PATENT DOCUMENT

Publication Number: US-11990687-B2
Application Number: US-202217867504-A
Country: US
Kind Code: B2

Title: Ultra-wideband antenna having fed and unfed arms

Abstract:
An electronic device may include an antenna disposed on a substrate. The antenna may include a ring of conductive traces, a fed arm, and an unfed arm. The fed arm and the unfed arm may extend from opposing segments of the ring. The ring may be coupled to ground by fences of conductive vias extending through the substrate. The first arm may have a first radiating edge. The second arm may have a second radiating edge. The first radiating edge may be separated from the second radiating edge by a gap. The first arm may indirectly feed the second arm via near-field electromagnetic coupling across the gap. The first and second arms may collectively radiate in an ultra-wideband (UWB) frequency band.

Claims:
What is claimed is: 
     
       1. An antenna comprising:
 a ring of conductive traces having first and second segments; 
 a fed arm having a first end that contacts the first segment and having a first radiating edge opposite the first end; 
 an antenna feed terminal coupled to the fed arm; and 
 an unfed arm having a second end that contacts the second segment and having a second radiating edge opposite the second end. 
 
     
     
       2. The antenna of  claim 1 , wherein the first radiating edge is separated from the second radiating edge by a gap. 
     
     
       3. The antenna of  claim 2 , wherein the fed arm is configured to indirectly feed the unfed arm via near-field electromagnetic coupling across the gap. 
     
     
       4. The antenna of  claim 3 , wherein the first radiating edge extends parallel to the second radiating edge. 
     
     
       5. The antenna of  claim 2 , wherein the fed arm has first and second edges that extend from the first end to the first radiating edge and the unfed arm has third and fourth edges that extend from the second end to the second radiating edge. 
     
     
       6. The antenna of  claim 5 , wherein the first, second, third, and fourth edges extend parallel to each other. 
     
     
       7. The antenna of  claim 1 , wherein the ring of conductive traces has a third segment that couples the first segment to the second segment and has a fourth segment opposite the third segment that couples the first segment to the second segment. 
     
     
       8. The antenna of  claim 7 , wherein the first radiating edge is separated from the second radiating edge by a first gap, the fed arm and the unfed arm are separated from the third segment by a second gap, and the fed arm and the unfed arm are separated from the fourth segment by a third gap, and the first gap couples the second gap to the third gap. 
     
     
       9. The antenna of  claim 1 , further comprising:
 ground traces; 
 a first fence of conductive vias that couple the ground traces to the first segment; and 
 a second fence of conductive vias that couple the ground traces to the second segment. 
 
     
     
       10. An antenna comprising:
 a substrate having a surface; 
 a ring of conductive traces disposed on the surface; 
 an arm disposed on the surface and extending from the ring of conductive traces; 
 an antenna feed coupled to the arm; and 
 a parasitic disposed on the surface and extending from the ring of conductive traces opposite the arm, wherein the arm is configured to indirectly feed the parasitic via near-field electromagnetic coupling. 
 
     
     
       11. The antenna of  claim 10 , wherein the arm extends from the ring of conductive traces to a first edge, the parasitic extends from the ring of conductive traces to a second edge, and the first edge is separated from the second edge by a slot. 
     
     
       12. The antenna of  claim 10 , further comprising:
 ground traces on the substrate; and 
 fences of conductive vias that extend through the substrate and that couple the ring of conductive traces to the ground traces. 
 
     
     
       13. The antenna of  claim 12 , wherein the fences of conductive vias comprise a first fence of conductive vias that couples the arm to the ground traces and a second fence of conductive vias that couples the parasitic to the ground traces. 
     
     
       14. An electronic device comprising:
 a substrate; 
 a first antenna arm on the substrate; 
 a radio-frequency transmission line path coupled to the first antenna arm at an antenna feed terminal; 
 a second antenna arm on the substrate, wherein the second antenna arm is separated from the first antenna arm by a slot and is indirectly fed by the first antenna arm, the first and second antenna arms being configured to radiate in a frequency band; 
 ground traces; 
 first conductive vias that couple the first arm to the ground traces through the substrate; and 
 second conductive vias that couple the second arm to the ground traces through the substrate. 
 
     
     
       15. The electronic device of  claim 14 , further comprising a ring of conductive traces on the substrate, the first and second antenna arms being coupled to the ring of conductive traces. 
     
     
       16. The electronic device of  claim 14 , further comprising:
 a flexible printed circuit, wherein the substrate is mounted to the flexible printed circuit. 
 
     
     
       17. The electronic device of  claim 1 , further comprising:
 a ground trace; and 
 a conductive via that couples the ring of conductive traces to the ground trace. 
 
     
     
       18. The electronic device of  claim 10 , further comprising:
 a ground trace; and 
 a conductive via that couples the ring of conductive traces to the ground trace. 
 
