PATENT DOCUMENT

Publication Number: US-11909101-B2
Application Number: US-202217670020-A
Country: US
Kind Code: B2

Title: Electronic devices with bent dielectric resonator antennas

Abstract:
An electronic device may be provided with a phased antenna array having a bent dielectric resonating element. The bent dielectric resonating element may have a first segment, a second segment nonparallel to the first segment, and an angled surface that couples the first segment to the second segment. One or more feed probes may be coupled to the first segment to excite the dielectric resonating element. A reflector may be provided on the angled surface to direct electromagnetic energy from the first segment to the second segment and vice versa. The bent dielectric resonating element may exhibit less overall height than dielectric resonators having straight columns of dielectric material, thereby allowing for a reduction in the thickness of the electronic device. The angled surface and the reflector may optimize the radio-frequency performance of the antenna despite the reduction in overall height.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a housing having peripheral conductive housing structures; 
 a dielectric cover layer on the housing; 
 a circuit board; 
 a dielectric substrate on the circuit board; 
 a bent dielectric resonating element embedded in the dielectric substrate and configured to convey radio-frequency signals through the dielectric cover layer; and 
 a display having a display panel, wherein the dielectric cover layer covers the display panel, the bent dielectric resonating element being configured to convey the radio-frequency signals through a gap between the display panel and the peripheral conductive housing structures. 
 
     
     
       2. The electronic device of  claim 1 , wherein the bent dielectric resonating element has a first segment extending along a first longitudinal axis and a second segment extending, from the first segment, along a second longitudinal axis that is nonparallel to the first longitudinal axis. 
     
     
       3. The electronic device of  claim 2 , wherein the second longitudinal axis is perpendicular to the first longitudinal axis. 
     
     
       4. The electronic device of  claim 3 , wherein the bent dielectric resonating element has a surface that extends nonparallel to the first and second longitudinal axes and that couples the first segment to the second segment. 
     
     
       5. The electronic device of  claim 4 , further comprising:
 a reflector on the surface. 
 
     
     
       6. The electronic device of  claim 5 , wherein the reflector comprises an air gap. 
     
     
       7. The electronic device of  claim 5 , wherein the reflector comprises metal. 
     
     
       8. The electronic device of  claim 3 , further comprising:
 a feed probe coupled to the first segment, soldered to the circuit board, and embedded within the dielectric substrate. 
 
     
     
       9. The electronic device of  claim 8 , further comprising:
 an additional feed probe coupled to the first segment, wherein the feed probe is configured to convey radio-frequency signals of a first polarization and the additional feed probe is configured to convey radio-frequency signals of a second polarization. 
 
     
     
       10. The electronic device of  claim 9 , wherein the bent dielectric resonating element has a hexagonal cross-sectional profile. 
     
     
       11. An electronic device comprising:
 a dielectric layer; 
 a dielectric resonating element having
 a first segment with a first sidewall extending along a first longitudinal axis, 
 a second segment with a second sidewall extending along a second longitudinal axis that is oriented nonparallel to the first longitudinal axis, and 
 a surface that couples the first sidewall to the second sidewall, the surface being oriented nonparallel to the first longitudinal axis and nonparallel to the second longitudinal axis; and 
 
 a feed probe coupled to the first segment and configured to excite the dielectric resonating element to radiate through the dielectric layer. 
 
     
     
       12. The electronic device of  claim 11 , further comprising:
 a dielectric substrate molded over the first and second segments. 
 
     
     
       13. The electronic device of  claim 11 , wherein the feed probe is coupled to the first sidewall, the electronic device further comprising:
 a printed circuit, wherein the feed probe is soldered to the printed circuit. 
 
     
     
       14. The electronic device of  claim 11 , further comprising:
 a reflector on the surface. 
 
     
     
       15. The electronic device of  claim 14 , wherein the reflector comprises metal. 
     
     
       16. The electronic device of  claim 15 , further comprising:
 a dielectric substrate molded over the first segment, the second segment, and the reflector. 
 
     
     
       17. The electronic device of  claim 11 , wherein the dielectric layer comprises a display cover layer, the first longitudinal axis extends parallel to a lateral surface of the display cover layer, and the second longitudinal axis extends perpendicular to the first longitudinal axis. 
     
     
       18. An antenna comprising:
 a dielectric resonating element having
 a first segment extending along a first longitudinal axis, 
 a second segment extending along a second longitudinal axis, 
 a first angled surface that couples the first segment to the second segment and that extends nonparallel to the first and second longitudinal axes, and 
 a second angled surface that couples the first segment to the second segment and that extends parallel to the first angled surface; 
 
 a first reflector on the first angled surface; 
 a second reflector on the second angled surface; and 
 first and second feed probes coupled to the first segment and configured to excite the dielectric resonating element to convey radio-frequency signals of first and second polarizations at a frequency greater than 10 GHz. 
 
     
     
       19. The antenna of  claim 18 , wherein the first segment and the second segment have a hexagonal cross-sectional profile.

Description:
BACKGROUND 
     This relates generally 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. 
     It may be desirable to support wireless communications in millimeter wave and centimeter wave communications bands. Millimeter wave communications, which are sometimes referred to as extremely high frequency (EHF) communications, and centimeter wave communications involve communications at frequencies of about 10-300 GHz. Operation at these frequencies can support high throughputs but may raise significant challenges. For example, radio-frequency signals at millimeter and centimeter wave frequencies can be characterized by substantial attenuation and/or distortion during signal propagation through various mediums. In addition, if care is not taken, the antennas can exhibit insufficient bandwidth and the presence of conductive electronic device components can make it difficult to incorporate components for handling millimeter and centimeter wave communications into the electronic device. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry and a housing. The housing may have peripheral conductive housing structures and a rear wall. A display may be mounted to the peripheral conductive housing structures opposite the rear wall. A phased antenna array may radiate at a frequency greater than 10 GHz through a display cover layer, an antenna window in the housing, a sapphire cover layer used for a camera window in the device, a dielectric cover layer on a rear housing wall for the device, or other dielectric cover layers. 
     The phased antenna array may include a dielectric resonator antenna having a bent dielectric resonating element. The bent dielectric resonating element may have a first segment that extends along a first longitudinal axis, a second segment that extends from the first segment along a second longitudinal axis, and an angled surface that couples the first segment to the second segment. The angled surface may extend nonparallel to the first and second longitudinal axes. One or more feed probes may be coupled to the first segment to excite the dielectric resonating element. A reflector may be provided on the angled surface to direct electromagnetic energy from the first segment to the second segment and vice versa. The bent dielectric resonating element may exhibit less overall height than dielectric resonators having straight columns of dielectric material, thereby allowing for a reduction in the thickness of the electronic device. The angled surface and the reflector may optimize the radio-frequency performance of the antenna despite the reduction in overall height. 
    
    
     
