PATENT DOCUMENT

Publication Number: US-10727570-B2
Application Number: US-201815884245-A
Country: US
Kind Code: B2

Title: Electronic devices having antennas that radiate through a display

Abstract:
An electronic device may be provided with a display and a phased array antenna that transmits radio-frequency signals at frequencies greater than 10 GHz. The display may include a conductive layer that is used to form pixel circuitry and/or touch sensor electrodes. A filter may be formed from conductive structures within the conductive layer. The conductive structures may include an array of conductive patches separated by slots or may include conductive paths that define an array of slots. The filter may include an additional array of conductive patches stacked under the array of conductive patches to allow the slots to be narrower than would be resolvable to the unaided human eye. The periodicity of the conductive structures and the slots in the filter may be selected to tune a cutoff frequency of the filter to be greater than frequencies handled by the phased antenna array.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 a display mounted to the housing, wherein the display comprises a display cover layer and a display module that is configured to display images through the display cover layer; 
 a spatial filter in the display module; and 
 an antenna in the housing that is aligned with the spatial filter, wherein the antenna is configured to transmit radio-frequency signals through the spatial filter in the display module. 
 
     
     
       2. The electronic device defined in  claim 1 , further comprising:
 radio-frequency transceiver circuitry in the housing and coupled to the antenna, wherein the radio-frequency transceiver circuitry is configured to generate the radio-frequency signals at a frequency that is greater than 10 GHz. 
 
     
     
       3. The electronic device defined in  claim 2 , further comprising an array that includes the antenna, wherein the array is configured to perform beam steering operations using the radio-frequency signals through the spatial filter in the display module. 
     
     
       4. The electronic device defined in  claim 2 , wherein the display module comprises a radio-frequency opaque region that blocks electromagnetic signals at the frequency. 
     
     
       5. The electronic device defined in  claim 4 , wherein the radio-frequency opaque region laterally surrounds at least one side of the spatial filter. 
     
     
       6. The electronic device defined in  claim 5 , wherein the radio-frequency opaque region laterally surrounds all sides of the spatial filter. 
     
     
       7. The electronic device defined in  claim 6  wherein the display module comprises a conductive layer and the spatial filter comprises conductive structures in the conductive layer. 
     
     
       8. The electronic device defined in  claim 4 , wherein the display module comprises a conductive layer and the spatial filter comprises conductive structures in the conductive layer. 
     
     
       9. The electronic device defined in  claim 8 , wherein the conductive structures in the conductive layer comprise inductive paths in the conductive layer that define an array of slots in the conductive layer. 
     
     
       10. The electronic device defined in  claim 8  wherein the conductive layer comprises indium tin oxide. 
     
     
       11. The electronic device defined in  claim 8 , wherein the conductive structures comprise conductive patches in the conductive layer that are separated by slots in the conductive layer. 
     
     
       12. The electronic device defined in  claim 11 , wherein the display module comprises an additional conductive layer and a dielectric layer that is interposed between the conductive layer and the additional conductive layer, the spatial filter comprises additional conductive patches in the additional conductive layer that are separated by additional slots in the additional conductive layer, and the additional conductive patches in the additional conductive layer are aligned with the conductive patches in the conductive layer. 
     
     
       13. The electronic device defined in  claim 11 , wherein the slots in the conductive layer have a width that is less than 200 microns. 
     
     
       14. The electronic device defined in  claim 11 , wherein the spatial filter is configured to form a low pass filter and the conductive patches and the slots in the conductive layer have a periodicity that is configured to establish a cutoff frequency for the low pass filter that is greater than the frequency. 
     
     
       15. The electronic device defined in  claim 11 , wherein the radio-frequency opaque region of the display module comprises touch sensor electrodes configured to gather a touch input through the display cover layer. 
     
     
       16. The electronic device defined in  claim 11 , wherein the radio-frequency opaque region of the display module comprises pixel circuitry for the display module. 
     
     
       17. The electronic device defined in  claim 1 , wherein the spatial filter is configured to pass electromagnetic signals at frequencies less than 300 GHz and is configured to block electromagnetic signals at frequencies greater than 300 GHz. 
     
     
       18. The electronic device defined in  claim 17  wherein the spatial filter is configured to pass electromagnetic signals at frequencies greater than 10 GHz and is configured to block electromagnetic signals at frequencies less than 10 GHz. 
     
     
       19. The electronic device defined in  claim 1 , wherein the antenna is configured to receive radio-frequency signals through the spatial filter in the display module. 
     
     
       20. The electronic device defined in  claim 1 , wherein the spatial filter comprises a frequency selective surface formed from a conductive layer in the display module, the spatial filter is laterally surrounded on at least one side by portion of the display that blocks the radio-frequency signals transmitted by the antenna, and the frequency selective surface is configured to pass the radio-frequency signals transmitted by the antenna.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless communications circuitry and display structures. 
     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. Electronic devices often include display structures such as one or more displays for displaying image data or video data to a user. 
     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, if care is not taken, conductive structures within the electronic device such as conductive structures in a display may block millimeter wave communications in certain directions. 
     It would therefore be desirable to be able to provide electronic devices with improved wireless communications capabilities for supporting communications at frequencies greater than 10 GHz. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry. The wireless circuitry may include antennas arranged in an array to form a phased array antenna and may include transceiver circuitry such as centimeter and millimeter wave transceiver circuitry (e.g., circuitry that transmits and receives radio-frequency signals at frequencies greater than 10 GHz). 
     The electronic device may include a touch screen display for displaying images and gathering touch input. The touch screen display may include a transparent display cover layer and a display module. The display module may include pixel circuitry that emits light through the display cover layer and touch sensor electrodes that receive touch input through the display cover layer. The display module may include a conductive layer that is used to form the pixel circuitry and/or the touch sensor electrodes. 
     A filter (e.g., a spatial filter such as a frequency selective surface) may be formed from conductive structures within the conductive layer. The conductive structures in the filter may include an array of conductive patches separated by slots in the conductive layer or may include inductive paths that define an array of slots in the conductive layer. If desired, the filter may also include an additional array of conductive patches in an additional conductive layer that are aligned with (e.g., stacked under) the array of conductive patches in the conductive layer. Stacking multiple arrays of conductive patches in the filter may allow the slots in the conductive layer to be reduced in size to below what is resolvable by the unaided human eye at a typical viewing distance from the display. 
     The filter may be configured to form a low pass filter. The periodicity of the conductive structures and the slots in the filter may be selected to be non-resonant (at the frequency of operation of the phased array antenna) and so that a cutoff frequency of the filter is greater than a frequency band handled by the phased array antenna (e.g., a frequency band including frequencies between 10 GHz and 300 GHz such as millimeter wave frequencies). The display module may include a radio-frequency opaque region that laterally surrounds the filter and that blocks (e.g., substantially or completely attenuates) electromagnetic signals in the frequency band handled by the phased array antenna. The filter may be transparent to electromagnetic signals in the frequency band and may thereby pass radio-frequency signals to and/or from phased array antenna through the display module without substantial attenuation. The phased array antenna may perform beam steering over its field of view through the filter. 
    
    
     