     
     
       19. The antenna of  claim 10 , wherein the arm is directly connected to the ring of conductive traces. 
     
     
       20. The antenna of  claim 10 , wherein the arm and the parasitic comprise conductive traces on the surface.

Description:
BACKGROUND 
     This disclosure relates generally to electronic devices and, more particularly, to electronic devices with wireless communications capabilities. 
     Electronic devices such as portable computers and cellular telephones are often provided with wireless communications capabilities. To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to implement wireless communications circuitry such as antenna components using compact structures. At the same time, there is a desire for wireless devices to cover a growing number of communications bands. 
     Because antennas have the potential to interfere with each other and with components in a wireless device, care must be taken when incorporating antennas into an electronic device. Moreover, care must be taken to ensure that the antennas and wireless circuitry in a device are able to exhibit satisfactory performance over a range of operating frequencies and with satisfactory efficiency bandwidth. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry. The wireless circuitry may include antennas. One of the antennas may be disposed on a substrate. The substrate may be mounted to a flexible printed circuit. The antenna may include a ring of conductive traces on the substrate. The antenna may have an antenna resonating element. The antenna resonating element may have a first arm coupled to a first segment of the ring. The ring may be coupled to ground traces by fences of conductive vias. 
     The antenna resonating element may have a second arm coupled to a second segment of the ring opposite the first arm. The first arm may be fed by a radio-frequency transmission line path at an antenna feed terminal. The second arm may be unfed and is not coupled to a radio-frequency transmission line path. The first arm may have a first radiating edge. The second arm may have a second radiating edge. The first radiating edge may be separated from the second radiating edge by a gap. The first arm may indirectly feed the second arm via near-field electromagnetic coupling across the gap. The first and second arms may collectively radiate in an ultra-wideband (UWB) frequency band. 
    
    
     