       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 phased antenna array in accordance with some embodiments. 
         FIG.  5    is a cross-sectional side view of an illustrative electronic device having phased antenna arrays for radiating through different sides of the device in accordance with some embodiments. 
         FIG.  6    is a cross-sectional side view of an illustrative dielectric resonator antenna that may be mounted within an electronic device in accordance with some embodiments. 
         FIG.  7    is a perspective view of an illustrative dielectric resonator antenna in accordance with some embodiments. 
         FIG.  8    is a cross-sectional side view of an illustrative bent dielectric resonator antenna that may be mounted within an electronic device in accordance with some embodiments. 
         FIG.  9    is a cross-sectional view of an illustrative bent dielectric resonator element for covering multiple polarizations 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. The antennas may include phased antenna arrays that are used for performing wireless communications and/or spatial ranging operations using millimeter and centimeter wave signals. Millimeter wave signals, which are sometimes referred to as extremely high frequency (EHF) signals, propagate at frequencies above about 30 GHz (e.g., at 60 GHz or other frequencies between about 30 GHz and 300 GHz). Centimeter wave signals propagate at frequencies between about 10 GHz and 30 GHz. If desired, device  10  may also contain antennas for handling satellite navigation system signals, cellular telephone signals, local wireless area network signals, near-field communications, light-based wireless communications, or other wireless communications. 
     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 or notch that extends into active area AA (e.g., at speaker port  16 ). 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.). 
     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 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 . 
     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 microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, central processing units (CPUs), graphics processing units (GPUs), 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 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 802.11ad protocols, cellular telephone protocols, MIMO protocols, antenna diversity protocols, satellite navigation system protocols, antenna-based spatial ranging protocols (e.g., radio detection and ranging (RADAR) protocols or other desired range detection protocols for signals conveyed at millimeter and centimeter wave frequencies), etc. 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 or other control components that form a part of wireless circuitry  34 . 
     Wireless circuitry  34  may include millimeter and centimeter wave transceiver circuitry such as millimeter/centimeter wave transceiver circuitry  38 . Millimeter/centimeter wave transceiver circuitry  38  may support communications at frequencies between about 10 GHz and 300 GHz. For example, millimeter/centimeter wave transceiver circuitry  38  may support communications in Extremely High Frequency (EHF) or millimeter wave communications bands between about 30 GHz and 300 GHz and/or in centimeter wave communications bands between about 10 GHz and 30 GHz (sometimes referred to as Super High Frequency (SHF) bands). As examples, millimeter/centimeter wave transceiver circuitry  38  may support communications in an IEEE K communications band between about 18 GHz and 27 GHz, a K a  communications band between about 26.5 GHz and 40 GHz, a K u  communications band between about 12 GHz and 18 GHz, a V communications band between about 40 GHz and 75 GHz, a W communications band between about 75 GHz and 110 GHz, or any other desired frequency band between approximately 10 GHz and 300 GHz. If desired, millimeter/centimeter wave transceiver circuitry  38  may support IEEE 802.11ad communications at 60 GHz (e.g., WiGig or 60 GHz Wi-Fi bands around 57-61 GHz), and/or 5 th  generation mobile networks or 5 th  generation wireless systems (5G) New Radio (NR) Frequency Range 2 (FR2) communications bands between about 24 GHz and 90 GHz. Millimeter/centimeter wave transceiver circuitry  38  may be formed from one or more integrated circuits (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.). 
     Millimeter/centimeter wave transceiver circuitry  38  (sometimes referred to herein simply as transceiver circuitry  38  or millimeter/centimeter wave circuitry  38 ) may perform spatial ranging operations using radio-frequency signals at millimeter and/or centimeter wave frequencies that are transmitted and received by millimeter/centimeter wave transceiver circuitry  38 . The received signals may be a version of the transmitted signals that have been reflected off of external objects and back towards device  10 . Control circuitry  28  may process the transmitted and received signals to detect or estimate a range between device  10  and one or more external objects in the surroundings of device  10  (e.g., objects external to device  10  such as the body of a user or other persons, other devices, animals, furniture, walls, or other objects or obstacles in the vicinity of device  10 ). If desired, control circuitry  28  may also process the transmitted and received signals to identify a two or three-dimensional spatial location of the external objects relative to device  10 . 
     Spatial ranging operations performed by millimeter/centimeter wave transceiver circuitry  38  are unidirectional. If desired, millimeter/centimeter wave transceiver circuitry  38  may also perform bidirectional communications with external wireless equipment such as external wireless equipment  10  (e.g., over a bi-directional millimeter/centimeter wave wireless communications link). The external wireless equipment may include other electronic devices such as electronic device  10 , a wireless base station, wireless access point, a wireless accessory, or any other desired equipment that transmits and receives millimeter/centimeter wave signals. Bidirectional communications involve both the transmission of wireless data by millimeter/centimeter wave transceiver circuitry  38  and the reception of wireless data that has been transmitted by external wireless equipment. The wireless data may, for example, include data that has been encoded into corresponding data packets such as wireless data associated with a telephone call, streaming media content, internet browsing, wireless data associated with software applications running on device  10 , email messages, etc. 
     If desired, wireless circuitry  34  may include transceiver circuitry for handling communications at frequencies below 10 GHz such as non-millimeter/centimeter wave transceiver circuitry  36 . For example, non-millimeter/centimeter wave transceiver circuitry  36  may handle wireless local area network (WLAN) communications bands such as the 2.4 GHz and 5 GHz Wi-Fi® (IEEE 802.11) bands, wireless personal area network (WPAN) communications bands such as the 2.4 GHz Bluetooth® communications band, cellular telephone communications bands such as a cellular low band (LB) (e.g., 600 to 960 MHz), a cellular low-midband (LMB) (e.g., 1400 to 1550 MHz), a cellular midband (MB) (e.g., from 1700 to 2200 MHz), a cellular high band (HB) (e.g., from 2300 to 2700 MHz), a cellular ultra-high band (UHB) (e.g., from 3300 to 5000 MHz, or other cellular communications bands between about 600 MHz and about 5000 MHz (e.g., 3G bands, 4G LTE bands, 5G New Radio Frequency Range 1 (FR1) bands below 10 GHz, etc.), a near-field communications (NFC) band (e.g., at 13.56 MHz), satellite navigations bands (e.g., an L1 global positioning system (GPS) band at 1575 MHz, an L5 GPS band at 1176 MHz, a Global Navigation Satellite System (GLONASS) band, a BeiDou Navigation Satellite System (BDS) band, etc.), ultra-wideband (UWB) communications band(s) supported by the IEEE 802.15.4 protocol and/or other UWB communications protocols (e.g., a first UWB communications band at 6.5 GHz and/or a second UWB communications band at 8.0 GHz), and/or any other desired communications bands. The communications bands handled by the radio-frequency transceiver circuitry may sometimes be referred to herein as frequency bands or simply as “bands,” and may span corresponding ranges of frequencies. Non-millimeter/centimeter wave transceiver circuitry  36  and millimeter/centimeter wave transceiver circuitry  38  may each include one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive radio-frequency components, switching circuitry, transmission line structures, and other circuitry for handling radio-frequency signals. 
     In general, the transceiver circuitry in wireless circuitry  34  may cover (handle) any desired frequency bands of interest. As shown in  FIG.  2   , wireless circuitry  34  may include antennas  40 . The transceiver circuitry 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  40  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. 
     In satellite navigation system links, cellular telephone links, and other long-range links, radio-frequency signals are typically used to convey data over thousands of feet or miles. In Wi-Fi® and Bluetooth® links at 2.4 and 5 GHz and other short-range wireless links, radio-frequency signals are typically used to convey data over tens or hundreds of feet. Millimeter/centimeter wave transceiver circuitry  38  may convey radio-frequency signals over short distances that travel over a line-of-sight path. To enhance signal reception for millimeter and centimeter wave communications, phased antenna arrays and beam forming (steering) techniques may be used (e.g., schemes in which antenna signal phase and/or magnitude for each antenna in an array are adjusted to perform beam steering). Antenna diversity schemes may also be used to ensure that the antennas that have become blocked or that are otherwise degraded due to the operating environment of device  10  can be switched out of use and higher-performing antennas used in their place. 