       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 diagram of an illustrative phased array antenna that may be adjusted using control circuitry to direct a beam of signals in accordance with an embodiment. 
         FIG. 4  is a diagram of an illustrative transceiver and antenna in accordance with an embodiment. 
         FIG. 5  is a perspective view of an illustrative patch antenna having a parasitic element in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative electronic device having a phased array antenna that is blocked by conductive layers in a display in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative electronic device having a filter in a conductive layer of a display that passes radio-frequency signals for a phased array antenna in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative electronic device having a filter formed from multiple conductive layers in a display in accordance with an embodiment. 
         FIG. 9  is a perspective view of an illustrative display of the types shown in  FIGS. 7 and 8  having a filter that passes radio-frequency signals for a phased array antenna in accordance with an embodiment. 
         FIG. 10  is a perspective view of a filter formed from multiple conductive layers in a display in accordance with an embodiment. 
         FIG. 11  is a graph of transmission as a function of frequency for a filter of the type shown in  FIGS. 8 and 10  in accordance with an embodiment. 
         FIG. 12  is a perspective view of an illustrative filter formed from inductive paths within a conductive layer in a display in accordance with an embodiment. 
         FIG. 13  is a graph of transmission as a function of frequency for a filter of the type shown in  FIG. 12  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 array antennas 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 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. 
     As shown in  FIG. 1 , device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material (e.g., glass, ceramic, plastic, sapphire, etc.). In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may have a display such as display  14 . Display  14  may be mounted on the front face of device  10 . Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. The rear face of housing  12  (i.e., the face of device  10  opposing the front face of device  10 ) may have a planar rear housing wall. If desired, the rear housing wall may have slots that pass entirely through the rear housing wall and that therefore separate housing wall portions of housing  12  from each other. The rear housing wall may include conductive portions and/or dielectric portions. If desired, the rear housing wall may include a planar metal layer covered by a thin layer or coating of dielectric such as glass, plastic, sapphire, or ceramic. Housing  12  (e.g., the rear housing wall, sidewalls, etc.) may also have shallow grooves that do not pass entirely through housing  12 . The slots and grooves may be filled with plastic or other dielectric. If desired, portions of housing  12  that have been separated from each other (e.g., by a through slot) may be joined by internal conductive structures (e.g., sheet metal or other metal members that bridge the slot). 
     Display  14  may include pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable pixel structures. A display cover layer such as a layer of clear glass or plastic may cover the surface of display  14  or the outermost layer of display  14  may be formed from a color filter layer, thin-film transistor layer, or other display layer. Display  14  may contain an active area with an array of pixels (e.g., a central substantially rectangular portion). Inactive areas of the display that are free of pixels may form borders for the active area. If desired, the active area of display  14  may extend across some or all (e.g., substantially all) of the lateral front face of device  10  (e.g., from the left edge to the right edge and from the bottom edge to the top edge of the front face of device  10 ). 
     Housing  12  may include peripheral housing structures  12 W. Peripheral housing structures  12 W may run around the periphery of device  10  and display  14 . In configurations in which device  10  and display  14  have a rectangular shape with four edges, peripheral housing structures  12 W may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges (as an example). Peripheral housing structures  12 W or part of peripheral housing structures  12 W may serve as a bezel for display  14  (e.g., a cosmetic trim that surrounds all four sides of display  14  and/or that helps hold display  14  to device  10 ). Peripheral housing structures  12 W may, if desired, form sidewall structures for device  10  (e.g., by forming a metal band with vertical sidewalls, curved sidewalls, etc.). 
     Peripheral housing structures  12 W may be formed of a conductive material such as metal and may therefore sometimes be referred to as peripheral conductive housing structures, conductive housing structures, peripheral metal structures, or a peripheral conductive housing member (as examples). Peripheral conductive housing structures  12 W may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, or more than two separate structures may be used in forming peripheral conductive housing structures  12 W. 
     It is not necessary for peripheral conductive housing structures  12 W to have a uniform cross-section. For example, the top portion of peripheral conductive housing structures  12 W may, if desired, have an inwardly protruding lip that helps hold display  14  in place. The bottom portion of peripheral conductive housing structures  12 W may also have an enlarged lip (e.g., in the plane of the rear surface of device  10 ). Peripheral conductive housing structures  12 W may have substantially straight vertical sidewalls, may have sidewalls that are curved, or may have other suitable shapes. In some configurations (e.g., when peripheral conductive housing structures  12 W serve as a bezel for display  14 ), the peripheral conductive housing structures may run around the lip of housing  12  (i.e., the peripheral conductive housing structures may cover only the edge of housing  12  that surrounds display  14  and not the rest of the sidewalls of housing  12 ). 
     If desired, housing  12  may have a conductive rear surface or wall such as wall  12 R (sometimes referred to herein as conductive rear housing wall  12 R). For example, housing  12  may be formed from a metal such as stainless steel or aluminum. The rear surface of housing  12  may lie in a plane that is parallel to display  14 . 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  12 W as integral portions of the housing structures forming the rear surface of housing  12 . For example, conductive rear housing wall  12 R may be formed from a planar metal structure and portions of peripheral conductive housing structures  12 W on the sides of housing  12  may be formed as flat or curved vertically extending integral metal portions of the planar metal structure. 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 . Conductive rear housing wall  12 R may have one or more, two or more, or three or more portions. Peripheral conductive housing structures  12 W and/or conductive rear housing wall  12 R may form one or more exterior surfaces of device  10  (e.g., surfaces that are visible to a user of device  10 ) and/or may be implemented using internal structures that do not form exterior surfaces of device  10  (e.g., conductive housing structures that are not visible to a user of device  10  such as conductive structures that are covered with layers such as thin cosmetic layers, protective coatings, and/or other coating layers that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device  10  and/or serve to hide peripheral conductive housing structures  12 W and/or conductive rear housing wall  12 R from view of the user). 
     One or more antennas may be mounted within device  10  at one or more locations such as locations  8  shown in  FIG. 1 . Locations  8  may include, for example, locations at the corners of housing  12 , locations at or near the center of display  14 , locations along the peripheral edges of housing  12 , locations between the peripheral edges of housing  12  and the center of display  14 , at the rear of housing  12 , under the display cover glass or other dielectric display cover layer that is used in covering and protecting display  14  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 . In general, it may be desirable for antennas within housing  12  to be able to cover a full sphere around device  10  (e.g., so that device  10  can maintain satisfactory wireless communications with external equipment regardless of the orientation of device  10  with respect to the external equipment). If care is not taken, conductive structures such as pixel circuitry and/or touch sensor circuitry in display  14  may block antennas within housing  12  from covering the full hemisphere above the front face of device  10 , particularly in scenarios where the active area of display  14  extends across substantially all of the front face of device  10 . 
     A schematic diagram showing illustrative components that may be used in an electronic device such as electronic device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include storage and processing circuitry such as control circuitry  16 . Control circuitry  16  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  16  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  16  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  16  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  16  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 802.1 lad protocols, cellular telephone protocols, MIMO protocols, antenna diversity protocols, satellite navigation system protocols, etc. 
     Device  10  may include input-output circuitry  18 . Input-output circuitry  18  may include input-output devices  20 . Input-output devices  20  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  20  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  18  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  30  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 WiFi® (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 a  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 802.1 lad 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 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. Millimeter wave transceiver circuitry  28  may convey signals that travel (over short distances) between a transmitter and a receiver over a line-of-sight path. To enhance signal reception for millimeter and centimeter wave communications, phased array antennas 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 a phased array (sometimes referred to herein as a phased array antenna) for handling millimeter wave communications. 
