PATENT DOCUMENT

Publication Number: US-10819029-B2
Application Number: US-201916271617-A
Country: US
Kind Code: B2

Title: Electronic device having multi-frequency ultra-wideband antennas

Abstract:
An electronic device may be provided with control circuitry and doublets of first and second antennas that are used to determine the position and orientation of the device relative to external wireless equipment. The control circuitry may determine the relative position and orientation of the external equipment by measuring the angle of arrival of radio-frequency signals from the external equipment. Each doublet may include first and second cavity-backed slot antennas. The first and second antennas may each include a first slot element that is directly fed and a second slot element that is parasitically fed by the first slot element. The first slot element may radiate in an ultra-wideband communications band at 8.0 GHz and the second slot element may radiate in an ultra-wideband communications band at 6.5 GHz. The doublet may be aligned with a dielectric window in a conductive sidewall for the device.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a conductive structure; 
 a first slot element in the conductive structure and configured to radiate in a first ultra-wideband communications band, wherein the first slot element has first and second opposing sides; 
 a second slot element in the conductive structure and configured to radiate in a second ultra-wideband communications band; and 
 an antenna feed having a first feed terminal coupled to the conductive structure on the first side of the first slot element and a second feed terminal coupled to the conductive structure on the second side of the first slot element, wherein the first slot element is configured to indirectly feed the second slot element. 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the second ultra-wideband communications band comprises lower frequencies than the first ultra-wideband communications band. 
     
     
       3. The electronic device defined in  claim 2 , wherein the first ultra-wideband communications band comprises an 8.0 GHz ultra-wideband communications band and the second ultra-wideband communications band comprises a 6.5 GHz ultra-wideband communications band. 
     
     
       4. The electronic device defined in  claim 1 , further comprising a dielectric substrate, wherein the conductive structure comprises conductive traces on the dielectric substrate. 
     
     
       5. The electronic device defined in  claim 4 , further comprising:
 a third slot element in the conductive structure and configured to radiate in the first ultra-wideband communications band; 
 a fourth slot element in the conductive structure and configured to radiate in the second ultra-wideband communications band; and 
 an additional antenna feed coupled across the third slot element, wherein the third slot element is configured to indirectly feed the fourth slot element. 
 
     
     
       6. The electronic device defined in  claim 5 , further comprising:
 a conductive housing; and 
 a dielectric antenna window in the conductive housing, wherein the first, second, third, and fourth slot elements are aligned with the dielectric antenna window. 
 
     
     
       7. The electronic device defined in  claim 6 , further comprising:
 conductive tape configured to ground the conductive traces to the conductive housing, wherein the conductive tape and the conductive traces form an antenna cavity for the first, second, third, and fourth slot elements. 
 
     
     
       8. The electronic device defined in  claim 7 , wherein the conductive housing comprises peripheral conductive housing structures that run around a periphery of the electronic device, the dielectric antenna window is formed in the peripheral conductive housing structures, and the electronic device further comprises a display having a display cover layer mounted to the peripheral conductive housing structures. 
     
     
       9. The electronic device defined in  claim 5 , wherein the first, second, third, and fourth slot elements form a doublet of antennas configured to receive radio-frequency signals in the first and second ultra-wideband communications bands, the electronic device further comprising:
 control circuitry configured to identify an angle of arrival of the radio-frequency signals received by the doublet of antennas. 
 
     
     
       10. The electronic device defined in  claim 9 , further comprising:
 an additional doublet of antennas configured to receive the radio-frequency signals in the first and second ultra-wideband communications bands, wherein the additional doublet of antennas is oriented orthogonally with respect to the doublet of antennas. 
 
     
     
       11. The electronic device defined in  claim 1 , further comprising a capacitor coupled across the second slot element. 
     
     
       12. An electronic device having a periphery, the electronic device comprising:
 a housing having peripheral conductive housing structures that run around the periphery; 
 a dielectric antenna window in the peripheral conductive housing structures and at one side of the periphery; and 
 an antenna mounted within the housing and aligned with the dielectric antenna window, wherein the antenna is configured to receive radio-frequency signals in a first ultra-wideband communications band and a second ultra-wideband communications band at lower frequencies than the first ultra-wideband communications band through the dielectric antenna window at the one side of the periphery. 
 
     
     
       13. The electronic device defined in  claim 12 , wherein the antenna comprises a slot antenna having a first slot element configured to radiate in the first ultra-wideband communications band and a second slot element configured to radiate in the second ultra-wideband communications band. 
     
     
       14. The electronic device defined in  claim 13 , wherein the first slot element is directly fed by an antenna feed coupled across the first slot element, the first slot element being configured to parasitically excite the second slot element to radiate in the second ultra-wideband communications band. 
     
     
       15. The electronic device defined in  claim 13 , further comprising:
 a dielectric substrate; 
 conductive traces on the dielectric substrate; and 
 conductive tape that couples the conductive traces to the conductive housing, the conductive traces being patterned to form the first and second slot elements. 
 
     
     
       16. The electronic device defined in  claim 15 , wherein the slot antenna comprises a cavity-backed slot antenna having an antenna cavity formed from the conductive tape and the conductive traces. 
     
     
       17. The electronic device defined in  claim 12 , wherein the dielectric antenna window comprises dielectric material disposed in an opening in the peripheral conductive housing structures and a dielectric coating that covers the dielectric material and at least part of the peripheral conductive housing structures. 
     
     
       18. The electronic device defined in  claim 12 , wherein the radio-frequency signals in the first and second ultra-wideband communications bands are transmitted by external wireless equipment, the electronic device further comprising:
 an additional antenna mounted within the housing and aligned with the dielectric antenna window, wherein the additional antenna is configured to receive the radio-frequency signals in the first and second ultra-wideband communications bands; and 
 control circuitry configured to process the radio-frequency signals received by the antenna and the additional antenna to identify a location of the external wireless equipment. 
 
     
     
       19. A doublet of antennas configured to receive ultra-wideband signals in first and second frequency bands, comprising:
 a conductive structure; 
 first and second slots in the conductive structure, wherein the first and second slots are directly fed by respective first and second antenna feeds and are configured to radiate in the first frequency band; and 
 third and fourth slots in the conductive structure, the first slot being configured to parasitically excite the third slot to radiate in the second frequency band, and the second slot being configured to parasitically excite the fourth slot to radiate in the second frequency band. 
 
     
     
       20. The doublet of antennas defined in  claim 19 , wherein the first slot has a longitudinal axis extending parallel to a longitudinal axis of the third slot, the second slot has a longitudinal axis extending parallel to a longitudinal axis of the fourth slot, the first frequency band comprises 8.0 GHz, and the second frequency band comprises 6.5 GHz.