     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, 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. 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 non-millimeter/centimeter wave wireless link for non-millimeter/centimeter wave transceiver circuitry  36  and another type of antenna may be used in conveying radio-frequency signals at millimeter and/or centimeter wave frequencies for millimeter/centimeter wave transceiver circuitry  38 . Antennas  40  that are used to convey radio-frequency signals at millimeter and centimeter wave frequencies may be arranged in one or more phased antenna arrays. 
     A schematic diagram of an antenna  40  that may be formed in a phased antenna array for conveying radio-frequency signals at millimeter and centimeter wave frequencies is shown in  FIG.  3   . As shown in  FIG.  3   , antenna  40  may be coupled to millimeter/centimeter (MM/CM) wave transceiver circuitry  38 . Millimeter/centimeter wave transceiver circuitry  38  may be coupled to antenna feed  44  of antenna  40  using a transmission line path that includes radio-frequency transmission line  42 . Radio-frequency transmission line  42  may include a positive signal conductor such as signal conductor  46  and may include a ground conductor such as ground conductor  48 . Ground conductor  48  may be coupled to the antenna ground for antenna  40  (e.g., over a ground antenna feed terminal of antenna feed  44  located at the antenna ground). Signal conductor  46  may be coupled to the antenna resonating element for antenna  40 . For example, signal conductor  46  may be coupled to a positive antenna feed terminal of antenna feed  44  located at the antenna resonating element. 
     In another suitable arrangement, antenna  40  may be a probe-fed antenna that is fed using a feed probe. In this arrangement, antenna feed  44  may be implemented as a feed probe. Signal conductor  46  may be coupled to the feed probe. Radio-frequency transmission line  42  may convey radio-frequency signals to and from the feed probe. When radio-frequency signals are being transmitted over the feed probe and the antenna, the feed probe may excite the resonating element for the antenna (e.g., may excite electromagnetic resonant modes of a dielectric antenna resonating element for antenna  40 ). The resonating element may radiate the radio-frequency signals in response to excitation by the feed probe. Similarly, when radio-frequency signals are received by the antenna (e.g., from free space), the radio-frequency signals may excite the resonating element for the antenna (e.g., may excite electromagnetic resonant modes of the dielectric antenna resonating element for antenna  40 ). This may produce antenna currents on the feed probe and the corresponding radio-frequency signals may be passed to the transceiver circuitry over the radio-frequency transmission line. 
     Radio-frequency transmission line  42  may include a stripline transmission line (sometimes referred to herein simply as a stripline), a coaxial cable, a coaxial probe realized by metalized vias, a microstrip transmission line, an edge-coupled microstrip transmission line, an edge-coupled stripline transmission lines, a waveguide structure, combinations of these, etc. Multiple types of transmission lines may be used to form the transmission line path that couples millimeter/centimeter wave transceiver circuitry  38  to antenna feed  44 . Filter circuitry, switching circuitry, impedance matching circuitry, phase shifter circuitry, amplifier circuitry, and/or other circuitry may be interposed on radio-frequency transmission line  42 , if desired. 
     Radio-frequency transmission lines in device  10  may be integrated into ceramic substrates, rigid printed circuit boards, and/or flexible printed circuits. In one suitable arrangement, radio-frequency transmission lines in device  10  may be 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) that may be folded or bent in multiple dimensions (e.g., two or three dimensions) and that 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). 
       FIG.  4    shows how antennas  40  for handling radio-frequency signals at millimeter and centimeter wave frequencies may be formed in a phased antenna array. As shown in  FIG.  4   , phased antenna array  54  (sometimes referred to herein as array  54 , antenna array  54 , or array  54  of antennas  40 ) may be coupled to radio-frequency transmission lines  42 . For example, a first antenna  40 - 1  in phased antenna array  54  may be coupled to a first radio-frequency transmission line  42 - 1 , a second antenna  40 - 2  in phased antenna array  54  may be coupled to a second radio-frequency transmission line  42 - 2 , an Nth antenna  40 -N in phased antenna array  54  may be coupled to an Nth radio-frequency transmission line  42 -N, etc. While antennas  40  are described herein as forming a phased antenna array, the antennas  40  in phased antenna array  54  may sometimes also be referred to as collectively forming a single phased array antenna. 
     Antennas  40  in phased antenna array  54  may be arranged in any desired number of rows and columns or in any other desired pattern (e.g., the antennas need not be arranged in a grid pattern having rows and columns). During signal transmission operations, radio-frequency transmission lines  42  may be used to supply signals (e.g., radio-frequency signals such as millimeter wave and/or centimeter wave signals) from millimeter/centimeter wave transceiver circuitry  38  ( FIG.  3   ) to phased antenna array  54  for wireless transmission. During signal reception operations, radio-frequency transmission lines  42  may be used to supply signals received at phased antenna array  54  (e.g., from external wireless equipment or transmitted signals that have been reflected off of external objects) to millimeter/centimeter wave transceiver circuitry  38  ( FIG.  3   ). 
     The use of multiple antennas  40  in phased antenna array  54  allows beam steering arrangements to be implemented by controlling the relative phases and magnitudes (amplitudes) of the radio-frequency signals conveyed by the antennas. In the example of  FIG.  4   , antennas  40  each have a corresponding radio-frequency phase and magnitude controller  50  (e.g., a first phase and magnitude controller  50 - 1  interposed on radio-frequency transmission line  42 - 1  may control phase and magnitude for radio-frequency signals handled by antenna  40 - 1 , a second phase and magnitude controller  50 - 2  interposed on radio-frequency transmission line  42 - 2  may control phase and magnitude for radio-frequency signals handled by antenna  40 - 2 , an Nth phase and magnitude controller  50 -N interposed on radio-frequency transmission line  42 -N may control phase and magnitude for radio-frequency signals handled by antenna  40 -N, etc.). 
     Phase and magnitude controllers  50  may each include circuitry for adjusting the phase of the radio-frequency signals on radio-frequency transmission lines  42  (e.g., phase shifter circuits) and/or circuitry for adjusting the magnitude of the radio-frequency signals on radio-frequency transmission lines  42  (e.g., power amplifier and/or low noise amplifier circuits). Phase and magnitude controllers  50  may sometimes be referred to collectively herein as beam steering circuitry (e.g., beam steering circuitry that steers the beam of radio-frequency signals transmitted and/or received by phased antenna array  54 ). 
     Phase and magnitude controllers  50  may adjust the relative phases and/or magnitudes of the transmitted signals that are provided to each of the antennas in phased antenna array  54  and may adjust the relative phases and/or magnitudes of the received signals that are received by phased antenna array  54 . Phase and magnitude controllers  50  may, if desired, include phase detection circuitry for detecting the phases of the received signals that are received by phased antenna array  54 . The term “beam” or “signal beam” may be used herein to collectively refer to wireless signals that are transmitted and received by phased antenna array  54  in a particular direction. The signal beam may exhibit a peak gain that is oriented in a particular pointing direction at a corresponding pointing angle (e.g., based on constructive and destructive interference from the combination of signals from each antenna in the phased antenna array). The term “transmit beam” may sometimes be used herein to refer to radio-frequency signals that are transmitted in a particular direction whereas the term “receive beam” may sometimes be used herein to refer to radio-frequency signals that are received from a particular direction. 
     If, for example, phase and magnitude controllers  50  are adjusted to produce a first set of phases and/or magnitudes for transmitted radio-frequency signals, the transmitted signals will form a transmit beam as shown by beam B 1  of  FIG.  4    that is oriented in the direction of point A. If, however, phase and magnitude controllers  50  are adjusted to produce a second set of phases and/or magnitudes for the transmitted signals, the transmitted signals will form a transmit beam as shown by beam B 2  that is oriented in the direction of point B. Similarly, if phase and magnitude controllers  50  are adjusted to produce the first set of phases and/or magnitudes, radio-frequency signals (e.g., radio-frequency signals in a receive beam) may be received from the direction of point A, as shown by beam B 1 . If phase and magnitude controllers  50  are adjusted to produce the second set of phases and/or magnitudes, radio-frequency signals may be received from the direction of point B, as shown by beam B 2 . 
     Each phase and magnitude controller  50  may be controlled to produce a desired phase and/or magnitude based on a corresponding control signal  52  received from control circuitry  28  of  FIG.  2    (e.g., the phase and/or magnitude provided by phase and magnitude controller  50 - 1  may be controlled using control signal  52 - 1 , the phase and/or magnitude provided by phase and magnitude controller  50 - 2  may be controlled using control signal  52 - 2 , etc.). If desired, the control circuitry may actively adjust control signals  52  in real time to steer the transmit or receive beam in different desired directions over time. Phase and magnitude controllers  50  may provide information identifying the phase of received signals to control circuitry  28  if desired. 