     Transmission line paths may be used to route antenna signals within device  10  (e.g., signals that are transmitted or received over-the-air by antennas  40 ). For example, transmission line paths may be used to couple antenna structures  40  to transceiver circuitry  30 . 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  16  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 array antenna, 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 arranged in arrays to form phased array antennas that implement beam steering functions. For example, the antennas that are used in handling millimeter wave and centimeter wave signals for transceiver circuitry  28  may be implemented in one or more phased array antennas. The radiating elements in a phased array antenna for supporting millimeter wave and centimeter wave communications may be patch antennas, dipole antennas, Yagi (Yagi-Uda) antennas, or other suitable antennas. Transceiver circuitry  28  can be integrated with the phased array antennas to form integrated phased array antenna and transceiver circuit modules or packages 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 array antennas 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 array antenna may be switched into use and, once switched into use, the phased array antenna may use beam steering to optimize wireless performance. Similarly, if a phased array antenna does not face or have a line of sight to an external device, another phased array antenna that has line of sight to the external device may be switched into use and that phased array antenna 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 array antenna, etc.). 
       FIG. 3  shows how antennas  40  on device  10  may be implemented as a phased array antenna. As shown in  FIG. 3 , antennas  40  may be arranged in an array. While the array includes multiple individual antennas  40 , the antennas in the array may sometimes be referred to herein collectively as phased array antenna  60 . Phased array antenna  60  (sometimes also referred to herein as array  60 , antenna array  60 , array  60  of antennas  40 , or phased antenna array  60 ) 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 array antenna  60  may be coupled to a first transmission line path  64 - 1 , a second antenna  40 - 2  in phased array antenna  60  may be coupled to a second transmission line path  64 - 2 , an Nth antenna  40 -N in phased array antenna  60  may be coupled to an Nth transmission line path  64 -N, etc. Individual antennas  40  in phased array antenna  60  may sometimes be referred to herein as antenna elements of phased array antenna  60 . 
     Antennas  40  in phased array antenna  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 array antenna  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 array antenna  60  from external equipment to transceiver circuitry  28  ( FIG. 2 ). 
     The use of multiple antennas  40  in phased array antenna  60  allows beam steering arrangements to be implemented by controlling the relative phases and magnitudes (amplitudes) of the radio-frequency signals conveyed by the antennas. In the example of  FIG. 3 , antennas  40  each have a corresponding radio-frequency phase and magnitude controller  62  (e.g., a first phase and magnitude controller  62 - 1  interposed on transmission line path  64 - 1  may control phase and magnitude for radio-frequency signals handled by antenna  40 - 1 , a second phase and magnitude controller  62 - 2  interposed on transmission line path  64 - 2  may control phase and magnitude for radio-frequency signals handled by antenna  40 - 2 , an Nth phase and magnitude controller  62 -N interposed on transmission line path  64 -N may control phase and magnitude for radio-frequency signals handled by antenna  40 -N, etc.). 
     Phase and magnitude controllers  62  may each include circuitry for adjusting the phase of the radio-frequency signals on transmission line paths  64  (e.g., phase shifter circuits) and/or circuitry for adjusting the magnitude of the radio-frequency signals on transmission line paths  64  (e.g., power amplifier and/or low noise amplifier circuits). Phase and magnitude controllers  62  may sometimes be referred to collectively herein as beam steering circuitry (e.g., beam steering circuitry that steers the beam of radio-frequency signals transmitted and/or received by phased array antenna  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 array antenna  60  and may adjust the relative phases and/or magnitudes of the received signals that are received by phased array antenna  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 array antenna  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. 3  that is oriented in the direction of point A. If, however, phase and magnitude controllers  62  are adjusted to produce a second set of phases and/or magnitudes for the transmitted millimeter wave signals, the transmitted signals will form a millimeter wave frequency transmit beam as shown by beam  68  that is oriented in the direction of point B. Similarly, if phase and magnitude controllers  62  are adjusted to produce the first set of phases and/or magnitudes, wireless signals (e.g., millimeter wave signals in a millimeter wave frequency receive beam) may be received from the direction of point A as shown by beam  66 . If phase and magnitude controllers  62  are adjusted to produce the second set of phases and/or magnitudes, signals may be received from the direction of point B, as shown by beam  68 . 
     Each phase and magnitude controller  62  may be controlled to produce a desired phase and/or magnitude based on a corresponding control signal  58  received from control circuitry  16  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  16  may actively adjust control signals  58  in real time to steer the transmit or receive beam in different desired directions over time. 
     When performing millimeter or centimeter wave communications, radio-frequency signals are conveyed over a line of sight path between phased array antenna  60  and external equipment. If the external equipment is located at location A of  FIG. 3 , phase and magnitude controllers  62  may be adjusted to steer the signal beam towards direction A. If the external equipment is located at location B, phase and magnitude controllers  62  may be adjusted to steer the signal beam towards direction B. In the example of  FIG. 3 , beam steering is shown as being performed over a single degree of freedom for the sake of simplicity (e.g., towards the left and right on the page of  FIG. 3 ). However, in practice, the beam is steered over two or more degrees of freedom (e.g., in three dimensions, into and out of the page and to the left and right on the page of  FIG. 3 ). 
     A schematic diagram of an antenna  40  coupled to transceiver circuitry  30  (e.g., transceiver circuitry  28  of  FIG. 2 ) is shown in  FIG. 4 . As shown in  FIG. 4 , radio-frequency transceiver circuitry  30  may be coupled to antenna feed  100  of antenna  40  using transmission line path  64 . Antenna feed  100  may include a positive antenna feed terminal such as positive antenna feed terminal  96  and may include a ground antenna feed terminal such as ground antenna feed terminal  98 . Transmission line path  64  may include a positive transmission line signal path such as path  91  that is coupled to terminal  96  and a ground transmission line signal path such as path  94  that is coupled to terminal  98 . 
     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 conveying radio-frequency signals at frequencies between 10 GHz and 300 GHz is shown in  FIG. 5 . 
     As shown in  FIG. 5 , antenna  40  may have a patch antenna resonating element  104  that is separated from and parallel to a ground plane such as antenna ground plane  102 . Patch antenna resonating element  104  may lie within a plane such as the X-Y plane of  FIG. 5  (e.g., the lateral surface area of element  104  may lie in the X-Y plane). Patch antenna resonating element  104  may sometimes be referred to herein as patch  104 , patch element  104 , patch resonating element  104 , antenna resonating element  104 , or resonating element  104 . Ground plane  102  may lie within a plane that is parallel to the plane of patch  104 . Patch  104  and ground plane  102  may therefore lie in separate parallel planes that are separated by a distance  110 . 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  104  may be selected so that antenna  40  resonates at a desired operating frequency. For example, the sides of patch  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  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. 5  is merely illustrative. Patch  104  may have a square shape in which all of the sides of patch  104  are the same length or may have a different rectangular shape. Patch  104  may be formed in other shapes having any desired number of straight and/or curved edges. If desired, patch  104  and ground plane  102  may have different shapes and relative orientations. 
     To enhance the polarizations handled by antenna  40 , antenna  40  may be provided with multiple feeds. As shown in  FIG. 5 , antenna  40  may have a first feed at antenna port P 1  that is coupled to a first transmission line path  64  such as transmission line path  64 V and a second feed at antenna port P 2  that is coupled to a second transmission line path  64  such as transmission line path  64 H. The first antenna feed may have a first ground feed terminal coupled to ground plane  102  (not shown in  FIG. 5  for the sake of clarity) and a first positive feed terminal  96 - 1  coupled to patch  104 . The second antenna feed may have a second ground feed terminal coupled to ground plane  102  (not shown in  FIG. 5  for the sake of clarity) and a second positive feed terminal  96 - 2  on patch  104 . 
     Holes or openings such as openings  117  and  119  may be formed in ground plane  102 . Transmission line path  64 V may include a vertical conductor (e.g., a conductive through-via, conductive pin, metal pillar, solder bump, combinations of these, or other vertical conductive interconnect structures) that extends through hole  117  to feed terminal  96 - 1  on patch  104 . Transmission line path  64 H may include a vertical conductor that extends through hole  119  to feed terminal  96 - 2  on patch  104 . This example is merely illustrative and, if desired, other transmission line structures may be used (e.g., coaxial cable structures, stripline transmission line structures, etc.). 
