Multi-band millimeter wave patch antennas

An electronic device may be provided with wireless circuitry including first and second patch antennas. The first patch antenna may include a first resonating element formed over a ground plane. The second patch antenna may include a second resonating element over the first resonating element. A cross-shaped parasitic element may be formed over the second resonating element. First and second feed terminals may be coupled to the second resonating element. An opening may be formed in the first resonating element. First and second transmission lines may be coupled to the first and second feed terminals through the opening. The cross-shaped parasitic element may include arms that overlap the first and second feed terminals. The first resonating element may cover first frequencies between 10 GHz and 300 GHz and the second resonating element may cover second frequencies that are higher than the first frequencies.

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 antenna structures and transceiver circuitry such as millimeter wave transceiver circuitry. Antenna structures in the wireless circuitry may include co-located patch antennas that are organized in a phased antenna array.

The antenna structures may include a first patch antenna and a second patch antenna formed on a dielectric substrate. The dielectric substrate may include multiple dielectric layers. A ground plane may be formed on a first dielectric layer. The first patch antenna may include a first patch antenna resonating element formed from metal traces on a second dielectric layer. The second patch antenna may include a second patch antenna resonating element over the first patch antenna resonating element. The second patch antenna resonating element may be formed from metal traces on a third dielectric layer. A cross-shaped parasitic antenna resonating element may be formed over the second patch antenna resonating element and on a fourth dielectric layer.

The first patch antenna may be fed using a first transmission line coupled to a first feed terminal and a second transmission line coupled to a second feed terminal on the first patch antenna resonating element. Third and fourth feed terminals may be coupled to the second patch antenna resonating element. An opening such as a cross-shaped opening may be formed in the first patch antenna resonating element and may be configured to enhance isolation between the first and second feed terminals on the first patch antenna resonating element. The second patch antenna may be fed using third and fourth transmission lines coupled to the third and fourth feed terminals through the opening in the first patch antenna resonating element.

The cross-shaped parasitic antenna resonating element may have a first conductive arm that extends along a first longitudinal axis and a second conductive arm that extends along the second longitudinal axis that is oriented at a non-parallel angle with respect to the first longitudinal axis. The first conductive arm may overlap the third feed terminal and the second conductive arm may overlap the fourth feed terminal on the second patch antenna resonating element. The arms of the cross-shaped parasitic antenna resonating element and the cross-shaped opening in the first patch antenna resonating element may be oriented at parallel angles with respect to the edges of the second patch antenna resonating element.

The first patch antenna may convey antenna signals (e.g., centimeter wave signals) in a first frequency band such as a frequency band between 27.5 GHz and 28.5 GHz. The second patch antenna may convey antenna signals (e.g., millimeter wave signals) in a second frequency band such as a frequency band between 57 GHz and 71 GHz. Forming the second patch antenna resonating element over the first patch antenna resonating element may minimize the amount of space required for covering the first and second frequency bands within the electronic device.

DETAILED DESCRIPTION

An electronic device such as electronic device10ofFIG. 1may 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, device10may 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 device10may 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'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 ofFIG. 1, device10is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device10if desired. The example ofFIG. 1is merely illustrative.

As shown inFIG. 1, device10may include a display such as display14. Display14may be mounted in a housing such as housing12. Housing12, 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. Housing12may be formed using a unibody configuration in which some or all of housing12is 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.).

Display14may 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.

Display14may 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.

Display14may 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 housing12to form communications ports (e.g., an audio jack port, a digital data port, charging port, etc.). Openings in housing12may also be formed for audio components such as a speaker and/or a microphone.

Antennas may be mounted in housing12. 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 display14(see, e.g., illustrative antenna locations50ofFIG. 1). Display14may contain an active area with an array of pixels (e.g., a central rectangular portion). Inactive areas of display14are free of pixels and may form borders for the active area. If desired, antennas may also operate through dielectric-filled openings in the rear of housing12or elsewhere in device10.

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 housing12. 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 housing12, blockage by a user's hand or other external object, or other environmental factors. Device10can 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 housing12(e.g., in corner locations50ofFIG. 1and/or in corner locations on the rear of housing12), along the peripheral edges of housing12, on the rear of housing12, under the display cover glass or other dielectric display cover layer that is used in covering and protecting display14on the front of device10, under a dielectric window on a rear face of housing12or the edge of housing12, or elsewhere in device10.

A schematic diagram showing illustrative components that may be used in device10is shown inFIG. 2. As shown inFIG. 2, device10may include storage and processing circuitry such as control circuitry14. Control circuitry14may 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 circuitry14may be used to control the operation of device10. 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 circuitry14may be used to run software on device10, 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 circuitry14may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry14include 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.

Device10may include input-output circuitry16. Input-output circuitry16may include input-output devices18. Input-output devices18may be used to allow data to be supplied to device10and to allow data to be provided from device10to external devices. Input-output devices18may 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 circuitry16may include wireless communications circuitry34for communicating wirelessly with external equipment. Wireless communications circuitry34may 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 antennas40, transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications).

Transceiver circuitry24may be wireless local area network (WLAN) transceiver circuitry. Transceiver circuitry24may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band.