     When performing wireless communications using radio-frequency signals at millimeter and centimeter wave frequencies, the radio-frequency signals are conveyed over a line of sight path between phased antenna array  54  and external communications equipment. If the external object is located at point A of  FIG.  4   , phase and magnitude controllers  50  may be adjusted to steer the signal beam towards point A (e.g., to steer the pointing direction of the signal beam towards point A). Phased antenna array  54  may transmit and receive radio-frequency signals in the direction of point A. Similarly, if the external communications equipment is located at point B, phase and magnitude controllers  50  may be adjusted to steer the signal beam towards point B (e.g., to steer the pointing direction of the signal beam towards point B). Phased antenna array  54  may transmit and receive radio-frequency signals in the direction of point B. In the example of  FIG.  4   , beam steering is shown as being performed over a single degree of freedom for the sake of simplicity (e.g., towards the left and right on the page of  FIG.  4   ). However, in practice, the beam may be steered over two or more degrees of freedom (e.g., in three dimensions, into and out of the page and to the left and right on the page of  FIG.  4   ). Phased antenna array  54  may have a corresponding field of view over which beam steering can be performed (e.g., in a hemisphere or a segment of a hemisphere over the phased antenna array). If desired, device  10  may include multiple phased antenna arrays that each face a different direction to provide coverage from multiple sides of the device. 
       FIG.  5    is a cross-sectional side view of device  10  in an example where device  10  has multiple phased antenna arrays. As shown in  FIG.  5   , peripheral conductive housing structures  12 W may extend around the (lateral) periphery of device  10  and may extend from rear housing wall  12 R to display  14 . Display  14  may have a display module such as display module  68  (sometimes referred to as a display panel). Display module  68  may include pixel circuitry, touch sensor circuitry, force sensor circuitry, and/or any other desired circuitry for forming active area AA of display  14 . Display  14  may include a dielectric cover layer such as display cover layer  56  that overlaps display module  68 . Display module  68  may emit image light and may receive sensor input through display cover layer  56 . Display cover layer  56  and display  14  may be mounted to peripheral conductive housing structures  12 W. The lateral area of display  14  that does not overlap display module  68  may form inactive area IA of display  14 . 
     Device  10  may include multiple phased antenna arrays  54  such as a rear-facing phased antenna array  54 - 1 . As shown in  FIG.  5   , phased antenna array  54 - 1  may transmit and receive radio-frequency signals  60  at millimeter and centimeter wave frequencies through rear housing wall  12 R. In scenarios where rear housing wall  12 R includes metal portions, radio-frequency signals  60  may be conveyed through an aperture or opening in the metal portions of rear housing wall  12 R or may be conveyed through other dielectric portions of rear housing wall  12 R. The aperture may be overlapped by a dielectric cover layer or dielectric coating that extends across the lateral area of rear housing wall  12 R (e.g., between peripheral conductive housing structures  12 W). Phased antenna array  54 - 1  may perform beam steering for radio-frequency signals  60  across the hemisphere below device  10 , as shown by arrow  62 . 
     Phased antenna array  54 - 1  may be mounted to a substrate such as substrate  64 . Substrate  64  may be an integrated circuit chip, a flexible printed circuit, a rigid printed circuit board, or other substrate. Substrate  64  may sometimes be referred to herein as antenna module  64 . If desired, transceiver circuitry (e.g., millimeter/centimeter wave transceiver circuitry  38  of  FIG.  2   ) may be mounted to antenna module  64 . Phased antenna array  54 - 1  may be adhered to rear housing wall  12 R using adhesive, may be pressed against (e.g., in contact with) rear housing wall  12 R, or may be spaced apart from rear housing wall  12 R. 
     The field of view of phased antenna array  54 - 1  is limited to the hemisphere under the rear face of device  10 . Display module  68  and other components  58  (e.g., portions of input-output circuitry  24  or control circuitry  28  of  FIG.  2   , a battery for device  10 , etc.) in device  10  include conductive structures. If care is not taken, these conductive structures may block radio-frequency signals from being conveyed by a phased antenna array within device  10  across the hemisphere over the front face of device  10 . While an additional phased antenna array for covering the hemisphere over the front face of device  10  may be mounted against display cover layer  56  within inactive area IA, there may be insufficient space between the lateral periphery of display module  68  and peripheral conductive housing structures  12 W to form all of the circuitry and radio-frequency transmission lines necessary to fully support the phased antenna array. 
     To mitigate these issues and provide coverage through the front face of device  10 , a front-facing phased antenna array may be mounted within peripheral region  66  of device  10 . The antennas in the front-facing phased antenna array may include dielectric resonator antennas. Dielectric resonator antennas may occupy less area in the X-Y plane of  FIG.  5    than other types of antennas such as patch antennas and slot antennas. Implementing the antennas as dielectric resonator antennas may allow the radiating elements of the front-facing phased antenna array to fit within inactive area IA between display module  68  and peripheral conductive housing structures  12 W. At the same time, the radio-frequency transmission lines and other components for the phased antenna array may be located behind (under) display module  68 . While examples are described herein in which the phased antenna array is a front-facing phased antenna array that radiates through display  14 , in another suitable arrangement, the phased antenna array may be a side-facing phased antenna array that radiates through one or more apertures in peripheral conductive housing structures  12 W. 
       FIG.  6    is a cross-sectional side view of an illustrative dielectric resonator antenna in a front-facing phased antenna array for device  10 . As shown in  FIG.  6   , device  10  may include a front-facing phased antenna array having a given antenna  40  (e.g., mounted within peripheral region  66  of  FIG.  5   ). Antenna  40  of  FIG.  6    may be a dielectric resonator antenna. In this example, antenna  40  includes a dielectric resonating element  92  mounted to an underlying substrate such as circuit board  72 . Circuit board  72  may be a flexible printed circuit or a rigid printed circuit board, as examples. 
     Circuit board  72  has a lateral area (e.g., in the X-Y plane of  FIG.  6   ) that extends along rear housing wall  12 R. Circuit board  72  may be adhered to rear housing wall  12 R using adhesive, may be pressed against (e.g., placed in contact with) rear housing wall  12 R, or may be separated from rear housing wall  12 R. Circuit board  72  may have a first end at antenna  40  and an opposing second end coupled to the millimeter/centimeter wave transceiver circuitry in device  10  (e.g., millimeter/centimeter wave transceiver circuitry  38  of  FIG.  2   ). In one suitable arrangement, the second end of circuit board  72  may be coupled to antenna module  64  of  FIG.  5   . 
     As shown in  FIG.  6   , circuit board  72  may include stacked dielectric layers  70 . Dielectric layers  70  may include polyimide, ceramic, liquid crystal polymer, plastic, and/or any other desired dielectric materials. Conductive traces such as conductive traces  82  may be patterned on a top surface  76  of circuit board  72 . Conductive traces such as conductive traces  80  may be patterned on an opposing bottom surface  78  of circuit board  72  or elsewhere within circuit board  72 . Conductive traces  80  may be held at a ground potential and may therefore sometimes be referred to herein as ground traces  80 . Ground traces  80  may be shorted to additional ground traces within circuit board  72  and/or on top surface  76  of circuit board  72  using conducive vias that extend through circuit board  72  (not shown in  FIG.  6    for the sake of clarity). Ground traces  80  may form part of the antenna ground for antenna  40 . Ground traces  80  may be coupled to a system ground in device  10  (e.g., using solder, welds, conductive adhesive, conductive tape, conductive brackets, conductive pins, conductive screws, conductive clips, combinations of these, etc.). For example, ground traces  80  may be coupled to peripheral conductive housing structures  12 W, conductive portions of rear housing wall  12 R, or other grounded structures in device  10 . The example of  FIG.  6    in which conductive traces  82  are formed on top surface  76  and ground traces  80  are formed on bottom surface  78  of circuit board  72  is merely illustrative. If desired, one or more dielectric layers  70  may be layered over conductive traces  82  and/or one or more dielectric layers  70  may be layered underneath ground traces  80 . 
