PATENT DOCUMENT

Publication Number: US-10594028-B2
Application Number: US-201815895482-A
Country: US
Kind Code: B2

Title: Antenna arrays having multi-layer substrates

Abstract:
An electronic device may be provided with a phased antenna array for conveying millimeter wave signals. The array may be mounted to a substrate that includes transmission line layers having a first dielectric permittivity and antenna layers having a second dielectric permittivity that is less than the first dielectric permittivity. A ground plane may be interposed between the antenna layers and the transmission line layers. The array may be mounted to the antenna layers and transceiver circuitry may be mounted to the transmission line layers. Transmission line traces may be formed on the transmission line layers. The relatively high permittivity of the first set of dielectric layers may allow the transmission line traces to be routed relatively close together with minimal electromagnetic interference. The relatively low permittivity of the second set of dielectric layers may allow the array to operate with satisfactory antenna efficiency, gain, and bandwidth.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a first set of dielectric layers having a first dielectric permittivity; 
 a second set of dielectric layers stacked over the first set of dielectric layers and having a second dielectric permittivity that is less than the first dielectric permittivity; 
 a ground layer interposed between the first set of dielectric layers and the second set of dielectric layers, wherein the second set of dielectric layers has a first layer and a second layer, the first set of dielectric layers has a third layer that has a same dielectric permittivity as the first layer and that has a different dielectric permittivity than the second layer; 
 a phased antenna array formed on the second set of dielectric layers; and 
 transceiver circuitry coupled to the phased antenna array and configured to convey radio-frequency signals at a frequency greater than 10 GHz using the phased antenna array. 
 
     
     
       2. The electronic device defined in  claim 1 , further comprising:
 a plurality of transmission line structures, wherein the plurality of transmission line structures comprises conductive traces on the first set of dielectric layers, the ground layer is interposed between the conductive traces and the second set of dielectric layers, and the transceiver circuitry is configured to convey the radio-frequency signals over the plurality of transmission line structures. 
 
     
     
       3. The electronic device defined in  claim 2 , wherein the transceiver circuitry is mounted to the first set of dielectric layers. 
     
     
       4. The electronic device defined in  claim 3 , further comprising:
 first vertical interconnects that extend through a first portion of the first set of dielectric layers between the transceiver circuitry and the conductive traces; and 
 second vertical interconnects that extend through a second portion of the first set of dielectric layers, the ground layer, and the second set of dielectric layers between the conductive traces and positive antenna feed terminals on the phased antenna array. 
 
     
     
       5. The electronic device defined in  claim 1 , wherein the transceiver circuitry is configured to convey the radio-frequency signals at a first frequency band between 27.5 GHz and 28.5 GHz, a second frequency band between 37 GHz and 41 GHz, and a third frequency band between 57 GHz and 71 GHz using a plurality of transmission line structures and the phased antenna array. 
     
     
       6. The electronic device defined in  claim 1 , wherein the first set of dielectric layers has a first thickness and the second set of dielectric layers has a second thickness that is greater than the first thickness. 
     
     
       7. The electronic device defined in  claim 1 , wherein the first and second sets of dielectric layers comprise ceramic material. 
     
     
       8. The electronic device defined in  claim 1 , wherein the first dielectric permittivity is between 3.0 and 4.0 and the second dielectric permittivity is between 6.0 and 8.0. 
     
     
       9. An antenna module comprising:
 a dielectric substrate having a set of transmission line layers and a set of antenna layers, wherein the set of transmission line layers has a first dielectric permittivity, the set of antenna layers has a second dielectric permittivity that is less than the first dielectric permittivity, the set of antenna layers comprises first and second layers, the set of transmission line layers comprises a third layer, and the first layer is interposed between the second and third layers, the third layer being formed from a same material as the first layer and being formed from a different material than a material from which the second layer is formed; 
 a phased antenna array, wherein the phased antenna array comprises antenna resonating elements mounted to the set of antenna layers, the phased antenna array being configured to transmit and receive radio-frequency signals at a frequency greater than 10 GHz; and 
 a plurality of radio-frequency transmission lines, wherein the plurality of radio-frequency transmission lines comprises conductive traces that are formed on the set of transmission line layers and that are coupled to the antenna resonating elements. 
 
     
     
       10. The antenna module defined in  claim 9 , further comprising:
 a ground plane interposed between the set of transmission line layers and the set of antenna layers, wherein the conductive traces are coupled to the antenna resonating elements through the ground plane and the set of antenna layers. 
 
     
     
       11. The antenna module defined in  claim 10 , further comprising:
 transceiver circuitry mounted to the set of transmission line layers, the set of transmission line layers being interposed between the transceiver circuitry and the set of antenna layers. 
 
