PATENT DOCUMENT

Publication Number: US-10741933-B2
Application Number: US-201816032953-A
Country: US
Kind Code: B2

Title: Dual-polarization phased antenna arrays

Abstract:
An electronic device may include a phased antenna array mounted in a conductive cavity for conveying radio-frequency signals above 10 GHz. The cavity may include sidewalls extending from a rear wall. The array may include rectangular patches each having first and second perpendicular edges. Each of the first edges in the array may be aligned with a first axis. Each of the second edges in the array may be aligned with a second axis perpendicular to the first axis. The first and second axes may be oriented at 45 degrees with respect to each of the sidewalls of the cavity. Each patch may be fed using first and second positive antenna feed terminals that cover orthogonal linear polarizations. The cavity may prevent interference while symmetrically loading the impedance of both the first and second positive antenna feed terminals in each patch.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a conductive cavity having a conductive rear wall and conductive sidewalls extending from the conductive rear wall; and 
 a phased antenna array mounted to the conductive rear wall within the conductive cavity and configured to transmit radio-frequency signals at a frequency between 10 GHz and 300 GHz, wherein the phased antenna array comprises a plurality of patch antenna resonating elements that are each oriented at 45 degrees with respect to the conductive sidewalls and that each comprise:
 a first positive antenna feed terminal configured to transmit the radio-frequency signals with a first polarization, and 
 a second positive antenna feed terminal configured to transmit the radio-frequency signals with a second polarization that is different than the first polarization. 
 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the conductive sidewalls comprise a first conductive sidewall, a second conductive sidewall extending parallel to the first conductive sidewall, a third conductive sidewall extending perpendicular to the first conductive sidewall, and a fourth conductive sidewall extending parallel to the third conductive sidewall. 
     
     
       3. The electronic device defined in  claim 2 , wherein each patch antenna resonating element in the plurality of patch antenna resonating elements is located at a first distance from both the first and second conductive sidewalls. 
     
     
       4. The electronic device defined in  claim 3 , wherein the first distance is approximately equal to one-half of a wavelength corresponding to the frequency. 
     
     
       5. The electronic device defined in  claim 3 , wherein the first and second positive antenna feed terminals in each patch antenna resonating element of the plurality of patch antenna resonating elements is located at a second distance from the first conductive sidewall. 
     
     
       6. The electronic device defined in  claim 1 , further comprising a substrate mounted to the conductive rear wall, wherein each patch antenna resonating element in the plurality of patch antenna resonating elements is formed on the substrate. 
     
     
       7. The electronic device defined in  claim 6 , wherein the substrate has a plurality of edges and each patch antenna resonating element in the plurality of patch antenna resonating elements is oriented at 45 degrees with respect to each edge in the plurality of edges of the substrate. 
     
     
       8. The electronic device defined in  claim 6 , wherein each patch antenna resonating element in the plurality of patch antenna resonating elements comprises a square conductive trace on the substrate. 
     
     
       9. The electronic device defined in  claim 8 , wherein each square conductive trace in the plurality of patch antenna resonating elements has first and second sides, the first positive antenna feed terminal in each patch antenna resonating element is located at the first side, and the second positive antenna feed terminal in each patch antenna resonating element is located at the second side. 
     
     
       10. The electronic device defined in  claim 1 , further comprising:
 a dielectric layer, wherein the conductive sidewalls are mounted to the dielectric layer and the phased antenna array is configured to transmit the radio-frequency signals through the dielectric layer. 
 
     
     
       11. Apparatus comprising:
 a conductive cavity having a rectangular rear wall and first, second, third, and fourth walls extending from a periphery of the rectangular rear wall; 
 a phased antenna array mounted to the rectangular rear wall and configured to transmit radio-frequency signals at a frequency greater than 10 GHz, wherein the phased antenna array comprises:
 a first rectangular patch having first and second perpendicular edges, 
 a second rectangular patch having a third and fourth perpendicular edges, wherein the third edge extends along an axis parallel to the first edge and the fourth edge extends along an axis parallel to the second edge, 
 a first positive antenna feed terminal coupled to the first rectangular patch at the first edge, 
 a second positive antenna feed terminal coupled to the first rectangular patch at the second edge, 
 a third positive antenna feed terminal coupled to the second rectangular patch at the third edge, and 
 a fourth positive antenna feed terminal coupled to the second rectangular patch at the fourth edge, wherein the first, second, third, and fourth edges each extend non-parallel with respect to the first, second, third, and fourth walls of the conductive cavity. 
 
 
     
     
       12. The apparatus defined in  claim 11 , wherein the first and second rectangular patches are both located at a first distance from the first wall of the conductive cavity. 
     
     
       13. The apparatus defined in  claim 12 , wherein the first and second rectangular patches are both located at the first distance from the second wall of the conductive cavity. 
     
     
       14. The apparatus defined in  claim 13 , wherein the first, second, third, and fourth positive antenna feed terminals are each located at a second distance from the first wall of the conductive cavity. 
     
     
       15. The apparatus defined in  claim 14 , wherein the first, second, third, and fourth positive antenna feed terminals are each located at a third distance from the second wall of the conductive cavity, the third distance being greater than the second distance. 
     
