PATENT DOCUMENT

Publication Number: US-10658762-B2
Application Number: US-201715650638-A
Country: US
Kind Code: B2

Title: Multi-band millimeter wave antenna arrays

Abstract:
An electronic device may be provided with wireless circuitry that includes a phased antenna array. The array may include first, second, and third rings of antennas on a dielectric substrate that cover respective first, second, and third communications bands greater than 10 GHz. The second ring of antennas may surround the first ring of antennas. The third ring of antennas may be formed over the second ring of antennas. Parasitic elements may be formed over the first ring of antennas to broaden the bandwidth of the first ring of antennas. Beam steering circuitry may be coupled to the rings of antennas. Control circuitry may control the beam steering circuitry to steer a beam of wireless signals in one or more of the first, second, and third communications bands. The array may exhibit relatively uniform antenna gain regardless of the direction in which the beam is steered.

Claims:
What is claimed is: 
     
       1. A phased antenna array, comprising:
 a dielectric substrate; 
 a first set of patch antenna resonating elements on the dielectric substrate and configured to convey radio-frequency signals in a first communications band at frequencies greater than 30 GHz; 
 a second set of patch antenna resonating elements disposed around the first set of patch antenna resonating elements on the dielectric substrate and configured to convey radio-frequency signals in a second communications band at frequencies that are lower than the first communications band; and 
 a third set of patch antenna resonating elements on the dielectric substrate and configured to convey radio-frequency signals in a third communications band at frequencies that are higher than the second communications band and lower than the first communications band, wherein an entirety of each of the patch antenna resonating elements in the third set of patch antenna resonating element overlaps a respective one of the patch antenna resonating elements in the second set of patch antenna resonating elements. 
 
     
     
       2. The phased antenna array defined in  claim 1 , wherein each patch antenna resonating element in the first set is located at a first distance from a point on the dielectric substrate, and each patch antenna resonating element in the second set is located at a second distance from the point on the dielectric substrate, the second distance being greater than the first distance. 
     
     
       3. The phased antenna array defined in  claim 2 , wherein the first set of patch antenna resonating elements is formed at a first set of angles about the point on the dielectric substrate and the second set of patch antenna resonating elements is formed at a second set of angles about the point on the dielectric substrate, the second set of angles being offset with respect to the first set of angles. 
     
     
       4. The phased antenna array defined in  claim 2 , wherein the first communications band comprises a communications band between 57 GHz and 71 GHz and the second communications band comprises a communications band between 27.5 GHz and 28.5 GHz. 
     
     
       5. The phased antenna array defined in  claim 1 , further comprising:
 a set of parasitic antenna resonating elements, wherein each parasitic antenna resonating element in the set of parasitic antenna resonating elements overlaps a respective one of the patch antenna resonating elements in the first set. 
 
     
     
       6. The phased antenna array defined in  claim 5 , wherein the set of parasitic antenna resonating elements comprises cross-shaped conductive patches. 
     
     
       7. The phased antenna array defined in  claim 6 , further comprising:
 an antenna ground plane coupled to the dielectric substrate, wherein the each patch antenna resonating element in the second set comprises: 
 a first antenna feed having a first antenna feed terminal coupled to a first location on that patch antenna resonating element and a second antenna feed terminal coupled to the antenna ground plane, and 
 a second antenna feed having a third antenna feed terminal coupled to a second location on that patch antenna resonating element and a fourth antenna feed terminal coupled to the antenna ground plane. 
 
     
     
       8. The phased antenna array defined in  claim 1 , wherein the patch antenna resonating elements in the first set are not overlapped by any parasitic antenna resonating elements. 
     
     
       9. The phased antenna array defined in  claim 1 , wherein the first communications band comprises a communications band between 57 GHz and 71 GHz, the second communications band comprises a communications band between 27.5 GHz and 28.5 GHz, and the third communications band comprises a communications band between 37 GHz and 41 GHz. 
     
     
       10. A phased antenna array, comprising:
 a dielectric substrate; 
 a first set of antennas on the dielectric substrate and configured to transmit and receive wireless signals in a first communications band at frequencies greater than 30 GHz; 
 a second set of antennas surrounding the first set of antennas on the dielectric substrate and configured to transmit and receive wireless signals in a second communications band at frequencies that are lower than the first communications band; 
 a third set of antennas on the dielectric substrate and configured to transmit and receive wireless signals in a third communications band at frequencies that are higher than the second communications band and lower than the first communications band, wherein the first set of antennas comprises a first set of patch antenna resonating elements, the second set of antennas comprises a second set of patch antenna resonating elements, and the third set of antennas comprises a third set of patch antenna resonating elements, each of the patch antenna resonating elements in the third set being formed over a respective patch antenna resonating element in the second set of patch antenna resonating elements; 
 a set of parasitic antenna resonating elements, wherein each parasitic antenna resonating element in the set of parasitic antenna resonating elements is formed over a respective one of the patch antenna resonating elements in the first set of patch antenna resonating elements; and 
 an antenna ground plane for the first, second, and third sets of antennas, wherein the dielectric substrate comprises a first dielectric layer, a second dielectric layer, and a third dielectric layer, the antenna ground plane is formed on the first dielectric layer, the first and second sets of patch antenna resonating elements are formed on the second dielectric layer, and the set of parasitic antenna resonating elements and the third set of patch antenna resonating elements are formed on the third dielectric layer. 
 
     
     
       11. The phased antenna array defined in  claim 10 , wherein the set of parasitic antenna resonating elements comprises cross-shaped conductive patches. 
     
     
       12. The phased antenna array defined in  claim 10 , wherein each antenna in the first set is located at a first distance from a point on the dielectric substrate and each antenna in the second set is located at a second distance from the point on the dielectric substrate, the second distance being greater than the first distance. 
     
     
       13. The phased antenna array defined in  claim 12 , wherein the first set of antennas is formed at a first set of angles about the point on the dielectric substrate and the second set of antennas is formed at a second set of angles about the point on the dielectric substrate, the second set of angles being offset with respect to the first set of angles. 
     
     
       14. The phased antenna array defined in  claim 13 , wherein the first communications band comprises a communications band between 57 GHz and 71 GHz, the second communications band comprises a communications band between 27.5 GHz and 28.5 GHz, and the third communications band comprises a communications band between 37 GHz and 41 GHz. 
     
     
       15. A phased antenna array, comprising:
 a dielectric substrate; 
 a ground plane on the dielectric substrate; 
 a first set of antennas configured to convey radio-frequency signals in a first communications band at frequencies greater than 30 GHz, wherein each antenna in the first set comprises a respective antenna resonating element and a respective parasitic antenna resonating element overlapping that antenna resonating element, the antenna resonating elements in the first set of antennas being interposed between the parasitic antenna resonating elements in the first set of antennas and the ground plane; 
 a second set of antennas disposed around the first set of antennas and configured to convey radio-frequency signals in a second communications band at frequencies that are lower than the first communications band; and 
 a third set of antennas on the dielectric substrate and overlapping the second set of antennas, wherein the third set of antennas are configured to convey radio-frequency signals in a third communications band at frequencies that are higher than the second communications band and lower than the first communications band, the second and third sets of antennas being free from parasitic antenna resonating elements. 
 
     
     
       16. The phased antenna array defined in  claim 15 , wherein the parasitic antenna resonating elements comprise cross-shaped patches. 
     
     
       17. The phased antenna array defined in  claim 15 , wherein the first communications band comprises a communications band between 57 GHz and 71 GHz, the second communications band comprises a communications band between 27.5 GHz and 28.5 GHz, and the third communications band comprises a communications band between 37 GHz and 41 GHz. 
     
     
       18. The phased antenna array defined in  claim 15 , wherein the third set of antennas comprise patch antenna resonating elements. 
     
