PATENT DOCUMENT

Publication Number: US-11088452-B2
Application Number: US-201816146705-A
Country: US
Kind Code: B2

Title: Electronic devices having antennas with symmetric feeding

Abstract:
An electronic device may be provided with a phased antenna array. Each antenna in the array may include a patch element having first, second, third, and fourth positive antenna feed terminals. The first and second terminals may convey first signals with a first polarization. The third and fourth terminals may convey second signals with a second polarization. Phase shifting components such as phase shifting transmission line segments or phase shifter circuits may ensure that the first signals at the first terminal are out of phase with respect to the first signals at the second terminal and may ensure that the second signals at the third terminal are out of phase with respect to the second signals at the fourth terminal. This may allow antenna current density for both polarizations to be symmetrically distributed about a normal axis of the patch element.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an antenna having a patch element and first and second positive antenna feed terminals on the patch element wherein the antenna is embedded in a substrate; 
 a transmission line path that provides radio-frequency signals to the first and second positive antenna feed terminals, wherein the transmission line path comprises a phase shifting segment that is overlapped by the patch element and that is configured to provide the radio-frequency signals to the first positive antenna feed terminal out of phase with respect to the radio-frequency signals at the second positive antenna feed terminal; and 
 a display having a display cover layer and pixel circuitry that emits light through the display cover layer, wherein the substrate is mounted against the display cover layer and the antenna is configured to radiate through the display cover layer. 
 
     
     
       2. The electronic device defined in  claim 1 , further comprising:
 a first conductive via coupled to the first positive antenna feed terminal and extending through the substrate; and 
 a second conductive via coupled to the second positive antenna feed terminal and extending through the substrate. 
 
     
     
       3. The electronic device defined in  claim 2 , wherein the phase shifting segment of the transmission line path is coupled between the first and second conductive vias. 
     
     
       4. The electronic device defined in  claim 3 , wherein the antenna is configured to radiate the radio-frequency signals in a frequency band, the phase shifting segment of the transmission line path having a length equal to one-half of an effective wavelength corresponding to a frequency in the frequency band. 
     
     
       5. The electronic device defined in  claim 4 , wherein the frequency band comprises frequencies higher than 10 GHz. 
     
     
       6. The electronic device defined in  claim 2 , further comprising a radio-frequency integrated circuit mounted to a surface of the substrate and having a port, wherein the transmission line path is coupled to the port. 
     
     
       7. The electronic device defined in  claim 1 , further comprising:
 third and fourth positive antenna feed terminals on the patch element; and 
 an additional transmission line path that provides additional radio-frequency signals to the third and fourth positive antenna feed terminals, wherein the additional transmission line path comprises an additional phase shifting segment that is configured to provide the additional radio-frequency signals to the third positive antenna feed terminal out of phase with respect to the additional radio-frequency signals at the fourth positive antenna feed terminal. 
 
     
     
       8. The electronic device defined in  claim 7 , wherein the first and second positive antenna feed terminals are configured to convey the radio-frequency signals with a first polarization and the third and fourth positive antenna feed terminals are configured to convey the additional radio-frequency signals with a second polarization orthogonal to the first polarization. 
     
     
       9. The electronic device defined in  claim 1 , wherein the phase shifting segment of the transmission line path is configured to provide the radio-frequency signals to the first positive antenna feed terminal between 160 and 200 degrees out of phase with the radio-frequency signals at the second positive antenna feed terminal. 
     
     
       10. An electronic device comprising:
 a dielectric substrate; 
 an antenna having a patch element on the dielectric substrate, wherein the antenna comprises first and second positive antenna feed terminals on opposing sides of the patch element; 
 a first phase shifter coupled to the first positive antenna feed terminal and configured to provide radio-frequency signals to the first positive antenna feed terminal at a first phase; and 
 a second phase shifter coupled to the second positive antenna feed terminal and configured to provide the radio-frequency signals to the second positive antenna feed terminal at a second phase that is different than the first phase; and 
 a dielectric cover layer that forms a quarter-wave impedance transformer for the antenna, wherein the dielectric substrate is mounted against the dielectric cover layer, the antenna being configured to transmit the radio-frequency signals in a frequency band higher than 10 GHz through the dielectric cover layer. 
 
     
     
       11. The electronic device defined in  claim 10 , wherein a difference between the first and second phases is between 160 and 200 degrees. 
     
     
       12. The electronic device defined in  claim 10 , wherein the antenna comprises third and fourth positive antenna feed terminals on opposing sides of the patch element. 
     
     
       13. The electronic device defined in  claim 12 , further comprising:
 a third phase shifter coupled to the third positive antenna feed terminal and configured to provide additional radio-frequency signals to the third positive antenna feed terminal at a third phase; and 
 a fourth phase shifter coupled to the fourth positive antenna feed terminal and configured to provide the additional radio-frequency signals to the fourth positive antenna feed terminal at a fourth phase that is different than the third phase. 
 
     
     
       14. The electronic device defined in  claim 13 , wherein the first and second positive antenna feed terminals are configured to convey the radio-frequency signals with a first polarization and the third and fourth positive antenna feed terminals are configured to convey the additional radio-frequency signals with a second polarization orthogonal to the first polarization. 
     
     
       15. The electronic device defined in  claim 10 , further comprising:
 an integrated circuit mounted to a surface of the dielectric substrate and having first and second ports, wherein the first and second phase shifters are located on the integrated circuit, the first phase shifter is coupled to the first port, and the second phase shifter is coupled to the second port; 
 a first transmission line path that couples the first positive antenna feed terminal to the first port; and 
 a second transmission line path that couples the second positive antenna feed terminal to the second port. 
 
     
     
       16. An antenna comprising:
 a ground plane; 
 vias extending from the ground plane to form a cavity; 
 a patch element over the ground plane in the cavity and configured to radiate at a frequency between 10 GHz and 300 GHz; 
 first, second, third, and fourth positive antenna feed terminals on the patch element; and 
 a transmission line path that provides radio-frequency signals to the first and second positive antenna feed terminals, wherein the transmission line path comprises a phase shifting segment and the ground plane is interposed between the phase shifting segment and the patch element. 
 
     
     
       17. The antenna defined in  claim 16 , wherein the first positive antenna feed terminal is at a first side of the patch element, the second positive antenna feed terminal is at a second side of the patch element opposite the first side, the third positive antenna feed terminal is at a third side of the patch element, and the fourth positive antenna feed terminal is at a fourth side of the patch element opposite the third side, the first and second positive antenna feed terminals are configured to convey first radio-frequency signals with a first polarization, and the third and fourth positive antenna feed terminals are configured to convey second radio-frequency signals with a second polarization orthogonal to the first polarization. 
     
     
       18. The antenna defined in  claim 16 , further comprising:
 a dielectric substrate, wherein the patch element is mounted in the dielectric substrate; 
 a dielectric cover layer that forms a quarter-wave impedance transformer for the antenna, wherein the dielectric substrate is mounted against the dielectric cover layer and the dielectric cover layer forms a display cover layer for pixel circuitry that emits light through the display cover layer. 
 
     
     
       19. The electronic device defined in  claim 1 , wherein the display cover layer forms a quarter-wave impedance transformer for the antenna, the electronic device further comprising:
 a ground plane; and 
 vias extending through the substrate from the ground plane to form a cavity, wherein the patch element is in the cavity and the ground plane is interposed between the phase shifting segment and the patch element. 
 
     
     
       20. The electronic device defined in  claim 10 , further comprising:
 pixel circuitry that emits display light through the dielectric cover layer 
 a ground plane; and 
 vias extending through the dielectric substrate from the ground plane to form a cavity, wherein the patch element is in the cavity.

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 may support high bandwidths, but may raise significant challenges. For example, millimeter wave communications signals generated by antennas can be characterized by substantial attenuation and/or distortion during signal propagation through various mediums. It may also be difficult to incorporate antennas for performing both wireless communications and spatial ranging operations within electronic devices, which are often subject to space constraints. 
     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. The wireless circuitry may include one or more antennas and transceiver circuitry such as centimeter and millimeter wave transceiver circuitry (e.g., circuitry that transmits and receives antennas signals at frequencies greater than 10 GHz). The antennas may be arranged in a phased antenna array. 
     Each antenna in the phased antenna array may include a patch element having first and second positive antenna feed terminals at opposing first and second sides of the patch element and third and fourth positive antenna feed terminals at opposing third and fourth sides of the patch element. The first and second positive antenna feed terminals may convey first radio-frequency signals with a first polarization. The third and fourth positive antenna feed terminals may convey second radio-frequency signals with a second polarization orthogonal to the first polarization. Antenna current density for both polarizations may be symmetrically distributed about a normal axis of the patch element. 
     The first and second positive antenna feed terminals may be fed using a first transmission line path. The third and fourth positive antenna feed terminals may be fed using a second transmission line path. The first transmission line path may include a phase shifting segment that provides the first radio-frequency signals to the first positive antenna feed terminal out of phase with respect to the first radio-frequency signals at the second positive antenna feed terminal. Similarly, the second transmission line path may include a phase shifting segment that provides the second radio-frequency signals to the third positive antenna feed terminal out of phase with respect to the second radio-frequency signals at the fourth positive antenna feed terminal. 
     In another suitable arrangement, respective phase shifters may be coupled to each of the positive antenna feed terminals over corresponding transmission line paths. Each phase shifter may provide the radio-frequency signals with selected phases so that positive antenna feed terminals on opposing sides of the patch element are provided with radio-frequency signals that are out of phase with respect to each other. This may allow the antenna to exhibit satisfactory antenna efficiency with a uniform radiation pattern for both polarizations. 
    