     
       16. The apparatus defined in  claim 12 , wherein the first and third edges each extend at a first angle between 30 degrees and 60 degrees with respect to the first and second walls, the first and third edges each extend at a second angle between 30 degrees and 60 degrees with respect to the third and fourth walls, the second and fourth edges each extend at a third angle between 30 degrees and 60 degrees with respect to the first and second walls, and the second and fourth edges each extend at a fourth angle between 30 degrees and 60 degrees with respect to the third and fourth walls. 
     
     
       17. The apparatus defined in  claim 16 , wherein the first, second, third, and fourth angles are each equal to 45 degrees. 
     
     
       18. An electronic device comprising:
 a touch-sensitive display; 
 a dielectric layer; 
 a conductive cavity having first and second perpendicular conductive walls extending from edges of a rear conductive wall; 
 a phased antenna array mounted to the rear conductive wall within the conductive cavity and configured to transmit radio-frequency signals at a frequency greater than 10 GHz through the dielectric layer, wherein the phased antenna array comprises a row of antennas, each antenna in the row of antennas comprising:
 a rectangular antenna resonating element having first and second perpendicular sides, 
 a first positive antenna feed terminal coupled to the rectangular antenna resonating element along the first side, and 
 a second positive antenna feed terminal coupled to the rectangular antenna resonating element along the second side, wherein the first and second sides each extend at 45 degrees with respect to both the first and second conductive walls. 
 
 
     
     
       19. The electronic device defined in  claim 18 , wherein the conductive cavity comprises a third conductive wall extending parallel to the first conductive wall, and the first and second positive antenna feed terminals from each antenna in the row of antennas are both located at a first distance from the first conductive wall and at a second distance that is greater than the first distance from the third conductive wall. 
     
     
       20. The electronic device defined in  claim 19 , wherein the dielectric layer comprises a dielectric cover layer for the touch-sensitive display.

