PATENT DOCUMENT

Publication Number: US-10200105-B2
Application Number: US-201715638060-A
Country: US
Kind Code: B2

Title: Antenna tuning components in patterned conductive layers

Abstract:
An electronic device may include a peripheral conductive housing wall. The housing wall may be patterned to form first and second continuous regions defining opposing edges of a patterned region. The patterned region may include slots that divide the wall into conductive structures between the first and second continuous regions. A tuning element for an antenna in the device may be formed from the conductive structures and the slots in the patterned region. The slots and the conductive structures in the patterned region may be configured to mitigate any excessive capacitances between the first and second continuous regions in one or more desired frequency bands to optimize antenna efficiency. The slots may be narrow enough so as to be invisible to the un-aided human eye. This may configure the first and second continuous regions to appear to a user as a single continuous piece of conductor.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing having a peripheral conductive sidewall that includes first and second segments; 
 an antenna having a resonating element arm that includes the first segment of the peripheral conductive sidewall, an antenna ground that includes the second segment of the peripheral conductive sidewall, and an antenna tuning component; and 
 a plurality of slots in the peripheral conductive sidewall between the first and second segments, wherein the plurality of slots divide the peripheral conductive sidewall into conductive structures between the first and second segments and the antenna tuning component comprises the plurality of slots and the conductive structures. 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the antenna tuning component comprises a capacitor and the conductive structures comprise a conductive patch. 
     
     
       3. The electronic device defined in  claim 2 , wherein the conductive patch is one of a plurality of conductive patches in the capacitor that are separated by the plurality of slots and that are arranged in a one-dimensional array between the first and second segments of the peripheral conductive sidewall. 
     
     
       4. The electronic device defined in  claim 2 , wherein the conductive patch is one of a plurality of conductive patches in the capacitor and the plurality of slots are arranged in a grid that divides the plurality of conductive patches into a two-dimensional array of conductive patches between the first and second segments of the peripheral conductive sidewall. 
     
     
       5. The electronic device defined in  claim 2 , wherein the antenna tuning component comprises an inductor and the conductive structures comprise a meandering conductive path having a first end coupled to the first segment of the peripheral conductive sidewall and a second end coupled to the second segment of the peripheral conductive sidewall. 
     
     
       6. The electronic device defined in  claim 5 , wherein the electronic device has opposing first and second faces, further comprising:
 a display having a display cover layer at the first face, wherein the housing comprises a rear wall at the second face, the peripheral conductive sidewall has a first edge at the first face and a second edge at the second face, the plurality of slots comprises a first set of slots extending from the first edge and a second set of slots extending from the second edge of the peripheral conductive sidewall, and the first set of slots are laterally offset with respect to the second set of slots. 
 
     
     
       7. The electronic device defined in  claim 1 , wherein the housing comprises a first additional peripheral conductive sidewall that includes third and fourth segments and a second additional peripheral conductive sidewall that extends between the third segment of the first additional peripheral conductive sidewall and the first segment of the peripheral conductive sidewall, further comprising:
 an additional plurality of slots in the first additional peripheral conductive sidewall between the third and fourth segments, wherein the additional plurality of slots divide the first additional peripheral conductive sidewall into additional conductive structures between the third and fourth segments, the resonating element arm includes the second additional peripheral conductive sidewall and the third segment, the antenna ground includes the fourth segment, and the antenna further includes an additional antenna tuning component that includes the additional plurality of slots and the additional conductive structures. 
 
     
     
       8. The electronic device defined in  claim 7 , wherein the antenna is configured to convey radio-frequency signals in a first frequency band and a second frequency band that is higher than the first frequency band, the first segment of the peripheral conductive sidewall and the antenna ground are configured to handle radio-frequency signals in the first frequency band, and the third segment of the first additional peripheral conductive sidewall and the antenna ground are configured to handle radio-frequency signals in the second frequency band. 
     
     
       9. The electronic device defined in  claim 8 , wherein the antenna tuning component comprises a capacitor, the conductive structures comprise a plurality of conductive patches that form series-coupled capacitances for the capacitor, the additional antenna tuning component comprises an inductor, and the additional conductive structures comprise a meandering conductive path having a first end coupled to the third segment and a second end coupled to the fourth segment of the first additional peripheral conductive sidewall. 
     
     
       10. The electronic device defined in  claim 1 , wherein the housing comprises a first additional peripheral conductive sidewall having third and fourth segments and a second additional peripheral conductive sidewall having fifth and sixth segments, the resonating element arm includes the sixth segment, and the antenna ground includes the fourth segment, the electronic device further comprising:
 a first additional plurality of slots in the first additional peripheral conductive sidewall between the third and fourth segments, wherein the first additional plurality of slots divide the first additional peripheral conductive sidewall into first additional conductive structures between the third and fourth segments; 
 a second additional plurality of slots in the second additional peripheral conductive sidewall between the fifth and sixth segments, wherein the second additional plurality of slots divide the second additional peripheral conductive sidewall into second additional conductive structures between the fifth and sixth segments; and 
 an additional antenna that includes an additional resonating element arm formed from the third and fifth segments, the antenna ground, and an additional antenna tuning component that includes the first additional plurality of slots and the first additional conductive structures in the first additional peripheral conductive sidewall. 
 
     
     
       11. The electronic device defined in  claim 10 , wherein the antenna tuning component comprises a first inductor, the conductive structures comprise a first meandering conductive path having a first end coupled to the first segment and a second end coupled to the second segment, the additional antenna tuning component comprises a second inductor, the first additional conductive structures comprise a second meandering conductive path coupled between the third and fourth segments, and the second additional conductive structures comprise a plurality of conductive patches that form series-coupled capacitances between the fifth and sixth segments of the second additional peripheral conductive sidewall. 
     
     
       12. The electronic device defined in  claim 1 , wherein the electronic device has opposing front and rear faces, the peripheral conductive sidewall extends from the front face to the rear face, and each slot in the plurality of slots extends from the front face to the rear face and has a width that is less than 100 microns. 
     
     
       13. An electronic device, comprising:
 a conductive layer that includes first and second continuous regions and a patterned region having opposing first and second edges, wherein the first edge is defined by the first continuous region, the second edge is defined by the second continuous region, and the patterned region comprises a plurality of openings in the conductive layer; and 
 an antenna having an antenna resonating element that includes the first continuous region of the conductive layer, an antenna ground that includes the second continuous region of the conductive layer, and an antenna tuning element formed from the patterned region of the conductive layer. 
 
     
     
       14. The electronic device defined in  claim 13 , wherein the first and second continuous regions have a first reflectivity to visible light and the patterned region has a second reflectivity to visible light that is within 20% of the first reflectivity. 
     
     
       15. The electronic device defined in  claim 14 , wherein the plurality of openings in the patterned region divide the conductive layer within the patterned region into an array of conductive patches that exhibit a series-coupled capacitance between the first and second continuous regions of the conductive layer. 
     
     
       16. The electronic device defined in  claim 14 , wherein the first continuous region is separated from the second continuous region by a given distance, the plurality of openings in the patterned region divide the conductive layer within the patterned region into a meandering conductive path that exhibits an inductance and has an electrical path length between the first and second continuous regions that is greater than the given distance. 
     
     
       17. The electronic device defined in  claim 14 , wherein the electronic device has a first face and an opposing second face, the conductive layer comprises a peripheral conductive housing wall for the electronic device that extends from the first face to the second face, and each opening in the patterned region extends from the first face to the second face. 
     
     
       18. The electronic device defined in  claim 17 , wherein the patterned region has a width from the first continuous region to the second continuous regions that is less than 3 mm, a dimension of the peripheral conductive housing wall from the first face to the second face is less than 10 mm, and each opening in the patterned region has a width that is less than 100 microns. 
     
     
       19. An electronic device comprising:
 a housing having a conductive housing wall, wherein the conductive housing wall comprises a first solid region, a second solid region, and a patterned region extending between the first and second solid regions, wherein the patterned region includes conductive structures that are separated by gaps in the conductive housing wall, the first and second solid regions have a first reflectivity to visible light, and the patterned region has a second reflectivity to visible light that is within 20% of the first reflectivity; and 
 an antenna having an antenna resonating element that includes the first solid region, an antenna ground that includes the second solid region, and a capacitor coupled between the antenna resonating element and the antenna ground, wherein the capacitor is formed from the patterned region of the conductive housing wall. 
 
     
     