     
     
       12. The antenna module defined in  claim 9 , wherein the first layer has the first dielectric permittivity. 
     
     
       13. The antenna module defined in  claim 12 , wherein the second layer has a third dielectric permittivity that is less than the first dielectric permittivity. 
     
     
       14. The antenna module defined in  claim 13 , wherein the set of antenna layers further comprises a fourth layer having the first dielectric permittivity and a fifth layer having the third dielectric permittivity. 
     
     
       15. The antenna module defined in  claim 14 , wherein the second layer is interposed between the first and fourth layers and the fourth layer is interposed between the second and fifth layers. 
     
     
       16. The antenna module defined in  claim 14 , wherein the second and fifth layers are interposed between the first and fourth layers. 
     
     
       17. The antenna module defined in  claim 14 , wherein the first and fourth layers are interposed between the second and fifth layers. 
     
     
       18. Apparatus comprising:
 a substrate having a dielectric layer, a first set of dielectric layers, and a second set of dielectric layers interleaved with the first set of dielectric layers, wherein the dielectric layer has a first dielectric permittivity, the first set of dielectric layers has the first dielectric permittivity, and the second set of dielectric layers has a second dielectric permittivity that is less than the first dielectric permittivity; 
 a ground plane interposed between the dielectric layer and the first and second sets of dielectric layers; and 
 an array of antenna radiating elements mounted to the substrate and configured to convey radio-frequency signals at a frequency greater than 10 GHz, wherein the first and second sets of dielectric layers are interposed between the array and the ground plane. 
 
     
     
       19. The apparatus defined in  claim 18 , further comprising:
 radio-frequency transceiver circuitry coupled to the array of antenna radiating elements, the dielectric layer having first and second opposing surfaces, the ground plane being formed at the first surface of the dielectric layer, and the radio-frequency transceiver circuitry being disposed at the second surface of the dielectric layer.

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. In order to support millimeter and centimeter wave communications, an array of antennas is formed on a substrate. Transmission lines for the array are embedded within the substrate. 
     Operation at these frequencies may support high bandwidths, but may raise significant challenges. For example, it can be difficult to ensure that the transmission lines on the substrate are sufficiently isolated from each other at millimeter wave frequencies. Forming the transmission lines far apart from each other typically improves isolation. However, at the same time, manufacturers are continually striving to implement wireless communications circuitry such as antenna arrays using compact structures to satisfy consumer demand for small form factor wireless devices. 
     It would therefore be desirable to be able to provide electronic devices with improved wireless communications circuitry such as communications circuitry that supports millimeter 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. 
     The phased antenna array and the transceiver circuitry may be mounted to a shared substrate to form an antenna module. The substrate may include a first set of dielectric layers (e.g., one or more dielectric layers) having a first dielectric permittivity and a second set of dielectric layers (e.g., one or more dielectric layers) having a second dielectric permittivity that is less than the first dielectric permittivity. A ground plane for the phased antenna array may be interposed between the first and second sets of dielectric layers. The transceiver circuitry may be mounted to the second set of dielectric layers. Transmission lines for the phased antenna array may be formed from conductive traces on the first set of dielectric layers. The phased antenna array may be formed on the second set of dielectric layers (e.g., the antenna resonating elements of the phased antenna array may be mounted to a surface of the second set of dielectric layers). If desired, the second set of dielectric layers may include a first subset of dielectric layers having the first permittivity and a second subset of dielectric layers having a third permittivity that is lower than the second permittivity (e.g., the second permittivity may be a bulk permittivity derived from the cumulative effects of both the first permittivity of the first subset of layers and the third permittivity of the second subset of layers). The first subset of layers may be interleaved among the second subset of layers. 
     The relatively high permittivity of the first set of dielectric layers may allow the transmission lines to be routed relatively close together without electromagnetically interfering with each other. The relatively low permittivity of the second set of dielectric layers may allow the phased antenna array to operate with satisfactory antenna efficiency, gain, and bandwidth. The permittivity of the second set of dielectric layers may be adjusted (e.g., using the interleaving subsets of layers) to change the thickness of the second set of layers to accommodate different device form factors if desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIGS. 2 and 3  are perspective views of an illustrative electronic device showing locations at which phased antenna arrays for millimeter wave communications 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 in accordance with an embodiment. 
         FIG. 7  is a side view of an illustrative patch antenna in accordance with an embodiment. 
         FIG. 8  is a perspective view of an illustrative antenna module in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of an illustrative antenna module having transmission line layers and antenna layers with different dielectric permittivities in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of an illustrative antenna module having dielectric layers that exhibit a bulk permittivity defined by alternating layers of relatively high and relatively low dielectric permittivities in accordance with an embodiment. 
         FIGS. 11-13  are cross-sectional side views of illustrative alternating layers of relatively high and relatively low dielectric permittivities that may be used in forming the antenna layers of an antenna module in accordance with an embodiment. 
     