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. In addition, antennas that support millimeter wave and centimeter wave communications are often particularly susceptible to electromagnetic interference from nearby electronic components. 
     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 antennas and transceiver circuitry such as millimeter wave transceiver circuitry. The antennas may be arranged in a phased antenna array. 
     The phased antenna array may be mounted to a conductive rear wall of a conductive cavity in the electronic device. The conductive rear wall may have a rectangular periphery. The conductive cavity may include first, second, third, and fourth sidewalls extending from the conductive rear wall. A dielectric layer may cover the conductive cavity. The phased antenna array may transmit radio-frequency signals at a frequency between 10 GHz and 300 GHz through the dielectric layer. 
     The phased antenna array may include multiple patch antennas arranged in a single row or in a two-dimensional rectangular pattern. Each patch antenna may include a rectangular (e.g., square) patch element. Each patch element may have first and second perpendicular edges. The first edges of all of the patch elements in the phased antenna array may be aligned with a first axis. The second edges of all of the patch elements in the phased antenna array may be aligned with a second axis perpendicular to the first axis. The first and second axes may extend at non-parallel angles with respect to each of the first, second, third, and fourth sidewalls of the conductive cavity. For example, the first and second axes may each be oriented at 45 degrees with respect to each of the first, second, third, and fourth sidewalls of the conductive cavity. 
     Each patch element in the phased antenna array may be fed using first and second positive antenna feed terminals. The first positive antenna feed terminal may be coupled to the patch element along the first edge. The second positive antenna feed terminal may be coupled to the patch element along the second edge. The first and second positive antenna feed terminals may cover orthogonal linear polarizations. When arranged in this way, the center of each patch element may be located at a given distance from both the first and second sidewalls of the conductive cavity. The first and second positive antenna feed terminals of each patch element may be located at a first distance from the first sidewall and a second distance from the second sidewall. 
     The conductive cavity may prevent electromagnetic interference with the phased antenna array while symmetrically loading the impedance of both the first and second positive antenna feed terminals in each patch element. This may allow the phased antenna array to operate with optimal antenna efficiency using both polarizations despite being mounted within a rectangular conductive cavity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIG. 3  is a rear perspective view of an illustrative electronic device showing exemplary locations at which antennas for communications at frequencies greater than 10 GHz may be located in accordance with an embodiment. 
         FIG. 4  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 an embodiment. 
         FIG. 5  is a schematic diagram of illustrative wireless communications circuitry in accordance with an embodiment. 
         FIG. 6  is a perspective view of an illustrative patch antenna having multiple feeds for covering different polarizations in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative electronic device having a phased antenna array mounted within a conductive shielding cavity in accordance with an embodiment. 
         FIG. 8  is a top-down view of an illustrative phased antenna array having polarizations that are differentially loaded by a conductive shielding cavity in accordance with an embodiment. 
         FIG. 9  is a top-down view of an illustrative phased antenna array mounted within a conductive shielding cavity and having polarizations that are equally loaded by the conductive shielding cavity in accordance with an embodiment. 
         FIG. 10  is a graph of illustrative antenna performance (standing wave ratio) as a function of frequency for a phased antenna arrays of the types shown in  FIGS. 8 and 9  in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device 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. If desired, device  10  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 computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a pendant device, a headphone or earpiece device, a virtual or augmented reality headset device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, a wireless access point or base station, a desktop computer, a keyboard, a gaming controller, a computer mouse, a mousepad, a trackpad or touchpad, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     As shown in  FIG. 1 , device  10  may include a display such as display  8 . Display  8  may be mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  8  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  8  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Display  8  may be protected using a display cover layer such as a layer of transparent glass, clear plastic, sapphire, or other transparent dielectric. Openings may be formed in the display cover layer. For example, openings may be formed in the display cover layer to accommodate one or more buttons, sensor circuitry such as a fingerprint sensor or light sensor, ports such as a speaker port or microphone port, etc. Openings may be formed in housing  12  to form communications ports (e.g., an audio jack port, a digital data port, charging port, etc.). Openings in housing  12  may also be formed for audio components such as a speaker and/or a microphone. 
     Antennas may be mounted in housing  12 . If desired, some of the antennas (e.g., antenna arrays that may implement beam steering, etc.) may be mounted under an inactive border region of display  8  (see, e.g., illustrative antenna locations  6  of  FIG. 1 ). Display  8  may contain an active area with an array of pixels (e.g., a central rectangular portion). Inactive areas of display  8  are free of pixels and may form borders for the active area. If desired, antennas may also operate through dielectric-filled openings in the rear of housing  12  or elsewhere in device  10 . 
     To avoid disrupting communications when an external object such as a human hand or other body part of a user blocks one or more antennas, antennas may be mounted at multiple locations in housing  12 . Sensor data such as proximity sensor data, real-time antenna impedance measurements, signal quality measurements such as received signal strength information, and other data may be used in determining when one or more antennas is being adversely affected due to the orientation of housing  12 , blockage by a user&#39;s hand or other external object, or other environmental factors. Device  10  can then switch one or more replacement antennas into use in place of the antennas that are being adversely affected. 
