Patent Publication Number: US-11658404-B2

Title: Electronic devices having housing-integrated dielectric resonator antennas

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, the presence of conductive electronic device components can make it difficult to incorporate circuitry for handling millimeter and centimeter wave communications into the electronic device. 
     It would therefore be desirable to be able to provide electronic devices with improved wireless communications circuitry such as communications circuitry that supports millimeter and centimeter wave communications. 
     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. An aperture may be formed in the peripheral conductive housing structures. The wireless circuitry may include a phased antenna array. The phased antenna array may include a dielectric resonator antenna. 
     The dielectric resonator antenna may include a dielectric resonating element aligned with the aperture. A feed probe may be coupled to the dielectric resonating element. The feed probe may excite the dielectric resonating element to radiate through the aperture at a frequency greater than 10 GHz. The dielectric resonator antenna may include an injection-molded plastic substrate that affixes the dielectric resonating element to the peripheral conductive housing structures, thereby integrating the dielectric resonating element into the peripheral conductive housing structures. The feed probe and the dielectric resonating element may be embedded within the injection-molded plastic substrate. The injection-molded plastic substrate may include a first shot of injection-molded plastic over the feed probe and a second shot of injection-molded plastic over the first shot of injection-molded plastic and the dielectric resonating element. 
     A hole or other machining operation may be used to expose the feed probe through the injection-molded plastic substrate. Conductive interconnect structures such as a conductive pin may be inserted into the hole and coupled to the feed probe. The conductive interconnect structures may be soldered to a circuit board. The circuit board may be coupled to the feed probe through the conductive interconnect structures. The circuit board may be interposed between the dielectric resonating element and the display. In another suitable arrangement, the dielectric resonating element may be interposed between the circuit board and the aperture. 
    
    
     
       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 perspective view of an illustrative dielectric resonator antenna in accordance with some embodiments. 
         FIG.  7    is a cross-sectional side view showing how an illustrative rear-fed dielectric resonator antenna may be integrated within conductive housing structures of an electronic device in accordance with some embodiments. 
         FIG.  8    is a cross-sectional side view showing how an illustrative side-fed dielectric resonator antenna may be integrated within conductive housing structures of an electronic device 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 . 
     In order to provide an end user of device  10  with as large of a display as possible (e.g., to maximize an area of the device used for displaying media, running applications, etc.), it may be desirable to increase the amount of area at the front face of device  10  that is covered by active area AA of display  14 . Increasing the size of active area AA may reduce the size of inactive area IA within device  10 . This may reduce the area behind display  14  that is available for antennas within device  10 . For example, active area AA of display  14  may include conductive structures that serve to block radio-frequency signals handled by antennas mounted behind active area AA from radiating through the front face of device  10 . It would therefore be desirable to be able to provide antennas that occupy a small amount of space within device  10  (e.g., to allow for as large of a display active area AA as possible) while still allowing the antennas to communicate with wireless equipment external to device  10  with satisfactory efficiency bandwidth. 
     In a typical scenario, device  10  may have one or more upper antennas and one or more lower antennas. An upper antenna may, for example, be formed in upper region  20  of device  10 . A lower antenna may, for example, be formed in lower region  22  of device  10 . Additional antennas may be formed along the edges of housing  12  extending between regions  20  and  22  if desired. An example in which device  10  includes three or four upper antennas and five lower antennas is described herein as an example. The antennas may be used separately to cover identical communications bands, overlapping communications bands, or separate communications bands. The antennas may be used to implement an antenna diversity scheme or a multiple-input-multiple-output (MIMO) antenna scheme. Other antennas for covering any other desired frequencies may also be mounted at any desired locations within the interior of device  10 . The example of  FIG.  1    is merely illustrative. If desired, housing  12  may have other shapes (e.g., a square shape, cylindrical shape, spherical shape, combinations of these and/or different shapes, etc.). 
     A schematic diagram of illustrative components that may be used in device  10  is shown in  FIG.  2   . As shown in  FIG.  2   , device  10  may include control circuitry  28 . Control circuitry  28  may include storage such as storage circuitry  30 . Storage circuitry  30  may include hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. 