       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 cross-sectional side view showing how an illustrative ultra-wideband may be mounted within an opening in a conductive support plate in accordance with some embodiments. 
         FIG.  7    is a schematic diagram of illustrative inverted-F antenna structures that may be used to form an ultra-wideband antenna in accordance with some embodiments. 
         FIG.  8    is a bottom view of an illustrative ultra-wideband antenna having fed and unfed arms in accordance with some embodiments. 
         FIG.  9    is a cross-sectional side view of an illustrative ultra-wideband antenna having fed and unfed arms in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG.  1    may be provided with wireless circuitry that includes antennas. The antennas may be used to transmit and/or receive wireless radio-frequency signals. 
     Device  10  may be a portable electronic device or other suitable electronic device. For example, 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, headset 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 (e.g., a dielectric cover layer). 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 materials. 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. Conductive portions of 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). In other words, device  10  may have a length (e.g., measured parallel to the Y-axis), a width that is less than the length (e.g., measured parallel to the X-axis), and a height (e.g., measured parallel to the Z-axis) that is less than the width. 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, alloys, 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 ledge 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/cover 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 of display  14  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. Inactive area IA may include a recessed region such as a notch that extends into active area AA. Active area AA may, for example, be defined by the lateral area of a display module for display  14  (e.g., a display module that includes pixel circuitry, touch sensor circuitry, etc.). The display module may have a recess or notch in upper region  20  of device  10  that is free from active display circuitry (i.e., that forms the notch of inactive area IA). The notch may be a substantially rectangular region that is surrounded (defined) on three sides by active area AA and on a fourth side by peripheral conductive housing structures  12 W. 
     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  in the notch 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 conductive support plate or backplate) that spans the walls of housing  12  (e.g., a substantially rectangular sheet formed from one or more metal parts that is welded or otherwise connected between opposing sides of peripheral conductive housing structures  12 W). The conductive support plate may form an exterior rear surface of device  10  or may be covered by a dielectric cover layer such as a thin cosmetic layer, protective coating, 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 conductive support plate from view of the user (e.g., the conductive support plate may form part of rear housing wall  12 R). 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 . Region  22  may sometimes be referred to herein as lower region  22  or lower end  22  of device  10 . Region  20  may sometimes be referred to herein as upper region  20  or upper end  20  of device  10 . 
     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 lower region  22  and/or upper region  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 dielectric-filled 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. The conductive segments 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. Antennas within device  10  may also be aligned with inactive area IA of display  14  for conveying radio-frequency signals through display  14 . 
     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. An upper antenna may, for example, be formed in upper region  20  of device  10 . A lower antenna may, for example, be formed in lower region  22  of device  10 . Additional antennas may be formed along the edges of housing  12  extending between regions  20  and  22  if desired. An example in which device  10  includes three or four upper antennas and five lower antennas is described herein as an example. 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. Other antennas for covering any other desired frequencies may also be mounted at any desired locations within the interior of device  10 . The example of  FIG.  1    is merely illustrative. If desired, housing  12  may have other shapes (e.g., a square shape, cylindrical shape, spherical shape, combinations of these and/or different shapes, 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 processors such as microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, central processing units (CPUs), graphics processing units, 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 internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, control circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  28  include internet protocols, wireless local area network (WLAN) protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol or other wireless personal area network (WPAN) protocols, IEEE 802.11ad protocols (e.g., ultra-wideband protocols), cellular telephone protocols (e.g., 3G protocols, 4G (LTE) protocols, 3GPP Fifth Generation (5G) New Radio (NR) protocols, etc.), antenna diversity protocols, satellite navigation system protocols (e.g., global positioning system (GPS) protocols, global navigation satellite system (GLONASS) protocols, etc.), antenna-based spatial ranging protocols, or any other desired communications protocols. Each communication 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  for wirelessly conveying radio-frequency signals. 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  may include baseband processor circuitry (e.g., one or more baseband processors) or other control components that form a part of wireless circuitry  34 . 