     Antennas may be mounted at the corners of housing  12  (e.g., in corner locations  6  of  FIG. 1  and/or in corner locations on the rear of housing  12 ), along the peripheral edges of housing  12 , on the rear of housing  12 , under the display cover glass or other dielectric display cover layer that is used in covering and protecting display  8  on the front of device  10 , under a dielectric window on a rear face of housing  12  or the edge of housing  12 , or elsewhere in device  10 . 
     A schematic diagram showing illustrative components that may be used in device  10  is shown in  FIG. 2 . 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, etc. 
     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  34  for communicating wirelessly with external equipment. Wireless communications 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 communications circuitry  34  may include transceiver circuitry  20  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  22 ,  24 ,  26 , and  28 . 
     Transceiver circuitry  24  may be wireless local area network (WLAN) transceiver circuitry. Transceiver circuitry  24  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band. 
     Circuitry  34  may use cellular telephone transceiver circuitry  26  for handling wireless communications in frequency ranges such as a communications band from 700 to 960 MHz, a communications band from 1710 to 2170 MHz, and a communications band from 2300 to 2700 MHz or other communications bands between 700 MHz and 4000 MHz or other suitable frequencies (as examples). Circuitry  26  may handle voice data and non-voice data. 
     Millimeter wave transceiver circuitry  28  (sometimes referred to as extremely high frequency (EHF) transceiver circuitry  28  or transceiver circuitry  28 ) may support communications at frequencies between about 10 GHz and 300 GHz. For example, 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, 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, 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, circuitry  28  may support communications at multiple frequency bands between 10 GHz and 300 GHz such as a first band from 27.5 GHz to 29.5 GHz, a second band from 37 GHz to 41 GHz, and a third band from 57 GHz to 71 GHz, or other communications bands between 10 GHz and 300 GHz. 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.). While circuitry  28  is sometimes referred to herein as millimeter wave transceiver circuitry  28 , millimeter wave transceiver circuitry  28  may handle communications at any desired communications bands at frequencies between 10 GHz and 300 GHz (e.g., in millimeter wave communications bands, centimeter wave communications bands, etc.). 
     Wireless communications circuitry  34  may include satellite navigation system circuitry such as Global Positioning System (GPS) receiver circuitry  22  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data (e.g., GLONASS signals at 1609 MHz). Satellite navigation system signals for receiver  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 WiFi® 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. Extremely high frequency (EHF) wireless transceiver circuitry  28  may convey signals over short distances that travel between transmitter and 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 communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. 
     Antennas  40  in wireless communications circuitry  34  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from stacked patch antenna structures, loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, monopoles, dipoles, helical antenna structures, Yagi (Yagi-Uda) antenna 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 one or more antennas such as antennas arranged in one or more phased antenna arrays for handling millimeter 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 antenna structures  40  to transceiver circuitry  20 . Transmission lines in device  10  may include coaxial probes realized by metalized vias, microstrip transmission lines, stripline transmission lines, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, waveguide structures, transmission lines formed from combinations of transmission lines of these types, etc. Transmission lines in device  10  may be integrated into rigid and/or flexible printed circuit boards. In one suitable arrangement, transmission lines in device  10  may also include transmission line conductors (e.g., signal and ground conductors) 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. 
     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. Accordingly, it may be desirable to incorporate multiple antennas or phased antenna arrays into device  10 , each of which is placed in a different location within device  10 . With this type of arrangement, an unblocked antenna or phased antenna array may be switched into use. In scenarios where a phased antenna array is formed in device  10 , once switched into use, the 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. 
       FIG. 3  is a rear perspective view of electronic device  10  showing illustrative locations  50  on the rear and sides of housing  12  in which antennas  40  (e.g., single antennas and/or phased antenna arrays for use with wireless circuitry  34  such as wireless transceiver circuitry  28 ) may be mounted in device  10 . Antennas  40  may be mounted at the corners of device  10 , along the edges of housing  12  such as edges formed by sidewalls  12 E, on upper and lower portions of rear housing portion (wall)  12 R, in the center of rear housing wall  12 R (e.g., under a dielectric window structure or other antenna window in the center of rear housing  12 R), at the corners of rear housing wall  12 R (e.g., on the upper left corner, upper right corner, lower left corner, and lower right corner of the rear of housing  12  and device  10 ), etc. 
     In configurations in which housing  12  is formed entirely or nearly entirely from a dielectric, antennas  40  may transmit and receive antenna signals through any suitable portion of the dielectric. In configurations in which housing  12  is formed from a conductive material such as metal, regions of the housing such as slots or other openings in the metal may be filled with plastic or other dielectric. Antennas  40  may be mounted in alignment with the dielectric in the openings. These openings, which may sometimes be referred to as dielectric antenna windows, dielectric gaps, dielectric-filled openings, dielectric-filled slots, elongated dielectric opening regions, etc., may allow antenna signals to be transmitted to external equipment from antennas  40  mounted within the interior of device  10  and may allow internal antennas  40  to receive antenna signals from external equipment. In another suitable arrangement, antennas  40  may be mounted on the exterior of conductive portions of housing  12 . 
     In devices with phased antenna arrays, circuitry  34  may include gain and phase adjustment circuitry that is used in adjusting the signals associated with each antenna  40  in an array (e.g., to perform beam steering). Switching circuitry may be used to switch desired antennas  40  into and out of use. If desired, each of locations  50  may include multiple antennas  40  (e.g., a set of three antennas or more than three or fewer than three antennas in a phased antenna array) and, if desired, one or more antennas from one of locations  50  may be used in transmitting and receiving signals while using one or more antennas from another of locations  50  in transmitting and receiving signals. 