       20. The electronic device defined in  claim 19 , wherein the conductive structures comprise a plurality of conductive patches that are arranged in an array between the first and second solid regions and each of the gaps in the patterned region has a width that is less than 100 microns.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless communications circuitry. 
     Electronic devices often include wireless circuitry with antennas. For example, cellular telephones, computers, and other devices often contain antennas for supporting wireless communications. 
     It can be challenging to form electronic device antenna structures with desired attributes. In some wireless devices, the presence of conductive structures such as conductive housing structures can influence antenna performance. Antenna performance may not be satisfactory if the housing structures are not configured properly and interfere with antenna operation. Device size can also affect performance. It can be difficult to achieve desired performance levels in a compact device, particularly when the compact device has conductive housing structures and is used in a variety of operating environments. 
     It would therefore be desirable to be able to provide improved wireless circuitry for electronic devices such as electronic devices that include conductive housing structures. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry. The wireless circuitry may include an antenna and transceiver circuitry. The antenna may include an antenna resonating element, an antenna ground, an antenna feed having a first feed terminal coupled to the resonating element and a second feed terminal coupled to the antenna ground, and an antenna tuning element that contributes to the response of the antenna (e.g., to adjust the overall frequency response and in-band antenna efficiency of the antenna). 
     The electronic device may include a conductive layer such as a peripheral conductive wall of an electronic device housing. The conductive housing wall may include first and second continuous or solid regions that define opposing edges of a patterned region. The patterned region may include multiple slots that divide the conductive housing wall into conductive structures between the first and second continuous regions. The antenna tuning element may be formed from the conductive structures and the slots in the patterned region of the conductive housing wall. In one suitable arrangement, the antenna tuning element may be an antenna tuning capacitor. In this scenario, the conductive structures may include a one or two-dimensional array of conductive patches that exhibit series-coupled capacitances between the first and second continuous regions of the conductive housing wall. In another suitable arrangement, the antenna tuning element may be an antenna tuning inductor. In this scenario, the conductive structures may include a meandering conductive path coupled between the first and second continuous regions of the conductive housing wall. 
     The antenna tuning component formed from the patterned region of the conductive housing wall may be configured to reduce the overall capacitance between the antenna resonating element and the antenna ground relative to scenarios where no conductive material is formed between the first and second continuous regions. In this way, the antenna tuning components may mitigate any excessive capacitances between the first and second continuous regions to optimize antenna efficiency within one or more desired frequency bands. The slots in the patterned region of the conductive housing wall may be narrow enough so as to be invisible to the un-aided human eye (e.g., less than 100 microns in width). This may, for example, allow the first and second continuous regions of the conductive housing wall to appear to a user of the electronic device as a single continuous piece of conductor despite the fact that an antenna tuning element is formed between the first and second continuous regions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of illustrative circuitry in an electronic device in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of illustrative wireless circuitry in accordance with an embodiment. 
         FIG. 4  is a graph in which illustrative antenna performance (standing-wave ratio) has been plotted as a function of operating frequency in accordance with an embodiment. 
         FIG. 5  is a diagram showing how electronic components such as antenna tuning components may be formed from an optically continuous patterned region of a conductive layer in accordance with an embodiment. 
         FIG. 6  is a perspective view of an antenna tuning capacitor formed from an optically continuous patterned region of a conductive layer in accordance with an embodiment. 
         FIG. 7  is a top-down view of an antenna tuning capacitor formed from an array of conductive patches within an optically continuous patterned region of a conductive layer in accordance with an embodiment. 
         FIG. 8  is a perspective view of an antenna tuning inductor formed from an optically continuous patterned region of a conductive layer in an electronic device in accordance with an embodiment. 
         FIG. 9  is a rear perspective view of an illustrative electronic device having conductive housing walls that include optically continuous patterned regions that form antenna tuning components in accordance with an embodiment. 
         FIG. 10  is a schematic diagram of an illustrative inverted-F antenna in accordance with an embodiment. 
         FIG. 11  is a schematic diagram of an illustrative slot antenna in accordance with an embodiment. 
         FIGS. 12 and 13  are diagrams of illustrative hybrid inverted-F slot antenna structures having tuning components formed from optically continuous patterned regions of conductive housing walls in accordance with an embodiment. 
         FIG. 14  is a graph of antenna performance (antenna efficiency) for illustrative antenna structures of the type shown in  FIGS. 12 and 13  in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands. 
     The wireless communications circuitry may include one more antennas. The antennas of the wireless communications circuitry can include loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, dipole antennas, monopole antennas, helical antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. Conductive structures for the antennas may, if desired, be formed from conductive electronic device structures. 
     The conductive electronic device structures may include conductive housing structures. The housing structures may include peripheral structures such as peripheral conductive structures that run around the periphery of an electronic device. The peripheral conductive structure may serve as a bezel for a planar structure such as a display, may serve as sidewall structures for a device housing, may have portions that extend upwards from an integral planar rear housing (e.g., to form vertical planar sidewalls or curved sidewalls), and/or may form other housing structures. 
     Gaps may be formed in the peripheral conductive structures that divide the peripheral conductive structures into peripheral segments. One or more of the segments may be used in forming one or more antennas for electronic device  10 . Antennas may also be formed using an antenna ground plane formed from conductive housing structures such as metal housing midplate structures and other internal device structures. Rear housing wall structures may be used in forming antenna structures such as an antenna ground. 
     Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, 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 virtual or augmented reality headset 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 is mounted in a kiosk, building, vehicle, or automobile, a wireless access point or base station, a desktop computer, a keyboard, a gaming controller, a computer mouse, a mousepad, a trackpad or touchpad device, equipment that implements the functionality of two or more of these devices, or other electronic equipment. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     Device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be mounted on the front face of device  10 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. 
     Display  14  may include pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable pixel structures. A display cover layer such as a layer of clear glass or plastic may cover the surface of display  14  or the outermost layer of display  14  may be formed from a color filter layer, thin-film transistor layer, or other display layer. Buttons such as button  24  may pass through openings in the cover layer or may be formed under the cover layer if desired. The cover layer may include openings such as an opening for speaker port  26  if desired. 
     Housing  12  may include peripheral housing structures such as structures  16 . Structures  16  may run around the periphery of device  10  and display  14 . In configurations in which device  10  and display  14  have a rectangular shape with four edges, structures  16  may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges (as an example). Peripheral structures  16  or part of peripheral structures  16  may serve as a bezel for display  14  (e.g., a cosmetic trim that surrounds all four sides of display  14  and/or that helps hold display  14  to device  10 ). Peripheral structures  16  may also, if desired, form sidewall structures for device  10  (e.g., by forming a metal band with vertical sidewalls, curved sidewalls, etc.). 
     Peripheral housing structures  16  may be formed of a conductive material such as metal and may therefore sometimes be referred to as peripheral conductive housing structures, conductive housing structures, peripheral metal structures, or a peripheral conductive housing member (as examples). Peripheral housing structures  16  may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, or more than two separate structures may be used in forming peripheral housing structures  16 . 
     It is not necessary for peripheral housing structures  16  to have a uniform cross-section. For example, the top portion of peripheral housing structures  16  may, if desired, have an inwardly protruding lip that helps hold display  14  in place. The bottom portion of peripheral housing structures  16  may also have an enlarged lip (e.g., in the plane of the rear surface of device  10 ). Peripheral housing structures  16  may have substantially straight vertical sidewalls, may have sidewalls that are curved, or may have other suitable shapes. In some configurations (e.g., when peripheral housing structures  16  serve as a bezel for display  14 ), peripheral housing structures  16  may run around the lip of housing  12  (i.e., peripheral housing structures  16  may cover only the edge of housing  12  that surrounds display  14  and not the rest of the sidewalls of housing  12 ). 
     If desired, housing  12  may have a conductive rear surface. For example, housing  12  may be formed from a metal such as stainless steel or aluminum. The rear surface of housing  12  may lie in a plane that is parallel to display  14 . In configurations for device  10  in which the rear surface of housing  12  is formed from metal, it may be desirable to form parts of peripheral conductive housing structures  16  as integral portions of the housing structures forming the rear surface of housing  12 . For example, a rear housing wall of device  10  may be formed from a planar metal structure and portions of peripheral housing structures  16  on the sides of housing  12  may be formed as vertically extending integral metal portions of the planar metal structure. Housing structures such as these may, if desired, be machined from a block of metal and/or may include multiple metal pieces that are assembled together to form housing  12 . The planar rear wall of housing  12  may have one or more, two or more, or three or more portions. 
     Display  14  may have an array of pixels that form an active area that displays images for a user of device  10 . An inactive border region may run along one or more of the peripheral edges of active area if desired. Display  14  may include conductive structures such as an array of capacitive electrodes for a touch sensor, conductive lines for addressing pixels, driver circuits, etc. 