     When using the first antenna feed associated with port P 1 , antenna  40  may transmit and/or receive radio-frequency signals having a first polarization (e.g., the electric field E 1  of antenna signals  115  associated with port P 1  may be oriented parallel to the Y-axis in  FIG. 5 ). When using the antenna feed associated with port P 2 , antenna  40  may transmit and/or receive radio-frequency signals having a second polarization (e.g., the electric field E 2  of antenna signals  115  associated with port P 2  may be oriented parallel to the X-axis of  FIG. 5  so that the polarizations associated with ports P 1  and P 2  are orthogonal to each other). 
     One of ports P 1  and P 2  may be used at a given time so that antenna  40  operates as a single-polarization antenna or both ports may be operated at the same time so that antenna  40  operates with other polarizations (e.g., as a dual-polarization antenna, a circularly-polarized antenna, an elliptically-polarized antenna, etc.). If desired, the active port may be changed over time so that antenna  40  can switch between covering vertical or horizontal polarizations at a given time. Ports P 1  and P 2  may be coupled to different phase and magnitude controllers  62  ( FIG. 3 ) or may both be coupled to the same phase and magnitude controller  62 . If desired, ports P 1  and P 2  may both be operated with the same phase and magnitude at a given time (e.g., when antenna  40  acts as a dual-polarization antenna). If desired, the phases and magnitudes of radio-frequency signals conveyed over ports P 1  and P 2  may be controlled separately and varied over time so that antenna  40  exhibits other polarizations (e.g., circular or elliptical polarizations). 
     If care is not taken, antennas  40  such as dual-polarization patch antennas of the type shown in  FIG. 5  may have insufficient bandwidth for covering an entirety of a communications band of interest (e.g., a communications band at frequencies greater than 10 GHz). For example, in scenarios where antenna  40  is configured to cover a millimeter wave communications band between 57 GHz and 71 GHz, patch  104  as shown in  FIG. 5  may have insufficient bandwidth to cover the entirety of the frequency range between 57 GHz and 71 GHz. If desired, antenna  40  may include one or more parasitic antenna resonating elements that serve to broaden the bandwidth of antenna  40 . 
     As shown in  FIG. 5 , a bandwidth-widening parasitic antenna resonating element such as parasitic antenna resonating element  106  may be formed from conductive structures located at a distance  112  over patch  104 . Parasitic antenna resonating element  106  may sometimes be referred to herein as parasitic resonating element  106 , parasitic antenna element  106 , parasitic element  106 , parasitic patch  106 , parasitic conductor  106 , parasitic structure  106 , parasitic  106 , or patch  106 . Parasitic element  106  is not directly fed, whereas patch  104  is directly fed via transmission line paths  64 V and  64 H and feed terminals  96 - 1  and  96 - 2 . Parasitic element  106  may create a constructive perturbation of the electromagnetic field generated by patch  104 , creating a new resonance for antenna  40 . This may serve to broaden the overall bandwidth of antenna  40  (e.g., to cover the entire millimeter wave frequency band from 57 GHz to 71 GHz). 
     At least some or an entirety of parasitic element  106  may overlap patch  104 . In the example of  FIG. 5 , parasitic element  106  has a cross or “X” shape. In order to form the cross shape, parasitic element  106  may include notches or slots formed by removing conductive material from the corners of a square or rectangular metal patch. Parasitic element  106  may have a rectangular (e.g., square) outline or footprint. Removing conductive material from parasitic element  106  to form a cross shape may serve to adjust the impedance of patch  104  so that the impedance of patch  104  is matched to both transmission line paths  64 V and  64 H, for example. The example of  FIG. 5  is merely illustrative. If desired, parasitic element  106  may have other shapes or orientations. 
     If desired, antenna  40  of  FIG. 5  may be formed on a dielectric substrate (not shown in  FIG. 5  for the sake of clarity). The dielectric substrate may be, for example, a rigid or printed circuit board or other dielectric substrate. The dielectric substrate may include multiple stacked dielectric layers (e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy, multiple layers of ceramic substrate, etc.). Ground plane  102 , patch  104 , and parasitic element  106  may be formed on different layers of the dielectric substrate if desired. 
     When configured in this way, antenna  40  may cover a relatively wide millimeter wave communications band of interest such as a frequency band between 57 GHz and 71 GHz. The example of  FIG. 5  is merely illustrative. Parasitic element  106  may be omitted if desired. Antenna  40  may have any desired number of feeds. Other antenna types may be used if desired. 
     In order to perform wireless communications in millimeter and centimeter wave communications bands over the hemisphere above the front face of device  10 , it may be desirable to mount phased array antenna  60  behind display  14  (e.g., within a corresponding region  8  as shown in  FIG. 1 ). However, as the active area of display  14  extends across the entire length and width of device  10 , conductive material used to form the active area of display  14  may also extend across the entire length and width of device  10 . If care is not taken, this conductive material may undesirably block phased array antenna  60  mounted behind display  14  from being able to satisfactorily communicate over the hemisphere above the front face of device  10 . 
       FIG. 6  is a cross-sectional side view showing how conductive structures in display  14  may block radio-frequency signals transmitted by phased array antenna  60 . As shown in  FIG. 6 , housing  12  ( FIG. 1 ) and display  14  may define an interior  121  of device  10 . Phased array antenna  60  may be formed on a dielectric substrate such as substrate  122  disposed within interior  121  of device  10 . 
     Substrate  122  may be, for example, a rigid or flexible printed circuit board or other dielectric substrate. Substrate  122  may include multiple stacked dielectric layers (e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy) or may include a single dielectric layer. Substrate  122  may include any desired dielectric materials such as epoxy, plastic, ceramic, glass, foam, or other materials. Antennas  40  in phased array antenna  60  may be mounted at a surface of substrate  122  or may be partially or completely embedded within substrate  122  (e.g., within a single layer of substrate  122  or within multiple layers of substrate  122 ). In one suitable example, ground plane  102 , patch  104 , and parasitic element  106  of each antenna  40  (as shown in the example of  FIG. 5 ) may be formed on separate layers of substrate  122  (e.g., parasitic element  106  may be formed on an exposed surface of substrate  122  whereas patch  104  and ground plane  102  are embedded within the layers of substrate  122 ). 
     Phased array antenna  60  and substrate  122  may sometimes be referred to herein collectively as antenna module  120 . If desired, transceiver circuitry  28  of  FIG. 2  or other transceiver circuits may be mounted to antenna module  120  (e.g., at a surface of substrate  122  or embedded within substrate  122 ). The example of  FIG. 6  is merely illustrative. In general, any desired number of antennas  40  may be included in phased array antenna  60  and mounted to substrate  122 . Additional phased array antennas may be mounted at other locations along substrate  122  and/or on the bottom side of substrate  122  if desired. 
     As shown in  FIG. 6 , display  14  may include a display cover layer  124  (e.g., a clear layer of plastic, glass, sapphire, etc.) and display structures  130  for producing images for a user. Display cover layer  124  may cover display structures  130  and may form an exterior surface of device  10  (e.g., the exterior surface at the front face of device  10 ). Display structures  130  may sometimes be referred to herein as display stack  130  or display module  130 . Display module  130  may include liquid crystal display structures, electrophoretic display structures, light-emitting diode display structures such as organic light-emitting diode display structures, or other suitable display structures. Display module  130  may include an array of pixels for displaying images for a user and may form the active area of display  14 . Pixels in display module  130  may emit (display) light (images) through display cover layer  124  that are to be viewed by a user. 
     Display module  130  may include multiple display layers  126 . Display layers  126  may include layers of backlight structures, layers of light guide structures, layers of light source structures such as layers that include an array of light-emitting diodes or other display pixel circuitry, light reflector structures, optical films, diffuser layers, light collimating layers, polarizer layers, planarization layers, liquid crystal layers, color filter layers, thin-film transistor layers, optically transparent substrate layers, optically opaque substrate layers, layers for forming touch sensor electrodes associated with touch sensing capabilities for display  14  (in scenarios where display  14  is a touch sensor), birefringent compensating films, antireflection coatings, scratch prevention coatings, oleophobic coatings, layers of adhesive, stretched polymer layers such as stretched polyvinyl alcohol layers, tri-acetyl cellulose layers, antiglare layers, plastic layers, and/or any other desired layers used to form display structures for displaying images to a user of device  10  and/or for receiving a touch or force input from a user of device  10 . 
     Dielectric materials within display layers  126  may have dielectric constants between about 2.0 and 5.0, as an example. Dielectric material in display cover layer  124  may have a dielectric constant between about 5.0 and 7.0, as an example. Display layers  126  may have thicknesses (e.g., in the direction of the Z-axis of  FIG. 6 ) of between about 1 micron and 200 microns whereas display cover layer  124  has a thickness of between about 600 microns and 1200 microns (e.g., 800 microns). These examples are merely illustrative and, in general, display layers  126  and display cover layer  124  may have any desired dielectric properties and thicknesses. 