     Antenna  40  may be fed using a radio-frequency transmission line that is formed on and/or embedded within circuit board  72  such as radio-frequency transmission line  74 . Radio-frequency transmission line  74  (e.g., a given radio-frequency transmission line  42  of  FIG.  3   ) may include ground traces  80  and conductive traces  82 . The portion of ground traces  80  overlapping conductive traces  82  may form the ground conductor for radio-frequency transmission line  74  (e.g., ground conductor  48  of  FIG.  3   ). Conductive traces  82  may form the signal conductor for radio-frequency transmission line  74  (e.g., signal conductor  46  of  FIG.  3   ) and may therefore sometimes be referred to herein as signal traces  82 . Radio-frequency transmission line  74  may convey radio-frequency signals between antenna  40  and the millimeter/centimeter wave transceiver circuitry. The example of  FIG.  6    in which antenna  40  is fed using signal traces  82  and ground traces  80  is merely illustrative. In general, antenna  40  may be fed using any desired transmission line structures in and/or on circuit board  72 . 
     Dielectric resonating element  92  of antenna  40  may be formed from a column (pillar) of dielectric material mounted to top surface  76  of circuit board  72 . If desired, dielectric resonating element  92  may be embedded within (e.g., laterally surrounded by) a dielectric substrate mounted to top surface  76  of circuit board  72  such as dielectric substrate  90 . Dielectric resonating element  92  may have a first (bottom) surface  100  at circuit board  72  to and an opposing second (top) surface  98  at display  14 . Bottom surface  100  may sometimes be referred to as bottom end  100 , bottom face  100 , proximal end  100 , or proximal surface  100  of dielectric resonating element  92 . Similarly, top surface  98  may sometimes be referred to herein as top end  98 , top face  98 , distal end  98 , or distal surface  98  of dielectric resonating element  92 . Dielectric resonating element  92  may have vertically extending sidewalls  102  that extend from top surface  98  to bottom surface  100 . Dielectric resonating element  92  may extend along a central/longitudinal axis (e.g., parallel to the Z-axis) that runs through the center of both top surface  98  and bottom surface  100 . The length of dielectric resonating element  92  (e.g., as measured parallel to the longitudinal axis and the Z-axis of  FIG.  6   ) may be greater than the width/thickness of dielectric resonating element  92  (e.g., as measured parallel to the X-axis and Y-axis of  FIG.  6   ). 
     The operating (resonant) frequency of antenna  40  may be selected by adjusting the dimensions of dielectric resonating element  92  (e.g., in the direction of the X, Y, and/or Z axes of  FIG.  6   ), which adjusts the resonance and boundary conditions of one or more electromagnetic modes of electromagnetic energy within the dielectric resonating element. Dielectric resonating element  92  may be formed from a column of dielectric material having dielectric constant ε r3 . Dielectric constant ε r3  may be relatively high (e.g., greater than 10.0, greater than 12.0, greater than 15.0, greater than 20.0, between 15.0 and 40.0, between 10.0 and 50.0, between 18.0 and 30.0, between 12.0 and 45.0, etc.). In one suitable arrangement, dielectric resonating element  92  may be formed from zirconia or a ceramic material. Other dielectric materials may be used to form dielectric resonating element  92  if desired. 
     Dielectric substrate  90  may be formed from a material having dielectric constant ε r4 . Dielectric constant ε r4  may be less than dielectric constant ε r3  of dielectric resonating element  92  (e.g., less than 18.0, less than 15.0, less than 10.0, between 3.0 and 4.0, less than 5.0, between 2.0 and 5.0, etc.). Dielectric constant ε r4  may be less than dielectric constant ε r3  by at least 10.0, 5.0, 15.0, 12.0, 6.0, etc. In one suitable arrangement, dielectric substrate  90  may be formed from molded plastic (e.g., injection-molded plastic). The molded plastic in dielectric substrate  90  may be molded over dielectric resonating element  92  after dielectric resonating element  92  has been mounted or affixed to circuit board  72 , for example. Dielectric substrate  90  may therefore sometimes also be referred to herein as plastic overmold  90 . Other dielectric materials may be used to form dielectric substrate  90  or dielectric substrate  90  may be omitted if desired. The difference in dielectric constant between dielectric resonating element  92  and dielectric substrate  90  may establish a radio-frequency boundary condition between dielectric resonating element  92  and dielectric substrate  90  from bottom surface  100  to top surface  98 . This may configure dielectric resonating element  92  to serve as a waveguide for propagating radio-frequency signals at millimeter and centimeter wave frequencies. 
     Dielectric substrate  90  may have a width (thickness)  106  on each side of dielectric resonating element  92 . Width  106  may be selected to isolate dielectric resonating element  92  from peripheral conductive housing structures  12 W and to minimize signal reflections in dielectric substrate  90 . Width  106  may be, for example, at least one-tenth of the effective wavelength of the radio-frequency signals in a dielectric material of dielectric constant ε r4 . Width  106  may be 0.4-0.5 mm, 0.3-0.5 mm, 0.2-0.6 mm, greater than 0.1 mm, greater than 0.3 mm, 0.2-2.0 mm, 0.3-1.0 mm, or greater than between 0.4 and 0.5 mm, as examples. The example of  FIG.  6    in which width  106  is constant across the height of dielectric resonating element  92  is merely illustrative. 
     Dielectric resonating element  92  may radiate radio-frequency signals  104  when excited by the signal conductor for radio-frequency transmission line  74 . In some scenarios, a slot is formed in ground traces on top surface  76  of flexible printed circuit, the slot is indirectly fed by a signal conductor embedded within circuit board  72 , and the slot excites dielectric resonating element  92  to radiate radio-frequency signals  104 . However, in these scenarios, the radiating characteristics of the antenna may be affected by how the dielectric resonating element is mounted to circuit board  72 . For example, air gaps or layers of adhesive used to mount the dielectric resonating element to the flexible printed circuit can be difficult to control and can undesirably affect the radiating characteristics of the antenna. To mitigate the issues associated with exciting dielectric resonating element  92  using an underlying slot, antenna  40  may be fed using a radio-frequency feed probe such as feed probe  85 . Feed probe  85  may form part of the antenna feed for antenna  40  (e.g., antenna feed  44  of  FIG.  3   ). 
     As shown in  FIG.  6   , feed probe  85  may include feed conductor  84 . Feed conductor  84  may include a first portion on a given sidewall  102  of dielectric resonating element  92 . Feed conductor  84  may be formed from a patch of stamped sheet metal that is pressed against sidewall  102  (e.g., by biasing structures and/or dielectric substrate  90 ). In another suitable arrangement, feed conductor  84  may be formed from conductive traces that are patterned directly onto sidewall  102  (e.g., using a sputtering process, a laser direct structuring process, or other conductive deposition techniques). Feed conductor  84  may include a second portion coupled to signal traces  82  using conductive interconnect structures  86 . Conductive interconnect structures  86  may include solder, welds, conductive adhesive, conductive tape, conductive foam, conductive springs, conductive brackets, and/or any other desired conductive interconnect structures. As one example, feed probe  85  may be pressed or mounted to dielectric resonating element  92 , dielectric resonating element  92  may then be molded within dielectric substrate  90  (e.g., dielectric substrate  90  may be molded over feed probe  85  and dielectric resonating element  92 ), and feed probe  85  may be soldered to signal traces  86  to surface-mount antenna  40  (e.g., dielectric resonating element  92  and dielectric substrate  90 ) to circuit board  72 . 
     Signal traces  82  may convey radio-frequency signals to and from feed probe  85 . Feed probe  85  may electromagnetically couple the radio-frequency signals on signal traces  82  into dielectric resonating element  92 . This may serve to excite one or more electromagnetic modes of dielectric resonating element  92  (e.g., radio-frequency cavity or waveguide modes). When excited by feed probe  85 , the electromagnetic modes of dielectric resonating element  92  may configure the dielectric resonating element to serve as a waveguide that propagates the wavefronts of radio-frequency signals  104  along the length of dielectric resonating element  92  (e.g., in the direction of the Z-axis of  FIG.  6   ), through top surface  98 , and through display  14 . 
     For example, during signal transmission, radio-frequency transmission line  74  may supply radio-frequency signals from the millimeter/centimeter wave transceiver circuitry to antenna  40 . Feed probe  85  may couple the radio-frequency signals on signal traces  82  into dielectric resonating element  92 . This may serve to excite one or more electromagnetic modes of dielectric resonating element  92 , resulting in the propagation of radio-frequency signals  104  up the length of dielectric resonating element  92  and to the exterior of device  10  through display cover layer  56 . Similarly, during signal reception, radio-frequency signals  104  may be received through display cover layer  56 . The received radio-frequency signals may excite the electromagnetic modes of dielectric resonating element  92 , resulting in the propagation of the radio-frequency signals down the length of dielectric resonating element  92 . Feed probe  85  may couple the received radio-frequency signals onto radio-frequency transmission line  74 , which passes the radio-frequency signals to the millimeter/centimeter wave transceiver circuitry. The relatively large difference in dielectric constant between dielectric resonating element  92  and dielectric substrate  90  may allow dielectric resonating element  92  to convey radio-frequency signals  104  with a relatively high antenna efficiency (e.g., by establishing a strong boundary between dielectric resonating element  92  and dielectric substrate  90  for the radio-frequency signals). The relatively high dielectric constant of dielectric resonating element  92  may also allow the dielectric resonating element  92  to occupy a relatively small volume compared to scenarios where materials with a lower dielectric constant are used. 