Description:
BACKGROUND 
     This relates to electronic devices and, more particularly, to electronic devices with wireless communications circuitry. 
     Electronic devices often include wireless communications circuitry. For example, cellular telephones, computers, and other devices often contain antennas and wireless transceivers for supporting wireless communications. Some electronic devices perform location detection operations to detect the location of an external device based on an angle of arrival of signals received from the external device (using multiple antennas). 
     To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to implement wireless communications circuitry such as antenna components for performing location detection operations using compact structures. At the same time, there is a desire for wireless devices to cover a growing number of frequency bands. 
     Because antennas have the potential to interfere with each other and with components in a wireless device, care must be taken when incorporating antennas into an electronic device. Moreover, care must be taken to ensure that the antennas and wireless circuitry in a device are able to exhibit satisfactory performance over the desired range of operating frequencies. 
     It would therefore be desirable to be able to provide improved wireless communications circuitry for wireless electronic devices. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may include doublets of first and second antennas that are used to determine the position and orientation of the electronic device relative to external wireless equipment. The control circuitry may determine the position and orientation of the electronic device relative to the external wireless equipment at least in part by measuring the angle of arrival of radio-frequency signals from the external wireless equipment. The radio-frequency signals may be received in at least first and second ultra-wideband communications bands. 
     Each doublet may include first and second slot antennas formed from a conductive structure such as conductive traces on a dielectric substrate. Each of the first and second slot antennas may include a first slot element that is directly fed by an antenna feed coupled across the first slot element. The first slot element may radiate in the first ultra-wideband communications band (e.g., an 8.0 GHz band). Each of the first and second slot antennas may include a second slot element that is indirectly fed. The first slot element may indirectly feed the second slot element by parasitically exciting the second slot element to radiate in the second ultra-wideband communications band (e.g., a 6.5 GHz band). A tuning capacitor may be coupled across the second slot element. 
     The device may have a housing with a conductive rear wall and peripheral conductive housing structures that run around a periphery of the device. Conductive tape may ground the conductive traces on the dielectric substrate to the conductive rear wall. The doublet may be aligned with a dielectric antenna window in the peripheral conductive housing structures. The doublet may receive the radio-frequency signals in the first and second ultra-wideband communications bands through the dielectric antenna window. The conductive traces and the conductive tape may form an antenna cavity for the doublet that shields the doublet from electromagnetic interference and that optimizes the radiation pattern of the doublet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device in accordance with some embodiments. 
         FIG. 2  is a schematic diagram of illustrative circuitry in an electronic device in accordance with some embodiments. 
         FIG. 3  is a schematic diagram of illustrative wireless circuitry in accordance with some embodiments. 
         FIG. 4  is a diagram of an illustrative electronic device in wireless communication with an external node in a network in accordance with some embodiments. 
         FIG. 5  is a diagram showing how the location (e.g., range and angle of arrival) of an external node in a network may be determined relative to an electronic device in accordance with some embodiments. 
         FIG. 6  is a diagram showing how illustrative antennas in an electronic device may be used for detecting angle of arrival in accordance with some embodiments. 
         FIG. 7  is a diagram of an illustrative multi-band antenna for performing angle of arrival and range detection operations in accordance with some embodiments. 
         FIG. 8  is a plot of antenna performance (antenna efficiency) for an illustrative multi-band antenna of the type shown in  FIG. 7  in accordance with some embodiments. 
         FIG. 9  is a top-down view of an illustrative electronic device having multiple doublets of multi-band antennas that are used in performing angle of arrival and range detection operations in accordance with some embodiments. 
         FIG. 10  is a perspective view of an illustrative electronic device having a doublet of multi-band antennas aligned with an opening in a housing sidewall in accordance with some embodiments. 
         FIG. 11  is a cross-sectional side view of an illustrative electronic device having a doublet of multi-band antennas that is backed by a conductive antenna cavity in accordance with some embodiments. 
     
    
    