    
     
       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 an illustrative electronic device with wireless communications circuitry in accordance with some embodiments. 
         FIG. 3  is a diagram of an illustrative phased antenna array that may be adjusted using control circuitry to direct a beam of signals in accordance with some embodiments. 
         FIG. 4  is a schematic diagram of illustrative wireless communications circuitry in accordance with some embodiments. 
         FIG. 5  is a perspective view of an illustrative patch antenna having multiple positive antenna feed terminals and a parasitic element in accordance with some embodiments. 
         FIG. 6  is a side view of an illustrative electronic device having dielectric cover layers at front and rear faces in accordance with some embodiments. 
         FIG. 7  is a cross-sectional side view of an illustrative patch antenna that has multiple positive antenna feed terminals and that may be mounted against a dielectric cover layer in an electronic device in accordance with some embodiments. 
         FIG. 8  is a cross-sectional side view of an illustrative patch antenna having multiple independently phased positive antenna feed terminals in accordance with some embodiments. 
         FIG. 9  is a side view of an illustrative radiation pattern envelope for a phased antenna array that includes antennas of the type shown in  FIGS. 5, 7, and 8  in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may contain wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include phased antenna arrays that are used for handling millimeter wave and centimeter wave communications. Millimeter wave communications, which are sometimes referred to as extremely high frequency (EHF) communications, involve signals at 60 GHz or other frequencies between about 30 GHz and 300 GHz. Centimeter wave communications involve signals at frequencies between about 10 GHz and 30 GHz. While uses of millimeter wave communications may be described herein as examples, centimeter wave communications, EHF communications, or any other types of communications may be similarly used. If desired, electronic devices may also contain wireless communications circuitry 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. 
     Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, or other small portable device. Device  10  may also be a set-top box, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, a wireless access point, 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  6 . Display  6  may be mounted on the front face of device  10 . Display  6  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. The rear face of housing  12  (i.e., the face of device  10  opposing the front face of device  10 ) may have a substantially planar housing wall such as rear housing wall  12 R (e.g., a planar housing wall). Rear housing wall  12 R may have slots that pass entirely through the rear housing wall and that therefore separate portions of housing  12  from each other. Rear housing wall  12 R may include conductive portions and/or dielectric portions. If desired, rear housing wall  12 R may include a planar metal layer covered by a thin layer or coating of dielectric such as glass, plastic, sapphire, or ceramic. Housing  12  may also have shallow grooves that do not pass entirely through housing  12 . The slots and grooves may be filled with plastic or other dielectric. If desired, portions of housing  12  that have been separated from each other (e.g., by a through slot) may be joined by internal conductive structures (e.g., sheet metal or other metal members that bridge the slot). 
     Housing  12  may include peripheral housing structures such as peripheral structures  12 W. Peripheral structures  12 W and conductive portions of rear housing wall  12 R may sometimes be referred to herein collectively as conductive structures of housing  12 . Peripheral structures  12 W may run around the periphery of device  10  and display  6 . In configurations in which device  10  and display  6  have a rectangular shape with four edges, peripheral structures  12 W may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges and that extend from rear housing wall  12 R to the front face of device  10  (as an example). Peripheral structures  12 W or part of peripheral structures  12 W may serve as a bezel for display  6  (e.g., a cosmetic trim that surrounds all four sides of display  6  and/or that helps hold display  6  to device  10 ) if desired. Peripheral structures  12 W may, if desired, form sidewall structures for device  10  (e.g., by forming a metal band with vertical sidewalls, curved sidewalls, etc.). 
     Peripheral structures  12 W may be formed of a conductive material such as metal and may therefore sometimes be referred to as peripheral conductive housing structures, conductive housing structures, peripheral metal structures, peripheral conductive sidewalls, peripheral conductive sidewall structures, conductive housing sidewalls, peripheral conductive housing sidewalls, sidewalls, sidewall structures, or a peripheral conductive housing member (as examples). Peripheral conductive housing structures  12 W may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, or more than two separate structures may be used in forming peripheral conductive housing structures  12 W. 
     It is not necessary for peripheral conductive housing structures  12 W to have a uniform cross-section. For example, the top portion of peripheral conductive housing structures  12 W may, if desired, have an inwardly protruding lip that helps hold display  6  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  6 ), 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  6  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  6 . In configurations for device  10  in which some or all of rear housing wall  12 R is formed from metal, it may be desirable to form parts of peripheral conductive housing structures  12 W as integral portions of the housing structures forming rear housing wall  12 R. For example, rear housing wall  12 R of device  10  may include a planar metal structure and portions of peripheral conductive housing structures  12 W on the sides of housing  12  may be formed as flat or curved vertically extending integral metal portions of the planar metal structure (e.g., housing structures  12 R and  12 W may be formed from a continuous piece of metal in a unibody configuration). Housing structures such as these may, if desired, be machined from a block of metal and/or may include multiple metal pieces that are assembled together to form housing  12 . Rear housing wall  12 R may have one or more, two or more, or three or more portions. Peripheral conductive housing structures  12 W and/or conductive portions of rear housing wall  12 R may form one or more exterior surfaces of device  10  (e.g., surfaces that are visible to a user of device  10 ) and/or may be implemented using internal structures that do not form exterior surfaces of device  10  (e.g., conductive housing structures that are not visible to a user of device  10  such as conductive structures that are covered with layers such as thin cosmetic layers, protective coatings, and/or other coating layers that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide peripheral conductive structures  12 W and/or conductive portions of rear housing wall  12 R from view of the user). 
     Display  6  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  6  may have an inactive border region that runs along one or more of the edges of active area AA. Inactive area IA may be free of pixels for displaying images and may overlap circuitry and other internal device structures in housing  12 . To block these structures from view by a user of device  10 , the underside of the display cover layer or other layers in display  6  that overlaps inactive area IA may be coated with an opaque masking layer in inactive area IA. The opaque masking layer may have any suitable color. 
     Display  6  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  8  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  6  may include conductive structures such as an array of capacitive electrodes for a touch sensor, conductive lines for addressing pixels, driver circuits, etc. Housing  12  may include internal conductive structures such as metal frame members and a planar conductive housing member (sometimes referred to as a backplate) that spans the walls of housing  12  (i.e., a substantially rectangular sheet formed from one or more metal parts that is welded or otherwise connected between opposing sides of peripheral conductive structures  12 W). The backplate may form an exterior rear surface of device  10  or may be covered by layers such as thin cosmetic layers, protective coatings, and/or other coatings that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide the backplate from view of the user. Device  10  may also include conductive structures such as printed circuit boards, components mounted on printed circuit boards, and other internal conductive structures. These conductive structures, which may be used in forming a ground plane in device  10 , may extend under active area AA of display  6 , for example. 
     In regions  2  and  4 , 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  6 , 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  2  and  4  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  2  and  4 . If desired, the ground plane that is under active area AA of display  6  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  2  and  4 ), thereby narrowing the slots in regions  2  and  4 . 
     In general, device  10  may include any suitable number of antennas (e.g., one or more, two or more, three or more, four or more, etc.). The antennas in device  10  may be located at opposing first and second ends of an elongated device housing (e.g., ends at regions  2  and  4  of device  10  of  FIG. 1 ), along one or more edges of a device housing, in the center of a device housing, in other suitable locations, or in one or more of these locations. The arrangement of  FIG. 1  is merely illustrative. 
     Portions of peripheral conductive housing structures  12 W may be provided with peripheral gap structures. For example, peripheral conductive housing structures  12 W may be provided with one or more gaps such as gaps  9 , 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  9  may divide peripheral conductive housing structures  12 W into one or more peripheral conductive segments. There may be, for example, two peripheral conductive segments in peripheral conductive housing structures  12 W (e.g., in an arrangement with two of gaps  9 ), three peripheral conductive segments (e.g., in an arrangement with three of gaps  9 ), four peripheral conductive segments (e.g., in an arrangement with four of gaps  9 ), six peripheral conductive segments (e.g., in an arrangement with six gaps  9 ), etc. The segments of peripheral conductive housing structures  12 W that are formed in this way may form parts of antennas in device  10 . 
