PATENT DOCUMENT

Publication Number: US-11863224-B2
Application Number: US-202117223888-A
Country: US
Kind Code: B2

Title: Multi-layer matching structures for high frequency signal transmission

Abstract:
An electronic device may include a transmission line path having a signal conductor embedded in a substrate. A contact pad may be patterned on a surface of the substrate. A radio-frequency component may be mounted to the contact pad using solder. Multi-layer impedance matching structures may couple the signal conductor to the contact pad. The matching structures may include a set of via pads and a set of conductive vias coupled in series between the signal conductor and the contact pad. The area of the via pads may vary across the set of via pads and/or the aspect ratio of the conductive vias may vary across the set of conductive vias. The matching structures may perform impedance matching between the signal conductor and the radio-frequency component at frequencies greater than 10 GHz while occupying a minimal amount of space in the device.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a dielectric substrate having stacked dielectric layers; 
 a contact pad on a surface of the dielectric substrate; 
 a radio-frequency component mounted to the contact pad; 
 a radio-frequency transmission line path having a signal trace embedded in the dielectric substrate, wherein the radio-frequency transmission line path and the radio-frequency component are configured to convey radio-frequency signals; and 
 impedance matching structures that are embedded in the dielectric substrate and that couple the signal trace to the contact pad, wherein the impedance matching structures comprise a set of conductive vias with different aspect ratios. 
 
     
     
       2. The electronic device of  claim 1 , the impedance matching structures comprising a set of via pads, the set of conductive vias being coupled in series between the signal trace and the contact pad, each via pad in the set of via pads having a lateral area, and wherein the lateral area varies across the set of via pads. 
     
     
       3. The electronic device of  claim 1 , the impedance matching structures comprising a set of via pads, and the set of conductive vias being coupled in series between the signal trace and the contact pad. 
     
     
       4. The electronic device of  claim 3 , wherein each via pad in the set of via pads has a lateral area and the lateral area varies across the set of via pads. 
     
     
       5. The electronic device of  claim 1 , further comprising:
 a dielectric resonator antenna having a dielectric resonating element mounted to the surface of the dielectric substrate, wherein the radio-frequency component comprises a feed probe for the dielectric resonator antenna. 
 
     
     
       6. The electronic device of  claim 1 , wherein the radio-frequency component comprises a board-to-board connector. 
     
     
       7. The electronic device of  claim 1 , wherein the radio-frequency component comprises an interposer. 
     
     
       8. The electronic device of  claim 1 , wherein the impedance matching structures comprise:
 a first via pad having a first lateral area; and 
 a second via pad having a second lateral area that is different from the first lateral area. 
 
     
     
       9. The electronic device of  claim 8 , further comprising:
 ground traces embedded in the dielectric substrate, wherein the ground traces have an opening that overlaps the radio-frequency component. 
 
     
     
       10. The electronic device of  claim 9 , wherein the impedance matching structures comprise:
 an additional signal trace that couples the first via pad to the signal trace, wherein the additional signal trace is wider than the signal trace. 
 
     
     
       11. An electronic device comprising:
 a dielectric substrate having stacked dielectric layers; 
 a contact pad on a surface of the dielectric substrate; 
 a radio-frequency component mounted to the contact pad; 
 a radio-frequency transmission line path having a signal trace embedded in the dielectric substrate, wherein the radio-frequency transmission line path and the radio-frequency component are configured to convey radio-frequency signals; and 
 impedance matching structures that are embedded in the dielectric substrate and that couple the signal trace to the contact pad, wherein the impedance matching structures comprise a set of conductive vias, a first via pad having a first lateral area, and a second via pad having a second lateral area that is different from the first lateral area. 
 
     
     
       12. The electronic device of  claim 11 , wherein the impedance matching structures comprise:
 a third via pad; 
 a first conductive via that couples the first via pad to the second via pad, the first conductive via having a first width; and 
 a second conductive via that couples the second via pad to the third via pad, the second conductive via having a second width that is different from the first width. 
 
     
     
       13. An electronic device comprising:
 a dielectric substrate having a first, second, and third layers, the second layer being interposed between the first and third layers; 
 a first via pad on the first layer; 
 a first conductive via coupled to the first via pad and having a first aspect ratio; 
 a second via pad on the second layer; 
 a second conductive via coupled to the second via pad and having a second aspect ratio that is different from the first aspect ratio; 
 a contact pad on the third layer; 
 a radio-frequency component surface-mounted to the contact pad; and 
 a radio-frequency transmission line path having a signal conductor in the dielectric substrate that is coupled to the radio-frequency component through the first via pad, the first conductive via, the second via pad, and the second conductive via, the radio-frequency transmission line path and the radio-frequency component being configured to convey radio-frequency signals at a frequency greater than 10 GHz. 
 