     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. Communications bands (sometimes referred to herein as frequency bands) handled by the wireless communications circuitry can include satellite navigation system communications bands, cellular telephone communications bands, wireless local area network communications bands, near-field communications bands, ultra-wideband communications bands, or other wireless communications bands. 
     The wireless communications circuitry may include one or more antennas. The antennas of the wireless communications circuitry can include loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. Conductive structures for the antennas may, if desired, be formed from conductive electronic device structures. 
     The conductive electronic device structures may include conductive housing structures. The conductive housing structures may include peripheral structures such as peripheral conductive structures that run around the periphery of the electronic device. The peripheral conductive structures may serve as a bezel for a planar structure such as a display, may serve as sidewall structures for a device housing, may have portions that extend upwards from an integral planar rear housing (e.g., to form vertical planar sidewalls or curved sidewalls), and/or may form other housing structures. 
     Gaps may be formed in the peripheral conductive structures that divide the peripheral conductive structures into peripheral segments. One or more of the segments may be used in forming one or more antennas for electronic device  10 . Antennas may also be formed using an antenna ground plane and/or an antenna resonating element formed from conductive housing structures (e.g., internal and/or external structures, support plate structures, etc.). 
     Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, or other small portable device. Device  10  may also be a set-top box, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, a wireless access point, a wireless base station, an electronic device incorporated into a kiosk, building, or vehicle, or other suitable electronic equipment. 
     Device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material (e.g., glass, ceramic, plastic, sapphire, etc.). In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be mounted on the front face of device  10 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. The rear face of housing  12  (i.e., the face of device  10  opposing the front face of device  10 ) may have a substantially planar housing wall such as rear housing wall  12 R (e.g., a planar housing wall). Rear housing wall  12 R may have slots that pass entirely through the rear housing wall and that therefore separate portions of housing  12  from each other. Rear housing wall  12 R may include conductive portions and/or dielectric portions. If desired, rear housing wall  12 R may include a planar metal layer covered by a thin layer or coating of dielectric such as glass, plastic, sapphire, or ceramic. Housing  12  may also have shallow grooves that do not pass entirely through housing  12 . The slots and grooves may be filled with plastic or other dielectric. If desired, portions of housing  12  that have been separated from each other (e.g., by a through slot) may be joined by internal conductive structures (e.g., sheet metal or other metal members that bridge the slot). 
     Housing  12  may include peripheral housing structures such as peripheral structures  12 W. Peripheral structures  12 W and conductive portions of rear housing wall  12 R may sometimes be referred to herein collectively as conductive structures of housing  12 . Peripheral structures  12 W 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, peripheral structures  12 W may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges and that extend from rear housing wall  12 R to the front face of device  10  (as an example). Peripheral structures  12 W or part of peripheral structures  12 W 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 ) if desired. Peripheral structures  12 W may, if desired, form sidewall structures for device  10  (e.g., by forming a metal band with vertical sidewalls, curved sidewalls, etc.). 
     Peripheral structures  12 W 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, peripheral conductive sidewalls, peripheral conductive sidewall structures, conductive housing sidewalls, peripheral conductive housing sidewalls, sidewalls, sidewall structures, or a peripheral conductive housing member (as examples). Peripheral conductive housing structures  12 W 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 conductive housing structures  12 W. 
     It is not necessary for peripheral conductive housing structures  12 W to have a uniform cross-section. For example, the top portion of peripheral conductive housing structures  12 W may, if desired, have an inwardly protruding lip that helps hold display  14  in place. The bottom portion of peripheral conductive housing structures  12 W may also have an enlarged lip (e.g., in the plane of the rear surface of device  10 ). Peripheral conductive housing structures  12 W 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 conductive housing structures  12 W serve as a bezel for display  14 ), peripheral conductive housing structures  12 W may run around the lip of housing  12  (i.e., peripheral conductive housing structures  12 W may cover only the edge of housing  12  that surrounds display  14  and not the rest of the sidewalls of housing  12 ). 
     Rear housing wall  12 R may lie in a plane that is parallel to display  14 . In configurations for device  10  in which some or all of rear housing wall  12 R is formed from metal, it may be desirable to form parts of peripheral conductive housing structures  12 W as integral portions of the housing structures forming rear housing wall  12 R. For example, rear housing wall  12 R of device  10  may include a planar metal structure and portions of peripheral conductive housing structures  12 W on the sides of housing  12  may be formed as flat or curved vertically extending integral metal portions of the planar metal structure (e.g., housing structures  12 R and  12 W may be formed from a continuous piece of metal in a unibody configuration). 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 . Rear housing wall  12 R may have one or more, two or more, or three or more portions. Peripheral conductive housing structures  12 W and/or conductive portions of rear housing wall  12 R may form one or more exterior surfaces of device  10  (e.g., surfaces that are visible to a user of device  10 ) and/or may be implemented using internal structures that do not form exterior surfaces of device  10  (e.g., conductive housing structures that are not visible to a user of device  10  such as conductive structures that are covered with layers such as thin cosmetic layers, protective coatings, and/or other coating layers that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide peripheral conductive housing structures  12 W and/or conductive portions of rear housing wall  12 R from view of the user). 
     Display  14  may have an array of pixels that form an active area AA that displays images for a user of device  10 . For example, active area AA may include an array of display pixels. The array of pixels may be formed from liquid crystal display (LCD) components, an array of electrophoretic pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels or other light-emitting diode pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. If desired, active area AA may include touch sensors such as touch sensor capacitive electrodes, force sensors, or other sensors for gathering a user input. 
     Display  14  may have an inactive border region that runs along one or more of the edges of active area AA. Inactive area IA may be free of pixels for displaying images and may overlap circuitry and other internal device structures in housing  12 . To block these structures from view by a user of device  10 , the underside of the display cover layer or other layers in display  14  that overlap inactive area IA may be coated with an opaque masking layer in inactive area IA. The opaque masking layer may have any suitable color. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass, clear plastic, transparent ceramic, sapphire, or other transparent crystalline material, or other transparent layer(s). The display cover layer may have a planar shape, a convex curved profile, a shape with planar and curved portions, a layout that includes a planar main area surrounded on one or more edges with a portion that is bent out of the plane of the planar main area, or other suitable shapes. The display cover layer may cover the entire front face of device  10 . In another suitable arrangement, the display cover layer may cover substantially all of the front face of device  10  or only a portion of the front face of device  10 . Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button. An opening may also be formed in the display cover layer to accommodate ports such as speaker port  16  or a microphone port. Openings may be formed in housing  12  to form communications ports (e.g., an audio jack port, a digital data port, etc.) and/or audio ports for audio components such as a speaker and/or a microphone 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 backplate) that spans the walls of housing  12  (i.e., a substantially rectangular sheet formed from one or more metal parts that is welded or otherwise connected between opposing sides of peripheral conductive structures  12 W). The backplate may form an exterior rear surface of device  10  or may be covered by layers such as thin cosmetic layers, protective coatings, and/or other coatings that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide the backplate from view of the user. Device  10  may also include conductive structures such as printed circuit boards, components mounted on printed circuit boards, and other internal conductive structures. These conductive structures, which may be used in forming a ground plane in device  10 , may extend under active area AA of display  14 , for example. 
     In regions  22  and  20 , openings may be formed within the conductive structures of device  10  (e.g., between peripheral conductive housing structures  12 W and opposing conductive ground structures such as conductive portions of rear housing wall  12 R, conductive traces on a printed circuit board, conductive electrical components in display  14 , etc.). These openings, which may sometimes be referred to as gaps, may be filled with air, plastic, and/or other dielectrics and may be used in forming slot antenna resonating elements for one or more antennas in device  10 , if desired. 