     If desired, openings in housing  12  such as grooves that extend partway or completely through housing  12  may extend across the width of the rear wall of housing  12  and may penetrate through the rear wall of housing  12  to divide the rear wall into different portions. These grooves may also extend into peripheral conductive housing structures  12 W and may form antenna slots, gaps  9 , and other structures in device  10 . Polymer or other dielectric may fill these grooves and other housing openings. In some situations, housing openings that form antenna slots and other structure may be filled with a dielectric such as air. 
     In a typical scenario, device  10  may have one or more upper antennas and one or more lower antennas (as an example). An upper antenna may, for example, be formed at the upper end of device  10  in region  4 . A lower antenna may, for example, be formed at the lower end of device  10  in region  2 . The antennas may be used separately to cover identical communications bands, overlapping communications bands, or separate communications bands. The antennas may be used to implement an antenna diversity scheme or a multiple-input-multiple-output (MIMO) antenna scheme. 
     Antennas in device  10  may be used to support any communications bands of interest. For example, device  10  may include antenna structures for supporting local area network communications, voice and data cellular telephone communications, global positioning system (GPS) communications or other satellite navigation system communications, Bluetooth® communications, near-field communications, etc. Two or more antennas in device  10  may be arranged in a phased antenna array for covering millimeter and centimeter wave communications if desired. 
     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  6 . 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  6  that is available for antennas within device  10 . For example, active area AA of display  6  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. 
       FIG. 2  is a schematic diagram showing illustrative components that may be used in an electronic device such as electronic device  10 . As shown in  FIG. 2 , device  10  may include storage and processing circuitry such as control circuitry  14 . Control circuitry  14  may include storage such as 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. Processing circuitry in control circuitry  14  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processor integrated circuits, application specific integrated circuits, etc. 
     Control circuitry  14  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  14  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  14  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. 
     The control circuitry in device  10  (e.g., control circuitry  14 ) 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  is stored on non-transitory computer readable storage media (e.g., tangible computer readable storage media) in control circuitry  14 . The software code may sometimes be referred to as program instructions, software, data, instructions, or code. The non-transitory computer readable storage media may include non-volatile memory such as non-volatile random-access memory (NVRAM), one or more hard drives (e.g., magnetic drives or solid state drives), one or more removable flash drives or other removable media, etc. Software stored on the non-transitory computer readable storage media may be executed on the processing circuitry of control circuitry  14 . The processing circuitry may include application-specific integrated circuits with processing circuitry, one or more microprocessors, a central processing unit (CPU) or other processing circuitry. 
     Device  10  may include input-output circuitry  16 . Input-output circuitry  16  may include input-output devices  18 . Input-output devices  18  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  18  may include user interface devices, data port devices, 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, 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  16  may include wireless communications circuitry such as wireless circuitry  34  for communicating wirelessly with external equipment. Wireless circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas  40 , transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless circuitry  34  may include radio-frequency transceiver circuitry  20  for handling various radio-frequency communications bands. For example, transceiver circuitry  20  may include Global Positioning System (GPS) receiver circuits  22 , local wireless transceiver circuits  24 , remote wireless transceiver circuits  26 , and/or millimeter wave transceiver circuits  28 . 
     Local wireless transceiver circuits  24  may include wireless local area network (WLAN) transceiver circuitry and may therefore sometimes be referred to herein as WLAN transceiver circuitry  24 . WLAN transceiver circuitry  24  may handle 2.4 GHz and 5 GHz bands for Wi-Fi® (IEEE 802.11) communications or other wireless local area network (WLAN) bands and may handle the 2.4 GHz Bluetooth® communications band or other wireless personal area network (WPAN) bands. 
     Remote wireless transceiver circuits  26  may include cellular telephone transceiver circuitry and may therefore sometimes be referred to herein as cellular telephone transceiver circuitry  26 . Cellular telephone transceiver circuitry  26  may handle wireless communications in frequency ranges such as a low communications band from 600 to 960 MHz, a midband from 1710 to 2170 MHz, a high band from 2300 to 2700 MHz, an ultra-high band from 3400 to 3700 MHz, or other communications bands between 600 MHz and 4000 MHz or other suitable frequencies (as examples). Cellular telephone transceiver circuitry  26  may handle voice data and non-voice data. 
     Millimeter wave transceiver circuits  28  (sometimes referred to herein as extremely high frequency (EHF) transceiver circuitry  28  or millimeter wave transceiver circuitry  28 ) may support communications at frequencies between about 10 GHz and 300 GHz. For example, millimeter wave transceiver circuitry  28  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 wave transceiver circuitry  28  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 wave transceiver circuitry  28  may support IEEE 802.11ad communications at 60 GHz and/or 5 th  generation mobile networks or 5 th  generation wireless systems (5G) communications bands between 27 GHz and 90 GHz. If desired, millimeter wave transceiver circuitry  28  may support communications at multiple frequency bands between 10 GHz and 300 GHz such as a first band from 24 GHz to 31 GHz, a second band from 37 GHz to 43 GHz, and/or other communications bands between 10 GHz and 300 GHz. Millimeter wave transceiver circuitry  28  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.). In one suitable arrangement that is sometimes described herein as an example, millimeter wave transceiver circuitry  28  may include spatial ranging circuitry (e.g., millimeter wave spatial ranging circuitry) that performs spatial ranging operations using millimeter and/or centimeter wave signals transmitted and received by antennas  40 . The spatial ranging circuitry may use the transmitted and received signals to detect or estimate a range between device  10  and external objects in the surroundings of device  10  (e.g., objects external to housing  12  and device  10  such as the body of the user or other persons, other devices, animals, furniture, walls, or other objects or obstacles in the vicinity of device  10 ). 
     GPS receiver circuits  22  may receive GPS signals at 1575 MHz or signals for handling other satellite positioning data (e.g., GLONASS signals at 1609 MHz). Satellite navigation system signals for GPS receiver circuits  22  are received from a constellation of satellites orbiting the earth. 
     In satellite navigation system links, cellular telephone links, and other long-range links, wireless 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, wireless signals are typically used to convey data over tens or hundreds of feet. Millimeter wave transceiver circuitry  28  may convey signals that travel (over short distances) between a transmitter and a receiver over a line-of-sight path. To enhance signal reception for millimeter and centimeter wave communications, phased antenna arrays and beam steering techniques may be used (e.g., schemes in which antenna signal phase and/or magnitude for each antenna in an array is 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. 
     Wireless circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless circuitry  34  may include circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. 
     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 loop antenna structures, patch antenna structures, stacked patch antenna structures, antenna structures having parasitic elements, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, monopoles, dipoles, helical antenna structures, Yagi (Yagi-Uda) antenna structures, surface integrated waveguide structures, hybrids of these designs, etc. If desired, one or more of antennas  40  may be cavity-backed antennas. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. Dedicated antennas may be used for receiving satellite navigation system signals or, if desired, antennas  40  can be configured to receive both satellite navigation system signals and signals for other communications bands (e.g., wireless local area network signals and/or cellular telephone signals). Antennas  40  can be arranged in phased antenna arrays for handling millimeter wave and centimeter wave communications. 
     Transmission line paths may be used to route antenna signals within device  10 . For example, transmission line paths may be used to couple antennas  40  to transceiver circuitry  20 . Transmission line paths in device  10  may include coaxial cable paths, microstrip transmission lines, stripline transmission lines, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, waveguide structures for conveying signals at millimeter wave frequencies (e.g., coplanar waveguides or grounded coplanar waveguides), transmission lines formed from combinations of transmission lines of these types, etc. 
     Transmission line paths in device  10  may be integrated into rigid and/or flexible printed circuit boards if desired. In one suitable arrangement, transmission line paths in device  10  may include transmission line conductors (e.g., signal and/or ground conductors) that are 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). Filter circuitry, switching circuitry, impedance matching circuitry, and other circuitry may be interposed within the transmission lines, if desired. 