     
     
       14. The electronic device of  claim 13 , wherein the first via pad has a first lateral area and the second via pad has a second lateral area that is different from the first lateral area. 
     
     
       15. The electronic device of  claim 13 , further comprising:
 a fourth layer in the dielectric substrate, the first layer being interposed between the fourth and second layers; 
 a third via pad on the fourth layer; and 
 a third conductive via coupled to the third via pad. 
 
     
     
       16. The electronic device of  claim 15 , wherein the third conductive via has a third aspect ratio that is different from the first and second aspect ratios. 
     
     
       17. An electronic device comprising:
 a dielectric substrate having a first, second, and third layers, the second layer being interposed between the first and third layers; 
 a first via pad on the first layer and having a first lateral area; 
 a first conductive via coupled to the first via pad; 
 a second via pad on the second layer and having a second lateral area that is different from the first lateral area; 
 a second conductive via coupled to the second via pad; 
 a contact pad on the third layer; 
 a radio-frequency component surface-mounted to the contact pad; and 
 a radio-frequency transmission line path having a signal conductor in the dielectric substrate that is coupled to the radio-frequency component through the first via pad, the first conductive via, the second via pad, and the second conductive via, the radio-frequency transmission line path and the radio-frequency component being configured to convey radio-frequency signals at a frequency greater than 10 GHz. 
 
     
     
       18. The electronic device of  claim 17 , further comprising:
 a fourth layer in the dielectric substrate, the first layer being interposed between the fourth and second layers; 
 a third via pad on the fourth layer and having a third lateral area that is different from the first and second lateral areas; and 
 a third conductive via coupled to the third via pad. 
 
     
     
       19. The electronic device of  claim 17 , further comprising:
 a dielectric resonator antenna having a dielectric resonating element mounted to the third layer, wherein the radio-frequency component comprises a feed probe for the dielectric resonator antenna.

Description:
This application claims the benefit of provisional patent application No. 63/086,748, filed Oct. 2, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless circuitry. 
     Electronic devices often include wireless 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, it can be difficult to provide satisfactory impedance matching at these frequencies without consuming an excessive amount of space in the electronic device. 
     It would therefore be desirable to be able to provide electronic devices with improved wireless circuitry for supporting millimeter and centimeter wave communications. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry. The wireless circuitry may include a radio-frequency transmission line path. The radio-frequency transmission line path may have a signal conductor embedded in a dielectric substrate. A contact pad may be patterned on a surface of the dielectric substrate. A radio-frequency component may be surface-mounted to the contact pad using solder. The radio-frequency component may be a board-to-board connector, a probe feed for an antenna, or an interposer, as examples. 
     Multi-layer impedance matching structures may be embedded in the dielectric substrate. The multi-layer impedance matching structures may couple the signal conductor to the contact pad. The multi-layer impedance matching structures may include a set of via pads and a set of conductive vias coupled in series between the signal conductor and the contact pad. The area of the via pads may vary across the set of via pads and/or the aspect ratio of the conductive vias may vary across the set of conductive vias. The signal trace may include a wide transition segment that forms a part of the multi-layer impedance matching structures. Ground traces in the dielectric substrate may have an opening that overlaps the radio-frequency component. The opening may help to counteract capacitances between the via pads and the ground traces. The multi-layer impedance matching structures may perform impedance matching between the signal conductor and the radio-frequency component at frequencies greater than 10 GHz while occupying a minimal amount of space in the device. 
    
    
     