     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, transmission lines, and other circuitry for handling RF wireless signals (e.g., one or more RF front end modules, etc.). Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless circuitry  34  may include radio-frequency transceiver circuitry for handling transmission and/or reception of radio-frequency signals within corresponding frequency bands at radio frequencies (sometimes referred to herein as communications bands or simply as “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 8.5 GHz (e.g., a 6.5 GHz UWB communications band, an 8 GHz UWB communications 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 wireless local area network (WLAN) frequency bands (e.g., Wi-Fi® (IEEE 802.11) or other WLAN communications bands) including a 2.4 GHz WLAN band (e.g., from 2400 to 2480 MHz), a 5 GHz WLAN band (e.g., from 5180 to 5825 MHz), a Wi-Fi® 6E band (e.g., from 5925-7125 MHz), and/or other Wi-Fi® bands (e.g., from 1875-5160 MHz), wireless personal area network (WPAN) frequency bands including the 2.4 GHz Bluetooth® band or other WPAN communications bands, cellular telephone frequency bands (e.g., bands from about 600 MHz to about 5 GHz, 3G bands, 4G LTE bands, 5G New Radio Frequency Range 1 (FR1) bands below 10 GHz, 5G New Radio Frequency Range 2 (FR2) bands between 20 and 60 GHz, etc.), other centimeter or millimeter wave frequency bands between 10-300 GHz, near-field communications frequency bands (e.g., at 13.56 MHz), satellite navigation frequency bands (e.g., a GPS band from 1565 to 1610 MHz, a Global Navigation Satellite System (GLONASS) band, a BeiDou Navigation Satellite System (BDS) band, etc.), communications bands under the family of 3GPP wireless communications standards, communications bands under the IEEE 802.XX family of standards, industrial, scientific, and medical (ISM) bands such as an ISM band between around 900 MHz and 950 MHz or other ISM bands below or above 1 GHz, one or more unlicensed bands, one or more bands reserved for emergency and/or public services, and/or any other desired frequency bands of interest. Non-UWB transceiver circuitry  38  may also be used to perform spatial ranging operations if desired. 
     UWB transceiver circuitry  36  and non-UWB transceiver circuitry  38  may include respective transceivers (e.g., transceiver integrated circuits or chips) that handle each of these frequency bands or any desired number of transceivers that handle two or more of these frequency bands. In scenarios where different transceivers are coupled to the same antenna, filter circuitry (e.g., duplexer circuitry, diplexer circuitry, low pass filter circuitry, high pass filter circuitry, band pass filter circuitry, band stop filter circuitry, etc.), switching circuitry, multiplexing circuitry, or any other desired circuitry may be used to isolate radio-frequency signals conveyed by each transceiver over the same antenna (e.g., filtering circuitry or multiplexing circuitry may be interposed on a radio-frequency transmission line shared by the transceivers). The transceiver circuitry may include one or more integrated circuits (chips), integrated circuit packages (e.g., multiple integrated circuits mounted on a common printed circuit in a system-in-package device, one or more integrated circuits mounted on different substrates, etc.), power amplifier circuitry, up-conversion circuitry, down-conversion circuitry, low-noise input amplifiers, passive radio-frequency components, switching circuitry, transmission line structures, and other circuitry for handling radio-frequency signals and/or for converting signals between radio-frequencies, intermediate frequencies, and/or baseband frequencies. 
     As shown in  FIG.  2   , wireless circuitry  34  may include antennas  40 . UWB transceiver circuitry  36  and non-UWB transceiver circuitry  38  may convey radio-frequency signals using one or more antennas  40  (e.g., antennas  40  may convey the radio-frequency signals for the transceiver circuitry). The term “convey radio-frequency signals” as used herein means the transmission and/or reception of the radio-frequency signals (e.g., for performing unidirectional and/or bidirectional wireless communications with external wireless communications equipment). Antennas  40  may transmit the radio-frequency signals by radiating the radio-frequency signals into free space (or to freespace through intervening device structures such as a dielectric cover layer). Antennas  40  may additionally or alternatively receive the radio-frequency signals from free space (e.g., through intervening devices structures such as a dielectric cover layer). The transmission and reception of radio-frequency signals by antennas each involve the excitation or resonance of antenna currents on an antenna resonating element in the antenna by the radio-frequency signals within the frequency band(s) of operation of the antenna. 
     Antennas  40  in wireless circuitry  34  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from stacked patch antenna structures, loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, waveguide structures, monopole antenna structures, dipole antenna structures, helical antenna structures, Yagi (Yagi-Uda) antenna structures, hybrids of these designs, etc. In another suitable arrangement, antennas  40  may include antennas with dielectric resonating elements such as dielectric resonator antennas. If desired, one or more of antennas  40  may be cavity-backed antennas. Two or more antennas  40  may be arranged in a phased antenna array if desired (e.g., for conveying centimeter and/or millimeter wave signals). Different types of antennas may be used for different bands and combinations of bands. In one suitable arrangement that is described herein as an example, antennas  40  include a UWB antenna having a fed arm (e.g., a planar inverted-F antenna arm) and an un-fed arm (e.g., a grounded planar arm or parasitic arm). 
     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 radio-frequency transmission line path such as radio-frequency transmission line 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. 