     The dimensions of feed probe  85  (e.g., in the direction of the X-axis and Z-axis of FIG.  6 ) may be selected to help match the impedance of radio-frequency transmission line  74  to the impedance of dielectric resonating element  92 . Feed probe  85  may be located on a particular sidewall  102  of dielectric resonating element  92  to provide antenna  40  with a desired linear polarization (e.g., a vertical or horizontal polarization). If desired, multiple feed probes  85  may be formed on multiple sidewalls  102  of dielectric resonating element  92  to configure antenna  40  to cover multiple orthogonal linear polarizations at once. The phase of each feed probe may be independently adjusted over time to provide the antenna with other polarizations such as an elliptical or circular polarization if desired. Feed probe  85  may sometimes be referred to herein as feed conductor  85 , feed patch  85 , or probe feed  85 . Dielectric resonating element  92  may sometimes be referred to herein as a dielectric radiating element, dielectric radiator, dielectric resonator, dielectric antenna resonating element, dielectric column, dielectric pillar, radiating element, or resonating element. When fed by one or more feed probes such as feed probe  85 , dielectric resonator antennas such as antenna  40  of  FIG.  6    may sometimes be referred to herein as probe-fed dielectric resonator antennas. 
     Display cover layer  56  may be formed from a dielectric material having dielectric constant ε r1  that is less than dielectric constant ε r3 . For example, dielectric constant ε r1  may be between about 3.0 and 10.0 (e.g., between 4.0 and 9.0, between 5.0 and 8.0, between 5.5 and 7.0, between 5.0 and 7.0, etc.). In one suitable arrangement, display cover layer  56  may be formed from glass, plastic, or sapphire. If care is not taken, the relatively large difference in dielectric constant between display cover layer  56  and dielectric resonating element  92  may cause undesirable signal reflections at the boundary between the display cover layer and the dielectric resonating element. These reflections may result in destructive interference between the transmitted and reflected signals and in stray signal loss that undesirably limits the antenna efficiency of antenna  40 . 
     To mitigate these effects, antenna  40  may be provided with an impedance matching layer such as dielectric matching layer  94 . Dielectric matching layer  94  may be mounted to top surface  98  of dielectric resonating element  92  between dielectric resonating element  92  and display cover layer  56 . If desired, dielectric matching layer  94  may be adhered to dielectric resonating element  92  using a layer of adhesive  96 . Adhesive may also or alternatively be used to adhere dielectric matching layer  94  to display cover layer  56  if desired. Adhesive  96  may be relatively thin so as not to significantly affect the propagation of radio-frequency signals  104 . 
     Dielectric matching layer  94  may be formed from a dielectric material having dielectric constant ε r2 . Dielectric constant Ea may be greater than dielectric constant ε r1  and less than dielectric constant ε r3 . As an example, dielectric constant ε r1  may be equal to SQRT(ε r1 *ε r3 ), where SQRT( ) is the square root operator and “*” is the multiplication operator. The presence of dielectric matching layer  94  may allow radio-frequency signals to propagate without facing a sharp boundary between the material of dielectric constant ε r1  and the material of dielectric constant ε r3 , thereby helping to reduce signal reflections. 
     Dielectric matching layer  94  may be provided with thickness  88 . Thickness  88  may be selected to be approximately equal to (e.g., within 15% of) one-quarter of the effective wavelength of radio-frequency signals  104  in dielectric matching layer  94 . The effective wavelength is given by dividing the free space wavelength of radio-frequency signals  104  (e.g., a centimeter or millimeter wavelength corresponding to a frequency between 10 GHz and 300 GHz) by a constant factor (e.g., the square root of ε r2 ). When provided with thickness  88 , dielectric matching layer  94  may form a quarter wave impedance transformer that mitigates any destructive interference associated with the reflection of radio-frequency signals  104  at the boundaries between display cover layer  56 , dielectric matching layer  94 , and dielectric resonating element  92 . This is merely illustrative and dielectric matching layer  94  may be omitted if desired. 
     When configured in this way, antenna  40  may radiate radio-frequency signals  104  through the front face of device  10  despite being coupled to the millimeter/centimeter wave transceiver circuitry over a circuit board located at the rear of device  10 . The relatively narrow width of dielectric resonating element  92  may allow antenna  40  to fit in the volume between display module  68 , other components  58 , and peripheral conductive housing structures  12 W. Antenna  40  of  FIG.  6    may be formed in a front-facing phased antenna array that conveys radio-frequency signals across at least a portion of the hemisphere above the front face of device  10 . 
       FIG.  7    is a perspective view of the probe-fed dielectric resonator antenna of  FIG.  6    in a scenario where the dielectric resonating element is fed using multiple feed probes for covering multiple polarizations. Peripheral conductive housing structures  12 W, dielectric substrate  90 , dielectric matching layer  94 , adhesive  96 , rear housing wall  12 R, display  14 , and other components  58  of  FIG.  6    are omitted from  FIG.  7    for the sake of clarity. 
     As shown in  FIG.  7   , dielectric resonating element  92  of antenna  40  (e.g., bottom surface  100  of  FIG.  6   ) may be mounted to top surface  76  of circuit board  72 . Antenna  40  may be fed using multiple feed probes  85  such as a first feed probe  85 V and a second feed probe  85 H mounted to dielectric resonating element  92  and circuit board  72 . Feed probe  85 V includes feed conductor  84 V on a first sidewall  102  of dielectric resonating element  92 . Feed probe  8511  includes feed conductor  84 H on a second (orthogonal) sidewall  102  of dielectric resonating element  92 . 
     Antenna  40  may be fed using multiple radio-frequency transmission lines  74  such as a first radio-frequency transmission line  74 V and a second radio-frequency transmission line  74 H. First radio-frequency transmission line  74 V may include conductive traces  122 V and  120 V on top surface  76  of circuit board  72 . Conductive traces  122 V and  120 V may form part of the signal conductor (e.g., signal traces  82  of  FIG.  6   ) for radio-frequency transmission line  74 V. Similarly, second radio-frequency transmission line  7411  may include conductive traces  12211  and  120 H on top surface  76  of circuit board  72 . Conductive traces  122 H and  120 H may form part of the signal conductor (e.g., signal traces  82  of  FIG.  6   ) for radio-frequency transmission line  74 H. 
     Conductive trace  122 V may be narrower than conductive trace  120 V. Conductive trace  122 H may be narrower than conductive trace  120 H. Conductive traces  120 V and  120 H may, for example, be conductive contact pads on top surface  76  of circuit board  72 . Feed conductor  84 V of feed probe  85 V may be mounted and coupled to conductive trace  120 V (e.g., using conductive interconnect structures  86  of  FIG.  6   ). Similarly, feed conductor  8411  of feed probe  8511  may be mounted and coupled to conductive trace  120 H. 
     Radio-frequency transmission line  74 V and feed probe  85 V may convey first radio-frequency signals having a first linear polarization (e.g., a vertical polarization). When driven using the first radio-frequency signals, feed probe  85 V may excite one or more electromagnetic modes of dielectric resonating element  92  associated with the first polarization. When excited in this way, wave fronts associated with the first radio-frequency signals may propagate along the length of dielectric resonating element  92  (e.g., along central/longitudinal axis  109 ) and may be radiated through the display (e.g., through display cover layer  56  of  FIG.  6   ). Sidewalls  102  may extend in the direction of central/longitudinal axis  109  (e.g., in the +Z direction). Central/longitudinal axis  109  may pass through the center of both the top and bottom surfaces of dielectric resonating element  92  (e.g., top surface  98  and bottom surface  100  of  FIG.  6   ). 
     Similarly, radio-frequency transmission line  74 H and feed probe  8511  may convey radio-frequency signals of a second linear polarization orthogonal to the first polarization (e.g., a horizontal polarization). When driven using the second radio-frequency signals, feed probe  85 H may excite one or more electromagnetic modes of dielectric resonating element  92  associated with the second polarization. When excited in this way, wave fronts associated with the second radio-frequency signals may propagate along the length of dielectric resonating element  92  and may be radiated through the display (e.g., through display cover layer  56  of  FIG.  6   ). Both feed probes  85 H and  85 V may be active at once so that antenna  40  conveys both the first and second radio-frequency signals at any given time. In another suitable arrangement, a single one of feed probes  85 H and  85 V may be active at once so that antenna  40  conveys radio-frequency signals of only a single polarization at any given time. 