       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 cross-sectional side view of illustrative multi-layer impedance matching structures in accordance with some embodiments. 
         FIG.  5    is a top view showing how illustrative multi-layer impedance matching structures may include transmission line transition segments with different widths in accordance with some embodiments. 
         FIG.  6    is a transmission line model of illustrative multi-layer impedance matching structures in accordance with some embodiments. 
         FIG.  7    is a perspective view of an illustrative dielectric resonator antenna that may be fed using multi-layer impedance matching structures 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  8  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. The phased antenna arrays may convey radio-frequency signals using signal beam that is steered (e.g., by adjusting the phase and magnitude of each antenna) to point in a desired beam direction (e.g., towards external communications equipment). 
     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 radio-frequency transmission line path such as transmission line path  42 . Transmission line path  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. Transmission line path  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. 
     Transmission line path  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 transmission line path  42 , if desired. 
     Radio-frequency transmission lines transmission line path  42  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). 
     In general, it may be desirable to perform impedance matching along transmission line  42  to minimize signal reflections along the transmission line. This may in turn serve to maximize the antenna efficiency of antenna  40 . However, contact pads along transmission line path  42  are not naturally matched. In addition, it can be difficult to perform impedance matching at relatively high frequencies such as frequencies greater than 10 GHz. For example, packaged impedance matching components for performing impedance matching at these frequencies and any associated switching circuitry may be undesirably bulky and may not fit within the small form factor of device  10 . 
     In order to mitigate these issues, device  10  may include multi-layer impedance matching structures interposed along transmission line path  42 .  FIG.  4    is a cross sectional side view showing how transmission line path  42  may include multi-layer impedance matching structures. As shown in  FIG.  4   , transmission line path  42  may include multi-layer impedance matching structures  74 . Multi-layer impedance matching structures  74  may be integrated (embedded) within a dielectric substrate such as substrate  50 . 
     Substrate  50  may be, for example, a rigid printed circuit board, a flexible printed circuit, or another dielectric substrate. Substrate  50  may include multiple stacked dielectric layers  52  (e.g., layers of printed circuit board substrate, layers of fiberglass-filled epoxy, layers of polyimide, layers of ceramic substrate, or layers of other dielectric materials). If desired, a radio-frequency integrated circuit (RFIC) may be mounted to substrate  50  to form an integrated antenna module. Substrate  50  may be used to route transmission lines for each of the antennas  40  in a given phased antenna array, if desired. 
     Substrate  50  may include ground traces such as ground traces  62 . Ground traces  62  may, for example, be patterned onto a first layer  52  of substrate  50 . Ground traces  62  may form part of ground conductor  48  ( FIG.  3   ) for transmission line path  42 . The signal conductor  46  of transmission line path  42  may include signal traces  66  and  68  patterned onto a second layer  52  of substrate  50  (e.g., where the second layer  52  is layered over the first layer  52  of substrate  50 ). Multi-layer impedance matching structures  74  may couple signal traces  66  to contact pad  60  at upper-most surface  54  of substrate  50 . Contact pad  60  may be, for example, a surface-mount technology (SMT) contact pad patterned onto surface  54  of substrate  50  (e.g., on the upper-most layer  52  of substrate  50 ). If desired, an optional hole or opening such as opening  64  may be formed in ground traces  62 . Contact pad  60  may completely or partially overlap opening  64 . 
     Multi-layer impedance matching structures  74  may include signal trace  68 , opening  64 , and a set of N conductive via pads  70  and N conductive vias  72  coupled in series between signal trace  68  and contact pad  60 . Each conductive via pad  70  may be patterned onto a respective layer  52  of substrate  50 . Each conductive via  72  may extend through a respective layer  52  of substrate  50 . Conductive via pads  70  may include, for example, a first via pad  70 - 0  coupled to contact pad  60  by a first conductive via  72 - 0 , a second via pad  70 - 1  coupled to via pad  70 - 0  by a second conductive via  72 - 1 , an Nth via pad  70 -N coupled to signal trace  68  (e.g., via pad  70 -N, signal trace  68 , and signal trace  66  may be formed from the same layer of conductive traces on the same layer  52  of substrate  50 ), an (N−1)th via pad  70 -(N−1) coupled to via pad  70 -N by an Nth conductive via  72 -N, and N−4 via pads  70  coupled between via pads  70 - 1  and  70 - 2  by N−4 conductive vias  72  (e.g., including conductive vias  72 - 2  and  72 -(N−1)). N may be any desired integer (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, greater than thirteen, etc.). 