    
    
     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 devices (such as device  10  in  FIG. 1 ) 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 (e.g., a wireless router or other equipment for routing communications between other wireless devices and a larger network such as the internet or a cellular telephone network), 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. The above-mentioned examples are merely illustrative. Other configurations may be used for electronic devices if desired. 
       FIG. 1  is a schematic diagram showing illustrative components that may be used in an electronic device such as electronic device  10 . As shown in  FIG. 1 , 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 wireless personal area network protocols, IEEE 802.1 lad 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 radio-frequency 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 transceiver circuitry. 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. 
     Circuitry  34  may use cellular telephone transceiver circuitry  26  for handling 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). 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, communications band between about 26.5 GHz and 40 GHz, a Ku 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 802.11 ad communications at 60 GHz and/or 5th generation mobile networks or 5th 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 28.5 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., transceiver circuitry  28  may transmit and receive radio-frequency signals 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 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. Extremely high frequency (EHF) wireless 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 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 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. 
     As shown in  FIG. 1 , device  10  may include 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, metallic coatings on a substrate, 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.). Antennas  40  may be mounted in housing  12 . Dielectric-filled openings such as plastic-filled openings may be formed in metal portions of housing  12  (e.g., to serve as antenna windows and/or to serve as gaps that separate portions of antennas  40  from each other). 
     In scenarios where input-output devices  18  include a display, the display 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. The display 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. The display may be protected using a display cover layer such as a layer of transparent glass, clear plastic, sapphire, or other transparent dielectric. If desired, some of the antennas  40  (e.g., antenna arrays that may implement beam steering, etc.) may be mounted under an inactive border region of the display. The display may contain an active area with an array of pixels (e.g., a central rectangular portion). Inactive areas of the display are free of pixels and may form borders for the active area. If desired, antennas may also operate through dielectric-filled openings elsewhere in device  10 . 
     If desired, housing  12  may include a conductive rear surface. The rear surface of housing  12  may lie in a plane that is parallel to a display of device  10 . In configurations for device  10  in which the rear surface of housing  12  is formed from metal, it may be desirable to form parts of peripheral conductive housing structures as integral portions of the housing structures forming the rear surface of housing  12 . For example, a rear housing wall of device  10  may be formed from a planar metal structure, and portions of peripheral housing structures on the sides of housing  12  may be formed as vertically extending integral metal portions of the planar metal structure. 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 . The planar rear wall of housing  12  may have one or more, two or more, or three or more portions. The peripheral housing structures and/or the conductive rear wall of housing  12  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 internal structures from view of the user). 
     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 wave signals for extremely high frequency wireless transceiver circuits  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. 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. 2  is a perspective view of electronic device  10  showing illustrative locations  50  at which antennas  40  (e.g., single antennas and/or phased antenna arrays for use with wireless circuitry  34  such as millimeter wave wireless transceiver circuitry  28  in  FIG. 1 ) may be mounted in device  10 . As shown in  FIG. 2 , housing  12  of device  10  may include rear housing wall  12 R (sometimes referred to as wall  12 R, rear housing portion  12 R, or rear housing surface  12 R) and housing sidewalls  12 E. In one suitable arrangement, a display may be mounted to the side of housing  12  opposing rear housing wall  12 R. 