     Housing  12  may include internal conductive structures such as metal frame members and a planar conductive housing member (sometimes referred to as a midplate) that spans the walls of housing  12  (i.e., a substantially rectangular sheet formed from one or more parts that is welded or otherwise connected between opposing sides of member  16  or other sheet metal parts that provide housing  12  with structural support). Device  10  may also include conductive structures such as printed circuit boards, components mounted on printed circuit boards, and other internal conductive structures. These conductive structures, which may be used in forming a ground plane in device  10 , may be located in the center of housing  12 , may extend under inactive or active areas display  14 , etc. 
     In regions  22  and  20 , openings may be formed within the conductive structures of device  10  (e.g., between peripheral conductive housing structures  16  and opposing conductive ground structures such as conductive housing midplate or rear housing wall structures, a printed circuit board, and conductive electrical components in display  14  and device  10 ). These openings, which may sometimes be referred to as gaps, may be filled with air, plastic, and other dielectrics and may be used in forming slot antenna resonating elements for one or more antennas in device  10 . 
     Conductive housing structures and other conductive structures in device  10  such as a midplate, traces on a printed circuit board, display  14 , and conductive electronic components may serve as a ground plane for the antennas in device  10 . The openings in regions  20  and  22  may serve as slots in open or closed slot antennas, may serve as a central dielectric region that is surrounded by a conductive path of materials in a loop antenna, may serve as a space that separates an antenna resonating element such as a strip antenna resonating element or an inverted-F antenna resonating element from the ground plane, may contribute to the performance of a parasitic antenna resonating element, or may otherwise serve as part of antenna structures formed in regions  20  and  22 . If desired, the ground plane that is under display  14  and/or other metal structures in device  10  may have portions that extend into parts of the ends of device  10  (e.g., the ground may extend towards the dielectric-filled openings in regions  20  and  22 ), thereby narrowing the slots in regions  20  and  22 . In configurations for device  10  with narrow U-shaped openings or other openings that run along the edges of device  10 , the ground plane of device  10  can be enlarged to accommodate additional electrical components (integrated circuits, sensors, etc.) 
     In general, device  10  may include any suitable number of antennas (e.g., one or more, two or more, three or more, four or more, etc.). The antennas in device  10  may be located at opposing first and second ends of an elongated device housing (e.g., at ends  20  and  22  of device  10  of  FIG. 1 ), along one or more edges of a device housing, in the center of a device housing, in other suitable locations, or in one or more of these locations. The arrangement of  FIG. 1  is merely illustrative. 
     Portions of peripheral housing structures  16  may be provided with peripheral gap structures. For example, peripheral conductive housing structures  16  may be provided with one or more gaps such as gaps  18 , as shown in  FIG. 1 . The gaps in peripheral housing structures  16  may be filled with dielectric such as polymer, ceramic, glass, air, other dielectric materials, or combinations of these materials. Gaps  18  may divide peripheral housing structures  16  into one or more peripheral conductive segments. There may be, for example, two peripheral conductive segments in peripheral housing structures  16  (e.g., in an arrangement with two of gaps  18 ), three peripheral conductive segments (e.g., in an arrangement with three of gaps  18 ), four peripheral conductive segments (e.g., in an arrangement with four gaps  18 , etc.). The segments of peripheral conductive housing structures  16  that are formed in this way may form parts of antennas in device  10 . 
     If desired, openings in housing  12  such as grooves that extend partway or completely through housing  12  may extend across the width of the rear wall of housing  12  and may penetrate through the rear wall of housing  12  to divide the rear wall into different portions. These grooves may also extend into peripheral housing structures  16  and may form antenna slots, gaps  18 , and other structures in device  10 . Polymer or other dielectric may fill these grooves and other housing openings. In some situations, housing openings that form antenna slots and other structure may be filled with a dielectric such as air. 
     In a typical scenario, device  10  may have upper and lower antennas (as an example). An upper antenna may, for example, be formed at the upper end of device  10  in region  22 . A lower antenna may, for example, be formed at the lower end of device  10  in region  20 . The antennas may be used separately to cover identical communications bands, overlapping communications bands, or separate communications bands. The antennas may be used to implement an antenna diversity scheme or a multiple-input-multiple-output (MIMO) antenna scheme. 
     Antennas in device  10  may be used to support any communications bands of interest. For example, device  10  may include antenna structures for supporting local area network communications, voice and data cellular telephone communications, global positioning system (GPS) communications or other satellite navigation system communications, Bluetooth® communications, etc. 
     A schematic diagram showing illustrative components that may be used in device  10  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry such as storage and processing circuitry  28 . Storage and processing circuitry  28  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, multiple-input and multiple-output (MIMO) protocols, antenna diversity protocols, etc. 
     Input-output circuitry  30  may include input-output devices  32 . Input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include user interface devices, data port devices, and other input-output components. For example, input-output devices  32  may include touch screens, displays without touch sensor capabilities, buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, motion sensors (accelerometers), capacitance sensors, proximity sensors, fingerprint sensors (e.g., a fingerprint sensor integrated with a button such as button  24  of  FIG. 1  or a fingerprint sensor that takes the place of button  24 ), etc. 
     Input-output circuitry  30  may include wireless communications circuitry  34  for communicating wirelessly with external equipment. Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless communications circuitry  34  may include radio-frequency transceiver circuitry  42  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  44 ,  46 , and  48 . Transceiver circuitry  46  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications or other wireless local area network (WLAN) bands and may handle the 2.4 GHz Bluetooth® communications band or other wireless personal area network (WPAN) bands. Circuitry  34  may use cellular telephone transceiver circuitry  48  for handling wireless communications in frequency ranges such as a low communications band from 600 to 960 MHz, a low midband from 1400-1520 MHz, a midband from 1710 to 2170 MHz, and a high band from 2300 to 2700 MHz or other communications bands between 600 MHz and 4000 MHz or other suitable frequencies (as examples). Circuitry  48  may handle voice data and non-voice data. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. Wireless communications circuitry  34  may include global positioning system (GPS) receiver equipment such as GPS receiver circuitry  44  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless communications circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, monopole antenna structures, 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 and another type of antenna may be used in forming a remote wireless link antenna. 
     As shown in  FIG. 3 , transceiver circuitry  42  in wireless circuitry  34  may be coupled to antenna structures  40  using paths such as path  92 . Wireless circuitry  34  may be coupled to control circuitry  28 . Control circuitry  28  may be coupled to input-output devices  32 . Input-output devices  32  may supply output from device  10  and may receive input from sources that are external to device  10 . 
     To provide antenna structures such as antenna(s)  40  with the ability to cover communications frequencies of interest, antenna(s)  40  may be provided with circuitry such as filter circuitry (e.g., one or more passive filters and/or one or more tunable filter circuits). Discrete components such as capacitors, inductors, and resistors may be incorporated into the filter circuitry. Capacitive structures, inductive structures, and resistive structures may also be formed from patterned metal structures (e.g., part of an antenna). If desired, antenna(s)  40  may be provided with adjustable circuits such as tunable components  102  to tune antennas over communications bands of interest. Tunable components  102  may be part of a tunable filter or tunable impedance matching network, may be part of an antenna resonating element, may span a gap between an antenna resonating element and antenna ground, etc. Tunable components  102  may include tunable inductors, tunable capacitors, or other tunable components. Tunable components such as these may be based on switches and networks of fixed components, distributed metal structures that produce associated distributed capacitances and inductances, variable solid state devices for producing variable capacitance and inductance values, tunable filters, or other suitable tunable structures. During operation of device  10 , control circuitry  28  may issue control signals on one or more paths such as path  120  that adjust inductance values, capacitance values, or other parameters associated with tunable components  102 , thereby tuning antenna structures  40  to cover desired communications bands. 
     If desired, antenna  40  may be provided with fixed components such as fixed tuning components  104 . Fixed tuning components  104  may be part of a passive filter or fixed impedance matching network, may be part of an antenna resonating element, may span a gap between an antenna resonating element and antenna ground, etc. Fixed tuning components  104  may include one or more fixed inductors (e.g., components that exhibit a predetermined inductance), one or more fixed capacitors (e.g., components that exhibit a predetermined capacitance), or other electronic components. Fixed tuning components  104  may include distributed metal structures that produce associated distributed capacitances and inductances or discrete components such as surface mount inductors and surface mount capacitors. The capacitances and inductances of fixed tuning components  104  may be fixed and un-adjustable (e.g., set during design, manufacture, calibration, or testing of device  10  prior to use by an end user). Fixed tuning components  104  may be coupled to antenna structures  40  to tune the frequency response of antenna structures  40  (e.g., so that antenna structures  40  cover one or more desired frequency bands of interest with sufficient antenna efficiency). 
     Path  92  may include one or more transmission lines. As an example, signal path  92  of  FIG. 3  may be a transmission line having a positive signal conductor such as line  94  and a ground signal conductor such as line  96 . Lines  94  and  96  may form parts of a coaxial cable, a stripline transmission line, or a microstrip transmission line (as examples). A matching network formed from components such as fixed or tunable inductors, resistors, and capacitors may be used in matching the impedance of antenna(s)  40  to the impedance of transmission line  92 . Matching network components may be provided as discrete components (e.g., surface mount technology components) or may be formed from housing structures, printed circuit board structures, traces on plastic supports, etc. Components such as these may also be used in forming filter circuitry in antenna(s)  40  and may be tunable and/or fixed components (e.g., tunable components  102  and fixed components  104 ). 
     Transmission line  92  may be coupled to antenna feed structures associated with antenna structures  40 . As an example, antenna structures  40  may form an inverted-F antenna, a slot antenna, a hybrid inverted-F slot antenna or other antenna having an antenna feed with a positive antenna feed terminal such as terminal  98  and a ground antenna feed terminal such as ground antenna feed terminal  100 . Positive transmission line conductor  94  may be coupled to positive antenna feed terminal  98  and ground transmission line conductor  96  may be coupled to ground antenna feed terminal  92 . Other types of antenna feed arrangements may be used if desired. For example, antenna structures  40  may be fed using multiple feeds. The illustrative feeding configuration of  FIG. 3  is merely illustrative. 