     Each via pad  70  may have a corresponding lateral area A (e.g., as measured into and out of the plane of the page of  FIG.  4   ). Each conductive via may have a corresponding width W (e.g., as measured from the left to the right of the page of  FIG.  4   ). Each conductive via may also have a corresponding aspect ratio given by the ratio of the height of the conductive via (e.g., as measured from the top to the bottom of the page of  FIG.  4   ) to one-half of the width W (e.g., the radius) of the conductive via. The aspect ratios of conductive vias  72  and/or the areas A of via pads  70  may be varied across the N conductive vias  72  and the N via pads  70  to perform impedance matching between contact pad  60  and signal trace  66 . The aspect ratio of conductive vias  72  may vary between about 0.75 and 0.85, as one example. 
     For example, as shown in  FIG.  4   , conductive via  72 - 0  may have a first width W 0  and thus a first aspect ratio, conductive via  72 - 1  may have a second width W 1  that is less than width W 0  and thus may have a second aspect ratio that is greater than the first aspect ratio, conductive via  72 -N may have an Nth width WN that is different from widths W 0  and W 1  and thus may have an Nth aspect ratio that is different from the first and second aspect ratios, etc. In addition, as shown in  FIG.  4   , via pad  70 - 0  may have a first area A 0 , via pad  70 - 1  may have a second area A 1  that is less than area A 0 , via pad  70 -(N−1) may have an (N−1)th area A(N−1) that is greater than area A 2  and less than area A 1 , etc. These examples are merely illustrative and, in general, each via pad  70  may have any desired area A and each conductive via  72  may have any desired aspect ratio. 
     Each via pad  70  may have a different respective area A or two or more of the via pads  70  may have the same area A. Similarly, each conductive via  72  may have a different respective width W and thus a different respective aspect ratio or two or more of the conductive vias  72  may have the same aspect ratio. In other words, the aspect ratio of conductive vias  72  may vary across the set of N conductive vias in multi-layer impedance matching structures  74  and/or the lateral area of the via pads  70  may vary across the set of N via pads in multi-layer impedance matching structures  74 . The aspect ratios (e.g., widths W) and areas A in multi-layer impedance matching structures  74  may be selected to provide suitable impedance matching between signal trace  66  and contact pad  60  at the frequencies of the radio-frequency signals conveyed by transmission line path  42  (e.g., frequencies greater than 10 GHz). 
     For example, the width W of each conductive via  72  may be selected to interpose a desired inductance L between the conductive pads coupled to that conductive via  72 . In general, increasing width W (e.g., decreasing the aspect ratio) reduces the inductance L produced by a given conductive via  72  whereas decreasing width W (e.g., increasing the aspect ratio) increases the inductance L produced by the conductive via. At the same time, the area A of each via pad  70  may be selected to interpose a desired capacitance C between signal trace  68  and contact pad  60 . In general, increasing area A increases the capacitance produced by a given via pad  70  whereas decreasing area A decreases the capacitance produced by the via pad. The capacitances (e.g., areas A) and the inductances (e.g., widths W) may be selected to ensure that there is a smooth impedance transition between signal trace  66  and contact pad  60  at millimeter/centimeter wave frequencies. 
     In some scenarios, increasing the area A of via pads  70  may undesirably increase the capacitance between the via pads and ground traces  62 . In these scenarios, opening  64  in ground traces  62  may help to counteract this increased capacitance. Multi-layer impedance matching structures  74  may also include signal trace  68 . Signal trace  68  may have a width that is different from the width of signal trace  66 . This may configure signal trace  68  to help perform impedance matching between signal trace  66  and contact pad  60 . 
     A radio-frequency structure such as radio-frequency component  56  may be mounted to contact pad  60  (e.g., using solder  58 ). Radio-frequency component  56  may, for example, be surface-mounted to contact pad  60  (e.g., using an SMT process or hot-bar process). Radio-frequency component  56  may include any desired radio-frequency structures for conveying radio-frequency signals at frequencies greater than 10 GHz such as a board-to-board connector (e.g., for coupling contact pad  60  to other portions of transmission line path  42  that are located on another substrate and that are coupled to one or more antennas or to the millimeter/centimeter wave transceiver), an interposer (e.g., an interposer having conductive structures for coupling contact pad  60  to one or more antennas or to the millimeter/centimeter wave transceiver), or the antenna feed of a given antenna (e.g., antenna feed  44  of antenna  40  of  FIG.  3   ), as examples. 
       FIG.  5    is a top view showing how signal trace  68  may have a width that is different from the width of signal trace  66  (e.g., as taken in the direction of arrow  75  of  FIG.  4   ). As shown in  FIG.  5   , substrate  50  may be used to route multiple transmission line paths for multiple antennas (e.g., multiple antennas in a phased antenna array). In the example of  FIG.  5   , substrate  50  includes eight contact pads  60  for eight different antennas in a given eight-element phased antenna array (e.g., a first contact pad  60 - 0  for a first antenna in the phased antenna array, a second contact pad  60 - 1  for a second antenna in the phased antenna array, etc.). 