       FIG. 4  shows how antennas  40  for handling millimeter and centimeter wave communications may be formed in a phased antenna array. As shown in  FIG. 4 , 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 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 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. 4 , 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  60  in a particular direction. The term “transmit beam” may sometimes be used herein to refer to wireless radio-frequency signals that are transmitted in a particular direction whereas the term “receive beam” may sometimes be used herein to refer to wireless 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. 4  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. 4 , 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. 4 , beam steering is shown as being performed over a single degree of freedom for the sake of simplicity (e.g., towards the left and right on the page of  FIG. 4 ). However, in practice, the beam 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. 4 ). 
     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. 4 ) is shown in  FIG. 5 . As shown in  FIG. 5 , 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 positive antenna feed terminal  98  and a ground conductor such as ground conductor  90  that is coupled to ground antenna feed 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. 4  is shown in  FIG. 6 . 
     As shown in  FIG. 6 , 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 . Patch antenna resonating element  104  may lie within a plane such as the X-Y plane of  FIG. 6  (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  109 . Patch  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, as just one example. 
     The example of  FIG. 6  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. 6 , 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 antenna feed terminal coupled to ground plane  102  (not shown in  FIG. 6  for the sake of clarity) and a first positive antenna feed terminal  98  such as positive antenna feed terminal  98 V coupled to patch element  104 . The second antenna feed may have a second ground antenna feed terminal coupled to ground plane  102  (not shown in  FIG. 6  for the sake of clarity) and a second positive antenna feed terminal  98  such as positive antenna feed terminal  98 H coupled to 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  120 V (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 V on patch element  104 . Transmission line path  64 H may include a vertical conductor  120 H that extends through hole  119  to positive antenna feed terminal  98 H 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 linear 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. 6 ). When using the antenna feed associated with port P 2 , antenna  40  may transmit and/or receive radio-frequency signals having a second linear 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. 6  so that the linear 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. 4 ) 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. 6  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. 6  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  (e.g., to extend the bandwidth of antenna  40  to cover an entirety of the communications band between 57 GHz and 71 GHz). The parasitic antenna resonating elements may include one or more conductive patches located above patch element  104 , as an example. The length of the parasitic antenna resonating element may be greater than or less than the length of patch element  104  to add additional resonances that broaden the bandwidth of the antenna. The parasitic antenna resonating element may have a cross shape for impedance matching if desired. 
       FIG. 7  is a cross-sectional side view showing how phased antenna array  60  ( FIG. 4 ) of antennas  40  (e.g., dual-polarization patch antennas of the type shown in  FIG. 6 ) may be mounted within device  10 . The plane of the page of  FIG. 7  may, for example, lie in the X-Z plane of  FIG. 6 . 
     As shown in  FIG. 7 , phased antenna array  60  may be mounted within electronic device  10  behind a dielectric layer such as dielectric layer  122 . Dielectric layer  122  may be a dielectric rear housing wall for device  10  (e.g., rear housing wall  12 R of  FIG. 3 ), a dielectric sidewall for device  10  (e.g., sidewall  12 E of  FIG. 3 ), a dielectric cover layer for display  8  ( FIG. 1 ), a dielectric portion of a metal housing wall in device  10 , or any other dielectric layer in device  10 . If desired, dielectric layer  122  may form an exterior surface of device  10 . Dielectric layer  122  may sometimes be referred to herein as dielectric cover layer  122  or dielectric cover  122 . Dielectric layer  122  may be formed from an optically transparent or optically opaque material. Dielectric layer  122  may include glass, sapphire, ceramic, plastic, or any other desired material. An opaque masking layer (e.g., ink) may be coupled to an interior or exterior surface of dielectric layer  122  if desired. 
     Phased antenna array  60  may include any desired number of antennas  40  arranged in any desired number of rows and columns. In the example of  FIG. 7 , phased antenna array  60  includes a single row of N antennas  40  (e.g., phased antenna array  40  may include a first antenna  40 - 1 , a second antenna  40 - 2 , an Nth antenna  40 -N, etc.). Antennas  40  may each be dual-polarization patch antennas of the type shown in  FIG. 6 , for example. 
     The antennas  40  in phased antenna array  60  may be formed on a dielectric substrate such as substrate  124 . Substrate  124  may be, for example, a rigid or flexible printed circuit board or other dielectric substrate. Substrate  124  may include any desired dielectric materials such as epoxy, plastic, ceramic, glass, foam, or other materials. Substrate  124  may include multiple stacked dielectric layers (e.g., multiple layers of ceramic or multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy) or may include a single dielectric layer. Antennas  40  in phased antenna array  60  may be mounted at a surface of substrate  124  or may be partially or completely embedded within substrate  124  (e.g., within a single layer of substrate  124  or within multiple layers of substrate  124 ). 
     Ground plane  102  may include conductive traces embedded within substrate  124 . Ground plane  102  may divide substrate  124  into transmission line layers  126 B and antenna layers  126 A. Transmission line layers  126 B may include conductive traces used in forming transmission line paths  64  ( FIGS. 4-6 ) for the antennas  40  in phased antenna array  60 . In the example of  FIG. 7 , patch elements  104  of antennas  40  are shown as being mounted to a surface of antenna layers  126 A. This is merely illustrative. If desired, patch elements  104  may be embedded within antenna layers  126 A. Parasitic elements overlapping patch elements  104  may be embedded within antenna layers  126 A and/or formed on a surface of antenna layers  126 A, if desired. 