     Antenna structures  40  may include resonating element structures, antenna ground plane structures, an antenna feed, and other components (e.g., tunable components  102  and tuning components  104 ). Antenna structures  40  may be configured to form any suitable types of antenna. With one suitable arrangement, which is sometimes described herein as an example, antenna structures  40  are used to implement a hybrid inverted-F-slot antenna that includes both inverted-F and slot antenna resonating elements. A graph of antenna performance (standing wave ratio SWR) as a function of operating frequency for an illustrative hybrid antenna is shown in  FIG. 4 . As shown in  FIG. 4 , the hybrid antenna may exhibit resonances in multiple communications bands such as a low band LB from 600-960 MHz, a low-midband LMB from 1400-1520 MHz, a midband MB from 1700-2200 MHz, and a high band HB from 2300-2700 MHz. Other frequencies (e.g., local area network frequencies in a 5 GHz band) may also be supported (e.g., using a separate monopole, etc.). 
     If care is not taken, the presence of conductive structures such as conductive housing structures can influence the performance of antenna  40 . At the same time, the presence of conductive structures such as conductive housing structures may serve to enhance the aesthetic properties and mechanical strength device  10 . If desired, one or more electronic components within device  10  may be formed from optically continuous patterned regions of conductive structures within device  10 . 
       FIG. 5  is a diagram showing how electronic components may be formed from conductive structures within device  10 . As shown in  FIG. 5 , electronic device  10  may include conductive structures such as conductive layer  130 . If desired, conductive layer  130  may be formed on a dielectric substrate. Conductive layer  130  may include a metal trace, metal foil, stamped sheet metal, a conductive coating on a dielectric substrate, a conductive portion of housing  12  (e.g., peripheral conductive housing structures  16  of  FIG. 1 ), or any other desired conductive structure. Conductive layer  130  may have a planar shape, may be located within a non-planar or curved surface, or may have other shapes. Conductive layer  130  may include, for example, copper, aluminum, stainless steel, silver, gold, nickel, tin, other metals or metal alloys, or any other desired conductive materials. 
     Conductive layer  130  may be patterned to form an optically continuous pattern region such as region  132  and a continuous region such as region  134 . At least two slots or openings may be formed in conductive layer  130  within region  132 . The slots in region  132  may be arranged in a grid pattern or may divide the conductive material within layer  130  into one or more conductive segments, as examples. If desired, the slots in region  132  may divide the conductive material in layer  130  into a conductive path having a predetermined electrical path length within region  132 . Continuous region  134  may be formed from a single continuous portion of conductive layer  130  (e.g., region  134  may be formed from a solid portion of conductive layer  130  that is free from slots or openings). Region  134  may sometimes be referred to herein as un-patterned region  134 , solid region  134 , or continuous region  134 , whereas region  132  is sometimes referred to herein as patterned region  132 . Regions  134  and  132  may sometimes be referred to herein as portions of conductive layer  130 . 
     Un-patterned region  134  may surround some or all of patterned region  132  (e.g., at least one edge or at least part of the outline of patterned region  132  may be defined by un-patterned region  134 ). For example, the edges of conductive material in un-patterned region  134  may define the edges of one or more slots within patterned region  132 . If desired, layer  130  may include multiple un-patterned regions  134  that define one or more edges (e.g., one or more sides) of patterned region  132  (e.g., two continuous regions  134  may define opposing edges or sides of a corresponding patterned region  132 ). In one suitable arrangement, patterned region  132  may have first and second opposing edges that are defined by two un-patterned regions  134  and third and fourth opposing edges that are not surrounded by any part of layer  130  and that extend between the first and second edges. 
     If desired, patterned regions  132  may be used to form one or more electronic components for device  10 . The dimensions, shapes, and arrangement of the slots within patterned region  132  may configure region  132  to exhibit desired electrical properties (e.g., inductive and/or capacitive properties). For example, patterned region  132  may exhibit a predetermined capacitance to form a capacitor or may exhibit a predetermined inductance to form an inductor within (e.g., integral with) conductive layer  130 . The inductance and/or capacitance of patterned region  132  may be tuned (e.g., through the configuration of the corresponding slots) to form a short circuit across region  132  and/or an open circuit across region  132  at predetermined radio-frequencies. If desired, electronic components such as antenna tuning components  102  and/or  104  for antenna  40  ( FIG. 3 ) may be formed using one or more patterned regions  132  of one or more conductive layers  130 . 
     If desired, un-patterned regions  134  may be used to form portions of one or more antennas  40  in device  10 . For example, one or more un-patterned regions  134  of one or more conductive layers  130  may be used to form antenna resonating elements and/or antenna ground structures for one or more antennas  40  in device  10 . 
     The dimensions, shape, and arrangement of the slots within patterned region  132  of conductive layer  130  may, if desired, be selected so that the slots are substantially invisible or indiscernible to the unaided human eye. For example, the slots may be narrower than is resolvable to the unaided human eye at a predetermined distance from conductive layer  130  (e.g., a distance of 1 meter, 1 centimeter, 10 centimeters, etc.). This may allow the entirety of patterned region  132  and un-patterned region  134  to appear to a user as a single continuous (solid) piece of metal, thereby obscuring the potentially unsightly slots within region  132  from the user&#39;s view. This may serve to enhance the aesthetic properties of conductive layer  130  to the user (particularly in scenarios where conductive layer  130  is formed at the exterior of device  10  such as when conductive layer  130  is formed from a portion of device housing  12 , for example). 
     As an example, the optical characteristics of regions  132  and  134  of conductive layer  130  may be characterized by the reflectivity, absorption, and transmission of visible light by regions  132  and  134 . Region  132  may exhibit a first reflectivity, first absorptivity, and first transmissivity, whereas region  134  exhibits a second reflectivity, second absorptivity, and second transmissivity for visible light. In order to appear to the unaided eye as a single continuous piece of conductor, region  132  have a first reflectivity, first absorptivity, and/or first transmissivity that are within a predetermined margin of the second reflectivity, second absorptivity, and/or second transmissivity associated with region  134 , respectively (e.g., within a margin of 10%, 20%, 10-20%, 20-30%, 5%, 2%, 1-10%, etc.). 
     The example of  FIG. 5  is merely illustrative. If desired, multiple patterned regions  132  may be formed at different locations within conductive layer  130 . Each of the patterned regions in conductive layer  130  may be separated by some or all of un-patterned region  134 . Device  10  may include multiple conductive layers  130  having patterned regions  132 . Two or more edges (sides) of each region  132  may be defined by one or more un-patterned regions  134  of one or more conductive layers  130 . 
       FIG. 6  is a perspective view showing how a capacitive antenna tuning component (e.g., an antenna tuning capacitor) may be formed from a given patterned region  132  of conductive layer  130 . As shown in  FIG. 6 , conductive layer  130  may be formed on a substrate such as dielectric substrate  144 . Substrate  144  may be formed from plastic, polymer, glass, ceramic, epoxy, foam, a rigid or flexible printed circuit board substrate, or any other desired materials. Conductive layer  130  may include a conductive coating or metal coating, sheet metal, conductive or metal traces, or any other desired conductive structures formed on a surface of substrate  144 . Substrate  144  may have a thickness (height)  156 . Conductive layer  130  may have a thickness (height)  154  within un-patterned regions  134  and a thickness  154 ′ within patterned region  132 . Thickness  154 ′ may be less than, equal to, or greater than thickness  154 . Thickness  156  of substrate  144  may be, for example, between 1 mm and 6 mm, between 2 mm and 5.5 mm, between 3 mm and 5 mm, less than 1 mm, between 0.1 mm and 2 mm, or greater than 6 mm (e.g., 1 cm, 5 cm, 10 cm, etc.). Thicknesses  154  and  154 ′ of conductive layer  130  may be, for example, between 100 nm and 10 nm, between 75 nm and 25 nm, less than 25 nm, greater than 100 nm, between 0.1 mm and 0.5 mm, between 500 microns and 1 mm, between 1 and 500 microns, between 100 microns and 300 microns (e.g., within 15% of 200 microns), between 100 microns and 5 mm, or greater than 1 mm. Substrate  144  may be omitted if desired. 
     As shown in  FIG. 6 , a set of slots such as slots  140  may be formed in conductive layer  130  within patterned region  132 . As examples, slots  140  may be formed in conductive layer  130  by etching (e.g., laser etching), stripping, cutting, or otherwise removing conductive material in layer  130  from the surface of substrate  144 , or may be formed upon deposition of conductive layer  130  onto the surface of substrate  144 . Slots  140  (sometimes referred to as gaps, notches, or openings) may extend through thickness  154 ′ of region  132 , thereby exposing substrate  144  (or other structures under layer  130 ) through layer  130 . If desired, slots  140  may be filled with a dielectric material such as plastic, glass, ceramic, epoxy, adhesive, integral portions of substrate  144 , or other dielectric materials. If desired, slots  140  may be filled with air. In another suitable arrangement, slots  140  may be formed from integral portions of conductive layer  130  that have been processed to no longer be conductive (e.g., using oxidation or other processing techniques). In yet another suitable arrangement, slots  140  may extend only partially through the thickness  154 ′ of region  132  (e.g., some of the conductive material in layer  130  may remain within slots  140  if desired). 
     In the example of  FIG. 6 , slots  140  have a rectangular shape and are formed in a pattern that divides conductive layer  130  within patterned region  132  into multiple rectangular conductive patches  146  (e.g., a one-dimensional array of patches  146  each having edges defined by slots  140 ). Each of the rectangular patches  146  in patterned region  132  may be separated from other rectangular patches  146  and/or from un-patterned portions  134  of layer  130  by a corresponding slot  140 . The edges of patterned region  132  may be defined by the edges of at least two slots  140 . For example, a first slot  140  may separate conductive patches  146  in region  132  from a first un-patterned region  134 - 1  whereas a second slot  140  separates conductive patches  146  in region  132  from a second un-patterned region  134 - 2  of layer  130 . Conductive patches  146  may sometimes be referred to herein as conductive segments or conductive tiles. 