     Device  10  may contain multiple antennas  40 . The antennas may be used together or one of the antennas may be switched into use while other antenna(s) are switched out of use. If desired, control circuitry  14  may be used to select an optimum antenna to use in device  10  in real time and/or to select an optimum setting for adjustable wireless circuitry associated with one or more of antennas  40 . Antenna adjustments may be made to tune antennas to perform in desired frequency ranges, to perform beam steering with a phased antenna array, and to otherwise optimize antenna performance. Sensors may be incorporated into antennas  40  to gather sensor data in real time that is used in adjusting antennas  40  if desired. 
     In some configurations, antennas  40  may include antenna arrays (e.g., phased antenna arrays to implement beam steering functions). For example, the antennas that are used in handling millimeter and centimeter wave signals for millimeter wave transceiver circuitry  28  may be implemented as phased antenna arrays. The radiating elements in a phased antenna array for supporting millimeter wave communications may be patch antennas, dipole antennas, Yagi (Yagi-Uda) antennas, or other suitable antenna elements. Millimeter wave transceiver circuitry  28  can be integrated with the phased antenna arrays to form integrated phased antenna array and transceiver circuit modules or packages (sometimes referred to herein as integrated antenna modules or antenna modules) if desired. 
     In devices such as handheld devices, the presence of an external object such as the hand of a user or a table or other surface on which a device is resting has a potential to block wireless signals such as millimeter wave signals. In addition, millimeter wave communications typically require a line of sight between antennas  40  and the antennas on an external device. Accordingly, it may be desirable to incorporate multiple phased antenna arrays into device  10 , each of which is placed in a different location within or on device  10 . With this type of arrangement, an unblocked phased antenna array may be switched into use and, once switched into use, the phased antenna array may use beam steering to optimize wireless performance. Similarly, if a phased antenna array does not face or have a line of sight to an external device, another phased antenna array that has line of sight to the external device may be switched into use and that phased antenna array may use beam steering to optimize wireless performance. Configurations in which antennas from one or more different locations in device  10  are operated together may also be used (e.g., to form a phased antenna array, etc.). 
       FIG. 3  shows how antennas  40  on device  10  may be formed in a phased antenna array. As shown in  FIG. 3 , phased antenna array  60  (sometimes referred to herein as array  60 , antenna array  60 , or array  60  of antennas  40 ) may be coupled to signal paths such as transmission line paths  64  (e.g., one or more radio-frequency transmission lines). For example, a first antenna  40 - 1  in phased antenna array  60  may be coupled to a first transmission line path  64 - 1 , a second antenna  40 - 2  in phased antenna array  60  may be coupled to a second transmission line path  64 - 2 , an Nth antenna  40 -N in phased antenna array  60  may be coupled to an Nth transmission line path  64 -N, etc. While antennas  40  are described herein as forming a phased antenna array, the antennas  40  in phased antenna array  60  may sometimes be referred to as collectively forming a single phased array antenna. 
     Antennas  40  in phased antenna array  60  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, transmission line paths  64  may be used to supply signals (e.g., radio-frequency signals such as millimeter wave and/or centimeter wave signals) from millimeter wave transceiver circuitry  28  ( FIG. 2 ) to phased antenna array  60  for wireless transmission to external wireless equipment. During signal reception operations, transmission line paths  64  may be used to convey signals received at phased antenna array  60  from external equipment to millimeter wave transceiver circuitry  28  ( FIG. 2 ). 
     The use of multiple antennas  40  in phased antenna array  60  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. 3 , antennas  40  each have a corresponding radio-frequency phase and magnitude controller  62  (e.g., a first phase and magnitude controller  62 - 1  interposed on transmission line path  64 - 1  may control phase and magnitude for radio-frequency signals handled by antenna  40 - 1 , a second phase and magnitude controller  62 - 2  interposed on transmission line path  64 - 2  may control phase and magnitude for radio-frequency signals handled by antenna  40 - 2 , an Nth phase and magnitude controller  62 -N interposed on transmission line path  64 -N may control phase and magnitude for radio-frequency signals handled by antenna  40 -N, etc.). 
     Phase and magnitude controllers  62  may each include circuitry for adjusting the phase of the radio-frequency signals on transmission line paths  64  (e.g., phase shifter circuits) and/or circuitry for adjusting the magnitude of the radio-frequency signals on transmission line paths  64  (e.g., power amplifier and/or low noise amplifier circuits). Phase and magnitude controllers  62  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  60 ). 
     Phase and magnitude controllers  62  may adjust the relative phases and/or magnitudes of the transmitted signals that are provided to each of the antennas in phased antenna array  60  and may adjust the relative phases and/or magnitudes of the received signals that are received by phased antenna array  60  from external equipment. Phase and magnitude controllers  62  may, if desired, include phase detection circuitry for detecting the phases of the received signals that are received by phased antenna array  60  from external equipment. 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  42  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  62  are adjusted to produce a first set of phases and/or magnitudes for transmitted millimeter wave signals, the transmitted signals will form a millimeter wave frequency transmit beam as shown by beam  66  of  FIG. 3  that is oriented in the direction of point A. If, however, phase and magnitude controllers  62  are adjusted to produce a second set of phases and/or magnitudes for the transmitted millimeter wave signals, the transmitted signals will form a millimeter wave frequency transmit beam as shown by beam  68  that is oriented in the direction of point B. Similarly, if phase and magnitude controllers  62  are adjusted to produce the first set of phases and/or magnitudes, wireless signals (e.g., millimeter wave signals in a millimeter wave frequency receive beam) may be received from the direction of point A as shown by beam  66 . If phase and magnitude controllers  62  are adjusted to produce the second set of phases and/or magnitudes, signals may be received from the direction of point B, as shown by beam  68 . 
     Each phase and magnitude controller  62  may be controlled to produce a desired phase and/or magnitude based on a corresponding control signal  58  received from control circuitry  14  of  FIG. 2  or other control circuitry in device  10  (e.g., the phase and/or magnitude provided by phase and magnitude controller  62 - 1  may be controlled using control signal  58 - 1 , the phase and/or magnitude provided by phase and magnitude controller  62 - 2  may be controlled using control signal  58 - 2 , etc.). If desired, control circuitry  14  may actively adjust control signals  58  in real time to steer the transmit or receive beam in different desired directions over time. Phase and magnitude controllers  62  may provide information identifying the phase of received signals to control circuitry  14  if desired. 
     When performing millimeter or centimeter wave communications, radio-frequency signals are conveyed over a line of sight path between phased antenna array  60  and external equipment. If the external equipment is located at location A of  FIG. 3 , phase and magnitude controllers  62  may be adjusted to steer the signal beam towards direction A. If the external equipment is located at location B, phase and magnitude controllers  62  may be adjusted to steer the signal beam towards direction B. In the example of  FIG. 3 , 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. 3 ). However, in practice, the beam is 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. 3 ). 
     A schematic diagram of an antenna  40  that may be formed in phased antenna array  60  (e.g., as antenna  40 - 1 ,  40 - 2 ,  40 - 3 , and/or  40 -N in phased antenna array  60  of  FIG. 3 ) is shown in  FIG. 4 . As shown in  FIG. 4 , antenna  40  may be coupled to transceiver circuitry  20  (e.g., millimeter wave transceiver circuitry  28  of  FIG. 2 ). Transceiver circuitry  20  may be coupled to antenna feed  96  of antenna  40  using transmission line path  64  (sometimes referred to herein as radio-frequency transmission line  64 ). Antenna feed  96  may include a positive antenna feed terminal such as positive antenna feed terminal  98  and may include a ground antenna feed terminal such as ground antenna feed terminal  100 . Transmission line path  64  may include a positive signal conductor such as signal conductor  94  that is coupled to terminal  98  and a ground conductor such as ground conductor  90  that is coupled to terminal  100 . 
     Any desired antenna structures may be used for implementing antenna  40 . In one suitable arrangement that is sometimes described herein as an example, patch antenna structures may be used for implementing antenna  40 . Antennas  40  that are implemented using patch antenna structures may sometimes be referred to herein as patch antennas. An illustrative patch antenna that may be used in phased antenna array  60  of  FIG. 3  is shown in  FIG. 5 . 
     As shown in  FIG. 5 , antenna  40  may have a patch antenna resonating element  104  that is separated from and parallel to a ground plane such as antenna ground plane  102  (sometimes referred to herein as antenna ground  102 ). Patch antenna resonating element  104  may lie within a plane such as the X-Y plane of  FIG. 5  (e.g., the lateral surface area of element  104  may lie in the X-Y plane). Patch antenna resonating element  104  may sometimes be referred to herein as patch  104 , patch element  104 , patch resonating element  104 , antenna resonating element  104 , or resonating element  104 . Ground plane  102  may lie within a plane that is parallel to the plane of patch element  104 . Patch element  104  and ground plane  102  may therefore lie in separate parallel planes that are separated by a distance  110 . Patch element  104  and ground plane  102  may be formed from conductive traces patterned on a dielectric substrate such as a rigid or flexible printed circuit board substrate, metal foil, stamped sheet metal, electronic device housing structures, or any other desired conductive structures. 