     Antennas  40  (e.g., single antennas  40  or arrays of antennas  40 ) may be mounted at locations  50  at the corners of device  10 , along the edges of housing  12  such as on sidewalls  12 E, on the upper and lower portions of rear housing wall  12 R, in the center of rear housing  12  (e.g., under a dielectric window structure such as a plastic logo), etc. In configurations in which housing  12  is formed from a dielectric, antennas  40  may transmit and receive antenna signals through the dielectric, may be formed from conductive structures patterned directly onto the dielectric, or may be formed on dielectric substrates (e.g., flexible printed circuit board substrates) formed on the dielectric. In configurations in which housing  12  is formed from a conductive material such as metal, slots or other openings may be formed in the metal that are filled with plastic or other dielectric. Antennas  40  may be mounted in alignment with the dielectric (i.e., the dielectric in housing  12  may serve as one or more antenna windows for antennas  40 ) or may be formed on dielectric substrates (e.g., flexible printed circuit board substrates) mounted to external surfaces of housing  12 . 
     In the example of  FIG. 2 , rear housing wall  12 R has a rectangular periphery. Housing sidewalls  12 E surround the rectangular periphery of rear housing wall  12 R and extend from rear housing wall  12 R to the opposing face of device  10 . In another suitable arrangement, device  10  and housing  12  may have a cylindrical shape. As shown in  FIG. 3 , rear housing wall  12 R has a circular or elliptical periphery. Rear housing wall  12 R may oppose surface  52  of device  10 . Surface  52  may be formed from a portion of housing  12 , may be formed from a display or transparent display cover layer, or may be formed using any other desired device structures. Housing sidewall  12 E may extend between surface  52  and rear housing wall  12 R. Antennas  40  may be mounted at locations  50  along housing sidewall  12 E, on surface  52 , and/or on rear housing wall  12 R. By forming phased antenna arrays at different locations along housing sidewall  12 E, on surface  52  (sometimes referred to herein as housing surface  52 ), and/or on rear housing wall  12 R (e.g., as shown in  FIGS. 2 and 3 ), the different phased antenna arrays on device  10  may collectively provide line of sight coverage to any point on a sphere surrounding device  10  (or on a hemisphere surrounding device  10  in scenarios where phased antenna arrays are only formed on one side of device  10 ). 
     The examples of  FIGS. 2 and 3  are merely illustrative. In general, housing  12  and device  10  may have any desired shape or form factor. For example, rear housing wall  12 R may have a triangular periphery, hexagonal periphery, polygonal periphery, a curved periphery, combinations of these, etc. Housing sidewall  12 E may include straight portions, curved portions, stepped portions, combinations of these, etc. If desired, housing  12  may include other portions having any other desired shapes. The height of housing sidewall  12 E may be less than, equal to, or greater than the length and/or width of rear housing wall  12 R. 
       FIG. 4  shows how antennas  40  on device  10  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. 1 ) 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. 1 ). 
     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. 1  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. 1 ). 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. 4  is shown in  FIG. 6 . 
     As shown in  FIG. 6 , antenna  40  may have a patch antenna resonating element such as patch element  110  that is separated from a ground plane structure such as ground  112  (sometimes referred to as ground layer  112 , grounding layer  112 , or antenna ground  112 ). Patch element  110  and ground  112  may be formed from metal foil, machined metal structures, metal traces on a printed circuit or a molded plastic carrier, electronic device housing structures, or other conductive structures in an electronic device such as device  10 . Patch element  110  may sometimes be referred to herein as patch  110 , patch antenna resonating element  110 , patch radiating element  110 , or antenna resonating element  110 . 
     Patch element  110  may lie within a plane such as the X-Y plane of  FIG. 5 . Ground  112  may lie within a plane that is parallel to the plane of patch element  110 . Patch element  110  and ground  112  may therefore lie in separate parallel planes that are separated by a distance H. In general, greater distances (heights) H may allow antenna  40  to exhibit a greater bandwidth than shorter distances H. However, greater distances H may consume more volume within device  10  (where space is often at a premium) than shorter distances H. 
     Conductive path  114  may be used to couple terminal  98 ′ to positive antenna feed terminal  98 . Antenna  40  may be fed using a transmission line with a positive conductor coupled to terminal  98 ′ (and thus to positive antenna feed terminal  98 ) and with a ground conductor coupled to ground antenna feed terminal  100 . Other feeding arrangements may be used if desired. Moreover, patch element  110  and ground  112  may have different shapes and orientations (e.g., planar shapes, curved patch shapes, patch element shapes with non-rectangular outlines, shapes with straight edges such as squares, shapes with curved edges such as ovals and circles, shapes with combinations of curved and straight edges, etc.). 
     A side view of a patch antenna such as antenna  40  of  FIG. 6  is shown in  FIG. 7 . As shown in  FIG. 7 , antenna  40  may be fed using an antenna feed (with antenna feed terminals  98  and  100 ) that is coupled to a transmission line such as transmission line  64 . Patch element  110  of antenna  40  may lie in a plane parallel to the X-Y plane of  FIG. 7  and the surface of the structures that form ground (e.g., ground  112 ) may lie in a plane that is separated by vertical distance H from the plane of patch element  110 . 