     Conductive housing structures and other conductive structures in device  10  may serve as a ground plane for the antennas in device  10 . The openings in regions  22  and  20  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  22  and  20 . If desired, the ground plane that is under active area AA of display  14  and/or other metal structures in device  10  may have portions that extend into parts of the ends of device  10  (e.g., the ground may extend towards the dielectric-filled openings in regions  22  and  20 ), thereby narrowing the slots in regions  22  and  20 . 
     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., ends at regions  22  and  20  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 conductive housing structures  12 W may be provided with peripheral gap structures. For example, peripheral conductive housing structures  12 W may be provided with one or more gaps such as gaps  18 , as shown in  FIG. 1 . The gaps in peripheral conductive housing structures  12 W may be filled with dielectric such as polymer, ceramic, glass, air, other dielectric materials, or combinations of these materials. Gaps  18  may divide peripheral conductive housing structures  12 W into one or more peripheral conductive segments. There may be, for example, two peripheral conductive segments in peripheral conductive housing structures  12 W (e.g., in an arrangement with two gaps  18 ), three peripheral conductive segments (e.g., in an arrangement with three gaps  18 ), four peripheral conductive segments (e.g., in an arrangement with four gaps  18 ), six peripheral conductive segments (e.g., in an arrangement with six gaps  18 ), etc. The segments of peripheral conductive housing structures  12 W that are formed in this way may form parts of antennas in device  10  if desired. Other dielectric openings may be formed in peripheral conductive housing structures  12 W (e.g., dielectric openings other than gaps  18 ) and may serve as dielectric antenna windows for antennas mounted within the interior of device  10 . Antennas within device  10  may be aligned with the dielectric antenna windows for conveying radio-frequency signals through peripheral conductive housing structures  12 W. 
     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 conductive housing structures  12 W 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 order to provide an end user of device  10  with as large of a display as possible (e.g., to maximize an area of the device used for displaying media, running applications, etc.), it may be desirable to increase the amount of area at the front face of device  10  that is covered by active area AA of display  14 . Increasing the size of active area AA may reduce the size of inactive area IA within device  10 . This may reduce the area behind display  14  that is available for antennas within device  10 . For example, active area AA of display  14  may include conductive structures that serve to block radio-frequency signals handled by antennas mounted behind active area AA from radiating through the front face of device  10 . It would therefore be desirable to be able to provide antennas that occupy a small amount of space within device  10  (e.g., to allow for as large of a display active area AA as possible) while still allowing the antennas to communicate with wireless equipment external to device  10  with satisfactory efficiency bandwidth. 
     In a typical scenario, device  10  may have one or more upper antennas and one or more lower antennas (as an example). An upper antenna may, for example, be formed at the upper end of device  10  in region  20 . A lower antenna may, for example, be formed at the lower end of device  10  in region  22 . Additional antennas may be formed along the edges of housing  12  extending between regions  20  and  22  if desired. 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, near-field communications, ultra-wideband communications, etc. 
     A schematic diagram of illustrative components that may be used in device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry  28 . Control circuitry  28  may include storage such as storage circuitry  30 . Storage circuitry  30  may include 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. 
     Control circuitry  28  may include processing circuitry such as processing circuitry  32 . Processing circuitry  32  may be used to control the operation of device  10 . Processing circuitry  32  may include on one or more microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, central processing units (CPUs), etc. Control circuitry  28  may be configured to perform operations in device  10  using hardware (e.g., dedicated hardware or circuitry), firmware, and/or software. Software code for performing operations in device  10  may be stored on storage circuitry  30  (e.g., storage circuitry  30  may include non-transitory (tangible) computer readable storage media that stores the software code). The software code may sometimes be referred to as program instructions, software, data, instructions, or code. Software code stored on storage circuitry  30  may be executed by processing circuitry  32 . 
     Control circuitry  28  may be used to run software on device  10  such as external node location applications, satellite navigation applications, internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, control circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol or other WPAN protocols, IEEE 802.1 lad protocols, cellular telephone protocols, MIMO protocols, antenna diversity protocols, satellite navigation system protocols (e.g., global positioning system (GPS) protocols, global navigation satellite system (GLONASS) protocols, etc.), IEEE 802.15.4 ultra-wideband communications protocols or other ultra-wideband communications protocols, etc. Each communications protocol may be associated with a corresponding radio access technology (RAT) that specifies the physical connection methodology used in implementing the protocol. 
     Device  10  may include input-output circuitry  24 . Input-output circuitry  24  may include input-output devices  26 . Input-output devices  26  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  26  may include user interface devices, data port devices, sensors, and other input-output components. For example, input-output devices may include touch screens, displays without touch sensor capabilities, buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, gyroscopes, accelerometers or other components that can detect motion and device orientation relative to the Earth, capacitance sensors, proximity sensors (e.g., a capacitive proximity sensor and/or an infrared proximity sensor), magnetic sensors, and other sensors and input-output components. 
     Input-output circuitry  24  may include wireless circuitry such as wireless circuitry  34  (sometimes referred to herein as wireless communications circuitry  34 ) for wirelessly conveying radio-frequency signals. To support wireless communications, wireless circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas such as antennas  40 , transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     While control circuitry  28  is shown separately from wireless circuitry  34  in the example of  FIG. 2  for the sake of clarity, wireless circuitry  34  may include processing circuitry that forms a part of processing circuitry  32  and/or storage circuitry that forms a part of storage circuitry  30  of control circuitry  28  (e.g., portions of control circuitry  28  may be implemented on wireless circuitry  34 ). As an example, control circuitry  28  (e.g., processing circuitry  32 ) may include baseband processor circuitry or other control components that form a part of wireless circuitry  34 . 
     Wireless circuitry  34  may include radio-frequency transceiver circuitry for handling various radio-frequency communications bands. For example, wireless circuitry  34  may include ultra-wideband (UWB) transceiver circuitry  36  that supports communications using the IEEE 802.15.4 protocol and/or other ultra-wideband communications protocols. Ultra-wideband radio-frequency signals may be based on an impulse radio signaling scheme that uses band-limited data pulses. Ultra-wideband signals may have any desired bandwidths such as bandwidths between 499 MHz and 1331 MHz, bandwidths greater than 500 MHz, etc. The presence of lower frequencies in the baseband may sometimes allow ultra-wideband signals to penetrate through objects such as walls. In an IEEE 802.15.4 system, a pair of electronic devices may exchange wireless time stamped messages. Time stamps in the messages may be analyzed to determine the time of flight of the messages and thereby determine the distance (range) between the devices and/or an angle between the devices (e.g., an angle of arrival of incoming radio-frequency signals). Ultra-wideband transceiver circuitry  36  may operate (i.e., convey radio-frequency signals) in frequency bands such as an ultra-wideband communications band between about 5 GHz and about 8.3 GHz (e.g., a 6.5 GHz frequency band, an 8 GHz frequency band, and/or at other suitable frequencies). 
     As shown in  FIG. 2 , wireless circuitry  34  may also include non-UWB transceiver circuitry  38 . Non-UWB transceiver circuitry  38  may handle communications bands other than UWB communications bands such as 2.4 GHz and 5 GHz bands for Wi-Fi® (IEEE 802.11) communications or communications in other wireless local area network (WLAN) bands, the 2.4 GHz Bluetooth® communications band or other wireless personal area network (WPAN) bands, and/or cellular telephone frequency bands such as a cellular low band (LB) from 600 to 960 MHz, a cellular low-midband (LMB) from 1410 to 1510 MHz, a cellular midband (MB) from 1710 to 2170 MHz, a cellular high band (HB) from 2300 to 2700 MHz, a cellular ultra-high band (UHB) from 3400 to 3600 MHz, or other communications bands between 600 MHz and 4000 MHz or other suitable frequencies (as examples). 
     Non-UWB transceiver circuitry  38  may handle voice data and non-voice data. Wireless circuitry  34  may include circuitry for other short-range and long-range wireless links if desired. For example, wireless circuitry  34  may include 60 GHz transceiver circuitry (e.g., millimeter wave transceiver circuitry), circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. 