     Patterned region  132  may have a width  148  (e.g., extending from the edges of the two slots  140  defining region  132  and along the X-axis of  FIG. 6 ). Each conductive patch  146  may have a longitudinal length  158 ′ (e.g., length  158 ′ may be the length of the longest side of each patch  146 ) and a perpendicular width  152 . Un-patterned regions  134 - 1  and  134 - 2  may have a length  158  (e.g., along the Y-axis). In the example of  FIG. 6 , length  158 ′ of patches  146  is equal to the length  158  of un-patterned regions  134 - 1  and  134 - 2 . However, this is merely illustrative. If desired, length  158 ′ may be less than width  158  or greater than width  158 . Regions  134 - 1  and  134 - 2  may have the same length  158  or may have different lengths. In scenarios where length  158 ′ is less than length  158 , additional slots  140  may extend along the X-axis from region  134 - 1  to region  134 - 2  at one or both ends of the longitudinal length of patches  146 . In another suitable arrangement, region  132  may be formed within a single un-patterned region  134  having continuous conductive portions that extend across width  148  of region  132  (e.g., at one or both of the ends of the longitudinal length of patches  146 ). In the example of  FIG. 6 , the edges of region  132  that are not defined by regions  134 - 1  and  134 - 2  also form edges of layer  130  itself (e.g., two of the edges of region  132  may be defined by air, dielectric, or other structures that are not a part of conductive layer  130 ). 
     Each slot  140  may have a longitudinal length (e.g., along the Y-axis) and a corresponding perpendicular width  150 . The longitudinal length of slots  140  may be less than, equal to, or greater than longitudinal length  158 ′ of patches  146  and/or width  158  of un-patterned regions  134 - 1  and  134 - 2 . Each rectangular patch  146  in region  132  may have the same size and dimensions or two or more patches  146  may have different sizes or dimensions. Each slot  140  in region  132  may have the same length and width or two or more slots  140  may have different lengths and/or widths. 
     The presence of patches  146  within region  132  may serve to decrease the capacitance between un-patterned regions  134 - 1  and  134 - 2  (relative to scenarios where no conductive material is formed between regions  134 - 1  and  134 - 2 ). For example, each patch  146  may effectively serve as a capacitor electrode (e.g., a capacitor plate) in a capacitor formed with the adjacent patches  146  and/or regions  134 - 1  and  134 - 2 . Taken collectively, patches  146  may effectively serve as a set of capacitors coupled in series between regions  134 - 1  and  134 - 2 . The corresponding capacitance of region  132  between regions  134 - 1  and  134 - 2  may be given by the series-added capacitances associated with each pair of patches  146  and/or associated with the outer-most patches  146  and regions  134 - 1  and  134 - 2 . This may serve to reduce the capacitance between regions  134 - 1  and  134 - 1  relative to scenarios where no patches  146  are formed in region  132 . The number of patches  146  and slots  140  within region  132  as well as dimensions  150 ,  152 , and  158 ′ may be selected so that region  132  provides a desired capacitance across width  148  (e.g., between a first capacitor terminal formed by region  134 - 1  and a second capacitor terminal formed by region  134 - 2  of conductive layer  130 ). In this way, slots  140  and patches  146  may effectively form a capacitor  142  embedded or integrated within conductive layer  130  having a predetermined capacitance. 
     At the same time, width  150  of slots  140  may be selected to adjust the visibility of slots  140  to the un-aided eye of a user of device  10 . In order for slots  140  to remain invisible or indiscernible to the un-aided human eye at a predetermined distance (e.g., for region  132  to appear as a continuous piece of conductor), slots  140  may have a width  150  that is less than or equal to the resolving power of the un-aided human eye at the predetermined distance (e.g., less than 200 microns). In general, given a fixed width  148  of region  132  (e.g., as determined by design requirements for device  10 ), width  150  may be selected to balance the desired capacitance across region  132  with the visibility of slots  140 . As examples, slots  140  may have widths  150  that are less than 200 microns or less than 100 microns such as a width of 50 microns, 40 microns, 70 microns, between 50 and 70 microns, between 70 and 100 microns, between 20 and 50 microns, between 2 and 5 microns, between 10 and 20 microns, between 1 and 10 microns, less than 1 micron, etc. 
     Patches  146  may have widths  152  that are equal to, less than, or greater to width  150  of slots  140 . As examples, width  152  may be between 20 microns and 30 microns, between 10 microns and 50 microns, between 1 micron and 100 microns, between 10 microns and 500 microns, or greater than 500 microns. Region  132  may have any desired width  148  (e.g., between 200 microns and 1 mm, between 1 mm and 3 mm, between 500 microns and 5 mm, greater than 5 mm, etc.). Regions  134  may have any desired length  158  (e.g., between 500 microns and 20 mm). In one suitable arrangement, in order to balance desired capacitance with the invisibility of slots  140  for a fixed width  148  of between 1 mm and 3 mm, width  150  of each slot  140  may be between 20 microns and 40 microns, width  152  of each patch  146  may be between 50 microns and 150 microns, there may be between seven and 23 patches  146  in region  132 , there may be between nine and 25 slots  140  in region  132 , and thickness  154 ′ of region  132  may be between 150 microns and 250 microns, and thickness  154  of region  132  may be between 500 microns and 10 mm, for example. 
     When configured in this way, patterned region  132  of conductive layer  130  may exhibit a desired (predetermined) capacitance while also exhibiting a visible light reflectivity, absorptivity, and/or transmissivity that are within 20%, within 10%, within less than 10% (e.g., within 5%, within 2%, etc.), or within 10-20% of the visible light reflectivity, absorptivity, and/or transmissivity of un-patterned regions  134  of conductive layer  130 , as examples. Patterned region  132  and un-patterned regions  134  of conductive layer  130  may thereby appear to the user of device  10  as a single continuous piece of metal despite there being an integrated capacitor  142  formed therein. 
     If desired, an optional protective cover layer may be formed over conductive layer  130  (e.g., on a side of layer  130  opposite to substrate  144 ). The protective layer may include, for example, a dielectric or polymer coating, and may mechanically protect layer  130  from damage or contaminants. If desired, the optional cover layer and/or substrate  144  may be omitted. In this scenario, dielectric adhesive may be formed within slots  140  to bind patches  146  together and to regions  134  of layer  130 , for example. 
     The example of  FIG. 6  is merely illustrative. In general, any desired number of slots  140  and patches  146  may be formed within region  132  (e.g., one patch  146  and two slots  140 , two patches  146  and three slots  140 , three patches  146 , between three patches  146  and twelve patches  146 , more than twelve patches  146 , between two and thirteen slots  140 , more than thirteen slots  140 , etc.). Patches  146  may have any desired shape (e.g., a triangular shape, a square shape, an elliptical shape, a hexagonal shape or other polygonal shape, a circular shape, shapes having curved and/or straight edges, etc.). In scenarios where patches  146  are non-rectangular, width  158  may be equal to the longest side of patch  146 , the maximum lateral dimension of patch  146 , the length of a side of a rectangular footprint of patch  146 , etc. Similarly, slots  140  may have any desired shape (e.g., shapes having any desired combination of curved and/or straight edges). If desired, substrate  144  may be formed under region  132  and omitted under regions  134  or other substrates may be formed under regions  134 . Conductive layer  130  may sometimes be referred to herein as conductive structures  130 . 
     If desired, slots  140  may be arranged in a grid pattern in conductive layer  130 .  FIG. 7  is a top-down view of conductive layer  130  showing how a grid of slots  140  may be formed in conductive layer  130 . As shown in  FIG. 7 , a grid of slots  140  may be formed in conductive layer  130  within patterned region  132 . Slots  140  may be formed in a rectangular grid pattern in which slots  140  divide conductive layer  130  into multiple rectangular conductive patches  146  (e.g., the edges of conductive patches  146  may be defined by slots  140 ). If desired, conductive patches  146  may be arranged in a two-dimensional array having aligned rows and columns. In another suitable arrangement, the rows and/or columns of patches  146  in the two-dimensional array may be misaligned (e.g., the even numbered rows or columns of patches  146  may all be aligned with each other whereas the odd numbered rows or columns of patches  146  are all aligned with each other but misaligned with respect to the even numbered rows and columns). Each of the rectangular patches  146  in patterned region  132  may be separated from other rectangular patches  146  and/or from un-patterned portions  134  of layer  130  by a corresponding segment of slots  140 . 
     Each column of patches  146  may serve as a set of series connected capacitors coupled between conductive region  134 - 1  and conductive region  134 - 2 . Collectively, the columns of patches  146  may serve as (series) capacitors that are coupled in parallel between conductive regions  134 - 1  and  134 - 2 . The dimensions, arrangement, and number of slots  140  and patches  146  may be selected so that region  132  exhibits a desired capacitance from region  134 - 1  to region  134 - 2  (e.g., so that region  132  forms capacitor  142  embedded or integrated within conductive layer  130  having a desired capacitance). The width  150  of slots  140  may be sufficiently narrow so as to remain invisible or indiscernible to the un-aided human eye at a predetermined distance (e.g., so that regions  134 - 1 ,  134 - 2 , and  132  appear as a continuous piece of conductor). Arranging slots  140  in a grid pattern and patches  146  in a two-dimensional array in this way may serve to increase the optical continuity of regions  134 - 1 ,  132 , and  134 - 2  to the un-aided human eye while also increasing the overall capacitance of region  132  relative to scenarios where patches  146  are arranged in a one-dimensional array and divided by a set of parallel slots  140  as shown in  FIG. 6 , for example. 
     The example of  FIG. 7  in which a grid of slots  140  divide conductive layer  130  into an array of rectangular patches  146  is merely illustrative. If desired, slots  140  may divide conductive layer  130  into an array of conductive patches of any desired shape. For example, a grid of slots  140  may divide layer  130  within region  132  into an array of hexagonal patches, triangular patches, pentagonal patches, rounded patches such as circular or elliptical patches, octagonal patches, other polygonal patches, patches having curved and/or straight edges, combinations of these, etc. Different sets of conductive patches  146  of different sizes, shapes, and dimensions may be formed within the same patterned region  132  if desired. Each slot  140  in region  132  may have the same width  150  or two or more slots  140  may have different widths  150  if desired. 
     If desired, the capacitance between regions  134 - 1  and  134 - 2  may be further reduced by increasing the inductance across region  132 .  FIG. 8  is a perspective view showing how an inductive antenna tuning component (e.g., an antenna tuning inductor) may be formed form patterned region  132  of conductive layer  130 . As shown in  FIG. 8 , slots  140  may divide conductive layer  130  into a meandering conductive path  174  extending from un-patterned region  134 - 1  to un-patterned region  134 - 2  within patterned region  132  (e.g., slots  140  may define the edges of conductive path  174 ). For example, a first set of open slots  140  (e.g., slots having three sides surrounded by conductive material in layer  130  and a fourth side that is not defined by any conductive material) may be formed in first edge  172  of conductive layer  130  whereas a second set of open slots  140  is formed in opposing second edge  170  of conductive layer  130 . The slots in edge  172  may be laterally offset (e.g., in the X-Y plane) with respect to the set of slots in edge  170  so that the conductive material in region  130  follows meandering path  174 . Each slot  140  may have width  150  that is sufficiently narrow so as to be invisible to the un-aided human eye (e.g., less than 200 microns such as between 20 microns and 40 microns). 