     Display layers  126  that include only dielectric materials (e.g., adhesive layers, color filter layers, polarizer layers, etc.) may be substantially transparent to radio-frequency signals (e.g., may transmit radio-frequency signals without significant attenuation). One or more display layers  126  in display module  130  such as layer  128  of  FIG. 6  may be opaque to radio-frequency signals. Radio-frequency opaque layers such as layer  128  may include conductive structures that block radio-frequency signals at relatively high frequencies (e.g., frequencies over 10 GHz such as centimeter and millimeter wave frequencies) and may therefore sometimes be referred to herein as conductive layer  128 , radio-frequency opaque layer  128 , centimeter wave opaque layer  128 , millimeter wave opaque layer  128 , or conductive radio-frequency opaque layer  128 . 
     Radio-frequency opaque layer  128  may include, for example, pixel circuitry, pixel electrode structures, thin-film transistors, or other conductive structures involved in displaying images using display  14 . Radio-frequency opaque layer  128  may additionally or alternatively include circuitry and/or electrodes involved in gathering touch or force sensor inputs for display  14  from a user (e.g., in scenarios where display  14  is also a touch-sensitive or force-sensitive display). For example, radio-frequency opaque layer  128  may include an array of capacitive electrodes (e.g., transparent electrodes such as indium tin oxide electrodes) or may include a touch sensor array based on other touch technologies (e.g., resistive touch sensor structures, acoustic touch sensor structures, piezoelectric sensors and other force sensor structures, etc.). Touch sensor structures for display  14  may be implemented on a dedicated touch sensor substrate in display module  130  such as a layer of glass or may be formed on the same substrate that is being used for other display functions. For example, touch sensor electrodes may be formed on a color filter array layer, a thin-film transistor layer, or other layers in a liquid crystal display. In general, radio-frequency opaque layer  128  may include any conductive display structures that are opaque to radio-frequency signals at frequencies greater than 10 GHz. 
     During millimeter wave communications, phased array antenna  60  may transmit radio-frequency signals  132  at frequencies greater than 10 GHz. Radio-frequency signals  132  may freely pass through dielectric display layers  126  of display module  130 . However, radio-frequency opaque layer  128  in display module  130  may block radio-frequency signals  132 , serving to reflect signals  132  back towards interior  121  of device  10 . Radio-frequency opaque layer  128  thereby prevents the transmission of signals  132  to the exterior of device  10  through display module  130 . If device  10  is attempting communications with external equipment located in the hemisphere above display  14 , signals  132  will thereby fail to be received at the external equipment. Similarly, radio-frequency opaque layer  128  may block radio-frequency signals from external equipment from being received at phased array antenna  60  through display module  130 . 
     In order to allow radio-frequency signals transmitted by phased array antenna  60  to be conveyed through display module  130 , display module  130  may include a filter within radio-frequency opaque layer  128 . The filter may, for example, be an electromagnetic filter such as a frequency selective filter that passes electromagnetic signals at some radio-frequencies (e.g., within a pass band of the filter) and that blocks electromagnetic signals at other frequencies (e.g., outside of the pass band of the filter). The frequency selective filter may, in one scenario, be a spatial filter that includes conductive structures that are arranged in a periodic manner to define the pass band of the filter (e.g., to allow transmission of electromagnetic signals within the pass band while blocking electromagnetic signals outside of the pass band). In this scenario, the conductive structures and/or slots between the conductive structures are resonant at the center frequency of the pass band. In one suitable arrangement, the frequency selective filter may include conductive structures that are arranged to form a low pass filter that passes electromagnetic signals below a cut off frequency. In this scenario, the conductive structures may be much smaller than the operating wavelength of phased array antenna  60  and may not in themselves be resonant (e.g., such that gaps between the conductive structures are invisible to the unaided human eye). In scenarios where the frequency selective filter is formed using a single layer of conductive material in display module  130  (e.g., using conductive material in a single radio-frequency opaque layer  128 ), the frequency selective filter may sometimes be referred to herein as a frequency selective surface (FSS). 
       FIG. 7  is a cross-sectional side view showing how display module  130  may include a filter in radio-frequency opaque layer  128  for passing radio-frequency signals handled by phased array antenna  60 . As shown in  FIG. 7 , radio-frequency opaque layer  128  may include a filter  140 . Filter  140  may sometimes be referred to herein as spatial filter  140 , frequency selective filter  140 , or frequency selective surface  140  (in scenarios where filter  140  is formed using a single radio-frequency opaque layer  128 ). 
     Filter  140  may be formed using a pattern of periodic slots in radio-frequency opaque layer  128  that divides radio-frequency opaque layer  128  into a pattern of periodic conductive structures within filter  140 . Filter  140  may allow radio-frequency signals at certain frequencies (e.g., below a cut off frequency of filter  140  where filter  140  serves as a low pass filter) to freely pass through layer  128  and thus display module  130 . The dimensions of the slots and conductive structures (e.g., the periodicity of the slots and conductive structures) within filter  140  may be selected so that the slots and conductive structures resonate at the center of a pass band of filter  140  (e.g., to tune the pass band of filter  140  to overlap with the frequency band of operation of phased array antenna  60 ) or may be selected so that the slots and conductive structures are much smaller than the operating wavelength of phased antenna array  60  and thus are not resonant at the operating frequency of phased array antenna  60  (e.g., to tune the cutoff frequency of filter  140  where filter  140  serves as a low pass filter). Configuring the slots and conductive structures to be much smaller than the operating wavelength of phased antenna array  60  may desirably allow the slots and conductive structures to be indiscernible to the user&#39;s eye, for example. When filter  140  is configured to pass radio-frequency signals in the frequency band of operation for phased array antenna  60 , radio-frequency signals  142  transmitted by phased array antenna  60  may freely pass through radio-frequency opaque layer  128  and display module  130  to the exterior of device  10 . Similarly, radio-frequency signals may be received by phased array antenna  60  through filter  140  in display module  130 . In this way, phased array antenna  60  may be able to communicate with external equipment located in the hemisphere above display  14  despite the presence of conductive structures in display module  130 . 
     In other words, when configured in this way, filter  140  may effectively form an antenna window in radio-frequency opaque layer  128  and thus display module  130  that is transparent at the frequencies of operation of phased array antenna  60  (e.g., an antenna window that is transparent to radio-frequency signals at frequencies greater than 10 GHz). The portion  150  of radio-frequency opaque layer  128  that laterally surrounds filter  140  may remain opaque to radio-frequency signals handled by phased array antenna  60 . Portion  150  of radio-frequency opaque layer  128  may therefore sometimes be referred to herein as radio-frequency opaque portion, region, or area  150  of display module  130 . 
     In the example of  FIG. 7 , filter  140  is formed in a single radio-frequency opaque layer  128  in display module  130 . This is merely illustrative. If desired, filter  140  may be formed using multiple radio-frequency opaque layers  128  in display module  130 .  FIG. 8  is a cross-sectional side view showing how filter  140  may be formed from two radio-frequency opaque layers  128  in display module  130 . 
     As shown in  FIG. 8 , display module  130  may include a first radio-frequency opaque layer  128 - 1  and a second radio-frequency opaque layer  128 - 2  under first radio-frequency opaque layer  128 - 1 . One or both of radio-frequency opaque layers  128 - 1  and  128 - 2  may include conductive structures associated with displaying images and/or receiving touch or force sensor inputs for display  14  (e.g., thin film transistor structures, indium tin oxide structures, etc.). For example, both radio-frequency opaque layers  128 - 1  and  128 - 2  may include indium tin oxide structures for gathering touch input using display  14 . 
     First radio-frequency opaque layer  128 - 1  may be vertically separated from second radio-frequency opaque layer  128 - 2  by distance  144  (e.g., by one intervening display layer  126  or multiple intervening display layers  126  of display module  130 ). First radio-frequency opaque layer  128 - 1  may be vertically separated from display cover layer  124  by distance  142  (e.g., across zero, one, or multiple display layers  126 ). Second radio-frequency opaque layer  128 - 2  may be vertically separated from the bottom of display module  130  by distance  146  (e.g., across zero, one, or multiple display layers  126 ). 
     In the example of  FIG. 8 , filter  140  may be formed using patterns of periodic slots in both first radio-frequency opaque layer  128 - 1  and second radio-frequency opaque layer  128 - 2 . The pattern of slots in first radio-frequency opaque layer  128 - 1  may divide radio-frequency opaque layer  128 - 1  into a first pattern of periodic conductive structures within filter  140 . Similarly, the pattern of slots in second radio-frequency opaque layer  128 - 2  may divide radio-frequency opaque layer  128 - 2  into a second pattern of periodic conductive structures within filter  140 . The slots and conductive structures in first radio-frequency opaque layer  128 - 1  may be aligned with the slots and conductive structures, respectively, in second radio-frequency opaque layer second  128 - 2  within filter  140 . 
