and/or display driver circuitry. Other types of components may be mounted in the stack of module  140  if desired. For example, a force sensor layer may be included in module  140 . As another example, the functions of two or more of these layers may be consolidated. For example, capacitive touch sensor electrodes for a capacitive touch sensor may be formed from metal traces on organic light-emitting diode display layer  142 - 2  and a separate touch sensor layer  142 - 1  may be omitted. Near-field communications antenna layer  142 - 3  may also be omitted (e.g., in a configuration for device  10  without near-field communications circuitry and/or in a configuration for device  10  in which the near-field communications antenna is located in a different portion of housing  12 ). The configuration of display module  140  of  FIG. 10  is illustrative. 
     As shown in  FIG. 10 , conductive interconnect structure  172  may be shorted to conductive structures such as conductive structures  210  of display module  140 . Conductive structures  210  may include conductive traces on layers  142 , conductive contact pads, conductive electrodes on layers  142 , portions of a conductive frame or back plate for module  140 , shielding structures in module  140 , NFC antenna structures, pixel circuitry, ground lines in module  140 , or any other desired conductive structures (e.g., structures coupled to feed terminal  70  and that include some or all of conductive display structures  110 ). 
     Conductive interconnect structure  172  may include a first region (portion)  172 P that is coupled to conductive structures  210  on module  140  and a second (tail) region  172 T. Region  172 P may be secured to layer  142 - 3  or other portions of module  140  using conductive adhesive, conductive screws, conductive springs (e.g., conductive springs that exert a force on region  172 P towards layer  142 - 3 ), or any other desired conductive fastening structures. Conductive interconnect structure  172  may include conductive traces on a flexible printed circuit, stamped sheet metal, metal foil, a layer of conductive adhesive, a conductive layer having adhesive and non-adhesive portions, combinations of these, or any other desired conductive structures or layers. 
     When display  14  is assembled on housing  12 , tail region  172 T may extend across gap  113  ( FIG. 7 ). Tail region  172 T may include one or more brackets or tabs  202  having corresponding holes  200  (e.g., a first tab  202 - 1  having a first hole  200 - 1  and a second tab  202 - 2  having a second hole  200 - 2 ). Tabs  202  may be secured to housing wall  12 W. Tabs  202  may be held in place by screws  170  ( FIG. 7 ) or other conductive fasteners to maintain a reliable mechanical and electrical connection between tabs  202  and housing wall  12 W. In this way, conductive display structures  110  may be shorted to housing wall  12 W across gap  113  using interconnect structure  172 , thereby defining the dimensions of slot element  104 . The example of  FIG. 10  is merely illustrative. If desired, holes  200  may be omitted. If desired, tail  172 T may include a single continuous conductor extending across any desired length of housing wall  12 W. 
       FIG. 11  is a perspective front view of device  10  showing how conductive interconnect  172  may be coupled between housing wall  12 W and display module  140 . In the perspective view of  FIG. 11 , display cover layer  146  and display module  140  have been removed from device  10  (e.g., one end of display  14  has been rotated upwards off of housing sidewalls  12 W as shown by arrow  203 ) to expose the components within device  10 . When device  10  is fully assembled, display  14  may be mounted onto sidewalls  12 W so that the bottom of cover layer  146  lies flush with the top edges of sidewalls  12 W. 