     The conductive material along meandering path  174  may include alternating first segments  176  extending parallel to slots  140  (e.g., along the Y-axis of  FIG. 8 ) and second segments  178  extending perpendicular to slots  140  (e.g., along the X-axis). Segments  176  may have width  180  and longitudinal length  158 ′. Width  180  may, for example, be less than, greater than, or equal to width  152  of  FIG. 6 . In one suitable arrangement, width  180  may be between 150 microns and 250 microns. Segments  178  may have a length equal to the width  150  of slots  140  and a perpendicular width  194 . Width  194  may be less than, equal to, or greater than width  180  of segments  176  (e.g., between 20 microns and 250 microns). Each slot  140  may have a longitudinal length  190  (e.g., parallel to the Y-axis) that extends across some but not all of length  158  of conductive layer  130 . Length  190  may, for example, be equal to length  158 ′ minus width  194  of segments  178 . 
     By forming alternating slots  140  within region  132 , slots  140  may increase the electrical path length between un-patterned regions  134 - 1  and  134 - 2 . For example, in the absence of any slots  140 , the electrical path length between regions  134 - 1  and  134 - 2  is equal to width  148  of region  132 . However, in the presence of alternating slots  140 , the electrical path length (e.g., the length over which currents flow between regions  134 - 1  and  134 - 2 ) may be equal to the sum of the lengths of each segment  178  and each segment  176  in region  132 . As the inductance of a conductor is proportional to the electrical path length of the conductor, this may serve to increase the inductance between un-patterned region  134 - 1  and  134 - 2  relative to scenarios where no slots  140  are formed. In this way, meandering path  174  may form an inductor  198  integrated or embedded within layer  130 . At the same time, segments  176  of inductor  198  and regions  134 - 1  and  134 - 2  may exhibit some capacitance (e.g., a self-capacitance) that can serve to tweak the impedance (e.g., frequency response) of region  132 . In this way, inductor  198  may exhibit an inductance coupled in parallel with a (self) capacitance between regions  134 - 1  and  134 - 2 . The number of slots  140 , the dimensions  150  and  190  of slots  140 , and the dimensions  158 ′,  180 , and  194  of conductive path  174  within region  132  may be selected for a given width  148  so that region  132  exhibits a desired inductance and self-capacitance between regions  134 - 1  and  134 - 2 . As an example, inductor  198  may be configured to exhibit an inductance of between 10 nH and 50 nH, between 10 nH and 20 nH, between 10 nH and 100 nH, etc. 
     At the same time, slots  140  may be sufficiently narrow (e.g., having width  140  that is less than the width resolvable by the un-aided human eye) so that region  132  appears to a user as single continuous piece of conductor with regions  134 - 1  and  134 - 2 . When configured in this way, patterned region  132  of conductive layer  130  may exhibit a desired (predetermined) inductance and (self) capacitance while also exhibiting a visible light reflectivity, absorptivity, and/or transmissivity that are within 20%, within 10%, within less than 10% (e.g., within 5%, within 2%, etc.), or within 10-20% of the visible light reflectivity, absorptivity, and/or transmissivity of un-patterned regions  134  of conductive layer  130 , as examples. Patterned region  132  and un-patterned regions  134  of conductive layer  130  may thereby appear to the user of device  10  as a single continuous piece of metal despite having an integrated inductor  198  formed therein. 
     In one suitable arrangement, in order to balance desired inductance with the invisibility of slots  140 , width  148  of region  132  is between 1 mm and 3 mm, width  150  of each slot  140  is between 20 microns and 40 microns, widths  180  and  194  of inductive path  174  are 150 microns and 250 microns, there are between three and fifteen segments  176  in conductive path  174 , there are between five and sixteen slots  140  within region  132 , thickness  154 ′ of path  174  is between 150 microns and 250 microns, and thickness  154  of regions  134  is between 500 microns and 10 mm. There may be, for example, one more slot  140  than segments  176  and there may be the same number of segments  178  as slots  140  within region  132 . Forming integrated inductor  198  between regions  134 - 1  and  134 - 2  may effectively reduce the capacitance between regions  134 - 1  and  134 - 2  relative to scenarios where no conductive material is formed in region  132  by a greater margin than forming integrated capacitor  142  between regions  134 - 1  and  134 - 2  (as shown in  FIGS. 7 and 8 ), for example. 
     The example of  FIG. 8  is merely illustrative. In general, any desired number of slots  140  and segments  176  and  178  may be formed within region  132  (e.g., three slots  140 , between three and twelve slots  140 , more than twelve slots  140 , etc.). Each slot  140  may have the same width  150  and length  190  or two or more slots  140  may have different lengths or widths. Each segment  178  of inductive path  174  may have the same width  94  or two or more segments  178  may have different widths. Each segment  176  of inductive path  174  may have the same length  158 ′ and width  180  or two or more segments  176  may have different lengths or widths. The edges of slots  140  (and the corresponding edges of path  174 ) may have any desired shape (e.g., curved and/or straight shapes). Different segments  176  may have different shapes or each segment  176  may have the same shape. Similarly, each segment  178  may have the same shape or two or more segments  178  may have different shapes. Slots  140  may extend at any desired angle with respect to other slots  140  and with respect to the edges of conductive regions  134 . Similarly, segments  176  and  178  of path  174  may extend at any desired angle with respect to other segments  176  and  178  and with respect to the edges of conductive regions  134 . Segments  176  need not extend perpendicularly from segments  178 . 
     Integrated capacitor  142  as shown in  FIGS. 6 and 7  and/or integrated inductor  198  as shown in  FIG. 8  may be embedded within any desired conductive structures  130  within electronic device  10 . For example, conductive structures  130  may include conductive traces on a printed circuit board within device  10 , a metal midplate that extends across the length and/or width of device  10  for providing structural support for device  10 , conductive bracket or frame components within device  10 , conductive portions of other conductive components within device  10 , or from external components such as portions of conductive housing  12 . 
       FIG. 9  is a perspective rear view of device  10  showing how conductive structures  130  may be formed from portions of conductive housing  12 . In configurations for device  10  in which housing  12  has portions formed from metal, openings may be formed in the metal portions to accommodate antennas  40 . For example, openings in a metal housing wall may be used in forming slot antenna structures and inverted-F antenna structures for cellular telephone antennas. As shown in  FIG. 9 , openings such as one or more dielectric gaps  18  (e.g., a first dielectric gap  18 - 1  and a second dielectric gap  18 - 2 ) may run up one or more conductive sidewalls  16  of housing  12 . For example, dielectric gap  18 - 2  may divide conductive sidewall  16  into a first conductive sidewall segment (portion)  16 - 1  and a second conductive sidewall segment (portion)  16 - 2 . Similarly, dielectric gap  18 - 1  may divide conductive sidewall  16  into a third segment (portion)  16 - 3 . If desired, an optional dielectric gap  18 - 3  may divide segment  16 - 2  into two separate sidewall segments. 
     As shown in  FIG. 9 , an additional opening  200  may be formed at the rear of device  10  and may separate rear housing wall  12 R from conductive housing sidewall segment  16 - 2 . Rear housing wall  12 R may form the rear face of device  10  and may be formed on an opposing side of device  10  from display  14 . If desired, rear housing wall  12 R and sidewall segments  16 - 1  and  16 - 3  may be formed from a single integrated piece of conductive material (e.g., machined metal). Opening  200  may run from dielectric gap  18 - 1  to dielectric gap  18 - 2  so that gaps  18 - 1 ,  18 - 2 , and opening  200  form a single continuous dielectric-filled opening in the conductive housing of device  10 . Openings  200  and  18  may be filled with dielectric such as plastic, epoxy, ceramic, glass, sapphire, or other dielectric materials. Opening  200  may follow the shape of housing segment  16 - 2  (e.g., opening  200  may have a U-shape) that defines extended portion  202  of rear wall  12 R if desired. The example of  FIG. 9  is merely illustrative. Openings such as opening  200  (e.g., plastic-filled openings or other dielectric filled openings) may be formed in other metal portions of housing  12  (e.g., front face housing portions on the front face of device  10 , sidewall housing portions, rear wall housing portions on the rear face of device  10 , etc.). Opening  200  may follow any desired path. 
     Openings  200  and  18  may accommodate antennas  40  within device  10 . For example, openings  200  and  18  may separate resonating elements and ground plane elements for one or more antennas  40  that are formed using portions of conductive housing  12 . In another suitable arrangement, openings  200  and  18  may form antenna windows for internal antennas  40  that are mounted within housing  12 . 
     In the example of  FIG. 9 , rear housing wall  12 R, opening  200 , dielectric gaps  18 , and housing sidewalls  16  all form exterior surfaces of device  10  and may thus be visible to a user of device  10 . If desired, rear housing wall  12 R may include a layer of metal covered by a dielectric cover layer that forms an exterior surface of device  10  (e.g., conductive wall  12 R may be obscured from view by a dielectric cover layer). If desired, conductive material such as integrated inductor  198  of  FIG. 8  and/or integrated capacitor  142  of  FIGS. 6 and 7  may be formed within dielectric-filled gaps  18 - 1 ,  18 - 2 ,  18 - 3 , and/or  200 . The conductive material in integrated components  198  and  142  may obscure some or all of gaps  18 - 1 ,  18 - 2 ,  18 - 3 , and/or  200  from view (e.g., so as to be invisible to the un-aided eye). In this way, sidewalls  16  and rear housing wall  12 R may appear to the user as a continuous, gap-free conductor. 
     In these scenarios, conductive layer  130  may be formed from conductive housing wall  12 R and sidewall segments  16 - 1 ,  16 - 2 , and/or  16 - 3 . For example, in a scenario where integrated components  198  or  142  are formed within gap  18 - 2 , conductive layer  130  may be formed from conductive housing sidewalls  16 , where un-patterned region  134 - 2  of  FIGS. 6-8  is formed from sidewall segment  16 - 1 , un-patterned region  134 - 1  is formed from sidewall segment  16 - 2 , and conductive patches  146  ( FIGS. 6 and 7 ) or path  174  ( FIG. 8 ) is formed within gap  18 - 2 . In a scenario where integrated components  198  or  142  are formed within gap  18 - 1 , conductive layer  130  may be formed from conductive housing sidewalls  16 , where un-patterned region  134 - 2  is formed from sidewall segment  16 - 2 , un-patterned region  134 - 1  is formed from sidewall segment  16 - 3 , and conductive patches  146  or path  174  are formed within gap  18 - 1 . Similarly, in a scenario where integrated components  198  or  142  are formed within gap  200 , conductive layer  130  may be formed from conductive housing sidewalls  16  and rear wall  12 R, where un-patterned region  134 - 2  is formed from rear wall  12 R, un-patterned region  134 - 1  is formed from sidewall segment  16 - 2 , and conductive patches  146  or path  174  are formed within gap  200 . 
     In scenarios where conductive portions of housing  12  are used to form portions of one or more antennas  40 , integrated antenna tuning components  142  and  198  may be used to adjust the radio-frequency performance of antennas  40  in one or more frequency bands (e.g., tuning components  142  and  198  may form fixed tuning components  104  of  FIG. 3 ). At the same time, integrated antenna tuning components  142  and  198  may serve to obscure the presence of gaps  18 - 1 ,  18 - 2 ,  18 - 3 , and  200  from view of a user. 
     Antenna  40  may be formed using any desired antenna type. For example, antenna  40  may include an antenna with a resonating element that is formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, monopole antenna structures, dipole antenna structures, hybrids of these designs, etc.  FIG. 10  is a diagram of illustrative inverted-F antenna structures that may be used in implementing antenna  40  for device  10 . 