     Radio-frequency transmission line path  50  may include one or more radio-frequency transmission lines (sometimes referred to herein simply as transmission lines). Radio-frequency transmission line path  50  (e.g., the transmission lines in radio-frequency transmission line path may include a positive signal conductor such as positive signal conductor  52  and a ground signal conductor such as ground conductor  54 . 
     The transmission lines in radio-frequency transmission line path  50  may, for example, include coaxial cable transmission lines (e.g., ground conductor  54  may be implemented as a grounded conductive braid surrounding signal conductor  52  along its length), stripline transmission lines (e.g., where ground conductor  54  extends along two sides of signal conductor  52 ), a microstrip transmission line (e.g., where ground conductor  54  extends along one side of signal conductor  52 ), coaxial probes realized by a metalized via, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, waveguide structures (e.g., coplanar waveguides or grounded coplanar waveguides), combinations of these types of transmission lines and/or other transmission line structures, etc. 
     Transmission lines in radio-frequency transmission line path  50  may be integrated into rigid and/or flexible printed circuit boards. In one suitable arrangement, radio-frequency transmission line path  50  may 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 radio-frequency transmission line path  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. 
     Radio-frequency transmission line path  50  may be coupled to antenna feed structures associated with antenna  40 . As an example, antenna  40  may form an inverted-F antenna, a planar inverted-F antenna, a patch antenna, or other antenna having an antenna feed  44  with a positive antenna feed terminal such as positive antenna feed terminal  46  and a ground antenna feed terminal such as ground antenna feed terminal  48 . Positive antenna feed terminal  46  may be coupled to an antenna resonating element for antenna  40  (e.g., a fed arm of antenna  40 ). Ground antenna feed terminal  48  may be coupled to an antenna ground for antenna  40 . If desired, antenna  40  may have one or more antenna resonating elements that are not coupled or directly connected to a corresponding positive antenna feed terminal (e.g., a parasitic or unfed arm of antenna  40 ). The unfed arm(s) in antenna  40  may, if desired, be fed by one or more fed arms of antenna  40  (e.g., via near-field electromagnetic coupling). 
     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 radio-frequency transmission line path  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 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 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 one or more 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  9  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  9  may be measured relative to local horizon  64  and reference vector  68 . As shown in  FIG.  5   , the elevation angle  9  (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  67  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 q 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 and/or may take other suitable action. 
     In one suitable arrangement, device  10  may determine the distance between the device and node  60  and the orientation of device  10  relative to node  60  using one 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 . In implementations where device  10  includes two or more ultra-wideband antennas, 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  9 ). 
     In angle of arrival measurement, node  60  transmits a radio-frequency signal to device (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 . 
     If desired, an antenna  40  in device  10  (e.g., an antenna  40  that conveys UWB signals) may be mounted to a flexible printed circuit (e.g., a flexible printed circuit substrate).  FIG.  6    is a cross-sectional side view showing how the flexible printed circuit may be mounted within device  10 . As shown in  FIG.  6   , antenna  40  may be mounted to flexible printed circuit  70 . Flexible printed circuit  70  may have multiple stacked layers of printed circuit material (e.g., polyimide). 
     Device  10  may include a dielectric cover layer such as dielectric cover layer  84  and a conductive support plate such as conductive support plate  86  layered over (on) dielectric cover layer  84 . Dielectric cover layer  84  and conductive support plate  86  may, for example, form a housing wall for device  10  (e.g., rear housing wall  12 R of  FIG.  1   ). Conductive support plate  86  may be an integral portion of peripheral conductive housing walls  12 W ( FIG.  1   ) or may be welded or otherwise affixed to peripheral conductive housing walls  12 W if desired. Conductive support plate  86  may have an opening such as opening  88 . 
     Flexible printed circuit  70  may extend along conductive support plate  86 . Portion  72  of flexible printed circuit  70  may extend within opening  88  in conductive support plate  86 . An antenna substrate such as substrate  92  may be mounted to portion  72  of flexible printed circuit  70 . Antenna  40  may be disposed on substrate  92 . Conductive traces  94  may be disposed on substrate  92 . Conductive traces  94  (sometimes referred to herein as antenna traces) may be used to form part of the antenna resonating element and/or antenna ground of antenna  40 . Antenna  40  may convey UWB signals or other radio-frequency signals through dielectric cover layer  84 . 
     Portion  72  of flexible printed circuit  70  and substrate  92  may be pressed against dielectric cover layer  84  within opening  88 , forming a bend such as bend  98  in flexible printed circuit  70 . Portion  72  and substrate  92  may, for example, be located between upper surface  85  of conductive support plate  86  and dielectric cover layer  84 . Substrate  92  (e.g., some or all of conductive traces  94 ) may be pressed against (e.g., in direct contact with) dielectric cover layer  84  (e.g., bend  98  may allow substrate  92  to be pressed against dielectric cover layer  84  despite the remainder of flexible printed circuit  70  being disposed outside of opening  88 ). If desired, adhesive may be used to help adhere substrate  92  and/or conductive traces  94  to dielectric cover layer  84 . 