     With the illustrative feeding arrangement of  FIG. 7 , a ground conductor of transmission line  64  (e.g., ground conductor  90  of  FIG. 5 ) is coupled to ground antenna feed terminal  100  on ground  112  and a positive conductor of transmission line  64  (e.g., signal conductor  94  of  FIG. 5 ) is coupled to positive antenna feed terminal  98  via an opening in ground  112  and conductive path  114  (which may be an extended portion of the transmission line&#39;s positive conductor). Conductive path  114  may be implemented using conductive pins, solder, welds, conductive wires, conductive springs, conductive through-vias, and/or any other desired conductive structures. Other feeding arrangements may be used if desired (e.g., feeding arrangements in which a microstrip transmission line in a printed circuit or other transmission line that lies in a plane parallel to the X-Y plane is coupled to terminals  98  and  100 , etc.). To enhance the frequency coverage and polarizations handled by antenna  40 , antenna  40  may be provided with multiple feeds (e.g., two feeds) if desired. These examples are merely illustrative and, in general, the patch element may have any desired shape. Other types of antennas may be used if desired. 
     Antennas of the types shown in  FIGS. 6 and 7  and/or other types of antennas such as dipole antennas and Yagi antennas may be arranged in a phased antenna array such as phased antenna array  60  ( FIG. 4 ). If desired, phased antenna array  60  may be integrated with other circuitry such as transceiver circuitry  20  to form an integrated antenna module. 
       FIG. 8  is a perspective view of an illustrative integrated antenna module for handling signals at frequencies greater than 10 GHz in device  10  (e.g., millimeter wave signals). As shown in  FIG. 8 , device  10  may be provided with an integrated antenna module such as integrated antenna module  118  (sometimes referred to herein as antenna module  118  or module  118 ). Module  118  may include phased antenna array  60  of antennas  40  formed on a dielectric substrate such as dielectric substrate  120 . Substrate  120  may be, for example, a rigid or printed circuit board or other dielectric substrate. Substrate  120  may be a stacked dielectric substrate that includes multiple stacked dielectric layers  122  (e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy, rigid printed circuit board material, flexible printed circuit board material, ceramic, plastic, glass, or other dielectrics). Phased antenna array  60  may include any desired number of antennas  40  arranged in any desired pattern. Additional phased antenna arrays  60  may be provided on the top and/or bottom surface of substrate  120  if desired. 
     Antennas  40  in phased antenna array  60  may include elements such as patch elements  110 , ground  112 , and/or other components such as parasitic elements that are interposed between or formed on layers  122  of substrate  120 . One or more electrical components  116  (e.g., transceiver circuitry such as transceiver circuitry  20  or transceiver circuitry  28  of  FIG. 1 ) may be mounted on substrate  120 . For example, components  116  may be mounted on a surface of substrate  120  such as the surface of substrate  120  opposite phased antenna array  60  or the same surface of substrate  120  on which phased antenna array  60  is formed. Components  116  may, for example, include integrated circuits (e.g., integrated circuit chips) or integrated circuit packages mounted to substrate  120 . Components  116  may sometimes be referred to herein as transceivers  116 , transceiver circuitry  116 , or transceiver chips  116 . If desired, components  116  may include control circuitry (e.g., some or all of circuitry  14  of  FIG. 1 ) or any other desired electrical components. 
     Conductive traces or other metal layers on substrate  120  may be used in forming transmission line structures such as transmission line paths  64  of  FIGS. 4, 5, and 7 . Conductive traces for forming transmission line paths  64  may be interposed between layers  122  of substrate  120 . The transmission lines may be used to convey radio-frequency antenna signals at frequencies greater than 10 GHz such as millimeter wave signals between transceiver circuitry  116  and antennas  40  in phased antenna array  60 . For example, a respective transmission line path  64  may be coupled between each antenna  40  in module  118  and transceiver circuitry  116 . 
     In practice, radio-frequency signals at relatively high frequencies such as frequencies greater than 10 GHz may be particularly susceptible to attenuation over relatively large distances. Mounting transceiver circuitry  116  to the same substrate as phased antenna array  60  (i.e., substrate  120  of module  18 ) may allow transceiver circuitry  116  to be located relatively close to phased antenna array  60 , thereby minimizing signal attenuation between transceiver circuitry  116  and phased antenna array  60 . At the same time, as the number of antennas  40  implemented on module  118  and the number of frequencies covered by phased antenna array  60  increases, the routing complexity of the corresponding transmission line paths increases. If care is not taken, it can be difficult to ensure that each of the transmission line paths in module  118  is sufficiently isolated from the other transmission line paths in module  118 . While placing the transmission line paths far apart from each other may serve to enhance isolation, doing so would cause the transmission lines and module  118  to occupy an excessive amount of space within device  10  (where space is at a premium). It would therefore be desirable to be able to minimize the volume of module  118  while still allowing for a satisfactory amount of isolation between the transmission line paths routed over substrate  120 . 