     In this way, filter  140  may include vertically stacked conductive structures formed from conductive material in two radio-frequency opaque layers  128  of display module  130 . The dimensions of the slots and conductive structures (e.g., the periodicity of the slots and conductive structures) within filter  140  may be selected to tune the cutoff frequency of filter  140  to be greater than the frequency band of operation of phased array antenna  60  (e.g., so that filter  140  serves as a low pass filter that passes radio-frequency signals handled by phased array antenna  60 ). When configured in this way, radio-frequency signals handled by phased array antenna  60  may freely pass through both radio-frequency opaque layers  128 - 1  and  128 - 2  and thus display module  130 . Forming filter  140  across two layers  128 - 1  and  128 - 2  may, for example, add transverse capacitances to filter  140  that allow the dimensions of the slots and conductive structures in filter  140  to be smaller than in scenarios where only a single layer  128  is used (e.g., as shown in  FIG. 7 ) while still passing radio-frequency signals at the same frequencies. The dimensions of the slots and conductive structures in filter  140  may be much smaller than the wavelength of operation of phased array antenna  60  and may therefore be non-resonant at the wavelength of operation of phased array antenna  60  (e.g., the structures may be resonant at a wavelength much smaller than the wavelength of operation). 
     In other words, when configured in this way, filter  140  may effectively form an antenna window in radio-frequency opaque layers  128 - 1  and  128 - 2  and thus display module  130  that is transparent at the frequencies of operation of phased array antenna  60  (e.g., an antenna window that is transparent to radio-frequency signals at greater than 10 GHz). In the example of  FIG. 8 , radio-frequency opaque portion  150  of display module  130  may be defined by radio-frequency opaque portions of one or both of radio-frequency opaque layers  128 - 1  and  128 - 2  that laterally surround filter  140  in display module  130 . 
     Filter  140  may extend across a sufficiently large lateral area of display  14  to allow phased array antenna  60  to perform beam steering over substantially all of the hemisphere above display  14 .  FIG. 9  is a perspective view of display  14  and antenna module  120  showing how phased array antenna  60  may be aligned with filter  140  for covering the hemisphere above display  14 . 
     As shown in  FIG. 9 , filter  140  may extend across a length  151  of the lateral surface area of display  14  (e.g., in the X-Y plane of  FIG. 9 ). Filter  140  may have a rectangular outline, a square outline, or any other suitable lateral outline (e.g., a circular outline, a polygonal outline, an outline having curved and/or straight edges, etc.). Length  151  may, for example, be between 5 mm and 15 mm (e.g., 10 mm), between 3 mm and 20 mm, 15 mm, greater than 15 mm, or any other desired length that would allow phased array antenna  60  to cover substantially all of the hemisphere above display  14 . 
     Radio-frequency opaque portion  150  of display module  130  laterally surrounds filter  140  in display module  130 . Filter  140  may be completely surrounded (e.g., on all sides) or may be partially surrounded on one or more sides by radio-frequency opaque portion  150  of display module  130  (e.g., radio-frequency opaque portion  150  may laterally surround one side of filter  140  when radio-frequency opaque portion  150  defines one edge of filter  140 , may laterally surround two sides of filter  140  when radio-frequency opaque portion  150  defines two edges of filter  140 , etc.). In one particular arrangement, filter  140  may be formed at an edge of display  14  such that one edge of filter  140  is defined by a peripheral conductive sidewall  12 W ( FIG. 1 ) and the remaining three sides of filter  140  are laterally surrounded by (e.g., the remaining three edges of filter  140  are defined by) radio-frequency opaque portion  150  of display module  130 . In another particular arrangement, filter  140  may be formed at a corner of display  14  such that two edges of filter  140  are defined by two peripheral conductive sidewalls  12 W ( FIG. 1 ) and the remaining two sides of filter  140  are laterally surrounded by (e.g., the remaining two edges of filter  140  are defined by) radio-frequency opaque portion  150  of display module  130 . In another suitable arrangement, radio-frequency opaque portion  150  of display module  130  defines all lateral edges of filter  140  (e.g., in scenarios where radio-frequency opaque portion  150  of display module  130  completely surrounds filter  140 ). The lateral edges of filter  140  may be straight and/or curved (e.g., may include straight portions, curved portions, straight portions with rounded corners, etc.). In contrast with radio-frequency opaque portion  150 , filter  140  is transparent to radio-frequency signals handled by phased array antenna  60  and therefore allows the radio-frequency signals to pass through display module  130 . 
     Phased array antenna  60  on substrate  122  may be aligned with filter  140  in display module  130 . When aligned with filter  140 , phased array antenna  60  may exhibit a radiation pattern associated with a pattern envelope such as pattern envelope  160  of  FIG. 9 . Pattern envelope (curve)  160  may be indicative of the gain of the radio-frequency signals transmitted by phased array antenna  60  when steered over the entire field of view for the phased array antenna (e.g., the beam of signals handled by phased array antenna  60  and steered in a particular direction at any given time only extends across a small subset of envelope  160 ). 
     The distance of pattern envelope  160  from the center of phased array antenna  60  is indicative of the gain of the phased array antenna at different beam steering angles. As shown by pattern envelope  160 , phased array antenna  60  may exhibit a relatively uniform gain when steered over all possible directions within its field of view (e.g., over substantially all of the hemisphere of coverage for the array). Phased array antenna  60  may be mounted at a selected vertical distance from filter  140  and the lateral area of filter  140  (e.g., as defined by length  151 ) may be selected so that the beam of signals transmitted and received by phased array antenna  60  can pass through frequency selective filter  140  across substantially all of the field of view of phased array antenna  60  (e.g., across substantially all of the hemisphere over display  10  regardless of the direction the beam is steered towards). 
     Display module  130  may emit display light through display cover layer  124  within the lateral outline of radio-frequency opaque portion  150  of display module  130  while also blocking radio-frequency signals at millimeter wave frequencies from passing through radio-frequency opaque portion  150  (e.g., display pixel circuits and other circuitry associated with displaying image light may be present in display module  130  within the lateral outline of radio-frequency opaque portion  150  of display module  130 ). Display module  130  may receive touch sensor and/or force sensor inputs associated with a user pressing on display cover layer  124  within the lateral outline of radio-frequency opaque portion  150  while also blocking radio-frequency signals at millimeter wave frequencies from passing through radio-frequency opaque portion  150  (e.g., touch sensor electrodes, force sensor circuitry, and/or other touch sensor circuitry may be present within the lateral outline of radio-frequency opaque portion  150  of display module  130 ) 
     The example of  FIG. 9  is merely illustrative. In general, pattern envelope  160  may have any shape (e.g., corresponding to the particular arrangement of antennas  40  in phased array antenna  60 , the geometry of phased array antenna  60 , the materials used to form substrate  120  and display  14 , the frequency of operation of phased array antenna  60 , the transmission characteristics of filter  140 , etc.). Phased array antenna  60  may include any desired number of antennas  40  arranged in any desired pattern. 
       FIG. 10  is a perspective view of one suitable arrangement for filter  140  in which filter  140  is formed using first radio-frequency opaque layer  128 - 1  and second radio-frequency opaque layer  128 - 2  in display module  130  (e.g., as shown in  FIG. 8 ). In the example of  FIG. 10 , filter  140  may include a first pattern  180  of conductive structures  186  formed on a first side of a given display layer  126  and a second pattern  182  of conductive structures  186  formed on an opposing second side of the display layer  126 . Conductive structures  186  may sometimes be referred to herein as conductive patches  186 . Conductive patches  186  in first pattern  180  may, for example, be arranged in an array. First pattern  180  of conductive patches  186  may therefore sometimes be referred to herein as first array  180  of conductive patches  186 . Similarly, the conductive patches  186  in second pattern  182  may be arranged in an array. Second pattern  182  of conductive patches  186  may therefore sometimes be referred to herein as second array  182  of conductive patches  186 . 
     First array  180  of conductive patches  186  may be formed from conductive material in first radio-frequency opaque layer  128 - 1  whereas second array  182  of conductive patches  186  may be formed from conductive material in second radio-frequency opaque layer  128 - 2 . Radio-frequency opaque portion  150  of display module  130  laterally surrounds one or more sides of arrays  180  and  182  (e.g., as shown in  FIGS. 8 and 9 ) and is not shown in  FIG. 10  for the sake of clarity. Other display layers above and below filter  140  in display module  130  are also omitted from  FIG. 10  for the sake of clarity. 
     As shown in  FIG. 10 , filter  140  may extend across length  151  of display module  130 . Conductive patches  186  in first array  180  may be periodically distributed in the X-Y plane. Similarly, conductive patches  186  in second array  180  may be periodically distributed in the X-Y plane. Each conductive patch  186  in first array  180  may be aligned with and completely overlap a corresponding conductive patch  186  in second array  182 . First array  180  may include the same number of conductive patches  186  as second array  182  and each conductive patch  186  in first array  180  and second array  182  may have the same size and shape. 
     Conductive patches  186  may be formed from metal traces on display layer  126 , from metal foil, or any other desired conductive structures. Conductive patches  186  may be formed, for example, from copper, aluminum, stainless steel, silver, gold, nickel, tin, indium tin oxide, other metals or metal alloys, or any other desired conductive materials. Conductive patches  186  may be formed from the same material as the portions of radio-frequency opaque layers  128 - 1  and  128 - 2  laterally surrounding filter  140  (e.g., the portion of layers  128 - 1  and  128 - 2  forming radio-frequency opaque portion  150  of display module  130  as shown in  FIG. 9 ). In another suitable arrangement, conductive patches  186  may be formed from a different material than the portions of radio-frequency opaque layers  128 - 1  and  128 - 2  laterally surrounding filter  140 . As an example, conductive patches  186  and the surrounding portions of radio-frequency opaque layers  128 - 1  and  128 - 2  may both be formed from indium tin oxide. As another example, conductive patches  186  may be formed from copper whereas the surrounding portions of radio-frequency opaque layers  128 - 1  and  128 - 2  are formed from indium tin oxide. 