     As shown in  FIG. 11 , multiple display flex circuits  156  may be formed over logic board  163  (e.g., a first flex  156 - 1 , a second flex  156 - 2 , and a third flex  156 - 3 ). If desired, flexes  156 - 1 ,  156 - 2 , and  156 - 3  may be mounted on a support structure such as support structure  157  on logic board  163 . When display  14  is closed onto housing walls  12 W, display flex  156 - 3  may be electrically coupled to connector  154 - 3  on display module  140 , display flex  156 - 2  may be electrically coupled to connector  154 - 2  on display module  140 , and display flex  156 - 1  may be electrically coupled to connector  154 - 1  on display module  140 . Display flex  156 - 3  and connector  154 - 3  may, for example, convey near field communications signals between layer  142 - 3  on module  140  and other communications circuitry on logic board  163  such as a near field transceiver on logic board  163  (e.g., via interface circuitry on board  163  such as interface  158 ). Display flex  156 - 2  and connector  154 - 2  may, for example, convey image data between layer  142 - 2  on module  140  and display circuitry on logic board  163  (e.g., via display interface  158  on board  163 ). Display flex  156 - 1  and connector  154 - 1  may, for example, convey touch sensor data between layer  142 - 1  on module  140  and control circuitry on logic board  163  (e.g., via display interface  158  on board  163 ). 
     Tab  202 - 1  of conductive interconnect structure  172  may be secured to housing wall  12 W using conductive screw  170 - 1  and/or other conductive fastening structures. If desired, screw  170 - 1  may be received by a mating threaded hole  171 - 1  in housing wall  12 W. Tab  202 - 2  of conductive interconnect structure  172  may be secured to housing wall  12 W using conductive screw  170 - 2  and/or other conductive fastening structures. If desired, screw  170 - 1  may be received by a mating threaded hole  171 - 2  in housing wall  12 W. Conductive interconnect  172  may short conductive structures in display module  140  to housing sidewall  12 W over tabs  202  and screws  170 . When display  14  is closed over sidewalls  12 W, conductive interconnect  172  may bridge gap  113  to define the length L of slot element  104 . 
       FIG. 12  is a perspective front view of device  10  showing how conductive interconnect  174  ( FIG. 7 ) may be coupled between housing wall  12 W and display flexes  156 . Conductive interconnect  174  may be formed within device  10  in addition to or instead of conductive interconnect  172  of  FIGS. 10 and 11 . In the perspective view of  FIG. 12 , display cover layer  146  and display module  140  (i.e., display  14 ) are not shown for the sake of clarity. 
     As shown in  FIG. 12 , display flex circuits  156  may have conductive regions  220 . Conductive regions  220  may, for example, include ground traces or other grounded portions of flex circuits  156 . For example, flex circuit  156 - 1  may have a first conductive region  220 - 1 , flex circuit  156 - 2  may have a second conductive region  220 - 2 , and flex circuit  156 - 3  may have a third conductive region  220 - 3 . Conductive interconnect structure  174  may include tabs or brackets  222  each having a corresponding hole  224  (e.g., a first tab  222 - 1  having a first hole  224 - 1  and a second tab  222 - 2  having a second hole  224 - 2 ). 
     Conductive interconnect structure  174  may include one or more branches  226 . For example, conductive interconnect structure  174  may include a first branch  226 - 1 , a second branch  226 - 2 , and a third branch  226 - 3 . While the use of different branches may reduce the amount of space required to form interconnect structure  174  in device  10 , in another suitable arrangement, each of the branches may be formed as a part of a single continuous (e.g., planar) conductor. 
     When device  10  is fully assembled, conductive interconnect structure  174  may be lowered towards logic board  163  as shown by arrows  230 . This may place branch  226 - 1  into contact with conductive region  220 - 1 , may place branch  226 - 2  into contact with conductive region  220 - 2 , and may place branch  226 - 3  into contact with conductive region  220 - 3  on flex circuits  156 . If desired, conductive adhesive, conductive screws, solder, welds, clips, or other conductive fastening structures may be used to secure branches  226  to corresponding conductive regions  220  when interconnect structure  174  is lowered onto device  10 . Tab  224 - 1  may be secured to housing wall  12 W via a first screw  170  extending through opening  224 - 1  and mating with threaded hole  171 - 2  in housing wall  12 W. Tab  224 - 2  may be secured to housing wall  12 W via a second screw  170  extending through opening  224 - 2  and mating with threaded hole  171 - 1  in housing wall  12 W. This is merely illustrative and, if desired, other conductive fasteners may be used. One or more than two tabs  224  may be used to secure interconnect structure  174  to housing wall  12 W. 