     Wireless circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable types of antenna structures. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, dipole antenna structures, monopole antenna structures, hybrids of two or more of these designs, etc. If desired, one or more of antennas  40  may be cavity-backed antennas. 
     Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. Dedicated antennas may be used for conveying radio-frequency signals in a UWB communications band or, if desired, antennas  40  can be configured to convey both radio-frequency signals in a UWB communications band and radio-frequency signals in a non-UWB communications band (e.g., wireless local area network signals and/or cellular telephone signals). Antennas  40  can include two or more antennas for handling ultra-wideband wireless communication. In one suitable arrangement that is described herein as an example, antennas  40  include one or more pairs of antennas (sometimes referred to herein as doublets of antennas) for handling ultra-wideband wireless communication. 
     Space is often at a premium in electronic devices such as device  10 . In order to minimize space consumption within device  10 , the same antenna  40  may be used to cover multiple frequency bands. In one suitable arrangement that is described herein as an example, each antenna  40  that is used to perform ultra-wideband wireless communication may be a multi-band antenna that conveys radio-frequency signals in at least two ultra-wideband communications bands (e.g., the 6.5 GHz band and the 8.0 GHz band). Radio-frequency signals that are conveyed in UWB communications bands (e.g., using a UWB protocol) may sometimes be referred to herein as UWB signals or UWB radio-frequency signals. Radio-frequency signals in frequency bands other than the UWB communications bands (e.g., radio-frequency signals in cellular telephone frequency bands, WPAN frequency bands, WLAN frequency bands, etc.) may sometimes be referred to herein as non-UWB signals or non-UWB radio-frequency signals. 
     A schematic diagram of wireless circuitry  34  is shown in  FIG. 3 . As shown in  FIG. 3 , wireless circuitry  34  may include transceiver circuitry  42  (e.g., UWB transceiver circuitry  36  or non-UWB transceiver circuitry  38  of  FIG. 2 ) that is coupled to a given antenna  40  using a path such as path  50 . 
     To provide antenna structures such as antenna  40  with the ability to cover different frequencies of interest, antenna  40  may be provided with circuitry such as filter circuitry (e.g., one or more passive filters and/or one or more tunable filter circuits). Discrete components such as capacitors, inductors, and resistors may be incorporated into the filter circuitry. Capacitive structures, inductive structures, and resistive structures may also be formed from patterned metal structures (e.g., part of an antenna). If desired, antenna  40  may be provided with adjustable circuits such as tunable components that tune the antenna over communications (frequency) bands of interest. The tunable components 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. 
     Path  50  may include one or more transmission lines. As an example, path  50  of  FIG. 3  may be a transmission line having a positive signal conductor such as line  52  and a ground signal conductor such as line  54 . Path  50  may sometimes be referred to herein as transmission line  50  or radio-frequency transmission line  50 . Line  52  may sometimes be referred to herein as positive signal conductor  52 , signal conductor  52 , signal line conductor  52 , signal line  52 , positive signal line  52 , signal path  52 , or positive signal path  52  of transmission line  50 . Line  54  may sometimes be referred to herein as ground signal conductor  54 , ground conductor  54 , ground line conductor  54 , ground line  54 , ground signal line  54 , ground path  54 , or ground signal path  54  of transmission line  50 . 
     Transmission line  50  may, for example, include a coaxial cable transmission line (e.g., ground conductor  54  may be implemented as a grounded conductive braid surrounding signal conductor  52  along its length), a stripline transmission line, a microstrip transmission line, coaxial probes realized by a metalized via, an edge-coupled microstrip transmission line, an edge-coupled stripline transmission line, a waveguide structure (e.g., a coplanar waveguide or grounded coplanar waveguide), combinations of these types of transmission lines and/or other transmission line structures, etc. 
     Transmission lines in device  10  such as transmission line  50  may be integrated into rigid and/or flexible printed circuit boards. In one suitable arrangement, transmission lines such as transmission line  50  may also include transmission line conductors (e.g., signal conductors  52  and ground conductors  54 ) integrated within multilayer laminated structures (e.g., layers of a conductive material such as copper and a dielectric material such as a resin that are laminated together without intervening adhesive). The multilayer laminated structures may, if desired, be folded or bent in multiple dimensions (e.g., two or three dimensions) and may maintain a bent or folded shape after bending (e.g., the multilayer laminated structures may be folded into a particular three-dimensional shape to route around other device components and may be rigid enough to hold its shape after folding without being held in place by stiffeners or other structures). All of the multiple layers of the laminated structures may be batch laminated together (e.g., in a single pressing process) without adhesive (e.g., as opposed to performing multiple pressing processes to laminate multiple layers together with adhesive). 
     A matching network may include components such as inductors, resistors, and capacitors used in matching the impedance of antenna  40  to the impedance of transmission line  50 . Matching network components may be provided as discrete components (e.g., surface mount technology components) or may be formed from housing structures, printed circuit board structures, traces on plastic supports, etc. Components such as these may also be used in forming filter circuitry in antenna(s)  40  and may be tunable and/or fixed components. 
     Transmission line  50  may be coupled to antenna feed structures associated with antenna  40 . As an example, antenna  40  may form an inverted-F antenna, a slot antenna, a hybrid inverted-F slot antenna or other antenna having an antenna feed  44  with a positive antenna feed terminal such as terminal  46  and a ground antenna feed terminal such as ground antenna feed terminal  48 . Signal conductor  52  may be coupled to positive antenna feed terminal  46  and ground conductor  54  may be coupled to ground antenna feed terminal  48 . Other types of antenna feed arrangements may be used if desired. For example, antenna  40  may be fed using multiple feeds each coupled to a respective port of transceiver circuitry  42  over a corresponding transmission line. If desired, signal conductor  52  may be coupled to multiple locations on antenna  40  (e.g., antenna  40  may include multiple positive antenna feed terminals coupled to signal conductor  52  of the same transmission line  50 ). Switches may be interposed on the signal conductor between transceiver circuitry  42  and the positive antenna feed terminals if desired (e.g., to selectively activate one or more positive antenna feed terminals at any given time). The illustrative feeding configuration of  FIG. 3  is merely illustrative. 
     During operation, device  10  may communicate with external wireless equipment. If desired, device  10  may use radio-frequency signals conveyed between device  10  and the external wireless equipment to identify a location of the external wireless equipment relative to device  10 . Device  10  may identify the relative location of the external wireless equipment by identifying a range to the external wireless equipment (e.g., the distance between the external wireless equipment and device  10 ) and the angle of arrival (AoA) of radio-frequency signals from the external wireless equipment (e.g., the angle at which radio-frequency signals are received by device  10  from the external wireless equipment). 
       FIG. 4  is a diagram showing how device  10  may determine a distance D between device  10  and external wireless equipment such as wireless network node  60  (sometimes referred to herein as wireless equipment  60 , wireless device  60 , external device  60 , or external equipment  60 ). Node  60  may include devices that are capable of receiving and/or transmitting radio-frequency signals such as radio-frequency signals  56 . Node  60  may include tagged devices (e.g., any suitable object that has been provided with a wireless receiver and/or a wireless transmitter), electronic equipment (e.g., an infrastructure-related device), and/or other electronic devices (e.g., devices of the type described in connection with  FIG. 1 , including some or all of the same wireless communications capabilities as device  10 ). 
     For example, node  60  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, headset device (e.g., virtual or augmented reality headset devices), or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, or other small portable device. Node  60  may also be a set-top box, a camera device with wireless communications capabilities, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, or other suitable electronic equipment. Node  60  may also be a key fob, a wallet, a book, a pen, or other object that has been provided with a low-power transmitter (e.g., an RFID transmitter or other transmitter). Node  60  may be electronic equipment such as a thermostat, a smoke detector, a Bluetooth® Low Energy (Bluetooth LE) beacon, a Wi-Fi® wireless access point, a wireless base station, a server, a heating, ventilation, and air conditioning (HVAC) system (sometimes referred to as a temperature-control system), a light source such as a light-emitting diode (LED) bulb, a light switch, a power outlet, an occupancy detector (e.g., an active or passive infrared light detector, a microwave detector, etc.), a door sensor, a moisture sensor, an electronic door lock, a security camera, or other device. Device  10  may also be one of these types of devices if desired. 