     As shown in  FIG. 10 , antenna  40  may include inverted-F antenna resonating element  204  and antenna ground (ground plane)  210 . Antenna resonating element  204  may have a main resonating element arm such as arm  208 . The length of arm  208  and/or portions of arm  208  may be selected so that antenna  40  resonates at desired operating frequencies. For example, the length of arm  208  may be a quarter of a wavelength at a desired operating frequency for antenna  40 . Antenna  40  may also exhibit resonances at harmonic frequencies. 
     Main resonating element arm  208  may be coupled to ground  210  by return path  206 . An inductor or other component may be interposed in path  206  and/or tunable components  102  and  104  may be interposed in path  206 . If desired, tunable components  102  and/or  104  may be coupled in parallel with path  206  between arm  208  and ground  210 . For example, integrated capacitor  142  of  FIGS. 6 and 7  and/or integrated inductor  198  of  FIG. 8  may be coupled between arm  208  and ground  210  in parallel with path  206 . Additional return paths  206  may be coupled between arm  208  and ground  210  if desired. 
     Antenna  40  may be fed using one or more antenna feeds. For example, antenna  40  may be fed using antenna feed  212 . Antenna feed  212  may include positive antenna feed terminal  98  and ground antenna feed terminal  100  and may run in parallel to return path  206  between arm  208  and ground  210 . If desired, inverted-F antennas such as illustrative antenna  40  of  FIG. 10  may have more than one resonating arm branch (e.g., to create multiple frequency resonances to support operations in multiple communications bands) or may have other antenna structures (e.g., parasitic antenna resonating elements, tunable components to support antenna tuning, etc.). For example, arm  208  may have left and right branches that extend outwardly from feed  212  and return path  206 . Multiple feeds may be used to feed antennas such as antenna  40 . 
     Antenna  40  may be a hybrid antenna that includes one or more slot antenna resonating elements. As shown in  FIG. 11 , for example, antenna  40  may be based on a slot antenna configuration having an opening such as slot  214  that is formed within conductive structures such as antenna ground  210 . Slot  214  may be filled with air, plastic, and/or other dielectric. The shape of slot  214  may be straight or may have one or more bends (i.e., slot  214  may have an elongated shape following a meandering path). The antenna feed for antenna  40  may include positive antenna feed terminal  98  and ground antenna feed terminal  100 . Feed terminals  98  and  100  may, for example, be located on opposing sides of slot  214  (e.g., on opposing long sides). Slot-based antenna resonating elements such as slot antenna resonating element  214  of  FIG. 5  may give rise to an antenna resonance at frequencies in which the wavelength of the antenna signals is equal to the perimeter of the slot. In narrow slots, the resonant frequency of a slot antenna resonating element is associated with signal frequencies at which the slot length is equal to a half of a wavelength. Slot antenna frequency response can be tuned using one or more tuning components (e.g., adjustable components  102  and fixed tuning components  104  of  FIG. 3 ) such as integrated inductors  198  ( FIG. 8 ) or integrated capacitors  142  ( FIGS. 6 and 7 ). These components may have terminals that are coupled to opposing sides of the slot (i.e., the tunable components may bridge the slot). If desired, tunable components may have terminals that are coupled to respective locations along the length of one of the sides of slot  214 . Combinations of these arrangements may also be used. 
     Antenna  40  may be a hybrid slot-inverted-F antenna that includes resonating elements of the type shown in both  FIG. 10  and  FIG. 11 . An illustrative configuration for an antenna with slot and inverted-F antenna structures is shown in  FIG. 12 . As shown in  FIG. 12 , antenna  40  (e.g., a hybrid slot-inverted-F antenna) may be fed by transceiver circuitry  42  that is coupled to antenna feed  212  over radio-frequency transmission line  92  ( FIG. 2 ). Antenna  40  may include a slot such as slot  214  that is formed from an elongated gap between peripheral conductive structures  16  and ground  210 . Slot  214  may, for example, be formed from gap  200  of  FIG. 9 . Ground  210  may include portions of rear housing wall  12 R or other metal layers within device  10 . Slot  214  may be filled with dielectrics such as air, ceramic, glass, and/or plastic. For example, plastic may be inserted into portions of slot  214  and this plastic may be flush with the outside of housing  12 . Antenna  40  as shown in  FIG. 12  may be formed within upper region  22  or lower region  18  of device  10  ( FIG. 1 ), for example. 
     Feed  212  may be coupled across slot  214 . For example, positive antenna feed terminal  98  may be coupled to segment  16 - 2  of peripheral conductive structures  16  whereas ground antenna feed terminal  100  is formed on ground plane  214 . Portions of slot  214  may contribute slot antenna resonances to antenna  40 . Segment  16 - 2  of peripheral conductive structures  16  may form an antenna resonating element arm such as arm  208  of  FIG. 10  that extends between gaps  18 - 1  and  18 - 2  (e.g., gaps  18  in peripheral conductive structures  16  as shown in  FIGS. 1 and 9 ). Segment  16 - 2  may have a first end  224  that is separated from segment  16 - 3  of peripheral conductive structures  16  by gap  18 - 1  and a second end  222  that is separated from segment  16 - 2  of peripheral structures  16  by gap  18 - 2 . The length of antenna resonating element arm  208  (e.g., segment  16 - 2  extending from end  224  adjacent to gap  18 - 1  to end  222  adjacent to gap  18 - 2 ) may be selected so that antenna  40  resonates at desired operating frequencies. A return path such as path  206  of  FIG. 10  may be formed by a fixed conductive path bridging slot  214  or a tuning component such as components  102  and/or  104  of  FIG. 3 . 
     Slot  214  may have an elongated shape (e.g., a slot shape) or other suitable elongated gap shape. In the example of  FIG. 12 , slot  214  has a U shape that runs along the periphery of device  10  between segment  16 - 2  (e.g., housing sidewalls) and portions of the rear wall  12 R of device  10  (e.g., ground  210 ). The ends of slot  214  may be formed by gaps  18 - 1  and  18 - 2 . The length of slot  214  may be about 4-20 cm, more than 2 cm, more than 4 cm, more than 8 cm, more than 12 cm, less than 25 cm, less than 15 cm, less than 10 cm, or any other suitable length. Slot  214  may have a width of about 2 mm (e.g., less than 4 mm, less than 3 mm, less than 2 mm, more than 1 mm, more than 1.5 mm, 1-3 mm, etc.) or any other suitable width. If desired, slot  114  may have other shapes such as a straight slot shape. 
     Antenna  40  may be used to support communications in multiple frequency bands. For example, antenna  40  may support communications in a low band LB (e.g., frequencies from 600 MHz to 960 MHz as shown in  FIG. 4 ), a midband MB that includes higher frequencies than the low band (e.g., frequencies from 1710 MHz to 2170 MHz), and a high band HB that includes higher frequencies than the midband (e.g., frequencies from 2300 MHz to 2700 MHz). If desired, antenna  40  may also support communications in a low-mid band between the low band and the midband (e.g., frequencies from 960 MHz to 1710 MHz) or any other band from 600 MHz to 4000 MHz. As shown in  FIG. 12 , portion  226  of antenna resonating element arm  208  (e.g., peripheral housing segment  16 - 2 ) extending from positive feed terminal  98  to end  224  and ground plane  210  may be used to support a resonance in the midband. If desired, slot  214  between resonating element portion  226  and ground  210  (e.g., a fundamental or harmonic frequency of slot  214 ) or a parasitic antenna resonating element adjacent to portion  226  may support a resonance in the high band. Portion  228  of antenna resonating element arm  208  (e.g., peripheral housing segment  16 - 2 ) extending from positive feed terminal  98  to end  222  may be used to support a resonance in the low band. 
     The impedance of gaps  18 - 1  and  18 - 2  may be dependent upon the frequency of operation of portions  226  and  228  of resonating element arm  208 , respectively. For example, at frequencies in the midband, the capacitance across gap  18 - 1  (e.g., between end  224  and segment  16 - 3 ) may be excessively high and can reduce the antenna efficiency of antenna  40  within midband MB. At the same time, at least some capacitance across gap  18 - 1  is required in order for antenna  40  to exhibit satisfactory midband antenna efficiency. To counteract this excessive capacitance (e.g., without completely removing all capacitance between end  224  and segment  16 - 3 ), an inductive component such as integrated inductor  198  of  FIG. 8  may be formed in gap  18 - 1 . 
     For example, un-patterned region  134 - 1  of conductive layer  130  of  FIG. 8  may be formed from segment  16 - 3  and un-patterned region  134 - 2  of conductive layer  130  may be formed from segment  16 - 2  of housing sidewalls  16  (e.g., housing sidewall  16  may form conductive layer  130  of  FIG. 8 ). Patterned region  132  of conductive layer  130  of  FIG. 8  may be formed within gap  18 - 1  and may include slots  140  that divide the conductive material in gap  18 - 1  into meandering conductive path  174 . The width of gap  18 - 1  may be equal to width  148  of  FIG. 8  and may be fixed design constraints associated with device  10 , for example. While not shown for the sake of clarity in  FIG. 12 , a first end of conductive path  174  is connected to end  224  of segment  16 - 2  and a second end of conductive path  174  is connected to segment  16 - 3  of housing sidewalls  16 . 
     Conductive meandering path  174  may have dimensions that are selected to provide integrated inductor  198  with a selected inductance and self-capacitance. The inductance and self-capacitance may be selected to counteract any excessive capacitance associated with gap  18 - 1  in the absence of conductive material in gap  18 - 1 , thereby enhancing the midband antenna efficiency of antenna  40 . Slots  140  in component  198  may be sufficiently small (e.g., having a width  150  that is less than 200 microns as shown in  FIG. 8 ) so that gap  18 - 1  is invisible to the un-aided eye of a user of device  10 . In other words, when configured in this way, segment  16 - 2 , gap  18 - 1 , and segment  16 - 3  may appear to the user as a single continuous piece of conductive material. This may, for example, serve to enhance the overall aesthetic appearance of device  10  to the user without sacrificing antenna performance. 
     At frequencies in low band LB ( FIG. 4 ), the capacitance across gap  18 - 2  (e.g., between end  222  and segment  16 - 1 ) may be excessively high and can reduce the antenna efficiency for antenna  40  within low band LB. However, the impact of the capacitance across gap  18 - 2  in low band LB may be less than that of the capacitance across gap  18 - 1  in midband MB. As such, whereas introduction of inductance into gap  18 - 1  may be required to obtain satisfactory antenna efficiency in the midband for portion  226  of antenna  40 , an inductance need not be introduced into gap  18 - 2  to obtain satisfactory low band antenna efficiency. If desired, the capacitance of gap  18 - 2  may be reduced by forming a capacitive component such as integrated capacitor  142  of  FIGS. 6 and 7  in gap  18 - 2 . 