     
       19. The phased antenna array defined in  claim 15 , wherein the dielectric substrate comprises a plurality of stacked dielectric layers, the patch antenna resonating elements in the third set of antennas and the parasitic antenna resonating elements being patterned on the same dielectric layer in the plurality of stacked dielectric layers.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with wireless communications circuitry. 
     Electronic devices often include wireless communications circuitry. For example, cellular telephones, computers, and other devices often contain antennas and wireless transceivers for supporting wireless communications. 
     It may be desirable to support wireless communications in millimeter wave and centimeter wave communications bands. Millimeter wave communications, which are sometimes referred to as extremely high frequency (EHF) communications, and centimeter wave communications involve communications at frequencies of about 10-300 GHz. Operation at these frequencies may support high bandwidths, but may raise significant challenges. For example, millimeter wave communications are often line-of-sight communications and can be characterized by substantial attenuation during signal propagation. 
     It would therefore be desirable to be able to provide electronic devices with improved wireless communications circuitry such as communications circuitry that supports communications at frequencies greater than 10 GHz. 
     SUMMARY 
     An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas and transceiver circuitry such as millimeter wave transceiver circuitry. The antennas may be organized in a phased antenna array. The phased antenna array may transmit and receive a beam of wireless signals in frequency bands between 10 GHz and 300 GHz. Beam steering circuitry may be coupled to each of the antennas in the phased antenna array. Control circuitry in the electronic device may control the beam steering circuitry to steer a direction (orientation) of the beam. 
     The phased antenna array may include a dielectric substrate and first and second sets of antennas on the dielectric substrate. The first set of antennas may transmit and receive wireless signals in a first communications band between 10 GHz and 300 GHz. The second set of antennas may transmit and receive wireless signals in a second communications band between 10 GHz and 300 GHz. The first and second sets of antennas may, for example, include patch antennas having corresponding patch antenna resonating elements. The second communications band may include frequencies that are lower than the first communications band. The second set of antennas may surround the first set of antennas on the dielectric substrate. For example, the first set of antennas may be arranged in a first ring of antennas and the second set of antennas may be arranged in a second ring of antennas surrounding the first ring. Each antenna in the first ring may be located at a first distance from a given point on the dielectric substrate. Each antenna in the second ring may be located at a second distance from the given point that is greater than the first distance. The antennas in the first ring may be angularly offset with respect to the antennas in the second ring about the given point on the dielectric substrate. 
     A set of parasitic antenna resonating elements may be formed over the first set of antennas in the array and may serve to broaden a bandwidth of the first set of antennas. The set of parasitic antenna resonating elements may include cross-shaped conductive patches having arms that overlap with antenna feed terminals on the first set of antennas. A third set of antennas may be formed on the dielectric substrate and may transmit and receive wireless signals in a third communications band between 10 GHz and 300 GHz. The third communications band may include frequencies that are higher than the second communications band and lower than the first communications band. As an example, the first communications band may include frequencies from 57 GHz to 71 GHz, the second communications band may include frequencies from 27.5 GHz to 28.5 GHz, and the third communications band may include frequencies from 37 GHz to 41 GHz. The third set of antennas may include patch antenna resonating elements formed over the second set of antennas in the array. 
     The control circuitry may control the beam steering circuitry to steer a beam of wireless signals in one or more of the first, second, and third communications bands in a particular directions. The phased antenna array may exhibit uniform antenna gain regardless of the direction in which the beam is steered. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment. 
         FIG. 3  is a rear perspective view of an illustrative electronic device showing illustrative locations at which antenna arrays for communications at frequencies greater than 10 GHz may be located in accordance with an embodiment. 
         FIG. 4  is a diagram of an illustrative phased antenna array that may be adjusted using control circuitry to direct a beam of wireless wave signals in accordance with an embodiment. 
         FIGS. 5A and 5B  are diagrams showing a radiation pattern of an illustrative phased antenna array in accordance with an embodiment. 
         FIG. 6  is a perspective view of an illustrative patch antenna in accordance with an embodiment. 
         FIG. 7  is a perspective view of an illustrative patch antenna with dual ports in accordance with an embodiment. 
         FIG. 8  is a top-down view of an illustrative phased antenna array having concentric rings of antennas in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of illustrative co-located patch antennas in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of an illustrative patch antenna having a parasitic antenna resonating element in accordance with an embodiment. 
         FIG. 11  is a top-down view of an illustrative patch antenna of the type shown in  FIG. 10  in accordance with an embodiment. 
         FIG. 12  is a graph of antenna performance (antenna efficiency) for an illustrative patch antenna of the type shown in  FIGS. 10 and 11  in accordance with an embodiment. 
         FIG. 13  is a graph of antenna efficiency for an illustrative phased antenna array in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may contain wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include phased antenna arrays that are used for handling millimeter wave and centimeter wave communications. Millimeter wave communications, which are sometimes referred to as extremely high frequency (EHF) communications, involve signals at 60 GHz or other frequencies between about 30 GHz and 300 GHz. Centimeter wave communications involve signals at frequencies between about 10 GHz and 30 GHz. If desired, device  10  may also contain wireless communications circuitry for handling satellite navigation system signals, cellular telephone signals, local wireless area network signals, near-field communications, light-based wireless communications, or other wireless communications. 
     Electronic device  10  may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch device, a pendant device, a headphone or earpiece device, a virtual or augmented reality headset device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, a wireless access point or base station, a desktop computer, a keyboard, a gaming controller, a computer mouse, a mousepad, a trackpad or touchpad, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     As shown in  FIG. 1 , device  10  may include a display such as display  14 . Display  14  may be mounted in a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass, clear plastic, sapphire, or other transparent dielectric. Openings may be formed in the display cover layer. For example, openings may be formed in the display cover layer to accommodate one or more buttons, sensor circuitry such as a fingerprint sensor or light sensor, ports such as a speaker port or microphone port, etc. Openings may be formed in housing  12  to form communications ports (e.g., an audio jack port, a digital data port, charging port, etc.). Openings in housing  12  may also be formed for audio components such as a speaker and/or a microphone. 
     Antennas may be mounted in housing  12 . If desired, some of the antennas (e.g., antenna arrays that may implement beam steering, etc.) may be mounted under an inactive border region of display  14  (see, e.g., illustrative antenna locations  50  of  FIG. 1 ). Antennas may also operate through dielectric-filled openings in the rear of housing  12  or elsewhere in device  10 . 
     To avoid disrupting communications when an external object such as a human hand or other body part of a user blocks one or more antennas, antennas may be mounted at multiple locations in housing  12 . Sensor data such as proximity sensor data, real-time antenna impedance measurements, signal quality measurements such as received signal strength information, and other data may be used in determining when one or more antennas is being adversely affected due to the orientation of housing  12 , blockage by a user&#39;s hand or other external object, or other environmental factors. Device  10  can then switch one or more replacement antennas into use in place of the antennas that are being adversely affected. 
     Antennas may be mounted at the corners of housing  12  (e.g., in corner locations  50  of  FIG. 1  and/or in corner locations on the rear of housing  12 ), along the peripheral edges of housing  12 , on the rear of housing  12 , under the display cover glass or other dielectric display cover layer that is used in covering and protecting display  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 . 
     A schematic diagram showing illustrative components that may be used in device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include storage and processing circuitry such as control circuitry  14 . Control circuitry  14  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  14  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processor integrated circuits, application specific integrated circuits, etc. 
     Control circuitry  14  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, control circuitry  14  may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry  14  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol or other WPAN protocols, IEEE 802.11ad protocols, cellular telephone protocols, MIMO protocols, antenna diversity protocols, satellite navigation system protocols, etc. 
     Device  10  may include input-output circuitry  16 . Input-output circuitry  16  may include input-output devices  18 . Input-output devices  18  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  18  may include user interface devices, data port devices, and other input-output components. For example, input-output devices may include touch screens, displays without touch sensor capabilities, buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, accelerometers or other components that can detect motion and device orientation relative to the Earth, capacitance sensors, proximity sensors (e.g., a capacitive proximity sensor and/or an infrared proximity sensor), magnetic sensors, and other sensors and input-output components. 