     Slots or openings such as slots  194  may laterally separate the conductive patches  186  in first array  180  from each other. Slots or openings such as slots  195  may laterally separate the conductive patches  186  in second array  182  from each other. Slots  194  and  195  may sometimes be referred to herein as gaps, notches, or openings. Slots  194  may also separate conductive patches  186  in first array  180  from the portion of radio-frequency opaque layer  128 - 1  surrounding filter  140 . Similarly, slots  195  may separate conductive patches  186  in second array  182  from the portion of radio-frequency opaque layer  128 - 2  surrounding filter  140 . Slots  194  in first array  180  may be aligned with slots  195  in second array  182 . Slots  194  and  195  may be arranged in a grid pattern, for example. Slots  194  may, for example, extend completely through the thickness of the conductive material in radio-frequency opaque layer  128 - 1  whereas slots  195  extend completely through the thickness of the conductive material in radio-frequency opaque layer  128 - 2 . Slots  194  and  195  may be filled with dielectric material such as air, integral portions of other display layers  126 , or other dielectrics. 
     The dimensions of slots  194  and  195  and the dimensions of conductive patches  186  (e.g., the periodicity of conductive patches  186 ), the materials used to form conductive patches  186 , and the material used to form display layer  126  may each be selected to configure filter  140  to be transparent to radio-frequency signals at predetermined frequencies (e.g., to define the cut off frequency of filter  140  to be greater the frequencies that are handled by phased array antenna  60  of  FIGS. 8 and 9 ). 
     For example, the distance  196  between conductive patches  186  in first array  180  and second array  182  (e.g., the width  196  of slots  194  and  195 ), the width  192  of conductive patches  186  in first array  180  and second array  182 , the distance  144  between first array  180  and second array  182  (e.g., the thickness of intervening display layer  126 ), the material used to form display layer  126 , and/or the material used to form conductive patches  186  may be selected so that filter  140  passes (transmits) a satisfactory amount of radio-frequency energy through display module  130  below a desired cutoff frequency (e.g., within a millimeter wave frequency band covered by phased array antenna  60  of  FIGS. 8 and 9 ). These dimensions may be much less than the wavelength of operation of phased array antenna  60 . For example, the sum of width  196  and width  192  may be, for example, approximately equal to one-tenth the effective wavelength of operation of phased array antenna  60  (e.g., an effective wavelength given corresponding dielectric effects associated with phased array antenna  60  and display layer  126 ). 
     As just one example, width  192  may be between 0.1 mm and 0.3 mm (e.g., approximately 200 microns), width  196  may be between 0.05 mm and 0.15 mm (e.g., approximately 100 microns), and distance  144  may be between 20 microns and 80 microns (e.g., approximately 50 microns) to provide filter  140  with a transmission coefficient that is greater than a predetermined threshold for radio-frequency signals at millimeter wave frequencies (e.g., where conductive patches  186  are formed using copper and display layer  126  has a dielectric constant of approximately 2.5). These examples are merely illustrative and may be adjusted if desired to tweak the transmission response of filter  140 . 
     In practice, if care is not taken, slots in filter  140  may be visible to a user of device  10  when the user is viewing display  14 . Visible slots may be unsightly and can reduce the aesthetic appearance of images displayed using display  14 , for example. In order to mitigate these effects, the width  196  of slots  194  and  195  may be sufficiently small so as to be too narrow to be resolved by the unaided human eye. By implementing filter  140  using two stacked arrays of conductive patches  186 , the capacitance of filter  140  may be increased in the direction of the Z-axis of  FIG. 10  relative to scenarios where only a single array of conductive patches is used. This increase in Z-axis capacitance may allow width  196  of slots  194  and  195  to be reduced to significantly less than the wavelengths of operation of phased array antenna  60  while still allowing satisfactory transmission characteristics for the wavelengths of operation of phased array antenna  60  (e.g., a width  196  of 100 microns is significantly less than the millimeter or centimeter scale wavelength of the radio-frequency signals handled by phased array antenna  60 ). 
     This reduction in width  196  of slots  194  and  195  may reduce width  196  to below what is ordinarily resolvable by the unaided human eye at a predetermined distance from display  14  (e.g., a typical viewing distance from display  14  during operation of device  10 ). As an example, widths  196  that are less than 200 microns may narrower than what is resolvable by the unaided human eye at a typical viewing distance from display  14 . This may allow the entirety of filter  140  and the surrounding radio-frequency opaque portion  150  of display module  130  to appear to the user as a single continuous (solid) piece of metal, thereby obscuring the potentially unsightly appearance of slots  194  and  195  from the user&#39;s view. This may serve to enhance the aesthetic properties of the images displayed by display  14  to the user. 
     As an example, the optical characteristics of filter  140  and radio-frequency opaque portion  150  of display module  130  may be characterized by the reflectivity, absorption, and transmission of visible light when display  14  is turned off or not emitting light. For example, filter  140  may exhibit a first reflectivity, first absorptivity, and first transmissivity, whereas opaque portion  150  of display module  130  exhibits a second reflectivity, second absorptivity, and second transmissivity for visible light when display  14  is turned off or not emitting light. In order to appear to the unaided eye as a single continuous piece of conductor, the first reflectivity, first absorptivity, and/or first transmissivity may be within a predetermined margin of the second reflectivity, second absorptivity, and/or second transmissivity, respectively (e.g., within a margin of 10%, 20%, 10-20%, 20-30%, 5%, 2%, 1-10%, etc.). 
     The example of  FIG. 10  is merely illustrative. If desired, conductive patches  186  may have different shapes, sizes, and/or dimensions (e.g., conductive patches  186  may have any number of curved and/or straight sides). Similarly, slots  194  and  195  may follow any desired pattern of straight and/or curved paths. The conductive patches  186  in first array  180  may all have the same shape, size, and/or dimension or two or more conductive patches in first array  180  may have different shapes, sizes, and/or dimensions (as long as the conductive patches  186  in second array  180  match and align with the conductive patches  186  in second array  182 ). Any desired number of conductive patches  186  may be formed in arrays  180  and  182 . Filter  140  may have any desired shape and dimensions. One or more display layers  126  may be interposed between first array  180  and second array  182 . In another possible arrangement, arrays  180  and  182  may both be embedded within the same display layer  126  while being separated by distance  144 . 
     The example of  FIG. 10  in which filter  140  is formed from two stacked arrays of conductive patches  186  is merely illustrative. In other suitable arrangements, filter  140  may include only a single array of conductive patches (e.g., as shown in  FIG. 7 ) or may include more than two stacked arrays of conductive patches (e.g., three stacked arrays, four stacked arrays, more than four stacked arrays, etc.). In a scenario where filter  140  includes only a single array of conductive patches, filter  140  may sometimes be referred to as a frequency selective surface (e.g., because the slots and patches in the filter would be confined to a radio-frequency opaque layer  128 ). In these scenarios, the width of slots  194  may be greater than in the arrangement shown in  FIG. 10  to allow satisfactory transmission within the same frequency band (e.g., such that the slots may no longer be invisible to the unaided eye of the user). On the other hand, using only a single array of conductive patches may reduce the manufacturing complexity of display  14  relative to scenarios where stacked arrays are used, for example. In the arrangement of  FIG. 10 , filter  140  may sometimes be referred to as including two stacked frequency selective surfaces (e.g., a first frequency selective surface formed from layer  128 - 1  and array  180  and a second frequency selective surface formed from layer  128 - 2  and array  182 ). 
       FIG. 11  is a plot of the transmission coefficient of filter  140  of  FIG. 10  as a function of frequency. In particular, curve  200  illustrates the transmission coefficient T of filter  140  as a function of frequency (e.g., the proportion of radio-frequency energy that is passed through display module  130  as a function of frequency). As shown in  FIG. 11 , when filter  140  is formed using stacked arrays of conductive patches such as arrays  180  and  182  of  FIG. 10 , filter  140  serves as a low pass filter that passes radio-frequency signals below a cutoff frequency FD and that significantly attenuates (e.g., blocks) radio-frequency signals above cutoff frequency FD. Width  196  of slots  194  and  195 , width  192  of conductive patches  186 , the material used to form display layer  126 , and the material used to form conductive patches  186  (e.g., as shown in  FIG. 10 ) may be selected so that transmission coefficient T of filter  140  is greater than a predetermined threshold value (e.g., within a few percent of 1.0) within a frequency band of interest between frequencies FA and FB. Frequencies FA and FB may, for example, define the lower and upper limits of the frequency band of operation of phased array antenna  60  of  FIG. 9 . Frequency FA may be, for example, 10 GHz, 28 GHz, 30 GHz, 39 GHz, 60 GHz, or any other desired frequency greater than or equal to 10 GHz etc. Frequency FB may be, for example, 28 GHz, 30 GHz, 39 GHz, 60 GHz, 70 GHz, or any other desired frequency greater than frequency FA and less than 300 GHz. Frequency FD may be, for example, any desired frequency greater than frequency FB such as 300 GHz (e.g., filter  140  may block signals at frequencies greater than 300 GHz). 