     For example, un-patterned region  134 - 1  of conductive layer  130  of  FIGS. 6 and 7  may be formed from segment  16 - 2  and un-patterned region  134 - 2  of conductive layer  130  may be formed from segment  16 - 1  of housing sidewalls  16  (e.g., housing sidewall  16  may form conductive layer  130 ). The width of gap  18 - 2  may be equal to width  148  of  FIGS. 6 and 7  and may be fixed design constraints associated with device  10 , for example. Patterned region  132  of conductive layer  130  of  FIGS. 6 and 7  may be formed within gap  18 - 2  such that gap  18 - 2  includes a one or two-dimensional array of conductive patches  146  that are separated by slots  140 . Because conductive patches  146  form at least one set of series-coupled capacitors between end  222  and segment  16 - 1 , the corresponding capacitances add in series to reduce the overall capacitance between segment  16 - 2  and segment  16 - 1  relative to scenarios were no conductive material is formed in gap  18 - 2 . Conductive patches  146  and slots  140  may have dimensions that are selected to provide integrated capacitor  198  with a selected capacitance. The capacitance may be selected to reduce the overall capacitance associated with gap  18 - 2  relative to the capacitance in the absence of conductive material within gap  18 - 2  by a predetermined amount, thereby enhancing the low band antenna efficiency of antenna  40 . Slots  140  in component  142  may be sufficiently small (e.g., having a width  150  that is less than 200 microns as shown in  FIGS. 6 and 7 ) so that gap  18 - 2  is invisible to the un-aided eye of a user of device  10 . In other words, when configured in this way, segment  16 - 2 , gap  18 - 2 , and segment  16 - 1  may appear to the user as a single continuous piece of conductive material. This may, for example, serve to enhance the overall aesthetic appearance of device  10  to the user without sacrificing antenna performance. 
     As shown in  FIG. 12 , the thickness of conductive path  174  (e.g., thickness  154 ′ of  FIG. 8  or the dimension of path  174  in the direction of the Z-axis in  FIG. 12 ) may be less than the thickness of segments  16 - 2 ,  16 - 3 , and  16 - 1  (e.g., thickness  154  of regions  134 - 1  and  134 - 2  of  FIG. 8 ). Similarly, the thickness of conductive patches  146  (e.g., thickness  154 ′ of  FIGS. 6 and 7  or the dimension of patches  146  in the direction of the Z-axis in  FIG. 12 ) may be less than the thickness of segments  16 - 2 ,  16 - 3 , and  16 - 1 . If desired, conductive path  174  and/or patches  146  may be formed from conductive traces or other metal structures on a dielectric substrate (e.g., substrate  144  of  FIGS. 6-8 ) within the interior of device  10 . Segments  16 - 1 ,  16 - 3 , and  16 - 2  may also be formed on dielectric substrate  144  or may be free from substrate  144 . In another suitable arrangement, conductive path  174  and/or patches  146  may be formed from conductive housing sidewalls  16 . For example, slots  140  in components  142  and/or  198  may be formed from etching or cutting slots  140  directly into housing sidewalls  16 . 
     If desired, peripheral conductive segment  16  may include an additional dielectric gap such as optional dielectric gap  18 - 3  of  FIG. 9 . If desired, multiple antennas  40  may be formed using peripheral conductive housing structures  16  having additional gap  18 - 3 . An illustrative configuration in which two antennas are formed using three gaps  18  in sidewalls  16  is shown in  FIG. 13 . 
     As shown in  FIG. 13 , third gap  18 - 3  may divide conductive housing segment  16 - 2  into a first portion  16 - 2 ′ and  16 - 2 ″. A first antenna  40  may be formed in region  240  and may include antenna feed  212 , an antenna resonating element arm  208  formed from housing portion  16 - 2 ′ between a first end  224  and opposing second end  270 , return path  206 , and ground plane  210 . A second antenna  40 ′ may be formed in region  242  and may include antenna feed  212 ′, an antenna resonating element arm  208 ′ formed from housing portion  16 - 2 ″ between a first end  222  and opposing second end  272 , return path  206 ′, and ground plane  210 . Antenna feed  212 ′ may include a positive antenna feed terminal  98 ′ coupled to housing portion  16 - 2 ″ and a ground antenna feed terminal  100 ′ coupled to ground  210 . The length of arm  208  of antenna  40  may be selected so that antenna  40  covers low band and high band frequencies. The length of arm  208 ′ may be selected so that antenna  40 ′ covers midband and high band frequencies. This is merely illustrative and, in general, antennas  40  and  40 ′ may cover any desired frequencies. In one suitable arrangement, antennas  40  and  40 ′ are configured to concurrently transmit and receive signals using a MIMO protocol (e.g., a protocol in which copies of the same data stream are concurrently transmitted or received over the high band using both antennas  40  and  40 ′). In general, MIMO communications may involve communications with higher overall data rates (e.g., throughputs) than scenarios where only a single antenna is used to convey a data stream. 
     At frequencies in the high band, the capacitance across gap  18 - 1  may be excessively high and can reduce the overall high band antenna efficiency for antenna  40 . Similarly, at frequencies in the high band and midband, the capacitance across gap  18 - 2  may be excessively high and can reduce the overall high band and midband efficiency for antenna  40 ′. At the same time, at least some capacitance across gaps  18 - 1  and  18 - 2  is required in order for antennas  40  and  40 ′ to exhibit satisfactory midband and high band efficiency. To counteract this excessive capacitance (e.g., without completely removing all capacitance between end  224  and segment  16 - 3  and between end  222  and segment  16 - 1 ), inductive components such as integrated inductor  198  of  FIG. 8  may be formed in gaps  18 - 1  and  18 - 2 . 
     For example, un-patterned region  134 - 1  of conductive layer  130  of  FIG. 8  may be formed from segment  16 - 3  and un-patterned region  134 - 2  of conductive layer  130  may be formed from segment  16 - 2 ′ of housing sidewalls  16 . Patterned region  132  of conductive layer  130  of  FIG. 8  may be formed within gap  18 - 1  and may include slots  140  that divide the conductive material in gap  18 - 1  into meandering conductive path  174 . Similarly in antenna  40 ′, un-patterned region  134 - 1  may be formed from segment  16 - 2 ″ and un-patterned region  134 - 2  may be formed from segment  16 - 1 . Slots  140  may divide the conductive material in gap  18 - 2  into meandering conductive path  174 . Slots  140  and conductive meandering paths  174  in gaps  18 - 1  and  18 - 2  may have dimensions that are selected to provide integrated inductors  198  with predetermined inductances and self-capacitances. The predetermined inductances and self-capacitances may be selected to counteract any excessive capacitance associated with gaps  18 - 1  and  18 - 2 , thereby enhancing the high band antenna efficiency of antenna  40  and the midband and high band antenna efficiencies of antenna  40 ′. Slots  140  in component  198  may be sufficiently small so that gaps  18 - 1  and  18 - 2  are invisible to the un-aided eye of a user of device  10 . 
     In order to enhance isolation between antenna  40  and  40 ′, the capacitance of gap  18 - 3  may be reduced by forming a capacitive tuning component such as integrated capacitor  142  of  FIGS. 6 and 7  in gap  18 - 3 . For example, un-patterned region  134 - 1  may be formed from segment  16 - 2 ′ and un-patterned region  134 - 2  may be formed from segment  16 - 2 ″ of housing sidewalls  16  (e.g., housing sidewall  16  may form conductive layer  130  of  FIG. 8 ). Slots  140  may divide the conductive material in gap  18 - 3  into a one or two-dimensional array of conductive patches  146 . Because conductive patches  146  form a set of series-coupled capacitors between segment  16 - 2 ′ and segment  16 - 2 ″, the corresponding capacitances add in series to reduce the overall capacitance between segments  16 - 2 ′ and  16 - 2 ″. Conductive patches  146  and slots  140  may have dimensions that are selected to provide integrated capacitor  142  with a predetermined capacitance. The predetermined capacitance may be selected to reduce the overall capacitance associated with gap  18 - 3  by a predetermined amount, thereby enhancing isolation between antennas  40  and  40 ′. Slots  140  in component  142  may be sufficiently small so that gap  18 - 3  is invisible to the un-aided eye of a user of device  10 . In other words, when configured in this way, segment  16 - 2 ′, gap  18 - 3 , and segment  16 - 2 ″ may appear to the user as a single continuous piece of conductive material. 
     As shown in  FIG. 13 , the thickness of conductive paths  174  may be less than the thickness of segments  16 - 2 ′,  16 - 2 ″,  16 - 1 , and  16 - 3 . Similarly, the thickness of conductive patches  146  may be less than the thickness of segments  16 - 2 ′ and  16 - 2 ″. If desired, conductive paths  174  and/or patches  146  may be formed from conductive traces or other metal structures on a dielectric substrate (e.g., substrate  144  of  FIGS. 6-8 ) within the interior of device  10 . Segments  16 - 1 ,  16 - 3 ,  16 - 2 ′, and  16 - 2 ″ may also be formed on dielectric substrate  144  or may be free from substrate  144 . In another suitable arrangement, conductive paths  174  and/or patches  146  may be formed from conductive housing sidewalls  16 . For example, slots  140  in components  142  and/or  198  may be formed from etching or cutting slots  140  directly into housing sidewalls  16 . 
       FIG. 14  is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency f for an illustrative antenna such as antennas  40  and  40 ′ of  FIGS. 12 and 13  (including conductive antenna tuning components formed within gaps  18 ). As shown in  FIG. 14 , antennas  40  and/or  40 ′ may exhibit resonances in a low band LB, midband MB, and high band HB. Curve  250  exhibits the antenna efficiency of antennas  40  and/or  40 ′ in the absence of antenna tuning components within gaps  18 . Curve  252  exhibits the antenna efficiency of antenna  40  and/or  40 ′ when formed with antenna tuning components within gaps  18  (e.g., with integrated inductor  198  in gap  18 - 1  and integrated capacitor  142  in gap  18 - 2  as shown in  FIG. 12  or with integrated inductors  198  in gaps  18 - 1  and  18 - 2  and integrated capacitor  142  in gap  18 - 3  as shown in  FIG. 13 ). 
     Low band LB may extend from 600 MHz to 960 MHz or other suitable frequency range. Peripheral conductive structures  16  may serve as an inverted-F resonating element arm such as arm  208  of  FIG. 12 . The resonance of antenna  40  at low band LB may be associated with the distance along peripheral conductive structures  16 - 2  between feed  212  of  FIGS. 12 and 13  and gap  18 - 2 . 
     Midband MB may extend from 1710 MHz to 2170 MHz or other suitable frequency range. The resonance of antenna  40  and/or  40 ′ at midband MB may be associated with the distance along peripheral conductive structures  16 - 2  between feed  212  of  FIG. 12  and gap  18 - 1  or with the distance along peripheral conductive structures  16 - 2 ″ between feed  212 ′ and gap  18 - 2  of  FIG. 13 . 
     High band HB may extend from 2300 MHz to 2700 MHz or other suitable frequency range. Antenna performance in high band HB may be supported by the resonance of slot  214 . As shown in  FIG. 14 , in the absence of components  198  and  142 , antennas  40  and/or  40 ′ may exhibit a first antenna efficiency  250  having a first set of peaks. In the presence of components  198  and  142 , antennas  40  and/or  40 ′ may exhibit a second antenna efficiency  252  having a second set of peaks that are greater than the first set of peaks. The increase in antenna efficiency in low band LB may, for example, be generated by the presence of integrated capacitors  142  within gaps  18  (e.g., within gap  18 - 2  of  FIG. 12  or gap  18 - 3  as shown in  FIG. 13 ). The increase in antenna efficiency in midband MB and high band HB may, for example, be generated by the presence of integrated inductors  198  within gaps  18  (e.g., within gap  18 - 1  as shown in  FIG. 12  or gaps  18 - 1  and  18 - 2  as shown in  FIG. 13 ). The example of  FIG. 14  is merely illustrative. In general, the efficiency curve associated with antenna  40  may have any desired shape. Antenna  40  may exhibit peaks in efficiency in more than three frequency bands or in fewer than three frequency bands if desired. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20170629
Publication Date: 20190205
Grant Date: 20190205
Priority Date: 20170629
Inventors: HU, HONGFEI
JIANG, YI
TSAI, MING-JU
AYALA VAZQUEZ, ENRIQUE
IRCI, Erdinc
WU, JIANGFENG
ZHANG, LIJUN
YONG, Siwen
Assignee: APPLE INC
CPC Classifications: [{"code": "H04B7/0689", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B7/0602", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/401", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/364", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q23/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/328", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B7/0689", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/401", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B7/0602", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/328", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/364", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 62948331