     As shown in  FIG. 7 , each antenna  40  in phased antenna array  60  is fed using a respective pair of conductive vias  120  extending through substrate  124  (e.g., a first conductive via  120 V for covering a first linear polarization and a second vertical conductive via  120 H for covering a second linear polarization as shown in  FIG. 6 ). Conductive vias  120 V and  120 H may be coupled to transceiver circuitry  28  ( FIG. 2 ) and may convey radio-frequency signals between transceiver circuitry  28  and the antennas  40  in phased antenna array  60 . Each antenna  40  in phased antenna array  60  may include a first positive antenna feed terminal  98 V ( FIG. 6 ) coupled to the corresponding conductive via  120 V and a second positive antenna feed terminal  98 H ( FIG. 6 ) coupled to the corresponding conductive via  120 H. In this way, phased antenna array  60  may cover first and second orthogonal linear polarizations and/or other polarizations such as circular or elliptical polarizations. 
     Each antenna  40  in phased antenna array  60  may be laterally separated (e.g., in the X-Y plane of  FIG. 7 ) from an adjacent antenna  40  by approximately one-half of the effective wavelength of operation of phased antenna array  60  (e.g., one-half of the freespace wavelength of operation after adjusting for contributions from the dielectric materials used to form substrate  124 ). Antennas having different sizes for covering multiple different frequency bands may be formed within the same phased antenna array  60  if desired. 
     During operation, electronic components adjacent to phased antenna array  60  (e.g., display  8  of  FIG. 1 , antennas formed from housing  12  of  FIG. 1 , and/or any other electronic components in device  10 ) may generate electromagnetic signals. If care is not taken, these signals may electromagnetically couple into phased antenna array  60 , leading to interference on the radio-frequency signals handled by phased antenna array  60 . 
     In order to mitigate these effects, phased antenna array  60  may be mounted within a conductive shielding cavity such as conductive cavity  132 . Conductive cavity  132  may sometimes be referred to herein as conductive shielding can  132 , conductive shielding pocket  132 , or conductive shielding bucket  132 . Conductive cavity  132  may be mounted to dielectric layer  122 . For example, conductive cavity  132  may be coupled to dielectric layer  122  using adhesive or may be held against dielectric layer  122  by biasing structures. In another suitable arrangement, conductive cavity  132  may be spaced apart from dielectric layer  122 . 
     As shown in  FIG. 7 , conductive cavity  132  may include a conductive rear wall  138  and conductive sidewalls such as walls  136  and  134  that extend from conductive rear wall  138  towards dielectric layer  122 . Conductive rear wall  138  may extend parallel to dielectric cover layer  122  or may extend at a non-parallel angle with respect to dielectric cover layer  122 . Some or all of conductive rear wall  138  and/or dielectric layer  122  may be curved if desired. Conductive sidewalls  136  and  134  may extend parallel to each other or may extend at different respective angles from conductive rear wall  138 . Conductive sidewalls  136  and  134  may extend perpendicular from conductive rear wall  138  and/or dielectric layer  122 . If desired, one or both of conductive sidewalls  136  and  134  may extend at non-perpendicular angles from conductive rear wall  138  and/or dielectric layer  122 . Conductive cavity  132  may be formed using stamped sheet metal, conductive traces on underlying substrates, conductive portions of electronic components within device  10 , portions of the housing for device  10 , and/or any other desired conductive structures. 
     Phased antenna array  60  (dielectric substrate  124 ) may be mounted to conductive rear wall  138  of conductive cavity  132 . If desired, ground plane  102  may be shorted to conductive cavity  132  so that conductive cavity  132  serves as a part of the antenna ground for phased antenna array  60 . In another suitable arrangement, ground plane  102  within dielectric substrate  124  may be omitted and conductive cavity  132  may be held at a ground potential to serve as the antenna ground for phased antenna array  60 . Holes or openings may be formed in conductive cavity  132  to allow transmission line structures (e.g., transmission line paths  64  of  FIGS. 4-6 ) to be routed between phased antenna array  60  and transceiver circuitry. 
     Dielectric layer  122  may be separated from phased antenna array  60  in conductive cavity  132  by a gap such as gap  128  (sometimes referred to herein as cavity  128 , dielectric cavity  128 , or volume  128 ). Cavity  128  may be filled with a dielectric material such as plastic, foam, air, etc. Cavity  128  may have a height  130  (e.g., a height defined by the vertical distance between dielectric layer  122  and patch elements  104 ). Height  130  may be, for example, between 1 mm and 3 mm, between 1.5 mm and 2.5 mm, approximately 2 mm, less than 1 mm, or greater than 3 mm. The dielectric properties of cavity  128  and dielectric layer  122  may be selected to impedance match phased antenna array  60  to the exterior of device  10 . Dielectric layer  122  may have a uniform thickness or may have a varying thickness across its lateral area. Phased antenna array  60  may transmit and receive radio-frequency signals  142  (e.g., at millimeter and centimeter wave frequencies) through dielectric layer  122 . 
     Conductive sidewalls including sidewalls  136  and  134  may extend around all of the lateral sides of cavity  128  (e.g., to surround the lateral periphery of phased antenna array  60  and substrate  124 ). In this way, conductive cavity  132  and dielectric layer  122  may completely enclose or encapsulate phased antenna array  60  within cavity  128  (e.g., the edges of cavity  128  may be defined by conductive cavity  132  and dielectric layer  122 ). 
     Conductive cavity  132  may serve to block electromagnetic signals transmitted by phased antenna array  60  from escaping cavity  128  towards the interior of device  10 . Similarly, conductive cavity  132  may serve to block electromagnetic interference at phased antenna array due to the presence of other electronic components in the vicinity of phased antenna array  60 . Conductive cavity  132  may also serve to block surface waves generated at the interior surface of dielectric layer  122  within cavity  128  from propagating beyond cavity  128 . In this way, phased antenna array  60  may be mounted within a relatively small volume of device  10  without allowing electromagnetic interference with the operation of phased antenna array  60  at millimeter and centimeter wave frequencies. The example of  FIG. 7  is merely illustrative. If desired, conductive cavity  132  may have other shapes (e.g., shapes having straight and/or curved edges or walls). 