     Control circuitry  28  may include processing circuitry such as processing circuitry  32 . Processing circuitry  32  may be used to control the operation of device  10 . Processing circuitry  32  may include on one or more microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, central processing units (CPUs), etc. Control circuitry  28  may be configured to perform operations in device  10  using hardware (e.g., dedicated hardware or circuitry), firmware, and/or software. Software code for performing operations in device  10  may be stored on storage circuitry  30  (e.g., storage circuitry  30  may include non-transitory (tangible) computer readable storage media that stores the software code). The software code may sometimes be referred to as program instructions, software, data, instructions, or code. Software code stored on storage circuitry  30  may be executed by processing circuitry  32 . 
     Control circuitry  28  may be used to run software on device  10  such as 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  and/or across portions of hemispheres around the lateral edges 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. The presence of peripheral conductive housing structures  12 W may also prevent a front-facing phased antenna array from providing adequate coverage around the lateral periphery of device  10 . 
     In order to help mitigate these issues, a side-facing phased antenna array may be mounted within peripheral region  66 . The side-facing phased antenna array may radiate through one or more apertures in peripheral conductive housing structures  12 W (e.g., through the side of device  10 ). Additionally or alternatively, a front-facing phased antenna array may be mounted within peripheral region  66  of device  10  for radiating through display cover layer  56 . In one suitable arrangement that is described herein as an example, the antennas in the side-facing phased antenna array may include dielectric resonator antennas. Dielectric resonator antennas may occupy less area 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 side-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 . 
       FIG.  6    is a perspective view of an illustrative dielectric resonator antenna that may be formed in a side-facing phased antenna array of device  10 . As shown in  FIG.  6   , antenna  40  may include a dielectric resonating element such as dielectric resonating element  92 . Dielectric resonating element  92  may be mounted to an underlying substrate such as printed circuit  72 . Printed circuit  72  may be a flexible printed circuit or a rigid printed circuit board (PCB). Printed circuit  72  may include one or more stacked dielectric layers. The stacked dielectric layers may include polyimide, ceramic, liquid crystal polymer, plastic, and/or any other desired materials. Conductive traces may be patterned onto one or more of the stacked dielectric layers. This example is merely illustrative and, if desired, printed circuit  72  may be replaced with a plastic substrate or any other desired substrate. 
     As shown in  FIG.  6   , conductive traces such as conductive traces  70  may be patterned onto the bottom surface of printed circuit  72 . Conductive traces  70  may be held at a ground potential and may therefore sometimes be referred to herein as ground traces  70 . Ground traces  70  may be shorted to additional ground traces within printed circuit  72  and/or on the opposing surface  76  of printed circuit  72  (e.g., using conducive vias that extend through printed circuit  72 ). Ground traces  70  may form part of the antenna ground for antenna  40 . Ground traces  70  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  70  may be coupled to peripheral conductive housing structures  12 W ( FIG.  5   ), conductive portions of rear housing wall  12 R, or other grounded structures in device  10 . 
     Antenna  40  may be fed using one or more radio-frequency transmission lines that are formed on and/or embedded within printed circuit  72 . In the example of  FIG.  6   , antenna  40  is a dual-polarization antenna having a first radio-frequency transmission line  74 V and a second radio-frequency transmission line  74 H. The signal conductor of radio-frequency transmission line  74 V (e.g., signal conductor  46  of  FIG.  3   ) may be formed from conductive traces  88 V and  90 V patterned onto surface  76  of substrate  72 . The signal conductor of radio-frequency transmission line  74 H may be formed from conductive traces  88 H and  90 H patterned onto surface  76  of substrate  72 . Conductive trace  88 V may be narrower than conductive trace  90 V. Conductive trace  88 H may be narrower than conductive trace  90 H. Conductive traces  90 V and  90 H may, for example, be conductive contact pads on surface  76  of printed circuit  72 . 