     Input-output circuitry  16  may include wireless communications circuitry  34  for communicating wirelessly with external equipment. Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas  40 , transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless communications circuitry  34  may include transceiver circuitry  20  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  22 ,  24 ,  26 , and  28 . 
     Transceiver circuitry  24  may be wireless local area network transceiver circuitry. Transceiver circuitry  24  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band. 
     Circuitry  34  may use cellular telephone transceiver circuitry  26  for handling wireless communications in frequency ranges such as a communications band from 700 to 960 MHz, a communications band from 1710 to 2170 MHz, and a communications from 2300 to 2700 MHz or other communications bands between 700 MHz and 4000 MHz or other suitable frequencies (as examples). Circuitry  26  may handle voice data and non-voice data. 
     Millimeter wave transceiver circuitry  28  (sometimes referred to as extremely high frequency transceiver circuitry  28  or transceiver circuitry  28 ) may support communications at frequencies between about 10 GHz and 300 GHz. For example, transceiver circuitry  28  may support communications in Extremely High Frequency (EHF) or millimeter wave communications bands between about 30 GHz and 300 GHz and/or in centimeter wave communications bands between about 10 GHz and 30 GHz (sometimes referred to as Super High Frequency (SHF) bands). As examples, transceiver circuitry  28  may support communications in an IEEE K communications band between about 18 GHz and 27 GHz, a K a  communications band between about 26.5 GHz and 40 GHz, a K u  communications band between about 12 GHz and 18 GHz, a V communications band between about 40 GHz and 75 GHz, a W communications band between about 75 GHz and 110 GHz, or any other desired frequency band between approximately 10 GHz and 300 GHz. If desired, circuitry  28  may support IEEE 802.11ad communications at 60 GHz and/or 5 th  generation mobile networks or 5 th  generation wireless systems (5G) communications bands between 27 GHz and 90 GHz. If desired, circuitry  28  may support communications at multiple frequency bands between 10 GHz and 300 GHz such as a first band from 27.5 GHz to 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., in millimeter wave communications bands, centimeter wave communications bands, etc.). 
     Wireless communications circuitry  34  may include satellite navigation system circuitry such as Global Positioning System (GPS) receiver circuitry  22  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data (e.g., GLONASS signals at 1609 MHz). Satellite navigation system signals for receiver  22  are received from a constellation of satellites orbiting the earth. 
     In satellite navigation system links, cellular telephone links, and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. In WiFi® and Bluetooth® links at 2.4 and 5 GHz and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. Extremely high frequency (EHF) wireless transceiver circuitry  28  may convey signals over these short distances that travel between transmitter and receiver over a line-of-sight path. To enhance signal reception for millimeter and centimeter wave communications, phased antenna arrays and beam steering techniques may be used (e.g., schemes in which antenna signal phase and/or magnitude for each antenna in an array is adjusted to perform beam steering). Antenna diversity schemes may also be used to ensure that the antennas that have become blocked or that are otherwise degraded due to the operating environment of device  10  can be switched out of use and higher-performing antennas used in their place. 
     Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. 
     Antennas  40  in wireless communications circuitry  34  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, monopoles, dipoles, helical antenna structures, Yagi (Yagi-Uda) antenna structures, hybrids of these designs, etc. If desired, one or more of antennas  40  may be cavity-backed antennas. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. Dedicated antennas may be used for receiving satellite navigation system signals or, if desired, antennas  40  can be configured to receive both satellite navigation system signals and signals for other communications bands (e.g., wireless local area network signals and/or cellular telephone signals). Antennas  40  can include phased antenna arrays for handling millimeter and centimeter wave communications. 
     Transmission line paths may be used to route antenna signals within device  10 . For example, transmission line paths may be used to couple antenna structures  40  to transceiver circuitry  20 . Transmission lines in device  10  may include coaxial cable paths, microstrip transmission lines, stripline transmission lines, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, waveguide structures, transmission lines formed from combinations of transmission lines of these types, etc. Filter circuitry, switching circuitry, impedance matching circuitry, and other circuitry may be interposed within the transmission lines, if desired. 
     Device  10  may contain multiple antennas  40 . The antennas may be used together or one of the antennas may be switched into use while other antenna(s) are switched out of use. If desired, control circuitry  14  may be used to select an optimum antenna to use in device  10  in real time and/or to select an optimum setting for adjustable wireless circuitry associated with one or more of antennas  40 . Antenna adjustments may be made to tune antennas to perform in desired frequency ranges, to perform beam steering with a phased antenna array, and to otherwise optimize antenna performance. Sensors may be incorporated into antennas  40  to gather sensor data in real time that is used in adjusting antennas  40 . 
     In some configurations, antennas  40  may include antenna arrays (e.g., phased antenna arrays to implement beam steering functions). For example, the antennas that are used in handling millimeter and centimeter wave signals for transceiver circuits  28  may be implemented as one or more phased antenna arrays. The radiating elements in a phased antenna array for supporting millimeter wave communications may be patch antennas, dipole antennas, Yagi antennas (sometimes referred to as beam antennas), or other suitable antenna elements. Transceiver circuitry  28  may be integrated with the phased antenna arrays to form integrated phased antenna array and transceiver circuit modules if desired. 
     In devices such as handheld devices, the presence of an external object such as the hand of a user or a table or other surface on which a device is resting has a potential to block wireless signals such as millimeter and centimeter wave signals. Accordingly, it may be desirable to incorporate multiple phased antenna arrays into device  10 , each of which is placed in a different location within device  10 . With this type of arrangement, an unblocked phased antenna array may be switched into use and, once switched into use, the phased antenna array may use beam steering to optimize wireless performance. Configurations in which antennas from one or more different locations in device  10  are operated together may also be used. 
       FIG. 3  is a perspective view of electronic device  10  showing illustrative locations  50  on the rear of housing  12  in which antennas  40  (e.g., single antennas and/or phased antenna arrays for use with wireless circuitry  34  such as wireless transceiver circuitry  28 ) may be mounted in device  10 . Antennas  40  may be mounted at the corners of device  10 , along the edges of housing  12  such as edge  12 E, on upper and lower portions of rear housing portion (wall)  12 R, in the center of rear housing wall  12 R (e.g., under a dielectric window structure or other antenna window in the center of rear housing  12 R), at the corners of rear housing wall  12 R (e.g., on the upper left corner, upper right corner, lower left corner, and lower right corner of the rear of housing  12  and device  10 ), etc. 
     In configurations in which housing  12  is formed entirely or nearly entirely from a dielectric, antennas  40  may transmit and receive antenna signals through any suitable portion of the dielectric. In configurations in which housing  12  is formed from a conductive material such as metal, regions of the housing such as slots or other openings in the metal may be filled with plastic or other dielectric. Antennas  40  may be mounted in alignment with the dielectric in the openings. These openings, which may sometimes be referred to as dielectric antenna windows, dielectric gaps, dielectric-filled openings, dielectric-filled slots, elongated dielectric opening regions, etc., may allow antenna signals to be transmitted to external equipment from antennas  40  mounted within the interior of device  10  and may allow internal antennas  40  to receive antenna signals from external equipment. In another suitable arrangement, antennas  40  may be mounted on the exterior of conductive portions of housing  12 . 
     In devices with phased antenna arrays, circuitry  34  may include gain and phase adjustment circuitry that is used in adjusting the signals associated with each antenna  40  in an array (e.g., to perform beam steering). Switching circuitry may be used to switch desired antennas  40  into and out of use. Each of locations  50  may include multiple antennas  40  (e.g., a set of three antennas or more than three or fewer than three antennas in a phased antenna array) and, if desired, one or more antennas from one of locations  50  may be used in transmitting and receiving signals while using one or more antennas from another of locations  50  in transmitting and receiving signals. 
       FIG. 4  is a diagram showing how antennas  40  on device  10  may be formed in a phased antenna array. As shown in  FIG. 4 , an array  60  of antennas  40  may be coupled to a signal path such as path  64  (e.g., one or more radio-frequency transmission line structures, extremely high frequency waveguide structures or other extremely high frequency transmission line structures, etc.). Array  60  may include a number N of antennas  40  (e.g., a first antenna  40 - 1 , a second antenna  40 - 2 , an Nth antenna  40 -N, etc.). Antennas  40  in phased antenna array  60  may be arranged in any desired number of rows and columns or in any other desired pattern (e.g., the antennas need not be arranged in a grid pattern having rows and columns). During signal transmission operations, path  64  may be used to supply signals (e.g., millimeter wave signals) from transceiver circuitry  28  to phased antenna array  60  for wireless transmission to external wireless equipment. During signal reception operations, path  64  may be used to convey signals received at phased antenna array  60  from external equipment to transceiver circuitry  28 . 