     In order to dissipate heat associated with performing wireless communications at millimeter and centimeter wave frequencies (e.g., heat generated by phased antenna array  60 ), a heat spreader structure such as heat spreader  140  may be coupled to conductive rear wall  138  of conductive cavity  132 . Heat spreader  140  may include metal or other materials having a relatively high thermal conductivity. Heat spreader  140  and may serve as a heat sink for the heat generated by phased antenna array  60  (and may therefore sometimes be referred to herein as heat sink  140 ) or may serve to convey or dissipate heat from cavity  128  and conductive cavity  132  to other portions of device  10  (e.g., portions of device  10  far from transceiver  28  of  FIG. 2  and phased antenna array  60 ). 
     Heat spreader  140  may, for example, include fin structures to maximize the surface area of heat spreader  140  that is exposed to air (e.g., to maximize cooling rates for phased antenna array  60 ) or may include any other desired heat spreading structures. If desired, heat spreader  140  may be coupled to conductive rear wall  138  using adhesive, thermal paste, screws, pins, and/or any other desired interconnecting structures. Heat spreader  140  serve as part of the ground for antennas  40  if desired. The example of  FIG. 7  is merely illustrative. In general, heat spreader  140  may have any desired shape or configuration, may be coupled to conductive sidewall  136 , may be coupled to conductive sidewall  134 , etc. Heat spreader  140  may be omitted if desired. 
       FIG. 8  is a top-down view of phased antenna array  60  mounted within conductive cavity  132  (e.g., as taken in the direction of arrow  144  of  FIG. 7 ). The plane of the page of  FIG. 8  may, for example, lie in the X-Y plane of  FIG. 7 . In the example of  FIG. 8 , dielectric layer  122  of  FIG. 7  is omitted for the sake of clarity. 
     As shown in  FIG. 8 , the N antennas  40  in phased antenna array  60  are arranged in a single 1-by-N dimensional row. This is merely illustrative. In another suitable arrangement, the N antennas  40  in phased antenna array  60  may be arranged in a J-by-K rectangular pattern, where J is the number of rows in the pattern, K is the number of columns in the pattern, and J is less than or greater than K (e.g., phased antenna array  60  may be a non-square rectangular array having fewer rows than columns or fewer columns than rows of antennas  40 ). 
     Conductive cavity  132  may include conductive sidewalls  146  and  148  extending between conductive sidewalls  136  and  134 . Conductive sidewalls  146  and  148  extend vertically from conductive rear wall  138  (e.g., towards dielectric layer  122  of  FIG. 7  and in the direction of the Z-axis of  FIG. 8 ). Conductive sidewall  136  extends parallel to conductive sidewall  134  (e.g., parallel to the Y-axis of  FIG. 8 ). Conductive sidewall  146  extends parallel to conductive sidewall  148  (e.g., parallel to the X-axis of  FIG. 8 ). Conductive sidewalls  146  and  148  extend perpendicular to conductive sidewalls  136  and  134 . 
     In this way, conductive cavity  132  may have a rectangular lateral shape (e.g., in the X-Y plane of  FIG. 8 ). Conductive cavity  132  may have a length (parallel to the Y-axis of  FIG. 8 ) and a width (parallel to the X-axis of  FIG. 8 ) that is less than the length (e.g., because phased antenna array  60  includes more columns than rows of antennas  40 ). The length may sometimes be referred to herein as the lateral length and the width may sometimes be referred to herein as the lateral width of conductive cavity  132 . 
     Substrate  124  is mounted to conductive rear wall  138  of conductive cavity  132 . In the example of  FIG. 8 , substrate  124  has a rectangular shape with a first side  154  extending parallel to a second side  156  and with a third side  152  extending parallel to a fourth side  150 . Sides  152  and  150  each extend from side  154  to side  156 . When arranged in this way, side  152  of substrate  124  is located adjacent to (faces) conductive sidewall  146  of conductive cavity  132 , side  156  of substrate  124  is located adjacent to conductive sidewall  134 , side  150  of substrate  124  is located adjacent to conductive sidewall  148 , side  154  of substrate  124  is located adjacent to conductive sidewall  136 , sides  152  and  150  of substrate  124  extend parallel to conductive sidewalls  146  and  148 , and sides  154  and  156  of substrate  124  extend parallel to conductive sidewalls  136  and  134 . This is merely illustrative and, if desired, substrate  124  and conductive cavity  132  may have other shapes (e.g., other shapes having different numbers of straight and/or curved sides). Substrate  124  may be laterally separated from the conductive sidewalls of conductive cavity  132  (as shown in  FIG. 8 ) or may contact the conductive sidewalls of conductive cavity  132 . 
     As shown in the example of  FIG. 8 , each patch element  104  in phased antenna array  60  is oriented parallel to the sides of substrate  124  and the conductive sidewalls of conductive cavity  132 . For example, each patch element  104  in phased antenna array  60  has a first edge (side)  162 , a second edge (side)  164 , a third edge (side)  158 , and a fourth edge (side)  160 . Edge  162  of each patch element  104  faces and extends parallel to side  152  of substrate  124  and conductive sidewall  146 . Edge  164  of each patch element  104  faces and extends parallel to side  156  of substrate  124  and conductive sidewall  134 . Edge  158  of each patch element  104  faces and extends parallel to side  150  of substrate  124  and conductive sidewall  148 . Edge  160  of each patch element  104  faces and extends parallel to side  154  of substrate  124  and conductive sidewall  136 . 
     Each patch element  104  includes a first positive antenna feed terminal  98 V coupled to that patch element at edge  162  and a second positive antenna feed terminal  98 H coupled to that patch element at edge  164 . In this way, each patch element  104  can convey radio-frequency signals with first and second orthogonal linear polarizations (e.g., vertical and horizontal polarizations). However, when arranged in this way, the asymmetry of conductive cavity  132  due to conductive sidewall  146  being located closer to positive antenna feed terminals  98 V than positive antenna feed terminals  98 H may cause conductive cavity  132  to load the impedance of one polarization for phased antenna array  60  more than the other polarization (e.g., conductive cavity  132  may load the impedance of positive antenna feed terminals  98 V differently than  98 H). While the shape of conductive cavity  132  can be tweaked to load positive antenna feed terminals  98 V with a desired impedance, doing so would generate a non-proportionate change in the impedance of positive antenna feed terminals  98 H. Similarly, the shape of conductive cavity  132  can be tweaked to load positive antenna feed terminals  98 H with a desired impedance, but doing so would generate a non-proportionate change in the impedance of positive antenna feed terminals  98 V. This loading asymmetry across polarizations for phased antenna array  60  can limit the overall antenna efficiency for phased antenna array  60  in one of the polarizations during wireless communications. 