     The length of the sides of patch element  104  may be selected so that antenna  40  resonates at a desired operating frequency. For example, the sides of patch element  104  may each have a length  114  that is approximately equal to half of the wavelength of the signals conveyed by antenna  40  (e.g., the effective wavelength given the dielectric properties of the materials surrounding patch element  104 ). In one suitable arrangement, length  114  may be between 0.8 mm and 1.2 mm (e.g., approximately 1.1 mm) for covering a millimeter wave frequency band between 57 GHz and 70 GHz or between 1.6 mm and 2.2 mm (e.g., approximately 1.85 mm) for covering a millimeter wave frequency band between 37 GHz and 41 GHz, as just two examples. 
     The example of  FIG. 5  is merely illustrative. Patch element  104  may have a square shape in which all of the sides of patch element  104  are the same length or may have a different rectangular shape. Patch element  104  may be formed in other shapes having any desired number of straight and/or curved edges. If desired, patch element  104  and ground plane  102  may have different shapes and relative orientations. 
     To enhance the polarizations handled by antenna  40 , antenna  40  may be provided with multiple feeds. As shown in  FIG. 5 , antenna  40  may have a first feed at antenna port P 1  that is coupled to a first transmission line path  64  such as transmission line path  64 V and a second feed at antenna port P 2  that is coupled to a second transmission line path  64  such as transmission line path  64 H. The first antenna feed may have a first ground feed terminal coupled to ground plane  102  (not shown in  FIG. 5  for the sake of clarity) and a first positive feed terminal  98 - 1 A coupled to patch element  104 . The second antenna feed may have a second ground feed terminal coupled to ground plane  102  (not shown in  FIG. 5  for the sake of clarity) and a second positive feed terminal  98 - 2 A on patch element  104 . 
     Holes or openings such as openings  117  and  119  may be formed in ground plane  102 . Transmission line path  64 V may include a vertical conductor (e.g., a conductive through-via, conductive pin, metal pillar, solder bump, combinations of these, or other vertical conductive interconnect structures) that extends through hole  117  to positive antenna feed terminal  98 - 1 A on patch element  104 . Transmission line path  64 H may include a vertical conductor that extends through hole  119  to positive antenna feed terminal  98 - 2 A on patch element  104 . This example is merely illustrative and, if desired, other transmission line structures may be used (e.g., coaxial cable structures, stripline transmission line structures, etc.). 
     When using the first antenna feed associated with port P 1 , antenna  40  may transmit and/or receive radio-frequency signals having a first polarization (e.g., the electric field E 1  of antenna signals  115  associated with port P 1  may be oriented parallel to the Y-axis in  FIG. 5 ). When using the antenna feed associated with port P 2 , antenna  40  may transmit and/or receive radio-frequency signals having a second polarization (e.g., the electric field E 2  of antenna signals  115  associated with port P 2  may be oriented parallel to the X-axis of  FIG. 5  so that the polarizations associated with ports P 1  and P 2  are orthogonal to each other). 
     One of ports P 1  and P 2  may be used at a given time so that antenna  40  operates as a single-polarization antenna or both ports may be operated at the same time so that antenna  40  operates with other polarizations (e.g., as a dual-polarization antenna, a circularly-polarized antenna, an elliptically-polarized antenna, etc.). If desired, the active port may be changed over time so that antenna  40  can switch between covering vertical or horizontal polarizations at a given time. Ports P 1  and P 2  may be coupled to different phase and magnitude controllers  62  ( FIG. 3 ) or may both be coupled to the same phase and magnitude controller  62 . If desired, ports P 1  and P 2  may both be operated with the same phase and magnitude at a given time (e.g., when antenna  40  acts as a dual-polarization antenna). If desired, the phases and magnitudes of radio-frequency signals conveyed over ports P 1  and P 2  may be controlled separately and varied over time so that antenna  40  exhibits other polarizations (e.g., circular or elliptical polarizations). 
     If care is not taken, antennas  40  such as dual-polarization patch antennas of the type shown in  FIG. 5  may have insufficient bandwidth for covering an entirety of a communications band of interest (e.g., a communications band at frequencies greater than 10 GHz). For example, in scenarios where antenna  40  is configured to cover a millimeter wave communications band between 57 GHz and 71 GHz, patch element  104  as shown in  FIG. 5  may have insufficient bandwidth to cover the entirety of the frequency range between 57 GHz and 71 GHz. If desired, antenna  40  may include one or more parasitic antenna resonating elements that serve to broaden the bandwidth of antenna  40 . 
     As shown in  FIG. 5 , a bandwidth-widening parasitic antenna resonating element such as parasitic antenna resonating element  106  may be formed from conductive structures located at a distance  112  over patch element  104 . Parasitic antenna resonating element  106  may sometimes be referred to herein as parasitic resonating element  106 , parasitic antenna element  106 , parasitic element  106 , parasitic patch  106 , parasitic conductor  106 , parasitic structure  106 , parasitic  106 , or patch  106 . Parasitic element  106  is not directly fed, whereas patch element  104  is directly fed via transmission line paths  64 V and  64 H and positive antenna feed terminals  98 - 1 A and  98 - 2 A. Parasitic element  106  may create a constructive perturbation of the electromagnetic field generated by patch element  104 , creating a new resonance for antenna  40 . This may serve to broaden the overall bandwidth of antenna  40  (e.g., to cover an entire millimeter wave frequency band from 24 GHz to 31 GHz). 
     At least some or an entirety of parasitic element  106  may overlap patch element  104 . In the example of  FIG. 5 , parasitic element  106  has a cross or “X” shape. In order to form the cross shape, parasitic element  106  may include notches or slots formed by removing conductive material from the corners of a square or rectangular metal patch. Parasitic element  106  may have a rectangular (e.g., square) outline or footprint. Removing conductive material from parasitic element  106  to form a cross shape may serve to adjust the impedance of patch element  104  so that the impedance of patch element  104  is matched to both transmission line paths  64 V and  64 H, for example. The example of  FIG. 5  is merely illustrative. If desired, parasitic element  106  may have other shapes or orientations. 
     If desired, antenna  40  of  FIG. 5  may be formed on a dielectric substrate (not shown in  FIG. 5  for the sake of clarity). The dielectric substrate may be, for example, a rigid or printed circuit board or other dielectric substrate. The dielectric substrate may include multiple stacked dielectric layers (e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy, multiple layers of ceramic substrate, etc.). Ground plane  102 , patch element  104 , and parasitic element  106  may be formed on different layers of the dielectric substrate if desired. 
     In scenarios where antenna  40  includes only a first positive antenna feed terminal  98 - 1 A for conveying radio-frequency signals at a first linear polarization and a second positive antenna feed terminal  98 - 2 A for conveying radio-frequency signals at a second linear polarization, positive antenna feed terminal  98 - 1 A may generate an antenna current density on patch element  104  that is asymmetric about the Z-axis of  FIG. 5 . Similarly, positive antenna feed terminal  98 - 2 A may generate an antenna current density on patch element  104  that is asymmetric about the Z-axis. This antenna current asymmetry may skew the radiation pattern of antenna  40  (e.g., antenna  40  may exhibit greater peak gain towards the bottom left and bottom right of  FIG. 5 ), thereby limiting the radio-frequency performance (e.g., antenna efficiency) for antenna  40  and thus phased antenna array  60  ( FIG. 3 ) in one or more directions. 
     In order to mitigate these issues, antenna  40  may be provided with additional positive antenna feed terminals that provide patch element  104  with symmetric antenna current distributions for both polarizations about the Z-axis. For example, as shown in  FIG. 5 , the antenna feed associated with port P 1  may include an additional positive antenna feed terminal  98 - 1 B located at the side of patch element  104  opposite to positive antenna feed terminal  98 - 1 A. Similarly, the antenna feed associated with port P 2  may include an additional positive antenna feed terminal  98 - 2 B located at the side of patch element  104  opposite to positive antenna feed terminal  98 - 1 B. Positive antenna feed terminals  98 - 1 A and  98 - 1 B may both handle radio-frequency signals of the same polarization (e.g., because the terminals are located at parallel edges of patch element  104 ). Similarly, positive antenna feed terminals  98 - 2 A and  98 - 2 B may both handle radio-frequency signals of the same polarization. 
     Positive antenna feed terminals  98 - 1 A and  98 - 1 B may both be coupled to the same transmission line path  64 V. Similarly, positive antenna feed terminals  98 - 2 A and  98 - 2 B may both be coupled to the same transmission line path  64 H. Transmission line path  64 V may include a vertical conductor such as a vertical conductive via that extends through hole  113  in ground plane  102  to positive antenna feed terminal  98 - 1 B on patch element  104 . Transmission line path  64 H may include a vertical conductor such as a vertical conductive via that extends through hole  111  in ground plane  102  to positive antenna feed terminal  98 - 1 B on patch element  104 . 
     When using the first antenna feed associated with port P 1 , antenna  40  may transmit and/or receive radio-frequency signals having the first polarization using both positive antenna feed terminals  98 - 1 A and  98 - 1 B. This may allow antenna  40  to exhibit a symmetric antenna current density about the Z-axis for the first polarization. When using the antenna feed associated with port P 2 , antenna  40  may transmit and/or receive radio-frequency signals having the second polarization. This may allow antenna  40  to exhibit a symmetric antenna current density about the Z-axis for the second polarization. When ports P 1  and P 2  are active at the same time, both polarizations may exhibit a symmetric current distribution across patch element  104 . This may serve to produce a uniform radiation pattern for antenna  40  across the hemisphere above antenna  40 . 