     In order to maximize isolation between transmission line paths  64  while minimizing the size of module  118 , the material used to form layers  122  may be selected to have a relatively high dielectric permittivity. Relatively high dielectric permittivity materials may minimize the electromagnetic influence of radio-frequency signals conveyed along transmission line paths  64  from other transmission line paths  64  in substrate  120 . However, at the same time, relatively high dielectric permittivity materials can lead to generation of surface waves at patch elements  110  and may serve to undesirably limit the bandwidth of antennas  40  in phased antenna array  60 . It would therefore be desirable to be able to provide modules  118  that minimize the volume of module  118  while still allowing for satisfactory antenna performance and a satisfactory amount of isolation between the transmission line paths on substrate  120 . 
       FIG. 9  is a cross-sectional side view of module  118  that exhibits satisfactory antenna bandwidth and transmission line isolation while minimizing space consumption within device  10 . As shown in  FIG. 9 , patch elements  110  of antennas  40  in phased antenna array  60  may be formed at a first (top) surface of substrate  120 . Transceiver circuitry  116  may be mounted to a second opposing (bottom) surface of substrate  120 . Ground  112  for the antennas  40  in phased antenna array  60  may be formed from conductive traces within substrate  120  (e.g., conductive traces held at a ground or other reference potential). 
     While  FIG. 9  shows two antennas, this is merely illustrative. In general, any desired number of antennas may be formed in phased antenna array  60 . The example of antenna elements  110  being patch elements is merely illustrative. Antenna elements  110  may be dipole antenna resonating elements, Yagi antenna resonating elements, slot antenna resonating elements, or any other desired antenna resonating elements of antennas of any desired type. 
     The layers  122  in substrate  120  ( FIG. 8 ) may include a first set of layers  122 A (sometimes referred to herein as antenna layers  122 A) and a second set of layers  122 T (sometimes referred to herein as transmission line layers  122 T). Antenna layers  122 A may be vertically stacked over transmission line layers  122 T. The conductive traces of ground  112  may be formed on a surface of transmission line layers  122 T and may separate transmission line layers  122 T from antenna layers  122 A. Antenna layers  122 A may include a single dielectric layer  122  ( FIG. 8 ) or may include multiple dielectric layers  122 . Transmission line layers  122 T may include a single dielectric layer  122  ( FIG. 8 ) or may include multiple dielectric layers  122 . 
     Antenna layers  122 A may support antennas  40  on module  118 . Antenna layers  122 A may have a thickness (height) Z 1  extending from ground  112  to patch elements  110  (e.g., thickness Z 1  may establish height H of  FIGS. 6 and 7 ). Thickness Z 1  may be, for example, 1 millimeter or less. 
     Transceiver circuitry  116  may include transceiver ports  124 . Each transceiver port  124  may be coupled to a respective antenna  40  over a corresponding transmission line path  64  ( FIGS. 4, 5, and 7 ). Ports  124  may include conductive contact pads, solder balls, microbumps, conductive pins, conductive pillars, conductive sockets, conductive clips, welds, conductive adhesive, conductive wires, interface circuits, or any other desired conductive interconnect structures. 
     Transmission line paths  64  for antennas  40  may be embedded within transmission line layers  122 T. Transmission line paths  64  may include conductive traces  136  in transmission line layers  122 T (e.g., conductive traces on a given dielectric layer within transmission line layers  122 T). Conductive traces  136  may form signal conductor  94  and/or ground conductor  90  of one, more than one, or all of transmission lines  64  ( FIG. 5 ) for the antennas  40  in phased antenna array  60 . If desired, additional grounded traces within transmission line layers  122 T and/or portions of ground  112  may form ground conductor  90  of the transmission lines ( FIG. 5 ). 
     Conductive traces  136  may be coupled to the positive antenna feed terminals of antennas  40  (e.g., positive antenna feed terminals  98  of  FIGS. 6 and 7 ) over vertical conductive structures  114 . Conductive traces  136  may be coupled to transceiver ports  124  over vertical conductive structures  126 . Vertical conductive structures  114  may extend through a portion of transmission line layers  122 T, a hole or opening in ground  112 , and antenna layers  122 A to patch elements  110 . Vertical conductive structures  126  may extend through a portion of transmission line layers  122 T. Vertical conductive structures  126  and  114  may include conductive through-vias, metal pillars, metal wires, conductive pins, or any other desired vertical conductive interconnects. 