     If desired, conductive traces  88 V and/or  88 H may include one or more impedance matching structures such as transmission line stubs  82 . Transmission line stubs  82  may have any desired shape or may be omitted. The impedance matching structures may help to match the impedance of the radio-frequency transmission lines to the impedance of antenna  40 . Conductive traces  88 V,  90 V,  88 H, and  90 H may have other shapes (e.g., shapes having any desired number of straight and/or curved edges). 
     Dielectric resonating element  92  of antenna  40  may be formed from a column (pillar) of dielectric material mounted or otherwise coupled to surface  76  of printed circuit  72 . If desired, dielectric resonating element  92  may be embedded within (e.g., laterally surrounded by) a dielectric substrate mounted to surface  76  of printed circuit  72  (not shown in  FIG.  6    for the sake of clarity). The operating (resonant) frequency of antenna  40  may be selected by adjusting the dimensions of dielectric resonating element  92 . 
     Dielectric resonating element  92  may be formed from a column of dielectric material having a first dielectric constant d k1 . Dielectric constant d k1  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. The dielectric substrate surrounding dielectric resonating element  92  may have a dielectric constant that differs from the dielectric constant of dielectric resonating element  92  by at least a predetermined margin. The difference in dielectric constant between dielectric resonating element  92  and the surrounding dielectric substrate may establish a strong radio-frequency boundary condition that configures dielectric resonating element  92  to serve as a waveguide for propagating radio-frequency signals at millimeter and centimeter wave frequencies. 
     Dielectric resonating element  92  may radiate radio-frequency signals  106  when excited by the signal conductor for radio-frequency transmission lines  74 V or  74 H. Antenna  40  may be fed using one or more radio-frequency feed probes such as feed probes  78 V and  78 H. Feed probes  78 V and  78 H 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  78 V may include feed conductor  84 V. Feed probe  78 H may include feed conductor  84 H. In one suitable arrangement that is described herein as an example, feed conductors  84 V and  84 H may be formed from stamped sheet metal that has been folded into a desired shape and that is press against sidewalls  102  of dielectric resonating element  92 . If desired, biasing structures (not shown in  FIG.  6    for the sake of clarity) may hold or press feed conductors  84 V and  84 H against sidewalls  102  to help ensure a reliable coupling between the feed conductors and the dielectric resonating element. In another suitable arrangement, feed conductors  84 V and  84 H may be formed from conductive traces that are patterned directly onto sidewalls  102  (e.g., using a laser direct structuring (LDS) process, a sputtering process, or other conductive metallization techniques). 
     Feed conductor  84 V may have a first portion on a first sidewall  102  of dielectric resonating element  92 . Feed conductor  84 V may have a second portion coupled to conductive traces  90 V using conductive interconnect structures  86 . Conductive interconnect structures  86  may include solder, conductive pins (e.g., pogo pins), welds, conductive adhesive, conductive tape, conductive foam, conductive springs, conductive brackets, conductive traces, and/or any other desired conductive interconnect structures. Similarly, feed conductor  84 H may have a first portion on a second sidewall  102  of dielectric resonating element  92 . Feed conductor  84 H may have a second portion coupled to conductive traces  90 H using conductive interconnect structures  86 . 
     Radio-frequency transmission line  74 V may convey radio-frequency signals to and from feed probe  78 V. Radio-frequency transmission line  74 H may convey radio-frequency signals to and from feed probe  78 H. Feed probes  78 V and  78 H may electromagnetically couple the radio-frequency signals into dielectric resonating element  92 . This may serve to excite one or more electromagnetic modes (e.g., radio-frequency cavity or waveguide modes) of dielectric resonating element  92 . When excited by feed probe  78 V and/or feed probe  78 H, 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  106  along the length of dielectric resonating element  92  and through the top surface of dielectric resonating element  92  (e.g., in the direction of the central/longitudinal axis  80  of dielectric resonating element  92 ). 
     For example, during signal transmission, radio-frequency transmission lines  74 H and  74 V may supply radio-frequency signals from the millimeter/centimeter wave transceiver circuitry to antenna  40 . Feed probes  78 V and  78 H may couple the radio-frequency signals 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  106  up the length of dielectric resonating element  92 . Similarly, during signal reception, radio-frequency signals  106  may be received by dielectric resonating element  92 . 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 probes  78 V and  78 H may couple the received radio-frequency signals onto radio-frequency transmission lines  74 V and  74 H, which pass the radio-frequency signals to the millimeter/centimeter wave transceiver circuitry. 