     As shown in  FIG. 4 , device  10  may communicate with node  60  using wireless radio-frequency signals  56 . Radio-frequency signals  56  may include Bluetooth® signals, near-field communications signals, wireless local area network signals such as IEEE 802.11 signals, millimeter wave communication signals such as signals at 60 GHz, UWB signals, other radio-frequency wireless signals, infrared signals, etc. In one suitable arrangement that is described herein by example, radio-frequency signals  56  are UWB signals conveyed in multiple UWB communications bands such as the 6.5 GHz and 8 GHz UWB communications bands. Radio-frequency signals  56  may be used to determine and/or convey information such as location and orientation information. For example, control circuitry  28  in device  10  ( FIG. 2 ) may determine the location  58  of node  60  relative to device  10  using radio-frequency signals  56 . 
     In arrangements where node  60  is capable of sending or receiving communications signals, control circuitry  28  ( FIG. 2 ) on device  10  may determine distance D using radio-frequency signals  56  of  FIG. 4 . The control circuitry may determine distance D using signal strength measurement schemes (e.g., measuring the signal strength of radio-frequency signals  56  from node  60 ) or using time-based measurement schemes such as time of flight measurement techniques, time difference of arrival measurement techniques, angle of arrival measurement techniques, triangulation methods, time-of-flight methods, using a crowdsourced location database, and other suitable measurement techniques. This is merely illustrative, however. If desired, the control circuitry may use information from Global Positioning System receiver circuitry, proximity sensors (e.g., infrared proximity sensors or other proximity sensors), image data from a camera, motion sensor data from motion sensors, and/or using other circuitry on device  10  to help determine distance D. In addition to determining the distance D between device  10  and node  60 , the control circuitry may determine the orientation of device  10  relative to node  60 . 
       FIG. 5  illustrates how the position and orientation of device  10  relative to nearby nodes such as node  60  may be determined. In the example of  FIG. 5 , the control circuitry on device  10  (e.g., control circuitry  28  of  FIG. 2 ) uses a horizontal polar coordinate system to determine the location and orientation of device  10  relative to node  60 . In this type of coordinate system, the control circuitry may determine an azimuth angle θ and/or an elevation angle φ to describe the position of nearby nodes  60  relative to device  10 . The control circuitry may define a reference plane such as local horizon  64  and a reference vector such as reference vector  68 . Local horizon  64  may be a plane that intersects device  10  and that is defined relative to a surface of device  10  (e.g., the front or rear face of device  10 ). For example, local horizon  64  may be a plane that is parallel to or coplanar with display  14  of device  10  ( FIG. 1 ). Reference vector  68  (sometimes referred to as the “north” direction) may be a vector in local horizon  64 . If desired, reference vector  68  may be aligned with longitudinal axis  62  of device  10  (e.g., an axis running lengthwise down the center of device  10  and parallel to the longest rectangular dimension of device  10 , parallel to the Y-axis of  FIG. 1 ). When reference vector  68  is aligned with longitudinal axis  62  of device  10 , reference vector  68  may correspond to the direction in which device  10  is being pointed. 
     Azimuth angle θ and elevation angle φ may be measured relative to local horizon  64  and reference vector  68 . As shown in  FIG. 5 , the elevation angle φ (sometimes referred to as altitude) of node  60  is the angle between node  60  and local horizon  64  of device  10  (e.g., the angle between vector  70  extending between device  10  and node  60  and a coplanar vector  66  extending between device  10  and local horizon  64 ). The azimuth angle θ of node  60  is the angle of node  60  around local horizon  64  (e.g., the angle between reference vector  68  and vector  66 ). In the example of  FIG. 5 , the azimuth angle θ and elevation angle φ of node  60  are greater than 0°. 
     If desired, other axes besides longitudinal axis  62  may be used to define reference vector  68 . For example, the control circuitry may use a horizontal axis that is perpendicular to longitudinal axis  62  as reference vector  68 . This may be useful in determining when nodes  60  are located next to a side portion of device  10  (e.g., when device  10  is oriented side-to-side with one of nodes  60 ). 
     After determining the orientation of device  10  relative to node  60 , the control circuitry on device  10  may take suitable action. For example, the control circuitry may send information to node  60 , may request and/or receive information from  60 , may use display  14  ( FIG. 1 ) to display a visual indication of wireless pairing with node  60 , may use speakers to generate an audio indication of wireless pairing with node  60 , may use a vibrator, a haptic actuator, or other mechanical element to generate haptic output indicating wireless pairing with node  60 , may use display  14  to display a visual indication of the location of node  60  relative to device  10 , may use speakers to generate an audio indication of the location of node  60 , may use a vibrator, a haptic actuator, or other mechanical element to generate haptic output indicating the location of node  60 , and/or may take other suitable action. 
     In one suitable arrangement, device  10  may determine the distance between the device  10  and node  60  and the orientation of device  10  relative to node  60  using two or more ultra-wideband antennas. The ultra-wide band antennas may receive radio-frequency signals from node  60  (e.g., radio-frequency signals  56  of  FIG. 4 ). Time stamps in the wireless communication signals may be analyzed to determine the time of flight of the wireless communication signals and thereby determine the distance (range) between device  10  and node  60 . Additionally, angle of arrival (AoA) measurement techniques may be used to determine the orientation of electronic device  10  relative to node  60  (e.g., azimuth angle θ and elevation angle φ). 
     In angle of arrival measurement, node  60  transmits a radio-frequency signal to device  10  (e.g., radio-frequency signals  56  of  FIG. 4 ). Device  10  may measure a delay in arrival time of the radio-frequency signals between the two or more ultra-wideband antennas. The delay in arrival time (e.g., the difference in received phase at each ultra-wideband antenna) can be used to determine the angle of arrival of the radio-frequency signal (and therefore the angle of node  60  relative to device  10 ). Once distance D and the angle of arrival have been determined, device  10  may have knowledge of the precise location of node  60  relative to device  10 . 
       FIG. 6  is a schematic diagram showing how angle of arrival measurement techniques may be used to determine the orientation of device  10  relative to node  60 . As shown in  FIG. 6 , device  10  may include multiple antennas (e.g., a first antenna  40 - 1  and a second antenna  40 - 2 ) coupled to UWB transceiver circuitry  36  over respective transmission lines (e.g., a first transmission line  50 - 1  and a second transmission line  50 - 2 ). 
     Antennas  40 - 1  and  40 - 2  may each receive radio-frequency signals  56  from node  60  ( FIG. 5 ). Antennas  40 - 1  and  40 - 2  may be laterally separated by a distance d 1 , where antenna  40 - 1  is farther away from node  60  than antenna  40 - 2  (in the example of  FIG. 6 ). Therefore, radio-frequency signals  56  travel a greater distance to reach antenna  40 - 1  than antenna  40 - 2 . The additional distance between node  60  and antenna  40 - 1  is shown in  FIG. 6  as distance d 2 .  FIG. 6  also shows angles a and b (where a+b=90°). 
     Distance d 2  may be determined as a function of angle a or angle b (e.g., d 2 =d 1 *sin(a) or d 2 =d 1 *cos(b)). Distance d 2  may also be determined as a function of the phase difference between the signal received by antenna  40 - 1  and the signal received by antenna  40 - 2  (e.g., d 2 =(PD)*λ/(2*π)), where PD is the phase difference (sometimes written “Δϕ”) between the signal received by antenna  40 - 1  and the signal received by antenna  40 - 2 , and h is the wavelength of radio-frequency signals  56 . Device  10  may include phase measurement circuitry coupled to each antenna to measure the phase of the received signals and to identify phase difference PD (e.g., by subtracting the phase measured for one antenna from the phase measured for the other antenna). The two equations for d 2  may be set equal to each other (e.g., d 1 *sin(a)=(PD)*λ/(2*π)) and rearranged to solve for the angle a (e.g., a=sin −1 ((PD)*λ/(2*π*d 1 )) or the angle b. Therefore, the angle of arrival may be determined (e.g., by control circuitry  28  of  FIG. 2 ) based on the known (predetermined) distance d 1  between antennas  40 - 1  and  40 - 2 , the detected (measured) phase difference PD between the signal received by antenna  40 - 1  and the signal received by antenna  40 - 2 , and the known wavelength (frequency) of the received radio-frequency signals  56 . Angles a and/or b of  FIG. 6  may be converted to spherical coordinates to obtain azimuth angle θ and elevation angle φ of  FIG. 5 , for example. Control circuitry  28  ( FIG. 2 ) may determine the angle of arrival of radio-frequency signals  56  by calculating one or both of azimuth angle θ and elevation angle φ. 
     Distance d 1  may be selected to ease the calculation for phase difference PD between the signal received by antenna  40 - 1  and the signal received by antenna  40 - 2 . For example, d 1  may be less than or equal to one half of the wavelength (e.g., effective wavelength) of the received radio-frequency signals  56  (e.g., to avoid multiple phase difference solutions). 
     With two antennas for determining angle of arrival (as in  FIG. 6 ), the angle of arrival within a single plane may be determined. For example, antennas  40 - 1  and  40 - 2  in  FIG. 6  may be used to determine azimuth angle θ of  FIG. 5 . A third antenna may be included to enable angle of arrival determination in multiple planes (e.g., azimuth angle θ and elevation angle φ of  FIG. 5  may both be determined). 