     Transmission line layers  122 T may have a thickness (height) Z 2  from the bottom surface of substrate  120  to ground  112 . Thickness Z 2  may be less than thickness Z 1  of antenna layers  122 A. In order to maximize isolation between the different transmission line paths formed from conductive traces  136  and conductive structures  126  and  114 , transmission line layers  122 T may be formed from a dielectric material having a relatively high dielectric permittivity DKH. Relatively high dielectric permittivity DKH may be defined by the particular material used to form transmission line layers  122 T and may be, for example, between 6.0 and 8.0, between 6.5 and 7.5, between 5.0 and 9.0, greater than 4.5, or any other desired permittivity greater than 4.0. In one suitable arrangement, transmission line layers  122 T may be formed using low-temperature co-fired ceramics (LTCC) or other ceramics/dielectrics having dielectric permittivity DKH. 
     Forming transmission line layers  122 T using dielectric permittivity DKH may allow the conductive traces for each transmission line path to be routed more closely together with satisfactory electromagnetic isolation than in scenarios where lower dielectric permittivities are used. This may allow substrate  120  to accommodate a greater number of transmission lines to cover signals at a greater number of different millimeter and centimeter wave frequencies given the same unit volume than when lower dielectric permittivities are used (while still maintaining satisfactory electromagnetic isolation). As one example, transceiver circuitry  116  may convey radio-frequency signals using conductive traces  136  and phased antenna array  60  in a first frequency band (e.g., between 27.5 GHz and 28.5 GHz), a second frequency band (e.g., between 37 GHz and 41 GHz), and/or a third frequency band (e.g., between 57 GHz and 71 GHz) with satisfactory isolation (e.g., due to relatively high dielectric permittivity DKH). 
     In practice, forming the entirety of substrate  120  (e.g., both transmission line layers  122 T and antenna layers  122 A) from the same material (e.g., a material having dielectric permittivity DKH) may minimize the manufacturing complexity and cost of module  118 . However, if antenna layers  122 A were to be formed using material with dielectric permittivity DKH, an excessive amount of surface waves may be generated between antenna ground  112  and patch elements  110  and the corresponding reduction in thickness may undesirably deteriorate the bandwidth and efficiency of antennas  40 . In order to minimize the generation of surface waves and maximize the efficiency and bandwidth of antennas  40 , antenna layers  122 A may be formed from a material that has a relatively low dielectric permittivity DKL (e.g., a different material than is used for transmission line layers  122 T). Relatively low dielectric permittivity DKL is less than relatively high permittivity DKH and may be, for example, between 3.0 and 4.0, between 2.0 and 5.0, between 3.3 and 3.7, less than 4.0, less than 4.5, or any other desired permittivity less than permittivity DKH. In one suitable arrangement, transmission line layers  122 T may be formed using low-temperature co-fired ceramics (LTCC) or other ceramics/dielectrics having dielectric permittivity DKL. 
     If desired, transmission line layers  122 T and antenna layers  122 A may be formed from materials having similar thermal properties (e.g., similar thermal expansion coefficients, heat transfer characteristics, etc.) and/or mechanical properties (e.g., similar stiffnesses, rigidities, etc.). For example, layers  122 T and  122 A may both be formed from ceramics such as LTCC (e.g., LTCC having different dielectric permittivities). Forming transmission line layers  122 T and antenna layers  122 A with similar thermal and/or mechanical properties may simplify the manufacturing cost and complexity of module  118 . In this way, the transmission line paths used by phased antenna array  60  may be sufficiently isolated even as multiple millimeter and centimeter wave frequency bands are used without sacrificing bandwidth and efficiency for antennas  40  and while also minimizing the overall volume of module  118 . 
     The example of  FIG. 9  is merely illustrative. If desired, transceiver circuitry  116  may be formed at the top surface of substrate  120 , may be embedded within substrate  120 , or may be located elsewhere. Additional dielectric layers or protective coatings may be formed over patch elements  110  if desired. Other transmission line schemes, feeding schemes, and/or antenna types may be used if desired. 
     If desired, some of the bandwidth and efficiency for antennas  40  may be sacrificed in order to further reduce the total thickness of substrate  120  (e.g., parallel to the Z-axis of  FIG. 10 ). For example, the dielectric permittivity of antenna layers  122 A may be increased to an intermediate dielectric permittivity that is greater than dielectric permittivity DKL but lower than dielectric permittivity DKH. This may reduce the thickness of antenna layers  122 A to less than thickness Z 1  of  FIG. 9  (e.g., thereby minimizing the size of module  118  and allowing module  118  to fit into and accommodate different form factors for housing  12  of device  10 ). 