     When configured in this way, filter  140  may be effectively transparent to radio-frequency signals conveyed by phased array antenna  60  while also including slots  194  and  195  that are too narrow to be resolved by the unaided human eye at a typical viewing distance from display  14 . In this way, filter  140  may serve as a radio-frequency transparent antenna window in display module  130  without substantially affecting the quality of images displayed using display  14 . In the example of  FIG. 11 , transmission curve  200  also exhibits a peak between frequency FC and cutoff frequency FD associated with the resonance of the conductive structures and slots in filter  140  (e.g., the filter may be non-resonant at the frequency of operation of phased array antenna  60  but resonant at frequencies greater than those handled by phased array antenna  60  such as around 400 GHz). This is merely illustrative and, in general, curve  200  may have any desired shape (e.g., as determined by the configuration of the conductive patches  186  and the material properties of display layer  126  in filter  140 ). 
     If desired, filter  140  may be implemented using inductive paths in a given radio-frequency opaque layer  128  of display module  130 .  FIG. 12  is a perspective view of one suitable arrangement for filter  140  in which filter  140  includes a single layer of conductive structures that form inductive paths in a corresponding radio-frequency opaque layer  128  (e.g., a radio-frequency opaque layer  128  as shown in  FIG. 7 ). 
     As shown in  FIG. 12 , filter  140  may include a pattern of slots  208  (sometimes referred to as notches, gaps, openings, or holes  208 ) formed in radio-frequency opaque layer  128 . Each slot  208  may be completely surrounded by conductive material from radio-frequency opaque layer  128 . The conductive material surrounding slots  208  may form inductive paths  210  (sometimes referred to herein as conductive paths  210 ) on a surface of an underlying display layer  126 . 
     Slots  208  may, for example, be arranged in an array. Conductive paths  210  may be arranged in a grid pattern defining the edges of slots  208 . Radio-frequency opaque portion  150  of display module  130  (as shown in  FIGS. 7 and 9 ) may be formed from a portion of radio-frequency opaque layer  128  laterally surrounding filter  140  on the top surface of display layer  126  and is not shown in  FIG. 12  for the sake of clarity. Other display layers above and below filter  140  in display module  130  are also omitted from  FIG. 12  for the sake of clarity. 
     As shown in  FIG. 12 , filter  140  may extend across length  151  of display module  130 . Conductive paths  210  may be formed from metal traces on display layer  126 , from metal foil, or any other desired conductive structure. Conductive paths  210  may be formed, for example, from copper, aluminum, stainless steel, silver, gold, nickel, tin, indium tin oxide, other metals or metal alloys, or any other desired conductive materials. Conductive paths  210  may be formed from the same material as the surrounding portions of radio-frequency opaque layer  128  (e.g., the portion of layer  128  forming radio-frequency opaque portion  150  of display module  130  as shown in  FIG. 9 ) or may be formed from a different material from the surrounding portions of radio-frequency opaque layer  128 . As an example, conductive paths  210  and the surrounding portions of radio-frequency opaque layer  128  may both be formed from indium tin oxide or conductive paths  210  may be formed from copper whereas the surrounding portions of radio-frequency opaque layer  128  are formed from indium tin oxide. 
     Slots  208  may, for example, extend completely through the thickness of radio-frequency opaque layer  128  (e.g., as shown in  FIG. 7 ). Slots  208  may be filled with dielectric material, with an integral portion of the underlying display layer  126 , or may be void of material. Conductive paths  210  (e.g., radio-frequency opaque layer  128 ) may have a thickness  202 . 
     The dimensions of slots  208  may be selected to adjust the inductance of conductive paths  210  and to tweak the transmission characteristics of filter  140 . More particularly, the dimensions of slots  208 , the materials used to form conductive paths  210 , and the material used to form display layer  126  may be selected to configure filter  140  to be transparent to radio-frequency signals at predetermined frequencies (e.g., to define the pass band of filter  140  to overlap with frequencies greater than 10 GHz that are handled by phased array antenna  60  of  FIGS. 7 and 9 ). If desired, conductive paths  210  may include conductive tabs  214  that extend into slots  208  to tweak the inductance of conductive paths  210  and the overall area of slots  208 . The presence of conductive tabs  214  may allow the shape of slots  208  to be characterized by an inner width  212  (e.g., the distance between adjacent conductive tabs  214 ) and an outer width  216  (e.g., the distance between opposing ends of slot  208 ). 
     Inner width  212 , outer width  216 , thickness  202  of radio-frequency opaque layer  128 , the material used to form display layer  126 , and the material used to form conductive paths  210  may be selected so that filter  140  transmits a satisfactory amount of radio-frequency energy through display module  130  within a desired pass band (e.g., a pass band overlapping a millimeter wave frequency band covered by phased array antenna  60  of  FIG. 9 ). As just one example, inner width  212  may be between 1.0 mm and 2.0 mm (e.g., approximately 1.4 mm), outer width  216  may be between 2.0 mm and 2.5 mm (e.g., approximately 2.3 mm), and thickness  202  may be between 0.2 mm and 0.5 mm to provide filter  140  with a transmission coefficient that is greater than a predetermined threshold for radio-frequency signals at millimeter wave frequencies. These examples are merely illustrative and may be adjusted if desired to tweak the transmission response of filter  140 . 
     The dimensions of slots  208  (e.g., widths  212  and  216 ) are much greater than 200 microns and therefore could be visible to a user of device  10  when viewing display  14 . However, while forming filter  140  using conductive paths  210  as shown in  FIG. 12  sacrifices display aesthetics relative to the stacked arrays of conductive patches as shown in  FIG. 10 , forming filter  140  using conductive paths  210  may be easier and less expensive to manufacture relative to the arrangement of  FIG. 10 , for example. Filter  140  may exhibit a satisfactory radiation pattern envelope such as pattern envelope  160  of  FIG. 9  that covers substantially all of the hemisphere above display  14  regardless of whether conductive paths  210  (e.g., as shown in  FIGS. 7 and 12 ) or one or more arrays of conductive patches  186  (e.g., as shown in  FIGS. 7, 8 , and  10 ) are used to form filter  140 . 
     The example of  FIG. 12  is merely illustrative. If desired, slots  208  may have different shapes, sizes, and/or dimensions (e.g., slots  208  may have any number of curved and/or straight sides). Similarly, slots  208  may be arranged in any desired pattern and need not be arranged in a grid of rows and columns. Conductive paths  210  may follow any desired pattern and may have straight and/or curved edges. Slots  208  in filter  140  may all have the same shape, size, and/or dimension or two or more slots  208  in filter  140  may have different shapes, sizes, and/or dimensions. Any desired number of slots  208  may be formed in filter  140 . Filter  140  may have any desired shape and dimensions. Because conductive paths  210  and slots  208  are limited to a single radio-frequency opaque layer  128  in display module  130 , conductive paths  210  and slots  208  (i.e., filter  140  when configured as shown in  FIG. 12 ) may form a frequency selective surface. 
       FIG. 13  is a plot of the transmission coefficient of the filter having conductive paths  210  and slots  208  of  FIG. 12  as a function of frequency. In particular, curve  220  illustrates the transmission coefficient T of filter  140  of  FIG. 12  as a function of frequency. As shown in  FIG. 13 , when filter  140  is formed using conductive paths  210  and slots  208 , filter  140  serves as a band pass filter that passes radio-frequency signals between a first cutoff frequency FA and a second cutoff frequency FB and that significantly attenuates (blocks) radio-frequency signals above cutoff frequency FB and below cutoff frequency FA. The dimensions of slots  208  and conductive paths  210 , the material used to form display layer  126 , the material used to form conductive paths  210 , and thickness  202  of layer  128  (e.g., as shown in  FIG. 12 ) may be selected so that transmission coefficient T of filter  140  is greater than a predetermined threshold value (e.g., within a few percent of 1.0) within a frequency band of interest between frequencies FA and FB. Frequencies FA and FB may, for example, define the lower and upper limits of the frequency band of operation of phased array antenna  60  of  FIG. 9  or may be lower than and greater than the limits of the frequency band of operation of phased array antenna  60  by a predetermined margin (e.g., frequencies FA and FB may define the pass band of filter  140  of  FIG. 12 ). Frequency FA may be, for example, 10 GHz, 28 GHz, 30 GHz, 39 GHz, 60 GHz, or any other desired frequency greater than or equal to 10 GHz etc. Frequency FB may be, for example, 28 GHz, 30 GHz, 39 GHz, 60 GHz, 70 GHz, or any other desired frequency greater than frequency FA and less than 300 GHz. In this way, filter  140  may serve as a radio-frequency transparent antenna window in display module  130  for phased array antenna  60 . The example of  FIG. 13  is merely illustrative and, in general, curve  220  may have any desired shape (e.g., as determined by the configuration of the conductive paths  210  and slots  208  and the material properties of display layer  126  in filter  140  of  FIG. 12 ). 
     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: 20180130
Publication Date: 20200728
Grant Date: 20200728
Priority Date: 20180130
Inventors: PAULOTTO, Simone
MOW, MATTHEW A.
PASCOLINI, MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q15/0026", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 70325583