     Dielectric resonating element  92  may have a first width  110 , a second width (thickness)  112 , and a height  114 . First width  110 , second width  112 , and height  114  may be selected to provide dielectric resonating element  92  with a corresponding mix of electromagnetic cavity/waveguide modes that, when excited by feed probes  85 H and/or  85 V, configure antenna  40  to radiate at desired frequencies. For example, height  114  may be 2-10 mm, 4-6 mm, 3-7 mm, 4.5-5.5 mm, 3-4 mm, 3.5 mm, or greater than 2 mm. Second width  112  and first width  110  may each be 0.5-1.0 mm, 0.4-1.2 mm, 0.7-0.9 mm, 0.5-2.0 mm, 1.5 mm-2.5 mm, 1.7 mm-1.9 mm, 1.0 mm-3.0 mm, etc. Second width  112  may be equal to first width  110  or, in other arrangements, may be different than first width  110 . Sidewalls  102  of dielectric resonating element  92  may contact the surrounding dielectric substrate (e.g., dielectric substrate  90  of  FIG.  6   ). The dielectric substrate may be molded over feed probes  85 H and  85 V or may include openings, notches, or other structures that accommodate the presence of feed probes  85 H and  85 V. The example of  FIG.  7    is merely illustrative and, if desired, dielectric resonating element  92  may have other shapes (e.g., shapes with any desired number of straight and/or curved sidewalls  102 ). 
     Feed conductors  84 V and  84 H may each have width  118  and height  116 . Width  118  and height  116  may be selected to match the impedance of radio-frequency transmission lines  74 V and  74 H to the impedance of dielectric resonating element  92 . As an example, width  118  may be between 0.3 mm and 0.7 mm, between 0.2 mm and 0.8 mm, between 0.4 mm and 0.6 mm, or other values. Height  116  may be between 0.3 mm and 0.7 mm, between 0.2 mm and 0.8 mm, between 0.4 mm and 0.6 mm, or other values. Height  116  may be equal to width  118  or may be different than width  118 . 
     If desired, transmission lines  74 V and  74 H may include one or more transmission line matching stubs such as matching stubs  124  coupled to traces  122 V and  122 H. Matching stubs  124  may help to ensure that the impedance of radio-frequency transmission lines  74 H and  74 V are matched to the impedance of dielectric resonating element  92 . Matching stubs  124  may have any desired shape or may be omitted. Feed conductors  84 V and  84 H may have other shapes (e.g., shapes having any desired number of straight and/or curved edges). 
     In general, it may be desirable for device  10  to exhibit as slim a thickness as possible (e.g., in the direction of the Z-axis of  FIG.  6   ). However, mounting dielectric resonating element  92  within peripheral region  66  can undesirably limit reductions in the thickness of device  10 . For example, the thickness of device  10  may be constrained by the height of dielectric resonating element  92  (e.g., height  114  of  FIG.  7   ) required to configure antenna  40  to convey radio-frequency signals at desired frequencies and with desired antenna efficiency. To allow for further reductions in the thickness of device  10 , the dielectric resonating elements  92  in peripheral region  66  of device  10  may be bent dielectric resonating elements (e.g., antenna  40  may be a bent dielectric resonator antenna). 
       FIG.  8    is a cross-sectional side view of device  10  showing one example of a bent dielectric resonating element that may be disposed in device  10  (e.g., for radiating through a dielectric cover layer such as display cover layer  56 ). As shown in  FIG.  8   , antenna  40  may be mounted to circuit board  72  and aligned with an opening between display module  68  and peripheral conductive housing structures  12 W. Rather than being formed from a single linear column of dielectric material (e.g., as shown in the examples of  FIGS.  6  and  7   ), dielectric resonating element  92  may be a bent dielectric resonating element. 
     When configured as a bent dielectric resonating element, dielectric resonating element  92  may have at least two segments that extend along different longitudinal axes (e.g., longitudinal axes that are non-parallel with respect to each other). For example, as shown in  FIG.  8   , dielectric resonating element  92  may include a first segment (portion)  128  that extends from bottom surface  100  of the dielectric resonating element and along a corresponding longitudinal axis  132 . Dielectric resonating element  92  may also have a second segment (portion)  130  that extends, from the end of first segment  128  opposite bottom surface  100 , and along longitudinal axis  134  to top surface  98  of dielectric resonating element  92 . Longitudinal axis  134  may be oriented at a non-parallel angle with respect to longitudinal axis  132 . For example, longitudinal axis  134  may be oriented perpendicular to longitudinal axis  132  (e.g., longitudinal axis  132  may extend parallel to the Y axis whereas longitudinal axis  134  extends parallel to the Z axis of  FIG.  8   ). This may configure dielectric resonating element  92  to have a perpendicular bend between bottom surface  100  and top surface  98 . The bent dielectric resonating element of  FIG.  8    may be manufactured using current sintering and a wire saw, as one example. First segment  128  and second segment  130  may be embedded (molded) within dielectric substrate  90  and mounted to circuit board  72 . 
     First segment  128  of dielectric resonating element  92  may have at least a first sidewall  140  and a second sidewall  146  opposite first sidewall  140  (e.g., on opposing sides of longitudinal axis  132 ). Feed probe  85  may be coupled to first sidewall  140  and may, if desired, be molded within dielectric substrate  90 . Feed probe  85  may be soldered to a signal trace on circuit board  72  (e.g., using a Surface Mount Technology (SMT) process when mounting antenna  40  to circuit board  72 ). Antenna  40  may also have a conductive structure  131  disposed on second sidewall  146  opposite feed probe  85 . Conductive structure  131  may include a feed probe for antenna  40  (e.g., a feed probe  85  for covering additional polarizations as shown in  FIG.  7   ), may include a parasitic element (e.g., a parasitic patch) pressed against dielectric resonating element  92  and coupled to ground, or may be omitted. When conductive structure  131  is a feed probe, conductive structure  131  may be coupled to a signal trace on circuit board  72  (e.g., conductive traces  82  of  FIG.  6   ). When conductive structure  131  is a parasitic element, conductive structure  131  may be soldered to a ground trace on circuit board  72 . Conductive structure  131  need not be disposed on the sidewall opposite feed probe  85  and may, if desired, be disposed on one or more sidewalls extending between sidewalls  146  and  140  (not shown in the cross-sectional side view of  FIG.  8   ). 
     First segment  128  may have a length extending parallel to longitudinal axis  132  from bottom surface  100  to second segment  130 . First segment  128  may also have a width measured from sidewall  146  to sidewall  140  that is less than the length of first segment  128 . The length of first segment  128  may be less than the length of the dielectric resonating element in scenarios where the dielectric resonating element is a straight, unbent column (e.g., height  114  of  FIG.  7   ). The width of first segment  128  may, for example, be less than the length of first segment  128 . 
     Second segment  130  of dielectric resonating element  92  may have at least a first sidewall  142  and a second sidewall  144  opposite first sidewall  142  (e.g., on opposing sides of longitudinal axis  134 ). Second segment  130  may have a length extending parallel to longitudinal axis  134  from first segment  128  to top surface  98 . Second segment  130  may also have a width measured from first sidewall  142  to second sidewall  144 . The width of second segment  130  may, for example, be less than the length of second segment  130 . The length of second segment  130  may be less than the length of the dielectric resonating element in arrangements where the dielectric resonating element is a straight, unbent column (e.g., height  114  of  FIG.  7   ). The dielectric resonating element  92  of  FIG.  8    having first segment  128  and second segment  130  may sometimes be referred to herein as a bent dielectric resonating element or an angled dielectric resonating element. 
     The length of first segment  128  and the length of the second segment  130  may be selected to configure dielectric resonating element  92  to exhibit an overall length (e.g., as given by the sum of the first length and the second length) that is approximately equal to the length of the dielectric resonating element in scenarios where the dielectric resonating element is a straight, unbent column (e.g., the length of the first segment plus the length of the second segment may be approximately equal to height  114  of  FIG.  7   ). This may configure dielectric resonating element  92  to exhibit a similar mix of electromagnetic resonant modes as in arrangements where dielectric resonating element  92  is a straight, unbent column (e.g., as shown in  FIGS.  6  and  7   ), which configures dielectric resonating element  92  to convey radio-frequency signals at the desired frequencies greater than 10 GHz with satisfactory antenna efficiency when excited by feed probe  85 . 
     At the same time, bending dielectric resonating element  92  in this way may configure antenna  40  to exhibit an overall height  126 , as defined by the sum of the width of first segment  128 , the length of second segment  130 , and the portion of dielectric substrate  90  between first segment  128  and bottom end  148  of dielectric substrate  90 . Overall height  126  may be less than the length of the dielectric resonating element in arrangements where the dielectric resonating element is a straight, unbent column (e.g., overall height  126  may be less than height  114  of  FIG.  6   ). This may allow antenna  40  to fit within device  10  while minimizing the overall thickness of device  10 . 