     If desired, the dimensions of feed probes  78 V and  78 H may be selected to help match the impedance of radio-frequency transmission lines  74 V and  74 H to the impedance of dielectric resonating element  92 . For example, feed conductors  84 V and  84 H may each have width  94  and height  96 . Width  94  and height  96  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 examples, width  94  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  96  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  96  may be equal to width  94  or may be different than width  94 . 
     Feed probes  78 V and  78 H may be coupled to orthogonal sidewalls  102  of dielectric resonating element  92 . Feeding antenna  40  using both feed probes  78 V and  78 H may 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 probes  78 V and  78 H may sometimes be referred to herein as feed conductors, feed patches, or probe feeds. 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 probes  78 V and  78 H, dielectric resonator antennas such as antenna  40  of  FIG.  6    may sometimes be referred to herein as probe-fed dielectric resonator antennas. 
     Radio-frequency transmission line  74 V and feed probe  78 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  78 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  80 ) and may be radiated into free space. Similarly, radio-frequency transmission line  74 H and feed probe  78 H 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  78 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 into free space. Both feed probes  78 H and  78 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  78 H and  78 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 length  100 , a width  104  (e.g., measured orthogonal to length  100 ), and a height  98  (e.g., measured parallel to central/longitudinal axis  80  and orthogonal to length  100  and width  104 ). Length  100 , width  104 , and height  98  may be selected to provide dielectric resonating element  92  with a corresponding mix of electromagnetic cavity/waveguide modes that, when excited by feed probes  78 H and/or  78 V, configure antenna  40  to radiate at desired frequencies. For example, height  98  may be 2-10 mm, 4-6 mm, 3-7 mm, 4.5-5.5 mm, or greater than 2 mm. Width  104  and length  100  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. Width  104  may be equal to length  100  or, in other arrangements, may be different than length  100 . Sidewalls  102  of dielectric resonating element  92  may contact the surrounding dielectric substrate (not shown in  FIG.  6    for the sake of clarity). 
     The example of  FIG.  6    is merely illustrative. Dielectric resonating element  92  may have other shapes (e.g., shapes having any desired number of curved and/or straight edges or surfaces). Antenna  40  need not be a dual-polarization antenna and may, if desired, be a single-polarization antenna. In arrangements where antenna  40  is a single-polarization antenna, feed probe  78 H and conductive traces  90 H and  88 H may be omitted. If desired, one or more optional parasitic patches may be coupled to one or more sidewalls  102  of dielectric resonating element  92 . 
     In one suitable arrangement that is described herein as an example, antenna  40  of  FIG.  6    may form a part of a side-facing phased antenna array that radiates through one or more apertures in peripheral conductive housing structures  12 W ( FIG.  5   ). This is merely illustrative and, in other arrangements, antenna  40  may not be a part of any phased antenna array. In some scenarios, antennas such as antenna  40  are formed within an integrated antenna module along with each other antenna in a corresponding phased antenna array. A dielectric substrate is molded around each of the dielectric resonating elements in the phased antenna array on the antenna module. The antenna module is then mounted within device  10 . However, forming the phased antenna array within an integrated antenna module that is mounted into device  10  may undesirably increase the cost and manufacturing complexity of device  10  and can undesirably limit mechanical reliability. In order to mitigate these issues, antenna  40  of  FIG.  6    may be integrated directly into the housing of device  10  (e.g., housing  12  of  FIG.  1   ). 
       FIG.  7    is a cross-sectional side view showing one example of how antenna  40  may be integrated directly into the housing of device  10 . As shown in  FIG.  7   , antenna  40  may be a side-facing antenna that is aligned with an aperture such as aperture  118  in peripheral conductive housing structures  12 W. Antenna  40  of  FIG.  7    may form a part of a larger phased antenna array (e.g., a one-dimensional phased antenna array having multiple antennas  40  for radiating through peripheral conductive housing structures  12 W). Each antenna in the phased antenna array may radiate through the same aperture  118  or may radiate through multiple apertures  118  (e.g., respective apertures for each antenna in the phased antenna array). 