     The use of multiple antennas  40  in array  60  allows beam steering arrangements to be implemented by controlling the relative phases and amplitudes of the signals for the antennas. In the example of  FIG. 4 , antennas  40  each have a corresponding phase and amplitude controller  62  (e.g., a first controller  62 - 1  coupled between signal path  64  and first antenna  40 - 1 , a second controller  62 - 2  coupled between signal path  64  and second antenna  40 - 2 , an Nth controller  62 -N coupled between path  64  and Nth antenna  40 -N, etc.). 
     Beam steering circuitry such as control circuitry  70  may use phase and amplitude controllers  62  to adjust the relative phases and amplitudes of the transmitted signals that are provided to each of the antennas in array  60  and to adjust the relative phases of the received signals that are received by array  60  from external equipment. The term “beam” or “signal beam” may be used herein to collectively refer to wireless signals that are transmitted and received by array  60  in a particular direction. The term “transmit beam” may sometimes be used herein to refer to wireless signals that are transmitted in a particular direction whereas the term “receive beam” may sometimes be used herein to refer to wireless signals that are received from a particular direction. In scenarios in which device  10  includes multiple phased antenna arrays, each phased antenna array may be steered using a respective beam steering circuit  70  (e.g., each phased antenna array may communicate using a respective beam that is steered using a corresponding set of phase and amplitude settings). 
     If, for example, control circuitry  70  is adjusted to produce a first set of phases and amplitudes on the transmitted signals (e.g., based on control signals received from control circuitry  14 ), the transmitted signals will form a transmit beam as shown by beam  66  of  FIG. 4  that is oriented in the direction of point A. If, however, control circuitry  70  adjusts controllers  62  to produce a second set of phases and amplitudes on the transmitted signals, the transmitted signals will form a beam as shown by beam  68  that is oriented in the direction of point B. Similarly, if control circuitry  70  adjusts controllers  62  to produce the first set of phases and amplitudes, wireless signals (e.g., millimeter wave signals in a millimeter wave frequency beam) may be received from the direction of point A as shown by beam  66 . If control circuitry  70  adjusts controllers  62  to produce the second set of phases and amplitudes, signals may be received from the direction of point B, as shown by beam  68 . Control circuit  70  may be controlled by control circuitry  14  of  FIG. 2  or by other control and processing circuitry in device  10  if desired. 
     When performing millimeter and centimeter wave communications, wireless signals are conveyed over a line of sight path between phased antenna array  60  and external equipment. If the external equipment is located at location A of  FIG. 4 , circuit  70  may be adjusted to steer the signal beam towards direction A. If the external equipment is located at location B, circuit  70  may be adjusted to steer the signal beam towards direction B. In the example of  FIG. 4 , beam steering is shown as being performed over a single degree of freedom for the sake of simplicity (e.g., towards the left and right on the page of  FIG. 4 ). However, in practice, the beam is steered over two degrees of freedom (e.g., into and out of the page and to the left and right on the page of  FIG. 4 ). 
     The radiation pattern of array  60  may depend on the particular arrangement of antennas  40  within the array. In scenarios where antennas  40  in array  60  are arranged in a rectangular grid of aligned rows and columns, the radiation pattern of the array may be excessively non-uniform (e.g., millimeter wave signals transmitted by the array may have a greater gain in certain directions than in others). If desired, antennas  40  may be arranged in array  60  so that array  60  exhibits a radiation pattern that is sufficiently uniform over all beam steering angles. 
       FIG. 5A  is a side-view showing how antenna array  60  may exhibit a uniform radiation pattern. As shown in  FIG. 5A , antenna array  60  may lie in the X-Y plane of  FIG. 5A . Array  60  may transmit and receive millimeter wave signals or other wireless signals at frequencies between 10 GHz and 300 GHz in the positive Z-direction of  FIG. 5A  (e.g., in a hemisphere of possible coverage extending above the X-Y plane in the Z-direction). In scenarios where antennas  40  are arranged in a rectangular grid within a corresponding phased antenna array, the array may exhibit a radiation pattern such as a radiation pattern associated with pattern envelope  82 . Pattern envelope (curve)  82  may be indicative of the gain of the wireless signals transmitted by the array when steered over the entire hemisphere of coverage for the array. The distance of curve  82  from the origin of  FIG. 5A  is indicative of the gain of the array at different beam steering angles. As shown by envelope  82 , the array can exhibit greater gain in some directions than in others. This may cause the array to exhibit insufficient gain when steered in some directions. If array  60  is transmitting wireless signals to external equipment in those directions, errors may be introduced in the data received by the external equipment or the corresponding communications link may be dropped. 
     If desired, antennas  40  may be arranged in non-rectangular patterns that configure array  60  to exhibit a uniform radiation pattern such as a radiation pattern associated with pattern envelope  80  of  FIG. 5A . As shown by pattern envelope  80 , array  60  may exhibit a relatively uniform gain when steered over all possible elevation angles θ (e.g., over the entire hemisphere of coverage for the array). The example of  FIG. 5A  shows a cut of the three-dimensional pattern envelope for array  60  within the X-Z plane (e.g., the pattern envelope as array  60  is steered over different elevation angles θ). 
       FIG. 5B  is a top-down view showing how array  60  may exhibit a uniform radiation pattern envelope as array  60  is steered over different azimuthal angles φ (e.g., showing a cut of the three-dimensional pattern envelope within the X-Y plane as array  60  is steered over different azimuthal angles φ). As shown in  FIG. 5B , pattern envelope  82  of a rectangular array may be associated with significantly higher gains at some azimuthal angles φ than at other azimuthal angles φ. Pattern envelope  80  associated with array  60  having antennas  40  arranged in non-rectangular patterns is more uniform (e.g., flatter or more smoothly curved) over all azimuthal angles φ. When configured in this way, array  60  may maintain a relatively high quality communications link with external equipment regardless of where the external equipment is located within the hemisphere of coverage of the array (e.g., regardless of the elevation angle θ or azimuthal angle φ to which the beam is steered). 
     Antennas  40  in array  60  may be formed using any desired type of antennas (e.g., inverted-F antennas, dipole antennas, patch antennas, etc.). Patch antenna structures that may be used for implementing antennas  40  are shown in  FIG. 6 . As shown in  FIG. 6 , patch antenna  40  may have a patch antenna resonating element such as patch  90  that is separated from a ground plane structure such as ground  92 . Antenna patch resonating element  90  and ground  92  may be formed from metal foil, machined metal structures, metal traces on a printed circuit or a molded plastic carrier, electronic device housing structures, or other conductive structures in an electronic device such as device  10 . 
     Antenna  40  may be coupled to transceiver circuitry such as transceiver circuitry  20  of  FIG. 2  using radio-frequency transmission line structures. As shown in  FIG. 6 , radio-frequency transmission line structures may be coupled to antenna feed structures associated with antenna  40 . As an example, antenna  40  may have an antenna feed with a positive antenna feed terminal such as terminal  96  coupled to patch resonating element  90  and a ground antenna feed terminal such as ground antenna feed terminal  98  coupled to ground  92 . A positive transmission line conductor in the radio-frequency transmission line structures may be coupled between transceiver circuitry  20  and positive antenna feed terminal  96 . A ground transmission line conductor in the radio-frequency transmission line structures may be coupled between transceiver circuitry  20  and ground antenna feed terminal  98 . If desired conductive path  94  may be used to couple terminal  96 ′ to terminal  96  so that antenna  40  is fed using a transmission line with a positive conductor coupled to terminal  96 ′ and thus terminal  96 . If desired, conductive path  94  may be omitted. Other types of antenna feed arrangements may be used if desired. The illustrative feeding configuration of  FIG. 6  is merely illustrative. 
     As shown in  FIG. 6 , antenna patch resonating element  90  may lie within a plane such as the X-Y plane of  FIGS. 5 and 6 . Ground  92  may line within a plane that is parallel to the plane of antenna patch resonating element (patch)  90 . Patch  90  and ground  92  may therefore lie in separate parallel planes that are separated by a distance H. The length of the sides of patch resonating element  90  may be selected so that antenna  40  resonates at a desired operating frequency. For example, the sides of element  90  may each have a length L 0  that is approximately equal to half of the wavelength (e.g., within 15% of half of the wavelength) of the signals conveyed by antenna  40  (e.g., in scenarios where patch element  90  is substantially square). 
     The example of  FIG. 6  is merely illustrative. Patch  90  may have a square shape in which all of the sides of patch  90  are the same length or may have a rectangular shape. In general, patch  90  and ground  92  may have different shapes and orientations (e.g., planar shapes, curved patch shapes, patch element shapes with non-rectangular outlines, shapes with straight edges such as squares, shapes with curved edges such as ovals and circles, shapes with combinations of curved and straight edges, etc.). In scenarios where patch  90  is non-rectangular, patch  90  may have a side or a maximum lateral dimension that is approximately equal to (e.g., within 15% of) half of the wavelength of operation, for example. 