     If desired, an electromagnetic shield such as conductive shielding layer  96  may be layered over conductive support plate  86  and flexible printed circuit  70 . Conductive shielding layer  96  may completely cover opening  88 . Conductive shielding layer  96  may be galvanically connected to conductive support plate  86  (e.g., using solder, welds, or other conductive adhesives), may be placed into contact with conductive support plate  86 , or may be separated from and capacitively coupled to conductive support plate  86 . Conductive shielding layer  96  may include sheet metal, conductive adhesive (e.g., copper tape having an adhesive layer), conductive traces on a dielectric substrate, conductive portions of the housing for device  10 , conductive foil, ferrite, or any other desired structures that block radio-frequency signals. In the absence of conductive shielding layer  96 , gap  90  may radiate in response to radio-frequency signals from polarizations other than the polarization handled by conductive traces  94 . This may introduce undesirable cross-polarization interference on the radio-frequency signals handled by conductive traces  94 . The presence of conductive shielding layer  96  may, for example, serve to block these radio-frequency signals from causing gap  90  to radiate, thereby mitigating cross-polarization interference for conductive traces  94 . 
     The example of  FIG.  6    is merely illustrative. If desired, conductive components may overlap gap  90  to prevent cross-polarization interference. Conductive shielding layer  96  may be omitted if desired. Gap  90  may have a width of zero mm if desired (e.g., portion  72  of flexible printed circuit  70  may completely fill the lateral area of opening  88 ). Pressing substrate  92  against dielectric cover layer  84  may help to provide a uniform impedance transition across the entire lateral area of conductive traces  94  from conductive traces  94  to free space at the exterior of device  10  (e.g., without any air gaps or bubbles between conductive traces  94  and dielectric cover layer  84  that would otherwise introduce undesirable impedance discontinuities to the system). 
     Any desired antenna structures may be used for implementing antenna  40  for conveying UWB signals through dielectric cover layer  84 . In one suitable arrangement that is sometimes described herein as an example, planar inverted-F antenna structures may be used for implementing antenna  40 . Antennas that are implemented using planar inverted-F antenna structures may sometimes be referred to as planar inverted-F antennas. Planar inverted-F antennas are inverted-F antennas having a planar radiating arm that extends across a corresponding lateral surface area. 
       FIG.  7    is a schematic diagram of inverted-F antenna structures that may be used to form antenna  40 . As shown in  FIG.  7   , antenna  40  may include an antenna resonating element such as antenna resonating element  104  (sometimes referred to herein as antenna resonator  104  or antenna radiator  104 ) and an antenna ground such as antenna ground  108  (sometimes referred to herein as ground  108 ). Antenna resonating element  104  may include one or more resonating element arms  102  (sometimes referred to herein as antenna resonating element arms  102 , radiating arms  102 , antenna radiating arms  102 , or simply arms  102 ). Each arm  102  may be shorted to antenna ground  108  by a corresponding return path  106 . 
     Antenna  40  may be fed by coupling a transmission line (e.g., a transmission line in radio-frequency transmission line path  50  of  FIG.  3   ) to positive antenna feed terminal  46  and ground antenna feed terminal  48  of antenna feed  44 . The arms  102  in antenna resonating element  104  may include one or more fed arms  102 F (such as the fed arm  102 F shown in  FIG.  7   ) and may include one or more unfed arms  102 U (not shown in  FIG.  7   ). Positive antenna feed terminal  46  may be coupled to fed arm  102 F and ground antenna feed terminal  48  may be coupled to antenna ground  108 . Return path  106  may be coupled between fed arm  102 F and antenna ground  108  in parallel with antenna feed  44 . The length of fed arm  102 F may determine the response (resonant) frequency of the antenna. 
     While  FIG.  7    shows a schematic diagram of an inverted-F antenna, fed arm  102 F may extend across a lateral surface area to implement antenna  40  as a planar inverted-F antenna. In the example of  FIG.  7   , antenna  40  is configured to cover only a single frequency band. To help broaden the bandwidth of antenna  40  (and thus the frequencies in the frequency band covered by antenna  40 ), antenna  40  may include one or more parasitic antenna resonating elements (sometimes referred to herein as parasitic elements, parasitic arms, or simply as parasitics). The parasitic antenna resonating elements may include an unfed arm  102 U. The unfed arm  102 U may be indirectly fed by fed arm  102 F via near-field electromagnetic coupling. 
       FIG.  8    is a bottom-up view showing one example of how antenna  40  may include both fed arm  102 F and an unfed arm  102 U. Antenna  40  of  FIG.  8    may be an antenna that conveys UWB signals (e.g., as part of a doublet of UWB antennas, a triplet of UWB antennas, or as a standalone UWB antenna for measuring time of flight). As shown in  FIG.  8   , antenna resonating element  104  of antenna  40  may be formed from conductive structures such as conductive traces on a surface of the underlying substrate  92 . Substrate  92  may be formed from any desired dielectric materials such as epoxy, plastic, ceramic, glass, foam, polyimide, liquid crystal polymer, or other materials. In one suitable arrangement that is described herein as an example, substrate  92  is a flexible printed circuit substrate having stacked layers of flexible printed circuit material (e.g., polyimide, liquid crystal polymer, etc.). 
     As shown in  FIG.  8   , antenna resonating element  104  may include fed arm  102 F. Fed arm  102 F may have a planar shape with a length L 2  (e.g., parallel to the X-axis). Fed arm  102 F may have a perpendicular width (e.g., parallel to the Y-axis) such that fed arm  102 F has a planar shape that laterally extends in a given plane (e.g., the X-Y plane of  FIG.  8   ) parallel to the underlying antenna ground (e.g., antenna ground  108  of  FIG.  7   ). Positive antenna feed terminal  46  may be coupled to fed arm  102 F. 