Circuitry34may use cellular telephone transceiver circuitry26for 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). Circuitry26may handle voice data and non-voice data.

Millimeter wave transceiver circuitry28(sometimes referred to as extremely high frequency (EHF) transceiver circuitry28or transceiver circuitry28) may support communications at frequencies between about 10 GHz and 300 GHz. For example, transceiver circuitry28may 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 circuitry28may support communications in an IEEE K communications band between about 18 GHz and 27 GHz, a Kacommunications band between about 26.5 GHz and 40 GHz, a Kucommunications 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, circuitry28may support IEEE 802.11ad communications at 60 GHz and/or 5thgeneration mobile networks or 5thgeneration wireless systems (5G) communications bands between 27 GHz and 90 GHz. If desired, circuitry28may 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. Circuitry28may 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 circuitry28is sometimes referred to herein as millimeter wave transceiver circuitry28, millimeter wave transceiver circuitry28may 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 circuitry34may include satellite navigation system circuitry such as Global Positioning System (GPS) receiver circuitry22for 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 receiver22are 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 circuitry28may 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 device10can be switched out of use and higher-performing antennas used in their place.

Wireless communications circuitry34can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry34may include circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc.

Antennas40in wireless communications circuitry34may be formed using any suitable antenna types. For example, antennas40may 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 antennas40may 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, antennas40can 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). Antennas40can one or more antennas such as antennas arranged in one or more phased antenna arrays for handling millimeter and centimeter wave communications.

Transmission line paths may be used to route antenna signals within device10. For example, transmission line paths may be used to couple antenna structures40to transceiver circuitry20. Transmission lines in device10may 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.

In devices such as handheld devices, the presence of an external object such as the hand of a user or a table or other surface on which a device is resting has a potential to block wireless signals such as millimeter wave signals. Accordingly, it may be desirable to incorporate multiple antennas or phased antenna arrays into device10, each of which is placed in a different location within device10. With this type of arrangement, an unblocked antenna or phased antenna array may be switched into use. In scenarios where a phased antenna array is formed in device10, 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 device10are operated together may also be used.

FIG. 3is a perspective view of electronic device10showing illustrative locations50on the rear of housing12in which antennas40(e.g., single antennas and/or phased antenna arrays for use with wireless circuitry34such as wireless transceiver circuitry28) may be mounted in device10. Antennas40may be mounted at the corners of device10, along the edges of housing12such as edge12E, on upper and lower portions of rear housing portion (wall)12R, in the center of rear housing wall12R (e.g., under a dielectric window structure or other antenna window in the center of rear housing12R), at the corners of rear housing wall12R (e.g., on the upper left corner, upper right corner, lower left corner, and lower right corner of the rear of housing12and device10), etc.

In configurations in which housing12is formed entirely or nearly entirely from a dielectric, antennas40may transmit and receive antenna signals through any suitable portion of the dielectric. In configurations in which housing12is 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. Antennas40may 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 antennas40mounted within the interior of device10and may allow internal antennas40to receive antenna signals from external equipment. In another suitable arrangement, antennas40may be mounted on the exterior of conductive portions of housing12.

In devices with phased antenna arrays, circuitry34may include gain and phase adjustment circuitry that is used in adjusting the signals associated with each antenna40in an array (e.g., to perform beam steering). Switching circuitry may be used to switch desired antennas40into and out of use. Each of locations50may include multiple antennas40(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 locations50may be used in transmitting and receiving signals while using one or more antennas from another of locations50in transmitting and receiving signals.

A schematic diagram of an antenna40coupled to transceiver circuitry20(e.g., transceiver circuitry28) is shown inFIG. 4. As shown inFIG. 4, radio-frequency transceiver circuitry20may be coupled to antenna feed100of antenna40using transmission line64. Antenna feed100may include a positive antenna feed terminal such as positive antenna feed terminal96and may have a ground antenna feed terminal such as ground antenna feed terminal98. Transmission line64may be formed form metal traces on a printed circuit or other conductive structures and may have a positive transmission line signal path such as path91that is coupled to terminal96and a ground transmission line signal path such as path94that is coupled to terminal98. Transmission line paths such as path64may be used to route antenna signals within device10. For example, transmission line paths may be used to couple antenna structures such as one or more antennas in an array of antennas to transceiver circuitry20. Transmission lines in device10may 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 transmission line64and/or circuits such as these may be incorporated into antenna40if desired (e.g., to support antenna tuning, to support operation in desired frequency bands, etc.).

Device10may contain multiple antennas40. 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 circuitry14may be used to select an optimum antenna to use in device10in real time and/or to select an optimum setting for adjustable wireless circuitry associated with one or more of antennas40. 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 antennas40to gather sensor data in real time that is used in adjusting antennas40.

In some configurations, antennas40may be arranged in one or more 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 wireless transceiver circuits28may be implemented as phased antenna arrays. The radiating elements in a phased antenna array for supporting millimeter and centimeter wave communications may be patch antennas, dipole antennas, dipole antennas with directors and reflectors in addition to dipole antenna resonating elements (sometimes referred to as Yagi antennas or beam antennas), or other suitable antenna elements. Transceiver circuitry can be integrated with the phased antenna arrays to form integrated phased antenna array and transceiver circuit modules.