     To enhance the polarizations handled by patch antenna  40 , antenna  40  may be provided with multiple feeds. An illustrative patch antenna with multiple feeds is shown in  FIG. 7 . As shown in  FIG. 7 , antenna  40  may have a first feed at antenna port P 1  that is coupled to transmission line  64 - 1  and a second feed at antenna port P 2  that is coupled to transmission line  64 - 2 . The first antenna feed may have a first ground feed terminal coupled to ground  92  and a first positive feed terminal  96 -P 1  coupled to patch antenna resonating element  90 . The second antenna feed may have a second ground feed terminal coupled to ground  92  and a second positive feed terminal  96 -P 2 . 
     Patch  90  may have a rectangular shape with a first pair of edges running parallel to dimension Y and a second pair of perpendicular edges running parallel to dimension X. The length of patch  90  in dimension Y is L 1  and the length of patch  90  in dimension X is L 2 . With this configuration, antenna  40  may be characterized by orthogonal polarizations. 
     When using the first antenna feed associated with port P 1 , antenna  40  may transmit and/or receive antenna signals in a first communications band at a first frequency (e.g., a frequency at which one-half of the corresponding wavelength is approximately equal to dimension L 1 ). These signals may have a first polarization (e.g., the electric field E 1  of antenna signals  100  associated with port P 1  may be oriented parallel to dimension Y). When using the antenna feed associated with port P 2 , antenna  40  may transmit and/or receive antenna signals in a second communications band at a second frequency (e.g., a frequency at which one-half of the corresponding wavelength is approximately equal to dimension L 2 ). These signals may have a second polarization (e.g., the electric field E 2  of antenna signals  100  associated with port P 2  may be oriented parallel to dimension X so that the polarizations associated with ports P 1  and P 2  are orthogonal to each other). In scenarios where patch  90  is square (e.g., length L 1  is equal to length L 2 ), ports P 1  and P 2  may cover the same communications band. In scenarios where patch  90  is rectangular, ports P 1  and P 2  may cover different communications bands if desired. During wireless communications using device  10 , device  10  may use port P 1 , port P 2 , or both port P 1  and P 2  to transmit and/or receive signals (e.g., millimeter wave and centimeter wave signals). 
     The example of  FIG. 7  is merely illustrative. Patch  90  may have a square shape in which all of the sides of patch  90  are the same length or may have a rectangular shape in which length L 1  is different from length L 2 . In general, patch  90  and ground  92  may have different shapes and orientations (e.g., planar shapes, curved patch shapes, patch element shapes with non-rectangular outlines, shapes with straight edges such as squares, shapes with curved edges such as ovals and circles, shapes with combinations of curved and straight edges, etc.). In scenarios where patch  90  is non-rectangular, patch  90  may have a side or a maximum lateral dimension (e.g., a longest side) that is approximately equal to (e.g., within 15% of) half of the wavelength of operation, for example. 
     Antennas  40  such as single-polarization patch antennas of the type shown in  FIG. 6  and/or dual-polarization patch antennas of the type shown in  FIG. 7  may be arranged within a corresponding phased antenna array  60  in device  10 . In general, it may be desirable for phased antenna array  60  to be able to provide coverage in multiple communications bands (e.g., bands between 10 GHz and 300 GHz) with a relatively uniform radiation pattern over all angles within the coverage area of array  60 . In one suitable arrangement, array  60  may provide coverage in a first communications band, a second communications band that includes higher frequencies than the first communications band, and/or a third millimeter band that includes higher frequencies than the second communications band. As examples, the first communications band (sometimes referred to herein as a low band or centimeter wave low band) may include frequencies from 27.5 GHz to 28.5 GHz, from 26 GHz to 30 GHz, from 20 to 36 GHz, or any other desired frequencies between 10 GHz and 300 GHz. The second communications band (sometimes referred to herein as a midband or millimeter wave midband) may include frequencies from 37 GHz to 41 GHz, from 36 GHz to 42 GHz, from 30 GHz to 56 GHz, or any other desired frequencies between 10 GHz and 300 GHz that are greater than the low band. The third communications band (sometimes referred to herein as a high band or millimeter wave high band) may include frequencies from 57 GHz to 71 GHz, from 58 GHz to 63 GHz, from 59 GHz to 61 GHz, from 42 GHz to 71 GHz, or any other desired frequencies between 10 GHz and 300 GHz that are greater than the midband. As one example, the low band and midband may include 5 th  generation mobile networks or 5 th  generation wireless systems (5G) communications bands whereas the high band includes IEEE 802.11ad communications bands. These examples are merely illustrative. 
     In order to provide coverage in multiple communications bands above 10 GHz, different antennas  40  having patch elements  90  of different sizes may be incorporated into the same phased antenna array  60 .  FIG. 8  is a top-down view of phased antenna array  60  showing how array  60  may be configured to perform multi-band millimeter and centimeter wave communications with a uniform radiation pattern. As shown in  FIG. 8 , phased antenna array  60  may include multiple sets of antennas  40  (e.g., a first set of antennas  40 A and a second set of antennas  40 B). Each antenna in the set of antennas  40 A (sometimes referred to herein as a group, sub-array, or ring of antennas  40 A) may be the same type of antenna having the same dimensions/shape (e.g., for covering the same frequencies). Similarly, each antenna in the second set of antennas  40 B (sometimes referred to herein as a group, sub-array, or ring of antennas  40 B) may be the same type of antenna having the same dimensions for covering the same frequencies. 
     As an example, each of antennas  40 A may be a single-polarization patch antenna of the type shown in  FIG. 6  or a dual-polarization patch antenna of the type shown in  FIG. 7 . Similarly, each of antennas  40 B may be a single-polarization patch antenna of the type shown in  FIG. 6  or a dual-polarization patch antenna of the type shown in  FIG. 7 . Each of antennas  40 A may include a corresponding patch antenna resonating element  90  such as patch antenna resonating element  90 A. Each of antennas  40 B may include a corresponding patch antenna resonating element  90  such as patch antenna resonating element  90 B. In one suitable arrangement, each of antennas  40 A and  40 B may include separate ground plane structures. In another suitable arrangement, each of antennas  40 A and  40 B may be formed using the same (common) antenna ground plane  92 . Patch elements  90 A and  90 B may be separated from ground plane  92  by a dielectric substrate, for example. 
     In order to provide coverage in multiple communications bands between 10 GHz and 300 GHz, each of antennas  40 A may provide coverage in a first communications band between 10 GHz and 300 GHz whereas each of antennas  40 B provides coverage in a second communications band between 10 GHz and 300 GHz. In the example of  FIG. 8 , antennas  40 B provide coverage in a millimeter wave communications band at higher frequencies than antennas  40 A. This is merely illustrative. If desired, antennas  40 B may provide coverage in a communications band at lower frequencies than antennas  40 A. 
     Patch antenna resonating elements  90 B of antennas  40 B may have sides of length V (e.g., a length V such as length L 0  of  FIG. 6 , length L 1  or L 2  of  FIG. 7 , a maximum lateral dimension V, etc.). Patch antenna resonating elements  90 A of antennas  40 A may have sides of length W (e.g., a length W such as length L 0  of  FIG. 6 , length L 1  or L 2  of  FIG. 7 , a maximum lateral dimension W, etc.). Because antennas  40 B are used to cover higher frequencies than antennas  40 A in the example of  FIG. 8 , dimension W may be greater than dimension V. As an example, dimension W may be approximately equal to twice length V (e.g., dimension W may be between 1.7 and 2.3 times length V, between 1.8 and 2.2 times length V, twice length V, etc.). 
     The length of sides W of elements  90 A may be approximately equal to half of the wavelength of operation of antennas  40 A and the lengths of sides V of elements  90 B may be approximately equal to half of the wavelength of operation of antennas  40 B in free space (i.e., in the absence of a dielectric substrate between ground plane  92  and elements  90 ). In practice, the lengths of sides W and V may be less than half of the corresponding wavelengths of operation by an offset that is dependent upon the dielectric constant of the substrate between ground plane  92  and elements  90 . As an example, in the absence of a dielectric substrate between ground plane  92  and elements  90 , when array  60  is configured to cover a first communications band from 27.5 GHz to 28.5 GHz and a second communications band from 57 GHz to 71 GHz, dimension W may be approximately equal to (e.g., within 15% of) 2.0-2.5 mm for covering the first communications band, whereas dimension V is approximately equal to 1.0-1.25 mm for covering the second communications band. In scenarios where a dielectric substrate having a dielectric constant of 3.0-3.5 is formed between ground plane  92  and elements  90 , dimension W may be approximately equal to 1.1-1.2 mm and dimension V may be approximately equal to 0.5-0.6 mm, for example. 
     In the example of  FIG. 8 , antenna resonating elements  90 A and  90 B are square, the sides of each element  90 A are parallel to corresponding sides of the other elements  90 A, the sides of each element  90 B are parallel to corresponding sides of the other elements  90 B, and the sides of each element  90 A are parallel to corresponding sides on each of elements  90 B. This is merely illustrative and, in other arrangements, antennas  40 A and  40 B may include patch antenna resonating elements  90  having any desired shapes and orientations (e.g., planar shapes, curved patch shapes, patch element shapes with non-rectangular outlines, shapes with straight edges such as squares, shapes with curved edges such as ovals having major axes with lengths W or V and circles having diameters with lengths W or V, shapes with combinations of curved and straight edges, polygonal shapes having side lengths of W or V or maximum lateral dimensions W or V, etc.). The sides of elements  90 A need not be parallel to corresponding sides on the other elements  90 A and the sides of elements  90 B need not be parallel to corresponding sides on the other elements  90 B, if desired. Similarly, the sides of elements  90 A need not be parallel to corresponding sides on elements  90 B, if desired. 