     When the antenna feed associated with port P 1  is active, care must be taken to ensure that the antenna current at antenna feed terminal  98 - 1 A is out of phase with respect to the antenna current at antenna feed terminal  98 - 1 B. Similarly, care must be taken to ensure that the antenna current at antenna feed terminal  98 - 2 A is out of phase with respect to the antenna current at antenna feed terminal  98 - 2 B when port P 1  is active. If these currents are in phase, antenna  40  may be unable to radiate with satisfactory antenna efficiency. In one suitable arrangement, transmission line paths  64 V and  64 H may include phase shifting segments that help to ensure that the antenna current at each positive antenna feed terminal is out of phase with respect to the opposing positive antenna feed terminal on patch element  104 . 
       FIG. 6  is a cross-sectional side view of device  10  showing how phased antenna array  60  ( FIG. 3 ) may convey radio-frequency signals through a dielectric cover layer for device  10 . The plane of the page of  FIG. 6  may, for example, lie in the Y-Z plane of  FIG. 1 . 
     As shown in  FIG. 6 , peripheral conductive housing structures  12 W may extend around the periphery of device  10 . Peripheral conductive housing structures  12 W may extend across the height (thickness) of device  10  from a first dielectric cover layer such as dielectric cover layer  120  to a second dielectric cover layer such as dielectric cover layer  122 . Dielectric cover layers  120  and  122  may sometimes be referred to herein as dielectric covers, dielectric layers, dielectric walls, or dielectric housing walls. If desired, dielectric cover layer  120  may extend across the entire lateral surface area of device  10  and may form a first (front) face of device  10 . Dielectric cover layer  122  may extend across the entire lateral surface area of device  10  and may form a second (rear) face of device  10 . 
     In the example of  FIG. 6 , dielectric cover layer  122  forms a part of rear housing wall  12 R for device  10  whereas dielectric cover layer  120  forms a part of display  6  (e.g., a display cover layer for display  6 ). Active circuitry in display  6  may emit light through dielectric cover layer  120  and may receive touch or force input from a user through dielectric cover layer  120 . Dielectric cover layer  122  may form a thin dielectric layer or coating under a conductive portion of rear housing wall  12 R (e.g., a conductive backplate or other conductive layer that extends across substantially all of the lateral area of device  10 ). Dielectric cover layers  120  and  122  may be formed from any desired dielectric materials such as glass, plastic, sapphire, ceramic, etc. 
     Conductive structures such as peripheral conductive housing structures  12 W may block electromagnetic energy conveyed by phased antenna arrays in device  10  such as phased antenna array  60  of  FIG. 3 . In order to allow radio-frequency signals to be conveyed with wireless equipment external to device  10 , phased antenna arrays such as phased antenna array  60  may be mounted behind dielectric cover layer  120  and/or dielectric cover layer  122 . 
     When mounted behind dielectric cover layer  120 , phased antenna array  60  may transmit and receive wireless signals (e.g., wireless signals at millimeter and centimeter wave frequencies) such as radio-frequency signals  124  through dielectric cover layer  120 . When mounted behind dielectric cover layer  122 , phased antenna array  60  may transmit and receive wireless signals such as radio-frequency signals  126  through dielectric cover layer  120 . 
     In practice, radio-frequency signals at millimeter and centimeter wave frequencies such as radio-frequency signals  124  and  126  may be subject to substantial attenuation, particularly through relatively dense mediums such as dielectric cover layers  120  and  122 . The radio-frequency signals may also be subject to destructive interference due to reflections within dielectric cover layers  120  and  122  and may generate undesirable surface waves at the interfaces between dielectric cover layers  120  and  122  and the interior of device  10 . For example, radio-frequency signals conveyed by a phased antenna array  60  mounted behind dielectric cover layer  120  may generate surface waves at the interior surface of dielectric cover layer  120 . If care is not taken, the surface waves may propagate laterally outward (e.g., along the interior surface of dielectric cover layer  120 ) and may escape out the sides of device  10 , as shown by arrows  125 . Surface waves such as these may reduce the overall antenna efficiency for the phased antenna array, may generate undesirable interference with external equipment, and may subject the user to undesirable radio-frequency energy absorption, for example. Similar surface waves can also be generated at the interior surface of dielectric cover layer  122 . 
       FIG. 7  is a cross-sectional side view of device  10  showing how an antenna  40  provided with phase shifting transmission line segments may be implemented within device  10 . As shown in  FIG. 7 , phased antenna array  60  may be formed on a dielectric substrate such as substrate  140  mounted within interior  134  of device  10  and against dielectric cover layer  130 . Phased antenna array  60  may include multiple antennas  40  arranged in an array of rows and columns (e.g., a one or two-dimensional array). A single antenna  40  is illustrated in  FIG. 7  for the sake of clarity. Dielectric cover layer  130  may form a dielectric rear wall for device  10  (e.g., dielectric cover layer  130  of  FIG. 7  may form dielectric cover layer  122  of  FIG. 6 ) or may form a display cover layer for device  10  (e.g., dielectric cover layer  130  of  FIG. 7  may form dielectric cover layer  120  of  FIG. 6 ), as examples. Dielectric cover layer  130  may be formed from a visually opaque material or may be provided with pigment so that dielectric cover layer  130  is visually opaque if desired. 
     Substrate  140  may be, for example, a rigid or flexible printed circuit board or other dielectric substrate. Substrate  140  may include multiple stacked dielectric layers  142  (e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy) or may include a single dielectric layer. Substrate  140  may include any desired dielectric materials such as epoxy, plastic, ceramic, glass, foam, or other materials. Antennas  40  in phased array antenna  60  may be mounted at a surface of substrate  140  or may be partially or completely embedded within substrate  140  (e.g., within a single layer of substrate  140  or within multiple layers of substrate  140 ). 
     The antennas  40  in phased antenna array  60  may include a ground plane (e.g., ground plane  102  of  FIG. 5 ) and patch elements (e.g., patch element  104  of  FIG. 5 ) that are formed from conductive traces embedded within layers  142  of substrate  140 . The ground plane for phased antenna array  60  may be formed from conductive traces  152  within substrate  140 . Antennas  40  in phased antenna array  60  may include parasitic elements  106  (e.g., cross-shaped parasitic elements as shown in  FIG. 5 ) that are formed from conductive traces at surface  150  of substrate  140 . For example, parasitic elements  106  may be formed from conductive traces on the top-most layer  142  of substrate  140 . In another suitable arrangement, one or more layers  142  may be interposed between parasitic elements  106  and dielectric cover layer  130 . In yet another suitable arrangement, parasitic elements  106  may be omitted and the patch elements in antennas  40  may be formed from conductive traces at surface  150  of substrate  140  (e.g., the patch elements may be in direct contact with adhesive layer  136  or interior surface  146  of dielectric cover layer  130 ). 
     Surface  150  of substrate  140  may be mounted against (e.g., attached to) interior surface  146  of dielectric cover layer  130 . For example, substrate  140  may be mounted to dielectric cover layer  130  using an adhesive layer such as adhesive layer  136 . This is merely illustrative. If desired, substrate  140  may be affixed to dielectric cover layer  130  using other adhesives, screws, pins, springs, conductive housing structures, etc. Substrate  140  need not be affixed to dielectric cover layer  130  if desired (e.g., substrate  140  may be in direct contact with dielectric cover layer  130  without being affixed to dielectric cover layer  130 ). Parasitic elements  106  in phased antenna array  60  may be in direct contact with interior surface  146  of dielectric cover layer  130  (e.g., in scenarios where adhesive layer  136  is omitted or where adhesive layer  136  has openings that align with parasitic elements  106 ) or may be coupled to interior surface  146  by adhesive layer  136  (e.g., parasitic elements  106  may be in direct contact with adhesive layer  136 ). 
     Phased antenna array  60  and substrate  140  may sometimes be referred to herein collectively as antenna module  138 . If desired, radio-frequency components such as radio-frequency components  166  may be mounted to surface  151  of substrate  140 . Radio-frequency components  166  may include phase and magnitude controllers (e.g., phase and magnitude controllers  62  of  FIG. 3 ), transceiver circuitry (e.g., millimeter wave transceiver circuitry  28  of  FIG. 2 ), and/or any other desired radio-frequency components. The circuitry in radio-frequency components  166  may be formed on an in integrated circuit (chip) mounted to surface  151  of substrate  140 . Radio-frequency components  166  may therefore sometimes be referred to herein as radio-frequency integrated circuit (RFIC)  166 . RFIC  166  may have one or more ports  168 . Ports  168  may include contact pads, solder balls, a ball grid array, conductive pins (e.g., input/output pins), conductive adhesive, conductive springs, and/or any other desired conductive interconnect structures. 
     If desired, a conductive layer (e.g., a conductive portion of rear housing wall  12 R when dielectric cover layer  130  forms dielectric cover layer  122  of  FIG. 6 ) may also be formed on interior surface  146  of dielectric cover layer  130 . In these scenarios, the conductive layer may provide structural and mechanical support for device  10  and may form a part of the antenna ground plane for device  10 . The conductive layer may have an opening that is aligned with phased antenna array  60  and/or antenna module  138  (e.g., to allow radio-frequency signals  162  to be conveyed through the conductive layer). 