     As shown in  FIG.  7   , dielectric resonating element  92  may be oriented such that central/longitudinal axis  80  lies within a plane parallel to the front/rear faces of device  10  (e.g., central/longitudinal axis  80  may lie within a plane parallel to the X-Y plane of  FIG.  7   ). Dielectric resonating element  92  may be aligned with aperture  118 . Aperture  118  (sometimes referred to herein as slot  118  or antenna window  118 ) may allow antenna  40  to convey radio-frequency signals  106  through peripheral conductive housing structures  12 W. A dielectric cover layer such as dielectric cover layer  120  (e.g., a cosmetic window) may overlap and fill aperture  118  to protect antenna  40  and the interior of device  10  from damage or contaminants. If desired, a layer of adhesive such as adhesive  122  may help to adhere dielectric cover layer  120  to peripheral conductive housing structures  12 W. Adhesive  122  may also adhere surface  128  of dielectric resonating element  92  to dielectric cover layer  120  if desired. 
     Dielectric resonating element  92  may have a surface  130  that opposes surface  128 . Sidewalls  102  of dielectric resonating element  92  may extend from surface  130  to surface  128  (e.g., along central/longitudinal axis  80 ). Feed conductor  84  (e.g., feed conductor  84 V or  84 H of  FIG.  6   ) of feed probe  78  (e.g., feed probe  78 V or  78 H of  FIG.  6   ) may be coupled to a given sidewall  102  of dielectric resonating element  92  at or adjacent to surface  130 . Conductive interconnect structures  86  may couple feed probe  78  to printed circuit  72 . The lateral area of printed circuit  72  may extend parallel to the X-Z plane of  FIG.  7    in this example. If desired, each of the antennas in the side-facing phased antenna array may be coupled to and fed by the same printed circuit  72 . If desired, a radio-frequency integrated circuit (RFIC) such as RFIC  110  may be mounted to printed circuit  72 . RFIC  110  may be encapsulated within overmold  108 , thereby forming a corresponding antenna module  111  that includes RFIC  110 , overmold  108 , and printed circuit  72 . RFIC  110  may include upconversion and downconversion circuitry and phase and magnitude controllers (e.g., phase and magnitude controllers  50  of  FIG.  4   ) for each of the antennas in the side-facing phased antenna array, for example. Antenna module  111  may rest against rear housing wall  12 R if desired. 
     Peripheral conductive housing structures  12 W may include a ledge structure such as ledge  114  (sometimes referred to herein as datum  114 ). Display  14  may be mounted to ledge  114  of peripheral conductive housing structures  12 W. If desired, a layer of adhesive such as adhesive  112  may be used to adhere display cover layer  56  to ledge  114 . Antenna  40  may be vertically interposed between ledge  114  and rear housing wall  12 R. 
     Dielectric resonating element  92  may be embedded within dielectric substrate  116 . Dielectric substrate  116  may surround each sidewall  102  of dielectric resonating element  92 . Dielectric substrate  116  may, for example, be an injection-molded plastic substrate that serves to affix dielectric resonating element  92  to peripheral conductive housing structures  12 W, thereby integrating dielectric resonating element  92  and thus antenna  40  directly into the housing of device  10 . Dielectric substrate  116  may cover an entirety of dielectric resonating element  92  except for surface  128  and portions of surface  130  that are not covered by conductive interconnect structures  86 , for example. Dielectric substrate  116  may extend from a first surface  126  to aperture  118  (e.g., dielectric substrate  116  may have a second surface opposite first surface  126  that lies flush with surface  128  of dielectric resonating element  92 ). Printed circuit  72  may be mounted to surface  126  of dielectric substrate  116 . Dielectric substrate  116  may be molded over feed probe  78  and/or may include openings, notches, or other structures that help to accommodate the presence of feed probe  78 . 