     In some scenarios, multiple separate phased antenna arrays are formed for covering different communications bands (i.e., antennas  40 A are formed in a separate array from antennas  40 B). However, separate phased antenna arrays may occupy an excessive amount of the limited space within device  10 . In order to reduce the amount of space required within device  10 , antennas  40 A and  40 B may be co-located within the same phased antenna array  60  (e.g., antennas  40 A and  40 B in array  60  may both combine to generate a single beam of wireless signals that is steered in a particular direction). 
     In some scenarios, antennas  40 A and  40 B are both arranged in a rectangular grid pattern within a single array. However, patterning antennas  40 A and  40 B in a rectangular grid pattern may cause the array to exhibit a non-uniform radiation pattern such that beam steering in some azimuthal directions results in a significantly higher gain than beam steering in other azimuthal directions (i.e., such that the array exhibits a radiation pattern such as a pattern associated with envelope  82  of  FIG. 5B ). In order to provide array  60  with a uniform antenna pattern envelope as the beam is steered over different azimuthal angles φ (e.g., as shown by pattern envelope  80  of  FIG. 5B ), antennas  40 A and  40 B may be arranged in a symmetric and non-rectangular pattern such as a pattern of one or more concentric rings. 
     As shown in  FIG. 8 , antennas  40 A and  40 B may be arranged within array  60  in a pattern of two concentric rings that are centered about a central axis such as axis  102  (sometimes referred to herein as center  102 , central point  102 , or center point  102 ). The first set of antennas  40 A may be arranged in a first ring around center axis  102  whereas the second set of antennas  40 B is arranged in a second ring around center axis  102 . The ring of antennas  40 A may surround the ring of antennas  40 B in array  60  (e.g., each antenna  40 B may be located closer to center point  102  than antennas  40 A). The ring of antennas  40 A may sometimes be referred to herein as an outer ring of antennas whereas the ring of antennas  40 B is sometimes referred to herein as an inner ring of antennas. 
     Each antenna  40 A in the outer ring may be located at a first distance D 1  with respect to center axis  102 . Each antenna  40 B in the inner ring may be located at a second distance D 2  with respect to center axis  102 . Second distance D 2  may be less than first distance D 1 . In order to optimize uniformity of the radiation pattern exhibited by array  60 , distance D 1  may approximately equal to the wavelength of operation of antennas  40 A (e.g., approximately equal to twice dimension W) whereas distance D 2  is approximately equal to the wavelength of operation of antennas  40 B (e.g., approximately equal to twice dimension V). 
     In the scenario where no dielectric substrate is formed between ground plane  92  and elements  90 , antennas  40 A cover a first band from 27.5 GHz to 28.5 GHz, and antennas  40 B cover a second band from 57 GHz to 71 GHz, distance D 1  may be approximately equal to (e.g., within 15% of, within 10% of, etc.) 2.0-2.5 mm whereas distance D 2  is approximately equal to 1.0-1.25 mm (e.g., distance D 1  may be approximately twice distance D 2  because the wavelength of operation of antennas  40 A and corresponding dimension W is approximately twice the wavelength of operation of antennas  40 B and corresponding dimension V, respectively). In scenarios where a dielectric substrate having a dielectric constant between 3.0 and 3.5 is formed between ground plane  92  and elements  90 , distance D 1  may be approximately equal to 1.1-1.2 mm and distance D 2  may be approximately equal to 0.5-0.6 mm, for example. 
     Array  60  may include a number N of antennas  40 A and a number M of antennas  40 B. In the example of  FIG. 8 , array  60  includes a total of twelve antennas  40  (e.g., six antennas  40 A and six antennas  40 B) arranged in two concentric hexagonal rings. Array  60  may include any desired number of antennas (e.g., sixteen antennas, fourteen antennas, between ten and fourteen antennas, between six and ten antennas, twenty-four antennas, between sixteen and twenty-four antennas, more than twenty-four antennas, etc.). In general, a greater number of antennas  40  may increase the overall gain of array  60  (but also the overall manufacturing and operating complexity of array  60 ) relative to scenarios where fewer antennas  40  are formed. The number N of antennas  40 A may be equal to the number M of antennas  40 B in array  60  or there may be more or fewer antennas  40 A than antennas  40 B in array  60  (e.g., N may be equal to, less than, or greater than M). 
     In order to further optimize the uniformity of the radiation pattern exhibited by array  60 , antennas  40 A and antennas  40 B may each be symmetrically (uniformly) arranged around center axis  102 . As shown in  FIG. 8 , each antenna  40 A in the outer ring may be angularly separated from the two adjacent antennas  40 A in the outer ring by angular separation A 1  about center axis  102 . Similarly, each antenna  40 B in the inner ring is angularly separated from the two adjacent antennas  40 B in the inner ring by angular separation A 2  about center axis A 1 . Each antenna  40 A may be separated from an opposing antenna  40 A in the outer ring by twice distance D 1  whereas each antenna  40 B is separated from an opposing antenna  40 B in the inner ring by twice distance D 2 . 
     Because antennas  40 A and  40 B are uniformly distributed across the outer ring and around point  102 , angle A 1  may be equal to 360 degrees divided by the number N of antennas  40 A in array  60 , whereas angle A 2  is equal to 360 degrees divided by the number M of antennas  40 B in array  60 . In scenarios where the number N of antennas  40 A equals the number M of antennas  40 B, angle A 1  is equal to angle A 2 . In the example of  FIG. 8  (where N and M are both equal to six), angle A 1  and angle A 2  are both equal to 60 degrees. This example is merely illustrative. If desired, antennas  40 A and/or antennas  40 B may be non-uniformly distributed about axis  102 . If desired, some antennas  40 A may be more closely grouped together about axis  102  than other antennas  40 A and/or some antennas  40 B may be more closely grouped together about axis  102  than other antennas  40 B. 
     If desired, antennas  40 B may be angularly offset with respect to antennas  40 A about axis  102 . As shown in  FIG. 8 , antennas  40 B are placed at locations that are offset by angle A 3  about axis  102  with respect to the locations of antennas  40 A (e.g., a radial line drawn from point  102  to a given antenna  40 A is angularly offset from a radial line drawn from point  102  to an adjacent antenna  40 B by angle A 3  about point  102 ). As an example, angle A 3  may be approximately equal to half of angle A 1  and A 2  (e.g., each antennas  40 B in the inner ring is angularly located approximately half way between adjacent antennas  40 A in the outer ring about point  102 ). In the example of  FIG. 8 , angle A 3  is approximately equal to 30 degrees (i.e., half of angle A 2  and angle A 1 ). This is merely illustrative and, in general, angle A 3  may be equal to any desired value between 0 degrees (e.g., in scenarios where antennas  40 A are each aligned with a corresponding antenna  40 B about point  102 ) and angle A 1  (e.g., between 20 and 40 degrees, between 25 and 35 degrees, etc.). 
     In other words, antennas  40 A in the outer ring may be located at a first set of angles around point  102  (e.g., at 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees with respect to the Y-axis of  FIG. 8 ), where each angle in the first set is separated from the next and previous angles in the first set by angle A 1 . Similarly, antenna  40 B in the inner ring may be located at a second set of angles around point  102  (e.g., at 30 degrees, 90 degrees, 150 degrees, 210 degrees, 270, and 330 degrees with respect to the Y-axis), where each angle in the second set is separated from the next and previous angles in the second set by angle A 2 . The first set of angles may be offset with respect to the second set of angles by offset A 3 . 
     In the example of  FIG. 8 , the center of each antenna  40 A (e.g., the center of patch  90 A) is shown as being located at distance D 1  from center axis  102  and at angle A 1  about axis  102  from the center of the adjacent antennas  40 A. Similarly, the center of each antenna  40 B (e.g., patch  90 B) is shown as being located at distance D 2  from center axis  102  and at angle A 2  about axis  102  from the center of the adjacent antennas  40 B. This is merely illustrative. In general, any desired point within the outline or on the edges of patches  90 A may be located at distance D 1  from center axis  102  and at angle A 1  about axis  102  from any desired point within the outline or on the edges of patch  90 A in the adjacent antennas  40 A. Similarly, any desired point within the outline or on the edges of patch  90 B on each antenna  40 B may be located at distance D 2  from center axis  102  and at angle A 2  about axis  102  from any desired point within the outline or on the edges of patch  90 B in the adjacent antennas  40 B. In one suitable arrangement (e.g., as shown in  FIG. 8 ), antennas  40 B are arranged in a circular ring in which antennas  40 B are located at distance D 2  from point  102  and antennas  40 A are arranged in a circular ring in which antennas  40 A are located at distance D 1  from point  102 . In this arrangement, D 1  and D 2  may be selected in such a way that each of the antennas  40 A are located at approximately half of the wavelength of operation of antennas  40 A from the two adjacent antennas  40 A in the outer ring and that each of the antennas  40 B are located at approximately half of the wavelength of operation of antennas  40 B from the two adjacent antennas  40 B in the inner ring. 
     The example of  FIG. 8  in which the outer ring of antennas  40 A and the inner ring of antennas  40 B are both circular is merely illustrative. If desired, the outer ring of antennas  40 A and/or the inner ring of antennas  40 B may be arranged in elliptical or other polygonal ring shapes. If desired, two or more antennas  40 A may be located at different distances from center axis  102 . Two or more antennas  40 B may be located at different distances from center axis  102  if desired. 