     Conductive traces  152  may sometimes be referred to herein as ground traces  152 , ground plane  152 , antenna ground  152 , or ground plane traces  152 . The layers  142  in substrate  140  between ground traces  152  and dielectric cover layer  130  may sometimes be referred to herein as antenna layers. The layers in substrate  140  between ground traces  152  and surface  151  of substrate  140  may sometimes be referred to herein as transmission line layers. The antenna layers may be used to support the patch elements and parasitic elements of the antennas  40  in phased antenna array  60 . The transmission line layers may be used to support transmission line paths (e.g., transmission line paths  64 V and  64 H of  FIG. 5 ) for phased antenna array  60 . 
     Transmission line paths  64  for antennas  40  may be embedded within the transmission line layers of substrate  140 . The transmission line paths may include conductive traces  158  within the transmission line layers of substrate  140  (e.g., conductive traces on one or more dielectric layers  142  within substrate  140 ). Conductive traces  158  may form the signal conductor (e.g., signal conductor  94  of  FIG. 4 ) and/or the ground conductor (e.g., ground conductor  90  of  FIG. 4 ) of one, more than one, or all of the transmission line paths  64  for the antennas  40  in phased antenna array  60 . If desired, additional grounded traces within the transmission line layers of substrate  140  and/or portions of ground traces  152  may form the ground conductor for one or more transmission line paths  64 . 
     As shown in  FIG. 7 , antenna  40  may include patch element  104  embedded within the antenna layers of substrate  140 . Antenna  40  may have an antenna feed (e.g., an antenna feed associated with port P 1  of  FIG. 5 ) that is coupled to patch element  104  at positive antenna feed terminals  98 - 1 A and  98 - 1 B (e.g., at opposing sides  161  and  163  of patch element  104 ). The other positive antenna feed terminals of antenna  40  (e.g., positive antenna feed terminals  98 - 2 A and  98 - 2 B of  FIG. 5 ) are not shown in the example of  FIG. 7  for the sake of clarity. 
     A first vertical conductive via  154 A may couple conductive traces  158  to positive antenna feed terminal  98 - 1 A on patch element  104  and a second vertical conductive via  154 B may couple conductive traces  158  to positive antenna feed terminal  98 - 1 B on patch element  104 . Vertical conductive via  154 A may extend through a portion of the transmission line layers of substrate  140 , hole  117  in ground traces  152 , and the antenna layers in substrate  140  to positive antenna feed terminal  98 - 1 A on patch element  104 . Similarly, vertical conductive via  154 B may extend through a portion of the transmission line layers of substrate  140 , hole  113  in ground traces  152 , and the antenna layers in substrate  140  to positive antenna feed terminal  98 - 1 B on patch element  104 . Parasitic element  106  may be provided over patch element  104  for extending the bandwidth of patch element  104 . Patch element  104  and parasitic element  106  may each be formed on respective dielectric layers  142  in substrate  140 . Zero, one, or more than one dielectric layer  142  may be interposed between the dielectric layer  142  supporting patch element  104  and the dielectric layer  142  supporting parasitic element  106 . 
     As shown in  FIG. 7 , positive antenna feed terminals  98 - 1 A and  98 - 1 B may both be fed using the same transmission line path  64 V formed using ground traces  152  and conductive traces  158 . Conductive traces  158  may be coupled to port  168  on RFIC  166  over conductive via  164 . When port  168  is active, radio-frequency signals are conveyed over transmission line path  64 V to both positive antenna feed terminals  98 - 1 A and  98 - 1 B. Transmission line path  64 V may include a phase shifting transmission line segment such as phase shifting segment  156  coupled between vertical conductive vias  154 A and  154 B. Phase shifting segment  156  may phase shift the radio-frequency signals provided to positive antenna feed terminal  98 - 1 A so that the radio-frequency signals at positive antenna feed terminal  98 - 1 A are out of phase (e.g., 160-200 degrees out of phase, 170-190 degrees out of phase, 175-185 degrees out of phase, 180 degrees out of phase, etc.) with respect to the radio-frequency signals at positive antenna feed terminal  98 - 1 B. 
     Because the radio-frequency signals for both positive antenna feed terminals follow the same vertical path length from conductive traces  158  to patch element  104  (e.g., the length of vertical conductive vias  154 A and  154 B), the length of phase shifting segment  156  may be selected so that the radio-frequency signals provided to positive antenna feed terminal  98 - 1 A must follow a greater path length than the radio-frequency signals provided to positive antenna feed terminal  98 - 1 B. This difference in path length may create a phase shift for the radio-frequency signals at positive antenna feed terminal  98 - 1 A relative to positive antenna feed terminal  98 - 1 B. 
     For example, if the radio-frequency signals conveyed over transmission line path  64 V exhibit a phase of φ=0 degrees at vertical conductive via  154 B and positive antenna feed terminal  98 - 1 B, the path length of phase shifting segment  156  may serve to impart a non-zero phase of φ=φ1 to the radio-frequency signals at vertical conductive via  154 A and positive antenna feed terminal  98 - 1 A. Phase φ1 and thus the phase difference between positive antenna feed terminals  98 - 1 A and  98 - 1 B may be, for example, 160-200 degrees, 170-190 degrees, 175-185 degrees, 180 degrees, or other non-zero values. In order to produce this phase shift, segment  156  of transmission line path  64 V may have a length (e.g., the distance between vertical conductive vias  154 A and  154 B) that is approximately equal to (e.g., within 10-20% of) one-half of the effective wavelength of operation of antenna  40  in substrate  140 . The effective wavelength is given by dividing the free space wavelength of operation of antenna  40  (e.g., a centimeter or millimeter wavelength corresponding to a frequency between 10 GHz and 300 GHz) by a constant factor (e.g., the square root of the dielectric constant of the material used to form dielectric substrate  140 ). 
     In this way, the radio-frequency signals and the antenna current on patch element  104  at positive antenna feed terminal  98 - 1 A may be out of phase with the radio-frequency signals and the antenna current on patch element  104  at positive antenna feed terminal  98 - 1 B. The antenna current on patch element  104  may produce an electric field profile as shown by curve  172 . The electric field may exhibit a minimum (zero) magnitude at the center of patch element  104 . The electric field may have a maximum value E MAX  at side  163  of patch element  104  (e.g., at positive antenna feed terminal  98 - 1 B). If the antenna current at positive antenna feed terminal  98 - 1 A is in phase with the antenna current at positive antenna feed terminal  98 - 1 B, the electric field would exhibit the same value at both sides of patch element  104 , antenna current would not flow across patch element  104 , and antenna  40  would not radiate radio-frequency signals with satisfactory antenna efficiency. However, because the antenna current is out of phase at positive antenna feed terminal  98 - 1 A, the electric field may exhibit a minimum value −E MAX  at side  161  of patch element  104  (e.g., at positive antenna feed terminal  98 - 1 A). This may allow antenna current to flow across patch element  104  to produce strong radio-frequency signals that are radiated through dielectric cover layer  130 . 
     If care is not taken, radio-frequency signals transmitted by antenna  40  may reflect off of interior surface  146  of dielectric cover layer  130 , thereby limiting the gain of phased antenna array  60  in some directions. Mounting conductive structures from antenna  40  (e.g., patch element  104  or parasitic element  106 ) directly against interior surface  146  (e.g., either through adhesive layer  136  or in direct contact with interior surface  146 ) may serve to minimize these reflections, thereby optimizing antenna gain for phased antenna array  60  in all directions. Adhesive layer  136  may have a sufficiently low thickness so as not to contribute to signal reflections while still allowing for a satisfactory adhesion between dielectric cover layer  130  and substrate  140 . As an example, the thickness of adhesive layer  136  may be between 300 microns and 400 microns, between 200 microns and 500 microns, between 325 microns and 375 microns, between 100 microns and 600 microns, etc. 
     In practice, the radio-frequency signals transmitted by phased antenna array  60  may reflect within dielectric cover layer  130  (e.g., at interior surface  146  and/or exterior surface  148  of dielectric cover layer  130 ). Such reflections may, for example, be due to the difference in dielectric constant between dielectric cover layer  130  and the space external to device  10  as well as the difference in dielectric constant between substrate  140  and dielectric cover layer  130 . If care is not taken, the reflected signals may destructively interfere with each other and/or with the transmitted signals within dielectric cover layer  130 . This may lead to a deterioration in antenna gain for phased antenna array  60  over some angles, for example. 
     In order to mitigate these destructive interference effects, the dielectric constant DK 1  of dielectric cover layer  130  and thickness  144  of dielectric cover layer  130  may be selected so that dielectric cover layer  130  forms a quarter wave impedance transformer for phased antenna array  60 . When configured in this way, dielectric cover layer  130  may optimize matching of the antenna impedance for phased antenna array  60  to the free space impedance external to device  10  and may mitigate destructive interference within dielectric cover layer  130 . 
     As examples, dielectric cover layer  130  may be formed of a material having a dielectric constant between about 3.0 and 10.0 (e.g., between 4.0 and 9.0, between 5.0 and 8.0, between 5.5 and 7.0, between 5.0 and 7.0, etc.). In one particular arrangement, dielectric cover layer  130  may be formed from glass, ceramic, or other dielectric materials having a dielectric constant of about 6.0. Thickness  144  of dielectric cover layer  130  may be selected to be between 0.15 and 0.25 times the effective wavelength of operation of antenna  40  in the material used to form dielectric cover layer  130  (e.g., approximately one-quarter of the effective wavelength). This example is merely illustrative and, if desired, thickness  144  may be selected to be between 0.17 and 0.23 times the effective wavelength, between 0.12 and 0.28 times the effective wavelength, between 0.19 and 0.21 times the effective wavelength, between 0.15 and 0.30 times the effective wavelength, etc. In practice, thickness  144  may be between 0.8 mm and 1.0 mm, between 0.85 mm and 0.95 mm, or between 0.7 mm and 1.1 mm, as examples. Adhesive layer  136  may be formed from dielectric materials having a dielectric constant that is less than dielectric constant DK 1  of dielectric cover layer  130 . 