     Dielectric substrate  116  may be formed from a material having dielectric constant d k2 . Dielectric constant d k2  may be less than the dielectric constant d k1  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 d k2  may be less than dielectric constant d k1  by at least 10.0, 5.0, 15.0, 12.0, 6.0, etc. The difference in dielectric constant between dielectric resonating element  92  and dielectric substrate  116  may establish a strong radio-frequency boundary condition between dielectric resonating element  92  and dielectric substrate  116  from surface  130  to surface  128 . This may configure dielectric resonating element  92  to serve as a waveguide for propagating radio-frequency signals at millimeter and centimeter wave frequencies. If desired, the width of dielectric substrate  116  (e.g., measured parallel to the Z-axis of  FIG.  7   ) may be selected to isolate dielectric resonating element  92  from peripheral conductive housing structures  12 W and to minimize signal reflections in dielectric substrate  116 . 
     The relatively large difference in dielectric constant between dielectric resonating element  92  and dielectric substrate  116  may allow dielectric resonating element  92  to convey radio-frequency signals  106  through dielectric cover layer  120  and aperture  118  with a relatively high antenna efficiency (e.g., by establishing a strong boundary between dielectric resonating element  92  and dielectric substrate  116  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. 
     Antenna  40  may be integrated into peripheral conductive housing structures  12 W using any desired manufacturing methods. Device  10  may be assembled using manufacturing equipment. In one suitable arrangement, the manufacturing equipment may perform a two-stage molding operation to integrate antenna  40  into device  10 . In the two-stage molding operation, the manufacturing equipment may first produce feed probe  78  (e.g., from stamped sheet metal). The manufacturing equipment may then press and hold feed probe  78  against dielectric resonating element  92  (e.g., using biasing structures, retention elements, or other equipment). The manufacturing equipment may then perform a first injection molding operation in which a portion of dielectric substrate  116  (e.g., a first shot of injection-molded plastic) is injection molded over feed probe  78  to ensure that feed probe  78  is held in place during further assembly. 
     The manufacturing equipment may then hold dielectric resonating element  92  and the molded feed probe  78  in place within a cavity in peripheral conductive housing structures  12 W (e.g., where the cavity is vertically interposed between ledge  114  and rear housing wall  12 R and is aligned with aperture  118 ). The manufacturing equipment may hold these components in place from the interior of device  10  or from the exterior of device  10  (e.g., through aperture  118  prior to deposition of adhesive  122  or dielectric cover layer  120 ). While these components are being held in place, the manufacturing equipment may perform a second injection molding operation in which the remainder of dielectric substrate  116  (e.g., a second shot of injection-molded plastic) is injection molded into the cavity and over the remainder of dielectric resonating element  92 . The second injection molding operation may lock dielectric resonating element  92  into place within the cavity, thereby integrating antenna  40  into peripheral conductive housing structures  12 W. 
     After dielectric substrate  116  has been injection-molded into peripheral conductive housing structures  12 W, the manufacturing equipment may drill or mill a hole in dielectric substrate  116  to accommodate conductive interconnect structures  86 . The manufacturing equipment may then couple conductive interconnect structures  86  to feed probe  78  through the hole in dielectric substrate  116 . This is merely illustrative and, in general, any desired machining operation may be used to expose feed probe  78  through dielectric substrate  116 . Once conductive interconnect structures  86  are in place, the manufacturing equipment may mount antenna module  111  (e.g., printed circuit  72 ) to conductive interconnect structures  86  (e.g., using low temperature solder). As an example, conductive interconnect structures  86  may include conductive pins that couple contact pads on printed circuit  72  (e.g., conductive traces  90 V and  90 H of  FIG.  6   ) to feed probe  78  through milled or drilled holes in dielectric substrate  116  or that are otherwise coupled to feed probe  78  as exposed through dielectric substrate  116 . 
     This process may be performed for each antenna in the side-facing phased antenna array in sequence or in parallel. Each antenna in the side-facing phased antenna array may be embedded within a respective dielectric substrate  116  if desired. Each antenna in the side-facing phased antenna array may convey radio-frequency signals within the same frequency band or, if desired, the side-facing phased antenna array may include at least first and second sets of antennas for covering at least first and second frequency bands. The first and second sets of antennas may be arranged in an interleaved pattern across the side-facing phased antenna array. 