     Antennas  40 - 1  and  40 - 2  may be referred to collectively herein as a doublet  72  of antennas  40 . Doublets  72  of antennas  40  may be used to determine angle of arrival within a single plane (e.g., to determine one of azimuth angle θ or elevation angle φ of  FIG. 5 ). If desired, three antennas  40  may be arranged in a triplet of antennas (e.g., where each antenna is arranged to lie on a respective corner of a right triangle). Triplets of antennas  40  may be used to determine angle of arrival in two planes (e.g., to determine both azimuth angle θ and elevation angle φ of  FIG. 5 ). In electronic devices such as device  10 , where space is at a premium, doublets of antennas may be placed at a greater number of potential locations in device  10  than triplets of antennas (e.g., because triplets of antennas occupy more space than doublets of antennas). If desired, different doublets of antennas may be oriented orthogonally with respect to each other in device  10  to recover angle of arrival in two dimensions (e.g., using two or more orthogonal doublets of antennas  40  that each measure angle of arrival in a single respective plane). 
     Any desired antenna structures may be used for implementing antennas  40 - 1  and  40 - 2  of  FIG. 6 . In one suitable arrangement that is sometimes described herein as an example, slot antenna structures may be used for implementing antennas  40 - 1  and  40 - 2 . Antennas that are implemented using slot antenna structures may sometimes be referred to herein as slot antennas. The slot antennas may be configured to radiate in multiple UWB communications bands (e.g., the 6.5 GHz UWB band and the 8.0 GHz UWB band). An illustrative slot antenna that radiates in multiple UWB communications bands is shown in  FIG. 7 . 
     As shown in  FIG. 7 , antenna  40  (e.g., a given one of antennas  40 - 1  and  40 - 2  of  FIG. 6 ) may include a conductive structure such as structure  74  that has been provided with dielectric-filled openings such as dielectric opening  76  and dielectric opening  78 . Openings such as openings  76  and  78  of  FIG. 5  are sometimes referred to as slots, slot elements, slot radiating elements, slot resonating elements, or slot antenna resonating elements of antenna  40 . In the configuration of  FIG. 7 , slots  76  and  78  are both closed slots, because portions of conductive structure  74  completely surround and enclose slots  76  and  78 . Open slot antenna structures may also be formed in conductive materials such as conductive structure  74  (e.g., by forming an opening in the right-hand left-hand end of conductive structure  74  so that slots  76  and/or  78  protrude through conductive structure  74 ). Slots  76  and  78  may be parallel slots that extend along parallel longitudinal axes. Forming antenna  40  with two slots  76  and  78  may allow antenna  40  to exhibit response peaks in multiple frequency (communications) bands. If desired, antenna  40  may include only slot  76  (e.g., slot  78  may be omitted). In this scenario, antenna  40  may cover only a single frequency band (e.g., a single UWB communications band). 
     As shown in  FIG. 7 , antenna  40  may be feed using antenna feed  44  coupled across slot  76 . In particular, positive antenna feed terminal  46  and ground antenna feed terminal  48  of antenna feed  44  may be coupled to opposing sides of slot  76  along the length  80  of slot  76 . Antenna current I may flow between antenna feed terminals  46  and  48  around the perimeter of slot  76 . Corresponding radio-frequency signals may be radiated by slot  76 . Similarly, radio-frequency signals received by antenna  40  may produce antenna currents I around slot  76 . 
     Antenna feed  44  may be coupled across slot  76  at a distance from the left or right edge (side) of slot  76  that is selected to match the impedance of antenna  40  to the impedance of the corresponding transmission line (e.g., transmission line  50  of  FIG. 3 ). For example, antenna current I flowing around slot  76  may experience an impedance of zero at the left and right edges of slot  76  (e.g., a short circuit impedance) and an infinite (open circuit) impedance at the center of slot  76  (e.g., at a fundamental frequency of the slot). Antenna feed  44  may be located between the center of slot  76  and one of the left or right edges at a location where antenna current I experiences an impedance that matches the impedance of the corresponding transmission line (e.g., 50 Ohms). 
     In scenarios where slot  76  is a closed slot, length  80  may be approximately equal to (e.g., within 15% of) one-half of a first wavelength of operation of the antenna (e.g., a wavelength corresponding to a frequency in a first UWB communications band). Harmonic modes of slot  76  may also be configured to cover desired frequency bands. In scenarios where slot  76  is an open slot, the length of slot  76  may be approximately equal to one-quarter of the first wavelength of operation of the antenna. The first wavelength of operation may, for example, be an effective wavelength of operation that is modified from a free-space wavelength by a constant value that is determined by the dielectric material within slot  76 . 
     Antenna current I may parasitically excite antenna current I′ to flow around the perimeter of slot  78  (e.g., slot  76  may serve as an indirect antenna feed for slot  78  and may indirectly feed slot  78  via near-field electromagnetic coupling  86 , whereas slot  76  is directly fed by antenna feed  44 ). While slot  76  has a length  80  that configures slot  76  to radiate radio-frequency signals in a first UWB communications band, slot  78  may have a length  82  that configures slot  78  to radiate radio-frequency signals in a second UWB communications band. Length  82  may be approximately equal to one-half of a second wavelength of operation of the antenna (e.g., a wavelength corresponding to a frequency in the second UWB communications band). The second UWB communications band may include lower frequencies than the first UWB communications band covered by slot  76  (e.g., because length  82  is greater than length  80 ). As one example, length  80  may be selected so that slot  76  radiates in the 8.0 GHz UWB band and length  82  may be selected so that slot  78  radiates in the 6.5 GHz UWB band (e.g., so that antenna  40  radiates with antenna efficiencies greater than a minimum threshold efficiency in both the 6.5 GHz and 8.0 GHz UWB bands). 
     The frequency response of slot  78  can be tuned using one or more tuning components. For example, as shown in  FIG. 7 , a tuning component such as capacitor  84  may be coupled across slot  78 . Capacitor  84  may have terminals that are coupled to conductive structure  74  at opposing sides of slot  78 . Capacitor  84  may serve to lower the resonating frequency of slot  78  so that length  82  is shorter than one-half of the second wavelength of operation of antenna  40 . This may, for example, serve to minimize the space within device  10  occupied by antenna  40 . Capacitor  84  may also perform impedance matching functions for antenna  40 . The example of  FIG. 7  is merely illustrative. Other components such as inductors may be coupled across slot  78 . One or more tuning components such as inductors and/or capacitors may be coupled across slot  76 . Slots  76  and  78  may have any other desired shapes (e.g., shapes having curved and/or straight edges, shapes following meandering paths, shapes following paths having multiple branches, etc.) 
     By using slot  76  to indirectly feed slot  78 , antenna  40  may cover both the 6.5 GHz UWB band and the 8.0 UWB band with satisfactory antenna efficiency and without requiring an additional set of antenna feed terminals to feed slot  78 . This may allow antenna  40  to be fed using only a single transmission line (e.g., the transmission line coupled to antenna feed  44 ), thereby minimizing the routing complexity required to feed antenna  40  and the amount of space required to implement antenna  40  within device  10 . If desired, antenna  40  may be a cavity-backed antenna having a conductive cavity located behind slots  76  and  78 . The conductive cavity may help to shield antenna  40  from electromagnetic interference with other components in device  10  and may help to optimize the uniformity of the radiation pattern for antenna  40 . 
       FIG. 8  is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency for antenna  40  of  FIG. 7 . As shown in  FIG. 8 , curve  88  plots an exemplary antenna efficiency of antenna  40 . As shown by curve  88 , antenna  40  may exhibit a first response peak  90  at frequency F 1 . Frequency F 1  may lie in the UWB communications band covered by slot  78  of  FIG. 7  (e.g., slot  78  may produce peak  90  of curve  88 ). Antenna  40  may exhibit a second response peak  92  at frequency F 2 . Frequency F 2  may lie in the UWB communications band covered by slot  76  of  FIG. 7  (e.g., slot  76  may produce peak  92  of curve  88 ). Frequencies F 1  and F 2  may lie within any desired UWB communications bands. For example, frequency F 1  may be 6.5 GHz whereas frequency F 2  is 8.0 GHz. 
     The example of  FIG. 8  is merely illustrative. In general, curve  88  may have other shapes if desired (e.g., response peaks  90  and  92  may lie at any desired frequencies and may have other bandwidths). Antenna  40  may cover more than two UWB communications bands if desired (e.g., antenna  40  may include any desired number of slots such as three slots, four slots, more than four slots, etc.). 
     Multiple doublets of antennas (e.g., doublets such as doublet  72  of  FIG. 6 ) may be located at different locations on device  10 .  FIG. 9  is a top view of device  10  showing different illustrative locations for forming multiple doublets of antennas. As shown in  FIG. 9 , device  10  may include peripheral conductive housing structures  12 W (e.g., four peripheral conductive housing sidewalls that surround the rectangular periphery of device  10 ). Display  14  may have a display module such as display module  94 . Peripheral conductive housing structures  12 W may run around the periphery of display module  94  (e.g., along all four sides of device  10 ). Display module  94  may be covered by a display cover layer (not shown). The display cover layer may extend across the entire length and width of device  10  and may, if desired, be mounted to or otherwise supported by peripheral conductive housing structures  12 W. 