     Antenna resonating element  104  may also include an unfed arm  102 U opposite fed arm  102 F. Unlike fed arm  102 F, unfed arm  102 U is not coupled or directly (galvanically) connected to a positive antenna feed terminal such as positive antenna feed terminal  46 . Unfed arm  102 U may have a planar shape with a length L 1  (e.g., parallel to the X-axis). Unfed arm  102 U may have a perpendicular width (e.g., parallel to the Y-axis) such that unfed arm  102 U has a planar shape that laterally extends in a given plane (e.g., the X-Y plane of  FIG.  8   ) parallel to the underlying antenna ground (e.g., antenna ground  108  of  FIG.  7   ). 
     Length L 2  may be selected to configure antenna resonating element  104  to radiate in a UWB frequency band such as UWB Channel 9. For example, length L 2  may be approximately equal to (e.g., within 15% of) one-quarter of the effective wavelength corresponding to a frequency in the UWB frequency band. The effective wavelength is modified from a corresponding free-space wavelength by a constant value associated with the dielectric material used to form substrate  92  (e.g., the effective wavelength is found by multiplying the freespace wavelength by a constant value that is based on the dielectric constant d k  of substrate  92 ). Length L 1  may be selected to configure unfed arm  102 U to radiate at slightly different frequencies from fed arm  102 F, thereby serving to broaden the overall frequency response and bandwidth of antenna  40 . 
     If desired, an electromagnetic shielding (guard) ring such as grounded shielding ring  110  may laterally surround antenna resonating element  104  at the upper-most surface of substrate  92 . Grounded shielding ring  110  may be formed from conductive traces on the surface of substrate  92 . The conductive traces of grounded shielding ring  110  may be shorted to the antenna ground (e.g., underlying planar ground traces) by fences of conductive vias  112  extending through substrate  92 . Each conductive via  112  may be separated from one or more adjacent conductive vias  112  by a sufficiently narrow distance such that the fence of conductive vias  112  appears as an open circuit (infinite impedance) to antenna currents in the UWB frequency band handled by antenna  40 . As an example, each conductive via  112  in the fence may be separated from one or more adjacent conductive vias  112  by one-sixth of a wavelength covered by antenna  40 , one-eighth of a wavelength covered by antenna  40 , one-tenth of a wavelength covered by antenna  40 , one-fifteenth of a wavelength covered by antenna  40 , less than one-fifteenth of a wavelength covered by antenna  40 , etc. Grounded shielding ring  110  may serve to isolate and shield antenna  40  from electromagnetic interference. 
     Grounded shielding ring  110 , conductive vias  112 , and the underlying planar ground traces on substrate  92  may collectively form antenna ground  108  of  FIG.  7    and may form (define) a conductive antenna cavity for antenna  40  that serves to optimize radio-frequency performance (e.g., antenna efficiency and bandwidth) for antenna  40 . The antenna ground may include ground traces on one or more layers of substrate  92  beneath the upper-most layer of substrate  92 . The ground traces may include planar ground traces extending underneath (e.g., overlapping) substantially all of antenna  40 . If desired, the ground traces may also include a ring of ground traces or ground traces in other shapes overlapping grounded shielding ring  110  but formed on a layer of substrate  92  between the planar ground trace and the upper-most layer of substrate  92 . Each layer of ground traces in antenna  40  may be coupled together using conductive vias if desired (e.g., so that all of the ground traces are held at the same ground potential). 
     Antenna  40  of  FIG.  8    may be fed using a radio-frequency transmission line path (e.g., radio-frequency transmission line path  50  of  FIG.  3   ). The radio-frequency transmission line path may include a transmission line such as stripline or microstrip transmission line, as examples. The transmission line may have signal traces  124  (e.g., forming a part of signal conductor  52  of  FIG.  3   ) coupled to positive antenna feed terminal  46  on fed arm  102 F. Fed arm  102 F is therefore fed by signal traces  124  and positive antenna feed terminal  46 . Unfed arm  102 U is not coupled to any radio-frequency transmission line path. 
     Fed arm  102 F of antenna  40  may extend from a first (right) segment of grounded shielding ring  110  leftwards to an opposing radiating edge  122  (e.g., length L 2  may be measured from grounded shielding ring  110  to radiating edge  122 ). Fed arm  102 F may have longitudinal edges  132  that extend along length L 2  (e.g., parallel to the X-axis) from grounded shielding ring  110  to radiating edge  122 . The uppermost edge  132  may be separated from grounded shielding ring  110  by gap  128 . Gap  128  may have a longitudinal axis extending parallel to the X-axis. The lowermost edge  132  may be separated from grounded shielding ring  110  by gap  130 . Gap  130  may have a longitudinal axis extending parallel to the X-axis (e.g., gaps  128  and  132  may extend in parallel). The conductive vias in the first segment of grounded shielding ring  110  (e.g., the right side of grounded shielding ring  110 ) may form a return path to ground for fed arm  102 F (e.g., return path  106  of  FIG.  7   ). 
     Unfed arm  102 U of antenna  40  may extend from a second (left) segment of grounded shielding ring  110  rightwards to opposing radiating edge  120  (e.g., length L 1  may be measured from grounded shielding ring  110  to radiating edge  120 ). Radiating edge  120  may extend parallel to radiating edge  122 . Unfed arm  102 U may have longitudinal edges  126  that extend along length L 1  (e.g., parallel to the X-axis) from grounded shielding ring  110  to radiating edge  120 . The uppermost edge  126  may be separated from grounded shielding ring  110  by gap  128 . The lowermost edge  126  may be separated from grounded shielding ring  110  by gap  130 . Edges  126  and  132  may extend in parallel to each other. The conductive vias in the second segment of grounded shielding ring  110  (e.g., the left side of grounded shielding ring  110 ) may form a return path to ground for unfed arm  102 U (e.g., return path  106  of  FIG.  7   ). 