     In this way, when fully assembled, conductive interconnect structure  170  may short grounded regions  220  on display flexes  156  to housing wall  12 W. This may serve to electrically define at least some of the boundaries of slot element  104  (e.g., length L of slot element  104 ). If desired, branches  226  may be capacitively coupled to conductive structures in display module  140 . In this scenario, branches  226  may short antenna currents flowing through display module  140  (e.g., conductive display structures  110 ) to housing sidewall  12 W via capacitive coupling. Branches  226  need not be coupled to regions  220  on flexes  156  in this scenario if desired. 
     The example of  FIGS. 5-12  in which positive antenna feed terminal  70  is coupled to display structures  110  and ground antenna feed terminal  72  is coupled to housing  12  is merely illustrative. If desired, positive antenna feed terminal  70  may be coupled to housing  12  whereas ground antenna feed terminal  72  may be coupled to display structures  110  (e.g., where the locations of feed terminals  72  and  70  in  FIGS. 5-7  are swapped). 
       FIG. 13  is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency f for antennas  40  of  FIGS. 5-12 . As shown in  FIG. 13 , curve  252  plots the antenna efficiency of antenna  40  in the absence of conductive interconnect paths  112  (e.g., interconnect structures  172  as shown in  FIGS. 10 and 11  or interconnect structures  174  as shown in  FIG. 12 ). It may be desirable to cover a lower frequency band B 1  and a higher frequency band B 2  using antenna  40  (e.g., a first frequency band B 1  between 1.5 GHz and 2.4 GHz and a second frequency band B 2  between 5.0 GHz and 6.0 GHz). Covering bands B 1  and B 2  may, for example, allow antenna  40  to cover WLAN and WPAN frequencies at 2.4 GHz and 5.0 GHz, cellular midband frequencies between 1.7 GHz and 2.2 GHz, and/or satellite navigation frequencies at 1.5 GHz, for example. Curve  252  may exhibit efficiency peaks outside of bands of interest B 1  and B 2 . When configured in this way, antenna  40  may have unsatisfactory efficiency within bands B 1  and B 2 . 
     Curve  250  plots the antenna efficiency of antenna  40  when slot antenna  40  has a length L defined at least in part by conductive interconnect paths  112  (e.g., interconnect structures  172  as shown in  FIGS. 10 and 11  and/or interconnect structures  174  as shown in  FIG. 12 ). When configured in this way, antenna  40  may exhibit efficiency peaks in bands B 1  and B 2 . For example, coverage in band B 1  may be supported by a fundamental mode of slot  104  (e.g., where length L is approximately equal to half of the wavelength of operation given the dielectric loading conditions of slot  104 ). Coverage in band B 2  may, for example, be supported by a harmonic mode of slot  104 . When configured in this way, antenna  40  may exhibit satisfactory efficiency within bands B 1  and B 2  and may therefore concurrently cover WLAN and WPAN frequencies at 2.4 GHz and 5.0 GHz, cellular midband frequencies between 1.7 GHz and 2.2 GHz, and/or satellite navigation frequencies at 1.5 GHz if desired. 
     The example of  FIG. 14  is merely illustrative. In general, efficiency curve  250  may have any desired shape. Curve  250  may exhibit peaks in efficiency in more than two frequency bands, in fewer than two frequency bands, or in any other desired frequency bands 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: 20200421
Publication Date: 20201229
Grant Date: 20201229
Priority Date: 20170907
Inventors: Ruaro, Andrea
DI NALLO, CARLO
DA COSTA BRAS LIMA, EDUARDO JORGE
NATH, JAYESH
Martinis, Mario
PASCOLINI, MATTIA
WANG, ZHEYU
PANDYA, SAMEER
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q13/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/528", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/528", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/52", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/52", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/528", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 63490711