     In one suitable arrangement that is described herein as an example, radio-frequency component  56  of  FIG.  4    includes a probe feed for a dielectric resonator antenna. Each contact pad  60  as shown in  FIG.  5    may be coupled to a respective probe feed for a respective dielectric resonator antenna in the phased antenna array. The phased antenna array may, if desired, be mounted in alignment with notch  8  in inactive area IA of display  14  ( FIG.  1   ) for radiating through a display cover in display  14  (e.g., for radiating through the front face of device  10  at notch  8 ). 
     As shown in  FIG.  5   , each contact pad  60  may be coupled to a respective signal trace  68  (e.g., by an underlying stack of conductive vias and via pads). Each signal trace  68  may, if desired, be thicker than the corresponding signal trace  66 . This may configure signal trace  68  to help perform impedance matching between the corresponding signal trace  66  and contact pad  60 . Fences of grounded vias may be interposed between signal traces  66  for isolation if desired. The example of  FIG.  5    is merely illustrative. The signal traces may have other shapes. The phased antenna array may include any desired number of antennas. 
       FIG.  6    shows a transmission line model  76  for multi-layer impedance matching structures  74  of  FIG.  4   . As shown in transmission line model  76  of  FIG.  6   , multi-layer impedance matching structures  74  may have a first terminal  78  (e.g., at signal trace  66  of  FIG.  4   ) and a second terminal  80  (e.g., at contact pad  60  of  FIG.  6   ). Multi-layer impedance matching structures  74  may have a transmission line transition  82  formed from signal trace  68  ( FIGS.  4  and  5   ). The width and length of signal trace  68  may be selected to transform real impedance to standard impedance (e.g., the impedance of signal trace  66  of  FIG.  4    such as 50 Ohm impedance). A capacitance CGND may be coupled between the signal trace and ground  84 . Capacitance CGND may be established between via pad  70 -N and ground traces  62  of  FIG.  4   . 
     Multi-layer impedance matching structures  74  may include N resonant circuits  86  coupled in series between transmission line transition  82  and terminal  80  (e.g., a first resonant circuit  86 - 0 , an Nth resonant circuit  86 -N, etc.). Each resonant circuit  86  may include a corresponding parallel-coupled capacitance C and inductance L (e.g., resonant circuit  86 -N may have a capacitance CN coupled in parallel with inductance LN, resonant circuit  86 - 0  may have a capacitance C 0  coupled in parallel with inductance L 0 , etc.). Each capacitance C is determined by the areas A of a respective pair of via pads  70  in multi-layer transmission line structures  74 . Each inductance L is determined by the width W and thus the aspect ratio of a respective conductive via  72  in multi-layer transmission line structures  74 . For example, the areas A of via pads  70 -N and  70 -(N−1) of  FIG.  4    may be selected to produce capacitance CN of resonant circuit  86 -N, the width WN of conductive via  72 -N may be selected to produce inductance LN of resonant circuit  86 -N, the areas A 0  and A 1  of via pads  70 - 0  and  70 - 1  may be selected to produce capacitance C 1  of resonant circuit  86 - 1 , the width W 1  of conductive via  72 - 1  may be selected to produce inductance L 1  of resonant circuit  86 - 1 , etc. A capacitance CPAD may also be coupled between the output of resonant circuit  86 - 0  and ground  84 . Capacitance CPAD may be established between contact pad  60  and ground traces  62  of  FIG.  4   . Opening  64  in ground traces  62  may be used to counteract an increase in the capacitances between the via pads and the ground traces. The widths W of conductive vias  72  and thus the inductances L in transmission line model  76 , the areas A of via pads  70  and thus the capacitances C in transmission line model  76 , and optionally the dimensions of opening  64  may be selected to have a real impedance at reference point R, which serves to match the impedance of terminal  78  to the impedance of terminal  80 . 
       FIG.  7    is a perspective view of an illustrative dielectric resonator antenna having a probe feed that may form radio-frequency component  56  of  FIG.  4   . As shown in  FIG.  7   , 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 substrate  50 . Contact pad  60  may be patterned onto surface  54  of substrate  50 . Multi-layer impedance matching structures  74  ( FIG.  4   ) may underly contact pad  60  and couple contact pad  60  to a corresponding signal trace  66  in substrate  50  (not shown in  FIG.  7    for the sake of clarity). 