     In order to mitigate these effects, the antennas  40  in phased antenna array  60  may be oriented as shown in the top-down view of  FIG. 9 . As shown in  FIG. 9 , each patch element  104  in phased antenna array  60  may be rotated at an angle such that none of edges  162 ,  164 ,  160  and  158  in each patch element  104  extends parallel to conductive sidewalls  146 ,  134 ,  148 , and  136  of conductive cavity  132 . Similarly, none of edges  162 ,  164 ,  160 , and  158  of patch elements  104  extend parallel to sides  150 ,  156 ,  152 , and  154  of substrate  124 . 
     For example, edges  160  and  164  of each patch element  104  may extend parallel to axis  168  of  FIG. 9 . Edges  162  and  158  of each patch element  104  may extend parallel to axis  166 . Axis  168  may be oriented at angle A 1  with respect to conductive sidewalls  146  and  148  and sides  152  and  150  of substrate  124 . Axis  168  may be oriented at angle A 2  with respect to conductive sidewalls  136  and  134  and sides  154  and  156  of substrate  124 . Axis  166  may be oriented at angle A 3  with respect to conductive sidewalls  136  and  134  and sides  154  and  156  of substrate  124 . Axis  166  may be oriented at angle A 4  with respect to conductive sidewalls  146  and  148  and sides  152  and  150  of substrate  124 . Angles A 1 , A 2 , A 3 , and A 4  are each non-zero. In one suitable arrangement, each patch element  104  is oriented at 45 degrees with respect to the sidewalls of conductive cavity  132  and the sides of substrate  124  (e.g., angles A 1 , A 2 , A 3 , and A 4  are each equal to 45 degrees). This example is merely illustrative and, if desired, angles A 1 , A 2 , A 3 , and/or A 4  may be any desired angles between approximately 30 degrees and 60 degrees, between 40 degrees and 50 degrees, or between 35 degrees and 55 degrees, as examples. 
     While patch elements  104  are rotated at non-parallel angles with respect to the conductive sidewalls of conductive cavity  132 , the center of each patch element  104  may be located at the same distance  172  from both conductive sidewalls  146  and  148 . Distance  172  may be approximately equal to one-half of the wavelength of operation of phased antenna array  60  (e.g., one-half of an effective wavelength compensated for dielectric loading effects from substrate  124 ). The center of antenna  40 - 1  may be located at distance  170  from conductive sidewall  136  and the center of antenna  40 -N may be located at distance  170  from conductive sidewall  134 . Distance  170  may, for example, be equal to distance  172  (e.g., distance  170  may be approximately one-half of the wavelength of operation of phased antenna array  60 ). 
     When oriented in this way, each positive antenna feed terminal  98 V and  98 H in phased antenna array  60  may be located at approximately the same distance from conductive sidewall  146 . Similarly, each positive antenna feed terminal  98 V and  98 H in phased antenna array  60  may be located at approximately the same distance from conductive sidewall  148 . This symmetry may allow conductive cavity  132  to load the impedance of one polarization for phased antenna array  60  the same as the other polarization (e.g., conductive cavity  132  may load the impedance of positive antenna feed terminals  98 V the same as positive antenna feed terminals  98 H). Any adjustment to conductive cavity  132  will therefore affect impedance loading across both polarizations equally. This balance in impedance loading across polarizations for phased antenna array  60  may serve to maximize the overall antenna efficiency for phased antenna array  60  for both of the polarizations. 
     The example of  FIG. 9  is merely illustrative. If desired, phased antenna array  60  may include multiple rows of antennas  40  oriented as shown in  FIG. 9  (e.g., phased antenna array  60  may include a non-square rectangular pattern of multiple rows and columns of antennas  40 ). Orienting the antennas as shown in  FIG. 9  for each row may similarly balance impedance loading by conductive cavity  132  for the entire array, thereby maximizing antenna efficiency across both polarizations. 
     If desired, parasitic antenna resonating elements may be mounted over patch elements  104  in phased antenna array  60 . The parasitic antenna resonating elements may be cross-shaped patches having arms that extend parallel to axes  168  and  166  (e.g., the arms may overlap positive antenna feed terminals  98 V and  98 H in patch elements  104 ). The parasitic antenna resonating elements may serve to broaden the bandwidth of antennas  40 . Patch antennas  40  that are provided with parasitic antenna resonating elements in this way may sometimes be referred to as stacked patch antennas. 
       FIG. 10  shows a plot of antenna performance (e.g., standing wave ratio) as a function of frequency for phased antenna array  60 . As shown in  FIG. 10 , curve  174  illustrates the performance of one of the polarizations covered by a phased antenna array having patch elements  104  that are aligned with the sidewalls of conductive cavity  132  (e.g., as shown in  FIG. 8 ). As shown by curve  174  of  FIG. 10 , the phased antenna array exhibits a relatively weak response across frequency band  178 . Frequency band  178  may be any desired frequency band between 10 GHz and 300 GHz. Even if one of the polarizations covered by the phased antenna array exhibits a relatively strong response, asymmetric loading of the polarizations by conductive cavity  132  will limit the performance of phased antenna array  60  for the other polarization. 
     Curve  176  illustrates the performance of both polarizations covered by phased antenna array  60  having patch elements  104  that are rotated with respect to the sidewalls of conductive cavity  132  (e.g., as shown in  FIG. 9 ). As shown by curve  176  of  FIG. 10 , phased antenna array  60  exhibits a relatively strong response across frequency band  178  (e.g., due to symmetric loading of both polarizations by conductive cavity  132 ). 
     The example of  FIG. 10  is merely illustrative. Phased antenna array  60  may exhibit any desired number of wireless performance peaks at any desired number of frequencies greater than 10 GHz. In general, curves  174  and  176  may exhibit other shapes. In this way, phased antenna array  60  may operate with satisfactory antenna efficiency at millimeter and centimeter wave frequencies for two orthogonal polarizations despite being located within a rectangular conductive shielding cavity. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20180711
Publication Date: 20200811
Grant Date: 20200811
Priority Date: 20180711
Inventors: YONG, Siwen
JIANG, YI
WU, JIANGFENG
ZHANG, LIJUN
PASCOLINI, MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q21/245", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/28", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q21/205", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/28", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q3/2635", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/2617", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q3/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/2617", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q3/2635", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/28", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q21/245", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q3/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 69138526