     Radiating edge  122  of fed arm  102 F may be separated from radiating edge  120  of unfed arm  102 U by gap  118  (e.g., radiating edge  122  may face radiating edge  120 ). Gap  118  may extend parallel to the Y-axis (e.g., perpendicular to edges  126  and  132  and gaps  128  and  130 ). Gap  118  may couple gap  128  to gap  130  (e.g., gaps  128 ,  118 , and  130  may collectively form an H-shaped gap in the conductive traces the surface of substrate  92 ). Gaps  118 ,  128 , and  130  may sometimes be referred to herein as slots (e.g., elongated slots) or openings in the conductive traces on the surface of substrate  92 . 
     During radio-frequency transmission, signal traces  124  convey antenna currents to fed arm  102 F over positive antenna feed terminal  46 . The antenna currents flow around the edges of fed arm  102 F. The electric fields produced by the antenna currents on fed arm  102 F may exhibit peak magnitudes at radiating edge  122  (e.g., within gap  118 ). This may configure fed arm  102 F (radiating edge  122 ) to cause (induce) corresponding antenna currents to flow on the edges of unfed arm  102 U (e.g., via near-field electromagnetic coupling across gap  118 ). The antenna currents on fed arm  102 F and unfed arm  102 U may radiate corresponding radio-frequency signals into free space. Conversely, during signal reception, antenna currents produced on unfed arm  102 U by incident radio-frequency signals may be coupled onto fed arm  102 F via near-field electromagnetic coupling across gap  118  and may be passed to positive antenna feed terminal  46 . In other words, fed arm  102 F may indirectly feed unfed arm  102 U via near-field electromagnetic coupling across gap  118  despite the fact that unfed arm  102 U does not have its own antenna feed. The corresponding resonance of unfed arm  102 U may contribute to the frequency response of fed arm  102 F, thereby broadening the bandwidth of antenna  40  within the UWB frequency band (e.g., such that the antenna efficiency of antenna  40  exceeds a threshold value across at least the entire 500 MHz bandwidth of the UWB frequency band, such as the 6.5 GHz UWB band or the 8 GHz UWB band). Unfed arm  102 U may sometimes also be referred to as a parasitic arm  102 U (e.g., a grounded parasitic) that is parasitically coupled to fed (non-parasitic) arm  102 F. The example of  FIG.  8    is merely illustrative. Fed arm  102 F and unfed arm  102 U may have other shapes having any desired number of curved and/or straight edges. 
       FIG.  9    is a cross-sectional side view of antenna  40  of  FIG.  8    (e.g., as taken along line AA′ of  FIG.  8   ). As shown in  FIG.  9   , unfed arm  102 U, fed arm  102 F, and grounded shielding ring  110  may be formed from conductive traces on surface  142  of substrate  92  (e.g., may form conductive traces  94  of  FIG.  6   ). Substrate  92  may include one or more stacked layers  136  of dielectric material (e.g., flexible printed circuit material such as polyimide or liquid crystal polymer, ceramic, etc.). This example is merely illustrative and, if desired, one or more additional layers  136  of substrate  92  may be disposed over surface  142 . 
     Substrate  92  may be mounted to surface  140  of flexible printed circuit  70 , which includes a tail that extends beyond the lateral outline of antenna  40 . Flexible printed circuit  70  may include one or more stacked layers  138  of dielectric material (e.g., flexible printed circuit material). A radio-frequency transmission line for antenna  40  may extend along flexible printed circuit  70  and may extend into substrate  92 . Flexible printed circuit  70  may include conductive traces that form a ground plane (layer) such as planar ground traces  146 . Planar ground traces  146  may form part of the antenna ground for antenna  40 . Planar ground traces  146  may be disposed on one or more surfaces of flexible printed circuit  92  and/or may be embedded within layers  138  of flexible printed circuit  70 . Planar ground traces  146  may form a part of the radio-frequency transmission line for antenna  40  and may extend under antenna  40 . Conductive vias may extend through flexible printed circuit  70  to short the planar ground traces  146  together if desired. 
     The signal traces  144  of the radio-frequency transmission line (e.g., signal traces  124  of  FIG.  8   ) may also be disposed on one or more layers  138  of flexible printed circuit  70 . Conductive feed via  134  may extend through substrate  92  and may couple signal traces  144  to positive antenna feed terminal  46  at fed arm  102 F. Conductive vias  112  may couple grounded shielding ring  110  to one or more layers of planar ground traces  146  on flexible printed circuit  70 . Conductive vias  112 , unfed arm  102 U, fed arm  102 F, grounded shielding ring  110 , and planar ground traces  146  may define a continuous antenna cavity (volume) for antenna  40 . The example of  FIG.  9    is merely illustrative and, in general, any desired stack up may be used to dispose antenna  40  on substrate  92  and flexible printed circuit  70 . 
     Device  10  may gather and/or use personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     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: 20220718
Publication Date: 20240521
Grant Date: 20240521
Priority Date: 20220718
Inventors: Rush, Alden T
AKBARZADEH, SOROUSH
HU, HONGFEI
WANG, HAN
GOMEZ TAGLE, JAVIER
CHEN, MING
DI NALLO, CARLO
PASCOLINI, MATTIA
IRCI, Erdinc
Pourghorban Saghati, Ali
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/25", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/242", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/25", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/242", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 89509281