     Dielectric resonating element  92  of antenna  40  may be formed from a column (pillar) of dielectric material mounted or otherwise coupled to surface  54  of substrate  50 . If desired, dielectric resonating element  92  may be embedded within (e.g., laterally surrounded by) an additional dielectric substrate mounted to surface  54  of substrate  50  (not shown in  FIG.  7    for the sake of clarity). The additional dielectric substrate may be an injection-molded plastic substrate in one suitable arrangement. Antenna  40  of  FIG.  7    may be formed in a phased antenna array of antennas having dielectric resonating elements such as dielectric resonating element  92 . Each dielectric resonating element in the phased antenna array may, if desired, be embedded within the same injection-molded plastic substrate. 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. The first dielectric constant 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, greater than 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 additional 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 additional 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  90  when excited by the transmission line path coupled to contact pad  60 . Antenna  40  may be fed using one or more radio-frequency feed probes such as feed probe  94 . Feed probe  94  may form part of the antenna feed for antenna  40  (e.g., antenna feed  44  of  FIG.  3   ). As shown in  FIG.  7   , feed probe  94  may include feed conductor  96 . In one suitable arrangement that is described herein as an example, feed conductors  96  may be formed from stamped sheet metal that has been folded into a desired shape and that is press against a given sidewall  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 conductor  96  against sidewall  102  to help ensure a reliable coupling between the feed conductor and the dielectric resonating element. In another suitable arrangement, feed conductor  96  may be formed from a conductive trace that is patterned directly onto sidewall  102  (e.g., using a laser direct structuring (LDS) process, a sputtering process, or other conductive metallization techniques). 
     Feed conductor  96  may have a first portion on a first sidewall  102  of dielectric resonating element  92 . Feed conductor  96  may have a second portion coupled to contact pad  60  using solder  58  (e.g., feed probe  94  may form radio-frequency component  56  of  FIG.  4   ). The transmission line path coupled to contact pad  60  may convey radio-frequency signals to and from feed probe  94 . Feed probe  94  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  94 , 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  90  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  104  of dielectric resonating element  92 ). 
     For example, during signal transmission, the transmission line path coupled to contact pad  60  may supply radio-frequency signals from the millimeter/centimeter wave transceiver circuitry to antenna  40 . Feed probes  94  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  90  up the length of dielectric resonating element  92 . Similarly, during signal reception, radio-frequency signals  90  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  94  may couple the received radio-frequency signals onto the underlying transmission line path, which passes the radio-frequency signals to the millimeter/centimeter wave transceiver circuitry. The multi-layer impedance matching structures  74  ( FIG.  4   ) coupled to contact pad  60  may ensure that there is a smooth impedance transition between feed probe  94  and the rest of the transmission line path. This may serve to minimize signal reflections along the transmission line path, thereby maximizing the antenna efficiency of antenna  40 . 
     Dielectric resonating element  92  may have a length  98 , a width  100  (e.g., measured orthogonal to length  98 ), and a height  88  (e.g., measured parallel to central/longitudinal axis  104  and orthogonal to length  98  and width  100 ). Length  98 , width  100 , and height  88  may be selected to provide dielectric resonating element  92  with a corresponding mix of electromagnetic cavity/waveguide modes that, when excited by feed probe  94  and/or the additional feed probe, configure antenna  40  to radiate at desired frequencies. For example, height  88  may be 2-10 mm, 4-6 mm, 3-7 mm, 4.5-5.5 mm, or greater than 2 mm. Width  100  and length  98  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  100  may be equal to length  98  or, in other arrangements, may be different than length  98 . 
     The example of  FIG.  7    is merely illustrative. If desired, dielectric resonating element  92  may also be fed by an additional feed probe coupled to a sidewall  102  orthogonal to that of feed probe  94 . The additional feed probe may be coupled to an additional transmission line path and additional multi-layer impedance matching structures. Feed probe  94  and the additional feed probe may allow dielectric resonating element  92  to cover orthogonal linear polarizations or other polarizations, for example. Feed probe  94  may sometimes be referred to herein as a feed conductor, feed patch, or probe feed. 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  94 , dielectric resonator antennas such as antenna  40  of  FIG.  7    may sometimes be referred to herein as probe-fed dielectric resonator antennas. Dielectric resonating element  92  may have other shapes. In general, any desired radio-frequency structures may form radio-frequency component  56  of  FIG.  4   . 
     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: 20210406
Publication Date: 20240102
Grant Date: 20240102
Priority Date: 20201002
Inventors: AVSER, BILGEHAN
RAJAGOPALAN, HARISH
EDWARDS, JENNIFER M.
PAULOTTO, Simone
YONG, Siwen
Assignee: APPLE INC
CPC Classifications: [{"code": "H04B1/40", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/335", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04B1/40", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B1/40", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/335", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 80932615