     Display module  94  (sometimes referred to as a display panel, active display circuitry, or active display structures) may be any desired type of display panel and 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. The lateral area of display module  94  may, for example, determine the size of the active area of display  14  (e.g., active area AA of  FIG. 1 ). Display module  94  may include active light emitting components, touch sensor components (e.g., touch sensor electrodes), force sensor components, and/or other active components. Because display module  94  includes conductive components, display module  94  may serve to block radio-frequency signals from passing through display  14 . Doublets of antennas may therefore be located within regions  96  around the periphery of display module  94  and device  10 . Each region  96  of  FIG. 9  may, for example, include a corresponding doublet  72  of antennas  40 - 1  and  40 - 2  ( FIG. 6 ). Dielectric antenna windows may be formed within peripheral conductive housing structures  12 W within regions  96  to allow the doublets of antennas in regions  96  to convey radio-frequency signals with the exterior of device  10 . 
     In the example of  FIG. 9 , each region  96  is located along a respective side (edge) of device  10 . This may allow the doublets of antennas to collectively cover all angles around device  10  (e.g., a full sphere around device  10 ). The doublet of antennas within each region  96  may receive radio-frequency signals that are used to identify angle of arrival within a single corresponding plane (e.g., to identify one of azimuth angle θ or an elevation angle φ of  FIG. 5 ). The doublets of antennas along the top and bottom edges of device  10  may be oriented perpendicular to the doublets of antennas along the left and right edges of device  10 . The doublets of antennas in each region  96  may therefore be used to collectively obtain angle of arrival within two orthogonal planes (e.g., to determine both azimuth angle θ and elevation angle φ of  FIG. 5 ). The example of  FIG. 9  is merely illustrative. Each edge of device  10  may include multiple regions  96  and some edges of device  10  may include no regions  96 . If desired, additional regions  96  may be located elsewhere on device  10  (e.g., for radiating through the front face of device  10  such as through inactive area IA of  FIG. 1 , for radiating through the rear face of device  10 , etc.). 
       FIG. 10  is a perspective view showing how one doublet of antennas may be mounted within a corresponding region  96  of device  10  (e.g., the bottom-right region  96  of  FIG. 9 ). As shown in  FIG. 10 , peripheral conductive housing structures  12 W may include a dielectric antenna window  98  that overlaps a given doublet  72  (e.g., antennas  40 - 1  and  40 - 2  of doublet  72  may be aligned with dielectric antenna window  98 ). Dielectric antenna window  98  may be filled with dielectric material such as plastic, ceramic, glass, or other dielectrics that serve to protect antennas  40 - 1  and  40 - 2  from damage and to hide antennas  40 - 1  and  40 - 2  from view. 
     Antennas  40 - 1  and  40 - 2  in doublet  72  may each include a corresponding slot  76  (e.g., for covering the 6.5 GHz UWB band) and a corresponding slot  78  (e.g., for covering the 8.0 GHz UWB band) in conductive structure  74 . The antenna feeds across slot  76  in antennas  40 - 1  and  40 - 2  are omitted from the example of  FIG. 10  for the sake of clarity. Slot  78  in antennas  40 - 1  and  40 - 2  may receive radio-frequency signals in the 6.5 GHz communications band through dielectric antenna window  98 . Slot  76  in antennas  40 - 1  and  40 - 2  may receive radio-frequency signals in the 8.0 GHz communications band through dielectric antenna window  98 . The received radio-frequency signals may be processed (e.g., by control circuitry  28  of  FIG. 2 ) to identify an angle of arrival of the received radio-frequency signals (e.g., within the X-Y plane of  FIG. 10 ). Antennas  40 - 1  and  40 - 2  may exhibit relatively uniform radiation patterns despite the presence of display  14  and rear housing wall  12 R. This may, for example, allow doublet  72  to receive radio-frequency signals for identifying angle of arrival even in scenarios where device  10  is placed face-down or face-up on an external object such as a table top. 
       FIG. 11  is a cross-sectional side view of doublet  72  within device  10  (e.g., as taken along line AA′ of  FIG. 10 ). Only antenna  40 - 1  of doublet  72  is shown in the cross-sectional side view of  FIG. 11 . However, similar structures may also be used in forming antenna  40 - 2  of doublet  72 . 
     As shown in  FIG. 11 , peripheral conductive housing structures  12 W may extend from rear housing wall  12 R (e.g., a conductive rear housing wall) to display  14 . Display  14  may include display module  94  and a display cover layer such as display cover layer  100  overlapping display module  94 . Display cover layer  100  may be formed from glass, sapphire, or other dielectric materials. Display cover layer  100  may be mounted to ledge (datum)  104  of peripheral conductive housing structures  12 W. If desired, peripheral conductive housing structures  12 W may include a raised lip that extends around the peripheral edges of display cover layer  100 . A layer of adhesive, brackets, or other interconnect structures (not shown) may be used to help secure display cover layer  100  to peripheral conductive housing structures  12 W. 
     As shown in  FIG. 11 , doublet  72  may include dielectric substrate  110  and conductive traces  114  on dielectric substrate  110  (sometimes referred to herein as antenna carrier  110 ). Conductive traces  114  may form conductive structure  74  of  FIGS. 7 and 10 . Dielectric substrate  110  may be formed from dielectric materials such as plastic (e.g., molded plastic). The plastic material that forms dielectric substrate  110  may be provided with metal particles or other filler material that sensitizes dielectric substrate  110  to exposure from laser light. Following exposure to laser light, portions of dielectric substrate  110  that have been exposed to laser light will promote coating with electroplated metal, whereas portions of dielectric substrate  110  that have not been exposed to laser light will not promote electroplating metal growth. With this approach, which may sometimes be referred to as laser direct structuring (LDS), metal structures such as conductive traces  114  may be deposited using electroplating. Conductive traces  114  may be patterned to form slots  76  and  78  for antenna  40 - 1 . This example is merely illustrative. If desired, some or all of conductive traces  114  may be replaced with metal foil, sheet metal, metal traces on a flexible printed circuit, metal portions of electronic components within device  10 , or other conductive structures (e.g., conductive structures used to form conductive structure  74  of  FIGS. 7 and 10 ). 
     Conductive traces  114  may be formed on one or more (e.g., all) sides of dielectric substrate  110 . Conductive traces  114  may be coupled to rear housing wall  12 R and/or peripheral conductive housing structures  12 W if desired (e.g., using solder, welds, conductive adhesive, etc.). If desired, a conductive interconnect structure such as conductive tape  116  may be used to couple conductive traces  114  to rear housing wall  12 R. Conductive tape  116  may include conductive adhesive that adheres the conductive tape to conductive traces  114  and rear housing wall  12 R. Solder and/or welds may also be used to couple conductive tape  116  to rear housing wall  12 R and/or conductive traces  114 . Rear housing wall  12 R may be held at a ground potential. In this way, conductive tape  116  may serve to ground conductive traces  114  to rear housing wall  12 R. Rear housing wall  12 R, conductive tape  116 , ledge  104 , and/or conductive traces  114  may surround and enclose dielectric substrate  110  (e.g., on all sides of the substrate) to form an antenna cavity such as antenna cavity  112  that backs slots  76  and  78 . Rear housing wall  12 R, conductive tape  116 , ledge  104 , and/or conductive traces  114  may serve to shield antenna  40 - 1  from electromagnetic interference with other components  102  within the interior of device  10 . 
     As shown in  FIG. 11 , dielectric antenna window  98  may be formed in peripheral conductive housing structures  12 W and may overlap slots  76  and  78 . Dielectric antenna window  98  may be filled with dielectric material  106 . A dielectric coating  108  may also cover dielectric antenna window  98 . Dielectric material  106  may be omitted, if desired, in scenarios where dielectric coating  108  covers dielectric antenna window  98 . Dielectric material  106  and dielectric coating  108  may include plastic, ceramic, glass, and/or any other desired material that is transparent to radio-frequency signals. If desired, dielectric material  106  and/or dielectric coating  108  may be provided with pigment or ink that configure dielectric material  106  and/or dielectric coating  108  to be optically opaque (e.g., to hide the interior of device  10  from view). Additional masking layers such as one or more ink layers may also be provided to hide the antennas within device  10  from view. 
     Slots  76  and  78  may transmit and receive radio-frequency signals  56  through dielectric antenna window  98 . Antenna cavity  112  may serve to boost the antenna efficiency and gain for antenna  40 - 1  through dielectric antenna window  98 . Antenna cavity  112  may also serve to optimize uniformity of the radiation pattern of antenna  40 - 1 . The example of  FIG. 11  is merely illustrative. In general, dielectric substrate  110  may have other shapes (e.g., shapes that accommodate the presence of other components within device  10 ). Similar structures may be used to form antenna  40 - 2  of doublet  72  (as shown in  FIGS. 6 and 10 ). Both antennas  40 - 1  and  40 - 2  in doublet  72  may share the same dielectric substrate  110 , antenna cavity  112 , conductive tape  116 , and conductive traces  114 . 
     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: 20190208
Publication Date: 20201027
Grant Date: 20201027
Priority Date: 20190208
Inventors: AMIRI, MIKAL ASKARIAN
DI NALLO, CARLO
Garrido Lopez, David
RAJAGOPALAN, HARISH
Kammersgaard, Nikolaj P.
GOMEZ ANGULO, RODNEY A.
AZAD, Umar
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/106", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q13/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/25", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/378", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q25/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/25", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 71945446