     This example is merely illustrative. In general, other manufacturing and assembly methods may be used to integrate antenna  40  within peripheral conductive housing structures  12 W. In another suitable arrangement, feed probe  78  may be formed from conductive traces that are patterned directly onto dielectric resonating element  92 . In this arrangement, antenna  40  may be embedded within peripheral conductive housing structures  12 W using only a single injection molding operation if desired (e.g., using only a single shot of injection-molded plastic). While only a single feed probe  78  is shown in  FIG.  7    for the sake of clarity, antenna  40  may include multiple feed probes if desired (e.g., feed probes  78 V and  78 H of  FIG.  6   ). 
     In the example of  FIG.  7   , antenna  40  is a rear-fed dielectric resonator antenna because printed circuit  72 , which feeds antenna  40 , is coupled to the rear surface of dielectric substrate  116  and dielectric resonating element  92  (e.g., surfaces  126  and  130 ). In another suitable arrangement, antenna  40  may be a side-fed dielectric resonator antenna in which printed circuit  72  is coupled to a side surface of dielectric substrate  116  and dielectric resonating element  92 .  FIG.  8    is a cross-sectional side view showing how antenna  40  may be a side-fed dielectric resonator antenna integrated (molded) into peripheral conductive housing structures  12 W. 
     As shown in  FIG.  8   , dielectric substrate  116  may have a side surface such as surface  134 . Surface  134  may contact the bottom side of ledge  114  of peripheral conductive housing structures  12 W. Surface  134  may extend from surface  126  to aperture  118 . Printed circuit  72  of antenna module  111  may be mounted to surface  134  of dielectric substrate  116 . Conductive interconnect structures  86  may be placed within a hole in dielectric substrate  116  and may couple printed circuit  72  to feed probe  78 . This is merely illustrative and, in general, any desired machining operation may be used to expose feed probe  78  through dielectric substrate  116  for conductive interconnect structures  86 . Printed circuit  72  may rest on surface  134  of dielectric substrate  116 . The lateral area of printed circuit  72  may extend parallel to the X-Y plane of  FIG.  8   . If desired, the housing of device  10  may include an optional retention member  132  that extends from rear housing wall  12 R towards display cover layer  56 . Retention member  132  may be formed from an integral portion of rear housing wall  12 R or from a conductive frame for device  10 , as examples. Retention member  132  may be formed from conductive material or from dielectric. Retention member  132  may help to hold dielectric substrate  116  and antenna  40  in place during and/or after the injection molding process. The same injection molding processes as described in connection with  FIG.  7    may be used to embed antenna  40  of  FIG.  8    within peripheral conductive housing structures  12 W. Side-feeding antenna  40  in this way may, if desired, allow dielectric resonating element  92  to be shorter (e.g., in the direction of central/longitudinal axis  80 ) than in arrangements where antenna  40  is rear-fed. 
     Integrating antenna  40  into peripheral conductive housing structures  12 W as shown in  FIGS.  7  and  8    may allow antenna  40  to convey radio-frequency signals  106  through peripheral conductive housing structures  12 W (e.g., to provide millimeter/centimeter wave coverage around the lateral periphery of device  10 ), may simplify the manufacturing process for the side-facing phased antenna array, may reduce manufacturing cost for the side-facing phased antenna array, may maximize reliability and performance antenna  40 , and/or may increase the stiffness and structural integrity of the housing for device  10 , as examples. The example of  FIGS.  7  and  8    in which antenna  40  is a side-facing antenna is merely illustrative. In general, antenna  40  may be integrated into peripheral conductive housing structures  12 W and/or rear housing wall  12 R for radiating through the front face of device  10  (e.g., through display cover layer  56  by orienting central/longitudinal axis  80  of dielectric resonating element  92  parallel to the Z-axis of  FIGS.  7  and  8   ) or through the rear face of device  10  (e.g., through a dielectric portion of rear housing wall  12 R by orienting central/longitudinal axis  80  parallel to the Z-axis of  FIGS.  7  and  8   ). 
     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.