     While bending (angling) dielectric resonating element  92  in this way may allow for a reduction in the thickness of device  10 , if care is not taken, the bent dielectric resonating element may exhibit deteriorated radio-frequency performance relative to arrangements in which the dielectric resonating element is a straight, unbent column. For example, if sidewalls  140  and  142  meet at a right angle, the right angle may cause unpredictable reflections of the radio-frequency signals excited in first segment  130 , preventing a substantial amount of the electromagnetic energy from radiating through top surface  98  of dielectric resonating element  92  and limiting the overall performance of the antenna. 
     To optimize the radio-frequency performance of antenna  40 , dielectric resonating element  92  may be provided with a surface  136  that couples sidewall  140  of first segment  128  to sidewall  142  of second segment  130 . Surface  136  may be referred to herein as an angled surface  136  because surface  136  extends from sidewall  140  to sidewall  142  at an angle that is nonparallel with respect to the lateral plane of both sidewall  140  and sidewall  142  (e.g., at an angle that is nonparallel and thus non-zero with respect to both longitudinal axes  132  and  134 ). Angled surface  136  may sometimes be referred to herein as angled face  136 , angled sidewall  136 , or angled wall  136  of dielectric resonating element  92 . If desired, the angle of angled surface  136  (e.g., as measured with respect to the Y-axis of  FIG.  8   ) may be selected to reflect electromagnetic energy propagating along dielectric resonating element  92  within a total internal reflection (TIR) range of the first segment  128  and second segment  130 . As examples, angled surface  136  may be oriented at a 45-degree angle, a 30-degree angle, a 60-degree angle, an angle between 30-60 degrees, an angle between 10-70 degrees, or other angles with respect to the Y-axis. Angled surface  136  may be planar or may be non-planar (e.g., curved). 
     For example, during signal transmission, feed probe  85  may excite first segment  128  of dielectric resonating element  92  to produce electromagnetic waves that propagate in direction  150 . The electromagnetic waves may reflect off angled surface  136  and into second segment  130 , which propagates the electromagnetic waves upwards (as shown by direction  152 ) and through top surface  98 . This process may be reversed during signal reception. Angled surface  136  may help to ensure that a maximum amount of the electromagnetic energy (radio-frequency signals) propagating through first segment  128  is transferred to second segment  130  and vice versa. 
     To further optimize the radio-frequency signal reflection performed by angled surface  136  and thus the radio-frequency performance of antenna  40 , a reflective structure such as reflector  138  may be provided at or on angled surface  136 . Reflector  138  is a different material from the material of dielectric substrate  90  and dielectric resonating element  92 . Reflector  138  may increase or augment the impedance discontinuity between dielectric material  92  and dielectric substrate  90  to maximize the reflective characteristics of angled surface  136  at radio frequencies. As one example, reflector  138  may include an air gap between dielectric substrate  90  and angled surface  136 . As another example, reflector  138  may include a dielectric material (e.g., a dielectric coating) disposed on angled surface  136  and embedded within dielectric substrate  90 . The dielectric material may have a dielectric constant that is farther from the dielectric constant of dielectric resonating element  92  than dielectric substrate  90 . As yet another example, reflector  138  may include a conductive material that is disposed on angled surface  136  and embedded within dielectric substrate  90 . The conductive material may include a conductive patch, stamped sheet metal, a metal plate, or metal foil that is affixed, pressed against, adhered to, or otherwise coupled to angled surface  136  (e.g., by dielectric substrate  90 ), or may include a conductive (e.g., metal) film, a conductive trace, or a conductive (e.g., metal) coating that is deposited (e.g., plated) onto angled surface  136  (e.g., using an LDS process, a sputtering process, a physical vapor deposition process, etc.) prior to molding dielectric substrate  90  over the dielectric resonating element. Reflector  138  may sometimes be referred to herein as reflector structure  138  or reflective structure  138 . Metal materials may be particularly suitable for reflector  138  because metal exhibits a high reflectance at frequencies greater than 10 GHz. Such a reflector may be disposed using additional masking, plating, and/or coating operations during the manufacturing process of antenna  40  (e.g., after fabricating dielectric resonating element  92  using sintering and a wire saw). 
     In this way, antenna  40  may be configured to exhibit similar radio-frequency performance (e.g., antenna efficiency) in conveying radio-frequency signals through display cover layer  56  as in arrangements where the dielectric resonating element is a straight, unbent column, while also decoupling the thickness of device  10  from the length of dielectric resonating element  92  required to cover desired frequencies of interest. In other words, providing antenna  40  with a bent dielectric resonating element in this way may reduce the overall thickness of device  10  without deteriorating the radio-frequency performance of antenna  40  (e.g., at frequencies greater than 10 GHz) relative to arrangements in which the dielectric resonating element is a straight, unbent column. 
     The example of  FIG.  8    is merely illustrative. If desired, dielectric resonating element  92  may include more than two segments that follow other longitudinal axes and that are coupled together using angled surfaces such as angled surface  136  and reflectors such as reflector  138 . This may allow the dielectric resonating element to follow a meandering path from bottom surface  100  to top surface  98  to fit into other device form factors. Reflector  138  may overlap or cover all of angled surface  136  or only a portion of angled surface  136 . Bottom end  148  of dielectric substrate  90  may be mounted to circuit board  72  or, if desired, circuit board  72  may be mounted (e.g., soldered) to bottom surface  100  of dielectric resonating element  92  (e.g., some or all of circuit board  72  may be oriented vertically such that the lateral surface of some or all of the circuit board extends within the X-Z plane of  FIG.  8   ). 
     Dielectric resonating element  92  may have any desired cross-sectional shape (e.g., as viewed in direction  150 , direction  152 , or a direction parallel to the plane of angled surface  136 ). As one example, dielectric resonating element  92  may have a rectangular (e.g., square) cross section. A rectangular cross section may maximize ceramic utilization, for example. As another example, dielectric resonating element  92  may have a hexagonal cross-sectional shape (profile). 
       FIG.  9    is a cross-sectional view (e.g., as viewed in direction  150 , direction  152 , or a direction parallel to the plane of angled surface  136 ) showing how dielectric resonating element  92  may have a hexagonal cross section or profile. As shown in  FIG.  9   , dielectric resonating element  92  may have a hexagonal cross section with six sidewalls  154  (e.g., sidewalls of equal length). The longitudinal axis of dielectric resonating element  92  may extend through the center of the dielectric resonating element into and out of the plane of the page. 
     Within first segment  128  ( FIG.  8   ), one or more feed probes  85  may be disposed on one or more sidewalls  154  of dielectric resonating element  92  (e.g., adjacent sidewalls  154 ). If desired, parasitic elements (e.g., conductive structure  131  of  FIG.  8   ) may be disposed on the sidewall(s)  154  opposite to the sidewall(s)  154  where the feed probes are disposed. Where first segment  128  meets second segment  130  ( FIG.  8   ), sidewalls  154  may form angled surfaces such as angled surface  136  of  FIG.  8    (e.g., six angled surfaces that extend parallel to each other and angled surface  136  of  FIG.  8   ). One or more sidewalls  154  (e.g., a pair of adjacent sidewalls  154 , a pair of opposing sidewalls  154 , all six sidewalls  154 , etc.) may be provided with respective reflectors  138  for reflecting radio-frequency signals between the first and second segments of the dielectric resonating element. This may allow the reflectors to fully reflect and couple radio-frequency signals of different polarizations between the first segment and the second segment, for example. The hexagonal profile of  FIG.  9    may be particularly suitable for reflecting horizontally and vertically polarized radio-frequency signals excited on the first segment by a pair of feed probes  85  (e.g., because dielectric resonating elements having a rectangular cross section may produce undesirable mixing between orthogonal polarizations in reflecting radio-frequency signals between the first and second segments, whereas reflecting off of angled surfaces that follow a hexagonal cross-sectional profile minimize such mixing). The example of  FIG.  9    is merely illustrative and, in general, dielectric resonating element  92  may have any desired cross-sectional shape or profile (e.g., having any desired number of straight and/or curved sides of any desired length). 
     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: 20220211
Publication Date: 20240220
Grant Date: 20240220
Priority Date: 20220211
Inventors: Compton, Lucas R.
RAJAGOPALAN, HARISH
HANDY, JAMES T.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q15/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0017", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q15/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2258", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/242", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0492", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/245", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q15/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0017", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 87558056