     Each antenna  40  may be separated from the other antennas  40  in phased antenna array  60  by vertical conductive structures such as vertical conductive vias  162  (sometimes referred to herein as conductive vias  162 ). Sets or fences of conductive vias  162  may laterally surround each antenna  40  in phased antenna array  60 . Conductive vias  162  may extend through substrate  140  from surface  141  to ground traces  152 . Conductive landing pads (not shown in  FIG. 7  for the sake of clarity) may be used to secure conductive vias  162  to each layer  142  as the conductive vias pass through substrate  140 . By shorting conductive vias  162  to ground traces  152 , conductive vias  162  may be held at the same ground or reference potential as ground traces  152 . 
     As shown in  FIG. 7 , the patch element  104  and parasitic element  106  may be mounted within a corresponding volume  160  (sometimes referred to herein as cavity  160 ). The edges of volume  160  may be defined by conductive vias  162 , ground traces  152 , and dielectric cover layer  130  (e.g., volume  160  for antenna  40  may be enclosed by conductive vias  162 , ground traces  152 , and dielectric cover layer  130 ). In this way, conductive vias  162  and ground traces  152  may form a conductive cavity for each antenna  40  in phased antenna array  60  (e.g., each antenna  40  in phased antenna array  60  may be a cavity-backed dual-polarization antenna having a conductive cavity formed from conductive vias  162  and ground traces  152 ). 
     The conductive cavity formed from ground traces  152  and conductive vias  162  may serve to enhance the gain of each antenna  40  in phased antenna array  60  (e.g., helping to compensate for attenuation and destructive interference associated with the presence of dielectric cover layer  130 ). Conductive vias  162  may also serve to isolate the antennas  40  in phased antenna array  60  from each other if desired (e.g., to minimize electromagnetic cross-coupling between the antennas). 
     Each antenna  40  in phased antenna array  60 , its corresponding conductive vias  162 , its corresponding volume  160 , and its corresponding portion of ground traces  152  may sometimes be referred to herein as an antenna unit cell  170 . Antenna unit cells  170  in phased antenna array  60  may be arranged in any desired pattern (e.g., a pattern having rows and/or columns or other shapes). Some conductive vias  162  may be shared by adjacent antenna unit cells  170  if desired. Conductive vias  162  may be omitted if desired. 
     Each antenna  40  in phased antenna array  60  may generate surface waves at interior surface  146  of dielectric cover layer  130  (e.g., surface waves such as surface waves  125  of  FIG. 6 ). However, the lateral placement (tiling) of antenna unit cells  170  at interior surface  146  of dielectric cover layer  130  may configure the surface waves generated by each antenna  40  to destructively interfere and cancel out at the lateral horizon of interior surface  146  (e.g., at relatively far lateral distances from phased antenna array  60  such as at the lateral edges of dielectric cover layer  130 ). This may prevent the surface waves generated by each antenna  40  in phased antenna array  60  from propagating out of device  10 , interfering with external equipment, being absorbed by the user, etc. In this way, phased antenna array  60  may transmit and receive radio-frequency signals  162  at millimeter and centimeter wave frequencies through dielectric cover layer  130  while minimizing reflective losses, destructive interference, and surface wave effects associated with the presence of dielectric cover layer  130 . 
     The example of  FIG. 7  is merely illustrative. If desired, each unit cell  170  may include multiple stacked patch antennas for covering other frequencies and/or antenna  40  may include multiple patch elements for covering multiple frequencies. The example of  FIG. 7  only illustrates the operation of positive antenna feed terminals  98 - 1 A and  98 - 1 B. Similar structures may be used to feed positive antenna feed terminals  98 - 2 A and  98 - 2 B of  FIG. 5  (e.g., using a phase shifting segment of transmission line path  64 H of  FIG. 5 ). Phased antenna array  60  need not be mounted against dielectric cover layer  130  and may be mounted at other locations in device  10  if desired. In general, phase shifts between positive antenna feed terminals  98 - 1 A and  98 - 1 B may be provided using other phase shifting components. In another suitable arrangement, each positive antenna feed terminal on patch element  104  may be coupled to respective phase shifters in RFIC  166  for providing radio-frequency signals with desired phases at the positive antenna feed terminals. 
       FIG. 8  is a cross-sectional side view showing how each of the positive antenna feed terminals on patch element  104  may be coupled to respective phase shifters in RFIC  166 . In the example of  FIG. 8 , conductive vias  162 , dielectric cover layer  130 , and ground traces  152  of  FIG. 7  have been omitted for the sake of clarity. 
     As shown in  FIG. 8 , positive antenna feed terminal  98 - 1 A may be coupled to port  168 A on RFIC  166  over transmission line path  180 . Positive antenna feed terminal  98 - 1 B may be coupled to port  168 B on RFIC  166  over transmission line path  182 . The other positive antenna feed terminals of antenna  40  (e.g., positive antenna feed terminals  98 - 2 A and  98 - 2 B of  FIG. 5 ) may be coupled to ports  168 C and  168 D of RFIC  166  over respective transmission line paths. Transmission line paths  180  and  182  may each include vertical conductive vias and conductive traces (e.g., portions of conductive traces  158  and portions of ground traces  152  of  FIG. 8 ) on substrate  140 . 
     Each port of RFIC  166  may be coupled to a respective phase shifter (e.g., phase shifters in phase and magnitude controllers  62  of  FIG. 3 ). For example, port  168 A may be coupled to phase shifter (PS)  184 A, port  168 C may be coupled to phase shifter  184 C, port  168 D may be coupled to phase shifter  184 D, and port  168 B may be coupled to phase shifter  184 B. Each phase shifter may provide the corresponding positive antenna feed terminal on patch element  104  with radio-frequency signals of selected phases. For example, phase shifter  184 B may provide radio-frequency signals at phase φ=0 degrees at positive antenna feed terminal  98 - 1 B whereas phase shifter  184 A may provide radio-frequency signals at phase φ=φ1 at positive antenna feed terminal  98 - 1 B. Phase φ1 may be selected to be 160-200 degrees, 170-190 degrees, 175-185 degrees, 180 degrees, etc. In this way, the antenna current at each positive antenna feed terminal on patch element  104  may be out of phase with the antenna current at the opposing positive antenna feed terminal on patch  104  and antenna  40  may convey corresponding radio-frequency signals (e.g., at different polarizations) with satisfactory antenna efficiency. 
     Concurrently feeding patch element  104  using both positive antenna feed terminals  98 - 1 A and  98 - 1 B (and/or both positive antenna feed terminals  98 - 2 A and  98 - 2 B of  FIG. 5 ) may allow antenna  40  to exhibit a symmetric current density and thus a symmetric radiation pattern about the Z-axis. Each antenna  40  across phased antenna array  60  may be formed using phase shifting transmission line segments (e.g., segments  156  of  FIG. 7 ), each antenna  40  across phased antenna array  60  may be formed using individually phased positive antenna feed terminals (e.g., as controlled using phase shifters  184 A- 184 D of  FIG. 8 ), or a first set of antennas  40  in phased antenna array  60  may be formed using the structures of  FIG. 7  whereas a second set of antennas  40  in phased antenna array  60  are formed using the structures of  FIG. 8 . 
       FIG. 9  is a side view of exemplary radiation pattern envelopes for phased antenna array  60 . Curve  190  of  FIG. 9  plots an exemplary radiation pattern envelope for phased antenna array  60  when provided with patch elements having only a single positive antenna feed terminal for covering each polarization (e.g., patch antennas having only positive antenna feed terminals  98 - 1 A and  98 - 2 A of  FIG. 5 ). As shown by curve  190 , the antenna currents on the patch element may exhibit asymmetric current density about the Z-axis. This may limit the gain of antennas  40  and thus phased antenna array  60  in some directions, skewing the radiation pattern envelope as shown in  FIG. 9 . 
     Curve  192  plots an exemplary radiation pattern envelope for phased antenna array  60  when provided with two positive antenna feed terminals for covering each polarization and a phase shifting transmission line segment (e.g., phase shifting segment  156  of  FIG. 7 ). As shown by curve  192 , by feeding patch element  104  with out-of-phase antenna current at opposing sides of the patch element, antenna  40  and thus phased antenna array  60  may be provided with uniform gain across the field of view of phased antenna array  60 . 
     Curve  194  plots an exemplary radiation pattern envelope for phased antenna array  60  when provided with individually phased positive antenna feed terminals (e.g., using the structures of  FIG. 8 ). As shown by curve  194 , by feeding patch element  104  with out-of-phase antenna current at opposing sides of the patch element, antenna  40  and thus phased antenna array  60  may be provided with uniform gain across the field of view of phased antenna array  60 . Because each positive antenna feed terminal is individually powered in this example (e.g., using amplifier circuitry in phase and magnitude controllers  62  of  FIG. 3 ), phased antenna array  60  may exhibit greater peak gain (e.g., 3 dB higher gain) using the structures of  FIG. 8  than when using the structures of  FIG. 7 . The example of  FIG. 9  is merely illustrative. In general, curves  190 ,  192 , and  194  may have other shapes. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20180928
Publication Date: 20210810
Grant Date: 20210810
Priority Date: 20180928
Inventors: AVSER, BILGEHAN
EDWARDS, JENNIFER M.
PAULOTTO, Simone
RAJAGOPALAN, HARISH
XU, HAO
GOMEZ ANGULO, RODNEY A.
MOW, MATTHEW A.
PASCOLINI, MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/045", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q21/065", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/045", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 69946703