     In order to minimize manufacturing cost and expense, the same materials used to form antenna layers  122 A and transmission line layers  122 T may be used to form antenna layers having the intermediate dielectric permittivity. For example, antenna layers  122 A may include alternating layers of dielectric material having dielectric permittivity DKH and layers of dielectric material having dielectric permittivity DKL. Collectively, the antenna layers may exhibit a bulk permittivity (e.g., a collective or effective dielectric permittivity) DKI that is greater than permittivity DKL but less than permittivity DKH. Dielectric permittivity DKI may sometimes referred to herein as intermediate dielectric permittivity DKI. 
       FIG. 10  is a cross-sectional side view of module  118  showing how antenna layers  122 A may be formed from alternating layers of relatively low and relatively high dielectric permittivity material. As shown in  FIG. 10 , antenna layers  122 A may include multiple individual stacked dielectric layers  138  (e.g., individual dielectric layers  122  as shown in  FIG. 8 ). Layers  138  within antenna layers  122 A may include a first set of layers each having relatively low dielectric permittivity DKL. This first set of layers may be interleaved or interposed among a second set of layers each having relatively high dielectric permittivity DKH. When configured in this way, antenna layers  122 A may collectively exhibit intermediate dielectric permittivity DKI. Increasing the dielectric permittivity of antenna layers  122 A may reduce the thickness of antenna layers  122 A to thickness Z 3  that is less than thickness Z 1  and greater than thickness Z 2  of  FIG. 9 . This may serve to sacrifice some of the bandwidth, efficiency, and/or gain of antennas  40  in exchange for a reduction in the size of module  118  (e.g., without deteriorating transmission line isolation for multiple frequency bands). 
       FIGS. 11-13  are cross-sectional side views showing how relatively low dielectric permittivity layers  138  may be interleaved among relatively high dielectric permittivity layers  138  within antenna layers  122 A of  FIG. 10 . The layers  138  having relatively low dielectric permittivity DKL may sometimes be referred to collectively herein as a first set of layers  138 . The layers  138  having relatively high dielectric permittivity DKH may sometimes be referred to collectively herein as a second set of layers  138 . 
     As shown in the example of  FIG. 11 , the layers  138  in the first set may alternate with the layers  138  in the second set (e.g., the first set of layers may include layers  138 - 1 ,  138 - 3 , and  138 - 5  whereas the second set of layers includes layers  138 - 2 ,  138 - 4 , and  138 - 6 ). In this way, every-other layer  138  in antenna layers  122 A may have low permittivity DKL or high permittivity DKH (e.g., there may be the same number of layers in the first and second sets). Collectively, layers  138  (i.e., antenna layers  122 A) may exhibit intermediate dielectric permittivity DKI. 
     As shown in the example of  FIG. 12 , the layers  138  in the first set may be separated by two layers  138  in the second set (e.g., the first set of layers may include layers  138 - 1  and  138 - 4  whereas the second set of layers includes layers  138 - 2 ,  138 - 3 ,  138 - 5 , and  138 - 6 ). In this way, every three layers  138  in antenna layers  122 A may have low permittivity DKL. Arranging layers  138  in this manner may configure antenna layers  122 A to exhibit a higher intermediate permittivity DKI than in the arrangement of  FIG. 11  (e.g., because more high permittivity material is used in the arrangement of  FIG. 12  than in the arrangement of  FIG. 11 ). 
     As shown in the example of  FIG. 13 , the layers  138  in the second set may be separated by two layers  138  in the first set (e.g., the second set of layers may include layers  138 - 1  and  138 - 4  whereas the first set of layers includes layers  138 - 2 ,  138 - 3 ,  138 - 5 , and  138 - 6 ). In this way, every three layers  138  in antenna layers  122 A may have high permittivity DKH. Arranging layers  138  in this manner may configure antenna layers  122 A to exhibit a lower intermediate permittivity DKI than in the arrangements of  FIGS. 11 and 12  (e.g., because more low permittivity material is used in the arrangement of  FIG. 13  than in the arrangements of  FIGS. 11 and 12 ). 
     By selecting the desired number and arrangement of low and high permittivity layers  138  in antenna layers  122 A, antenna layers  122 A may be provided with any desired intermediate dielectric permittivity DKI (e.g., to allow module  118  to conform to a desired housing form factor with predetermined antenna efficiencies and without sacrificing transmission line isolation). The examples of  FIGS. 11-13  are merely illustrative and, in general, any desired number of low and high permittivity layers  138  may be stacked or arranged in any desired order. 
     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: 20180213
Publication Date: 20200317
Grant Date: 20200317
Priority Date: 20180213
Inventors: YONG, Siwen
JIANG, YI
WU, JIANGFENG
ZHANG, LIJUN
PASCOLINI, MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/52", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q3/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/523", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/523", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 67540259