     When arranged in this manner, phased antenna array  60  may cover two different communications bands between 10 GHz and 300 GHz while exhibiting a uniform radiation pattern such as radiation pattern  80  of  FIGS. 5A and 5B . This may allow beam steering circuitry  70  ( FIG. 4 ) to steer the beam of wireless signals for array  60  within one or both of the two communications bands between 10 GHz and 300 GHz and in any desired direction with a relatively constant gain (e.g., within 10% regardless of the direction of the beam). By co-locating lower frequency antennas  40 A and higher frequency antennas  40 B within the same phased antenna array  60 , the antennas may occupy as much as half the space within device  10  relative to scenarios where antennas  40 A and  40 B are formed in separate arrays. 
     In some scenarios, it may be desirable to be able to cover a third communications band between 10 GHz and 300 GHz using array  60  such as a millimeter wave band from 37 GHz to 41 GHz. However, in practice, antennas  40 A in the outer ring may not have sufficient bandwidth for covering both a first communications band (e.g., a first communications band from 27.5 GHz to 28.5 GHz) and the third communications band from 37 GHz to 41 GHz. If desired, array  60  may include a third set of antennas  40 C for covering the third communications band. 
       FIG. 9  is a cross-sectional side view of phased antenna array  60  showing how a third set of antennas  40 C may be formed in array  60  for covering the third communications band. As shown in  FIG. 9 , phased antenna array  60  may be formed on a dielectric substrate such as substrate  120 . Substrate  120  may be, for example, a rigid or printed circuit board or other dielectric substrate. Substrate  120  may include multiple dielectric layers  122  (e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy) such as a first dielectric layer  122 - 1 , a second dielectric layer  122 - 2  over the first dielectric layer, a third dielectric layer  122 - 3  over the second dielectric layer, and a fourth dielectric layer  122 - 4  over the third dielectric layer. Additional dielectric layers  122  may be stacked within substrate  120  if desired. 
     With this type of arrangement, antenna  40 A may be embedded within the layers of substrate  120 . For example, ground plane  92  may be formed on a surface of second layer  122 - 2  whereas patch  90 A of antenna  40 A is formed on a surface of third layer  122 - 3 . Antenna  40 A may be fed using a first transmission line  64 A and a first antenna feed having positive antenna feed terminal  96 A coupled to patch  90 A and a ground antenna feed terminal coupled to ground plane  92 . First transmission line  64 A may, for example, be formed from a conductive trace such as conductive trace  126 A on a surface of first layer  122 - 1  and portions of ground layer  92 . Conductive trace  126 A may form the positive signal conductor for transmission line  64 A, for example. A first hole or opening  128 A may be formed in ground layer  92 . First transmission line  64 A may include a vertical conductor  124 A (e.g., a conductive through-via) that extends from trace  126 A through layer  122 - 2 , opening  128 A in ground layer  92 , and layer  122 - 3  to antenna feed terminal  96 A on patch element  90 A. 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.). 
     As shown in  FIG. 9 , dielectric layer  122 - 4  may be formed over patch  90 A. An additional patch antenna such as patch antenna  40 C may be formed using patch antenna resonating element  90 C and ground layer  92 . Patch antenna resonating element  90 C may be formed from a conductive trace patterned onto a surface of layer  122 - 4 . Antenna  40 C may be fed using a second transmission line  64 C and a second antenna feed having a positive antenna feed terminal  96 C coupled to patch  90 C and a ground antenna feed terminal coupled to ground  92 . Second transmission line  64 C may, for example, be formed from a conductive trace such as conductive trace  126 C on the surface of first layer  122 - 1  and portions of ground layer  92 . A second hole or opening  128 C may be formed in ground layer  92 . A hole or opening  130  may be formed in patch  90 A. Second transmission line  64 C may include a vertical conductor  124 C (e.g., a conductive through-via) that extends from trace  126 C through layer  122 - 2 , opening  128 C, layer  122 - 3 , opening  130 , and layer  122 - 4  to antenna feed terminal  96 C on patch element  90 C. 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.). 
     Patch element  90 C may have a width W′. As examples, patch element  90 C may be a rectangular patch (e.g., as shown in  FIGS. 6 and 7 ) having a side of length W′, a square patch having sides of length W′, a circular patch having diameter W′, an elliptical patch having a major axis length W′, or may have any other desired shape (e.g., where length W′ is the maximum lateral dimension of the patch). Dimension W′ of patch element  90 C may be less than dimension W of patches  90 A and greater than dimension V of patches  90 B. This may allow antenna  40 A to transmit and receive wireless signals at frequencies between 10 GHz and 300 GHz with external equipment without being blocked by element  90 ′, for example. 
     The size of dimension W′ may be selected so that antenna  40 C resonates at a desired operating frequency. For example, dimension W′ may be approximately equal to half of the wavelength (e.g., within 15% of half of the wavelength) of the signals conveyed by antenna  40 C or less than this by a factor determined by the dielectric constant of substrate  122 . In the scenario where antennas  40 A cover a first frequency band from 27.5 GHz to 28.5 GHz, antennas  40 B cover a millimeter wave frequency band from 57 GHz to 71 GHz, and antennas  40 C cover a millimeter wave frequency band from 37 GHz to 41 GHz, dimension W′ may be between 0.6 mm and 2.0 mm, for example. 
     In the example of  FIG. 9 , antennas  40 A and  40 C are shown as having only a single polarization (feed). If desired, antennas  40 A and/or  40 C may be dual-polarized patch antennas having two feeds (e.g., as shown in  FIG. 7 ). In this scenario, additional holes may be formed in ground layer  92  and/or patch  90 A to accommodate the additional feeds. 
     Antennas  40 C for covering the third frequency band (e.g., from 37 GHz to 41 GHz) may be distributed throughout array  60  in any desired fashion. For example, antennas  40 C may be formed over one, some, or all of antennas  40 A in array  60  ( FIG. 8 ). Co-locating antennas  40 C with antennas  40 A may reduce the overall space required within device  10  relative to scenarios where antennas  40 C are formed within a separate phased antenna array. One or more antennas  40 C may be formed separately from antennas  40 A if desired (e.g., a third ring of antennas  40 C may be formed in array  60  between the ring of antennas  40 A and the ring of antennas  40 B or antennas  40 C may be formed at any other desired locations within array  60 ). 
     The example of  FIG. 9  is merely illustrative. If desired, additional layers  122  may be interposed between trace  126 C and ground  92 , between ground  92  and patch  90 A, and/or between patch  90 A and patch  90 C. In another suitable arrangement, substrate  120  is formed from a single dielectric layer (e.g., antennas  40 A and  40 C may be embedded within a single dielectric layer such as a molded plastic layer). In yet another suitable arrangement, substrate  120  may be omitted and antennas  40 A and  40 C may be formed on other substrate structures or may be formed without substrates. 
     In practice, antennas  40 B may have insufficient bandwidth for covering an entirety of the millimeter wave communications band from 57 GHz to 71 GHz. If desired, antennas  40 B may include parasitic antenna resonating elements that serve to broaden the bandwidth of antennas  40 B. 
       FIG. 10  is a cross-sectional side view of phased antenna array  60  showing how antennas  40 B may be provided with parasitic antenna resonating elements. As shown in  FIG. 10 , antenna  40 B may be embedded within the layers of substrate  120 . For example, ground plane  92  may be formed on a surface of second layer  122 - 2  whereas patch  90 B of antenna  40 B is formed on a surface of third layer  122 - 3 . Antenna  40 B may be fed using a transmission line  64 B and an antenna feed that includes positive antenna feed terminal  96 B coupled to patch  90 B and a ground antenna feed terminal coupled to ground plane  92 . Transmission line  64 B may, for example, be formed from a conductive trace such as conductive trace  126 B on a surface of first layer  122 - 1  and portions of ground layer  92 . Conductive trace  126 B may form the positive signal conductor for transmission line  64 B, for example. A hole or opening  128 B may be formed in ground layer  92 . Transmission line  64 B may include a vertical conductor  124 B (e.g., a conductive through-via) that extends from trace  126 B through layer  122 - 2 , opening  128 B in ground layer  92 , and  122 - 3  to feed terminal  96 B on patch element  90 B. 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.). 
     As shown in  FIG. 10 , dielectric layer  122 - 4  may be formed over patch  90 B. A parasitic antenna resonating element such as element  140  may be formed from conductive traces on a surface of layer  122 - 4 . Parasitic antenna resonating element  140  may sometimes be referred to herein as parasitic resonating element  140 , parasitic antenna element  140 , parasitic element  140 , parasitic patch  140 , parasitic conductor  140 , parasitic structure  140 , or patch  140 . Parasitic element  140  is not directly fed, whereas patch antenna resonating element  90 B is directly fed via transmission line  64 B and feed terminal  96 B. Parasitic element  140  may create a constructive perturbation of the electromagnetic field generated by patch antenna resonating element  90 B, creating a new resonance for antenna  40 B. This may serve to broaden the overall bandwidth of antenna  40 B (e.g., to cover the entire millimeter wave frequency band from 57 GHz to 71 GHz). 
     Parasitic element  140  may have the same width V as patch  90 B. As examples, parasitic element  140  may be a rectangular patch having a side of length V, a square patch having sides of length V, a cross-shaped patch having a maximum lateral dimension V, a circular patch having diameter V, an elliptical patch having a major axis of length V, or may have any other desired shape (e.g., where length V is the maximum lateral dimension of the parasitic element). 
     Parasitic elements  140  may be formed over one, some, or all of antennas  40 B in array  60  ( FIG. 8 ) to broaden the bandwidth of the corresponding antennas  40 B and thus array  60 . The example of  FIG. 10  is merely illustrative. If desired, additional layers  122  may be interposed between trace  126 B and ground  92 , between ground  92  and patch  90 B, and/or between patch  90 B and parasitic element  140 . In the example of  FIG. 10 , antenna  40 B is shown as having only a single polarization (feed). If desired, antenna  40 B may be a dual-polarized patch antenna having two feeds (e.g., as shown in  FIG. 7 ). 
       FIG. 11  is a top-down view of antenna  40 B having parasitic antenna resonating element  140  and two feeds for covering two orthogonal polarizations. As shown in  FIG. 10 , antenna  40 B may have a first feed at antenna port P 1  that is coupled to a first transmission line  64 B-P 1  and a second feed at antenna port P 2  that is coupled to a second transmission line  64 B-P 2 . The first antenna feed may have a first ground feed terminal coupled to ground  92  and a first positive feed terminal  96 B-P 1  coupled to patch antenna resonating element  90 B at a first location. The second antenna feed may have a second ground feed terminal coupled to ground  92  and a second positive feed terminal  96 B-P 2  coupled to patch antenna resonating element  90 B at a second location. 
     Parasitic resonating element  140  may be formed over patch  90 B. At least some or an entirety of parasitic resonating element  140  may overlap patch  90 B. In the example of  FIG. 11 , parasitic resonating element  140  has the same width V as patch  90 B. If desired, parasitic element  140  may have a width that is less than width V. If desired, parasitic resonating element  140  may have a cross or “X” shape. As shown in  FIG. 11 , notches or slots  144  may be formed in patch  140  (e.g., by removing conductive material from the corners of a square patch having width V) to create a cross-shaped (X-shaped) parasitic resonating element  140 . Cross-shaped parasitic resonating element  140  may include a first arm  150  that opposes a second arm  152  and a third arm  146  that opposes a fourth arm  148  (e.g., the distance from the end of arm  146  to the end of arm  148  and the distance from the end of arm  150  to the end of arm  152  may each be approximately equal to dimension V). Arm  146  may extend in parallel with arm  148  from opposing sides of the center of patch  140 . Arm  150  may extend in parallel with arm  152  from opposing sides of the center of patch  140 . In the example of  FIG. 11 , arms  146  and  148  each extend perpendicular to arms  150  and  152 . 
     In a single-polarization patch antenna, the distance between the positive antenna feed terminal  96  and the edge of patch  90  may be adjusted to ensure that there is a satisfactory impedance match between patch  90  and transmission line  64 . However, such impedance adjustments may not be possible when the antenna is a dual-polarized patch antenna having two feeds. Removing conductive material from parasitic resonating element  140  to form notches  144  may serve to adjust the impedance of patch  90 B so that the impedance of patch  90 B is matched to both transmission lines  64 B-P 1  and  64 B-P 2 , for example. Notches  144  may therefore sometimes be referred to herein as impedance matching notches, impedance matching slots, or impedance matching structures. 
     The dimensions of impedance matching notches  144  may be adjusted (e.g., during manufacture of device  10 ) to ensure that antenna  40 B is sufficiently matched to both transmission lines  64 B-P 1  and  64 B-P 2  and to tweak the overall bandwidth of antenna  40 B. As an example, notches  144  may have sides with lengths that are equal to between 1% and 40% of dimension V. In order for antenna  40 B to be sufficiently matched to transmission lines  64 B-P 1  and  64 B-P 2 , feed terminals  96 B-P 1  need to overlap with the conductive material of parasitic element  140 . Notches  144  may therefore be suitably small so as not to uncover feed terminals  96 B-P 1  or  96 B-P 2 . In other words, each of antenna feed terminals  96 B-P 1  and  96 B-P 2  may overlap with a respective arm of the cross-shaped parasitic antenna resonating element  140 . During wireless communications using device  10 , device  10  may use ports P 1  and P 2  to transmit and/or receive signals with two orthogonal linear polarizations. The example of  FIG. 11  is merely illustrative. If desired, patch antenna resonating element  140  may have other shapes or orientations. 
       FIG. 12  is graph in which antenna efficiency has been plotted as a function of operating frequency F for antenna  40 B of  FIG. 11 . As shown in  FIG. 12 , efficiency curve  160  illustrates the antenna efficiency of patch  90 B when operated in the absence of parasitic element  140 . Curve  160  may have a peak at frequency F 0  and a corresponding bandwidth  164 . Bandwidth  164  may be too narrow to cover the entirety of the millimeter wave communications band of interest (e.g., an entire communication band from 57 GHz to 71 GHz). 
     Efficiency curve  162  illustrates the antenna efficiency of parasitic element  140 . Curve  162  may have a peak at frequency F 0 −ΔF that is offset from frequency F 0  by offset value ΔF. Efficiency curve  162  illustrates the antenna efficiency of patch  90 B combined with the field perturbation provided by parasitic element  140 . As shown in  FIG. 12 , the antenna efficiency of antenna  40 B may include contributions from both patch  90 B and parasitic  140  such that antenna  40 B exhibits an extended bandwidth  166  that is greater than bandwidth  164  of patch  90 B in the absence of parasitic  140 . Bandwidth  164  may extend between a lower threshold frequency F L  (e.g., 57 GHz) to an upper threshold frequency F H  (e.g., 71 GHz) that define the communications band of interest (e.g., the millimeter wave communications band from 57 GHz to 71 GHz). In this way, antenna  40 B may provide coverage for the entirety of the communications band from 57 GHz to 71 GHz (e.g., for performing IEEE 802.11ad communications). 
     When antennas  40 A having co-located antennas  40 C are formed in the same array as antennas  40 B having parasitic elements  140  (e.g., as shown in  FIG. 8 ), array  60  may cover first, second, and third different communications bands between 10 GHz and 300 GHz. Control circuitry  14  may control array  60  to steer the beam of signals (e.g., millimeter wave and centimeter wave signals in one, two, or each of the first, second, and third communications bands) in a desired direction. For example, when circuitry  70  of  FIG. 4  is provided with a first set of phase and amplitude settings, the multi-band beam of signals may be pointed in a first direction. When circuitry  70  is provided with a second set of phase and amplitude settings, the multi-band beam of signals may be pointed in a second direction that is different from the first direction. Array  60  may exhibit a relatively uniform radiation pattern regardless of the direction in which the beam is steered (e.g., as shown by pattern  80  of  FIG. 5B ). 
       FIG. 13  is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency F for phased antenna array  60 . As shown in  FIG. 13 , efficiency curve  170  shows the overall antenna efficiency of array  60  (e.g., including contributions from each of antennas  40 A,  40 B, and  40 C). Efficiency curve  170  may exhibit a first peak in a first communications band BI between frequencies FA and FB due to the contribution of antennas  40 A. Efficiency curve  170  may exhibit a second peak in a second communications band BII between frequencies FC and FD due to the contribution of antennas  40 C. Efficiency curve  170  may exhibit a third peak in a third communications band BIII between frequencies FE and FF due to the contribution of antennas  40 B (e.g., the contribution of patches  90 B and corresponding parasitic resonating elements  140 ). In one suitable example, frequency FA is 27.5 GHz, frequency FB is 28.5 GHz, frequency FC is 37 GHz, frequency FD is 41 GHz, frequency FE is 57 GHz, and frequency FF is 71 GHz. This is merely illustrative and, in general, bands BI, BII, and BIII may be any desired millimeter wave or centimeter wave communications bands and frequencies FA through FF may be any desired frequencies between 10 GHz and 300 GHz (e.g., where frequency FA is less than frequency FB, frequency FB is less than frequency FC, frequency FC is less than frequency FD, frequency FD is less than frequency FE, and frequency FE is less than frequency FF). In this way, array  60  may cover multiple frequency bands greater than 10 GHz while exhibiting a uniform gain regardless of the direction in which the array is steered and without occupying as much space within device  10  as when different arrays are formed for covering different frequencies, for example. 
     The example of  FIG. 13  is merely illustrative. In general, curve  170  may have any desired shape (e.g., as determined by the arrangement of array  60  and the antenna elements therein). If desired, control circuitry  14  may perform simultaneous communications in band BI, band BII, and/or band BIII using array  60  at any given time. If desired, antennas  40 A, antennas  40 B, and/or antennas  40 C may be omitted from array  60 . For example, in scenarios where the ring of antennas  40 A are omitted, array  60  may only cover bands BII and BIII (e.g., using concentric rings of antennas  40 B and  40 C). In scenarios where antennas  40 B are omitted, array  60  may cover bands BI and BII (e.g., using co-located antennas  40 A and  40 C or using two concentric rings of antennas  40 A and  40 C). In scenarios where antennas  40 C are omitted, array  60  may cover bands BI and BIII (e.g., using concentric rings of antennas  40 A and  40 B). In scenarios where antennas  40 A and  40 C are omitted, array  60  may only cover band BIII (e.g., using a single ring of symmetrically distributed antennas  40 B). In scenarios where antennas  40 B and  40 C are omitted, array  60  may only cover band BI (e.g., using a single ring of symmetrically distributed antennas  40 A). In scenarios where antennas  40 A and  40 B are omitted, array  60  may only cover band BII (e.g., using a single ring of symmetrically distributed antennas  40 B). Other arrangements may be used if desired. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20170714
Publication Date: 20200519
Grant Date: 20200519
Priority Date: 20170714
Inventors: PAULOTTO, Simone
NOORI, BASIM H.
MOW, MATTHEW A.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/392", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/24", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q5/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/24", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/392", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/065", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0485", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/392", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0435", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 62976289