An illustrative patch antenna is shown inFIG. 5. As shown inFIG. 5, patch antenna40may have a patch antenna resonating element104that is separated from and parallel to a ground plane such as antenna ground plane92. Positive antenna feed terminal96may be coupled to patch antenna resonating element104. Ground antenna feed terminal98may be coupled to ground plane92. If desired, conductive path88may be used to couple terminal96′ to terminal96so that antenna40is fed using a transmission line with a positive conductor coupled to terminal96′ and thus terminal96. If desired, path88may be omitted. Other types of antenna feed arrangements may be used if desired. The illustrative feeding configuration ofFIG. 5is merely illustrative.

As shown inFIG. 5, patch antenna resonating element104may lie within a plane such as the X-Y plane ofFIG. 5(e.g., the lateral surface area of element104may lie in the X-Y plane). Patch antenna resonating element104may sometimes be referred to herein as patch104, patch element104, patch resonating element104, or resonating element104. Ground92may line within a plane that is parallel to the plane of patch104. Patch104and ground92may therefore lie in separate parallel planes that are separated by a distance H. Patch104and ground92may be formed from conductive traces patterned on a dielectric substrate such as a rigid or flexible printed circuit board substrate, metal foil, stamped sheet metal, electronic device housing structures, or any other desired conductive structures. The length of the sides of patch104may be selected so that antenna40resonates at a desired operating frequency. For example, the sides of element104may each have a length L0that is approximately equal to half of the wavelength (e.g., within 15% of half of the wavelength) of the signals conveyed by antenna40(e.g., in scenarios where patch element104is substantially square).

The example ofFIG. 5is merely illustrative. Patch104may have a square shape in which all of the sides of patch104are the same length or may have a different rectangular shape. If desired, patch104and ground92may have different shapes and orientations (e.g., planar shapes, curved patch shapes, patch 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 patch104is non-rectangular, patch104may 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 antenna40, antenna40may be provided with multiple feeds. An illustrative patch antenna with multiple feeds is shown inFIG. 6. As shown inFIG. 6, antenna40may have a first feed at antenna port P1that is coupled to transmission line64-1and a second feed at antenna port P2that is coupled to transmission line64-2. The first antenna feed may have a first ground feed terminal coupled to ground92and a first positive feed terminal96-P1coupled to patch104. The second antenna feed may have a second ground feed terminal coupled to ground92and a second positive feed terminal96-P2on patch104.

Patch104may 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, for example. The length of patch104in dimension Y is L1and the length of patch104in dimension X is L2. With this configuration, antenna40may be characterized by orthogonal polarizations.

When using the first antenna feed associated with port P1, antenna40may 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 L1). These signals may have a first polarization (e.g., the electric field E1of antenna signals102associated with port P1may be oriented parallel to dimension Y). When using the antenna feed associated with port P2, antenna40may 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 L2). These signals may have a second polarization (e.g., the electric field E2of antenna signals102associated with port P2may be oriented parallel to dimension X so that the polarizations associated with ports P1and P2are orthogonal to each other). In scenarios where patch104is square (e.g., length L1is equal to length L2), ports P1and P2may cover the same communications band. In scenarios where patch104is rectangular, ports P1and P2may cover different communications bands if desired. During wireless communications using device10, device10may use port P1, port P2, or both port P1and P2to transmit and/or receive signals (e.g., millimeter wave signals).

The example ofFIG. 6is merely illustrative. Patch104may have a square shape in which all of the sides of patch104are the same length or may have a rectangular shape in which length L1is different from length L2. In general, patch104and ground92may 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 patch104is non-rectangular, patch104may 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.

Antennas40such as single-polarization patch antennas of the type shown inFIG. 5and/or dual-polarization patch antennas of the type shown inFIG. 6may be arranged within a corresponding phased antenna array in device10if desired. In practice, it may be desirable for antennas40within device10to be able to provide coverage in multiple communications bands between 10 GHz and 300 GHz. In one suitable arrangement, a first antenna40may provide coverage in a first communications band between 10 GHz and 300 GHz whereas a second antenna40provides coverage in a second communications band between 10 GHz and 300 GHz. As examples, the communications bands may include millimeter and/or centimeter wave frequencies from 27.5 GHz to 28.5 GHz, from 26 GHz to 30 GHz, from 20 to 36 GHz, from 37 GHz to 41 GHz, from 36 GHz to 42 GHz, from 30 GHz to 56 GHz, 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 bands of frequencies between 10 GHz and 300 GHz. As one example, the first communications band may include a 5thgeneration mobile networks or 5thgeneration wireless systems (5G) communication band between 27.5 GHz and 28.5 GHz whereas the second communications band includes a IEEE 802.11ad communications band from 57 GHz to 71 GHz. These examples are merely illustrative.

In some scenarios, a first antenna for covering the first communications band is formed at a first location and a second antenna for covering the second communications band is formed at a second location in the electronic device (e.g., first and second locations on opposing sides of the device). While a relatively large separation between the two antennas may enhance isolation between the antennas, forming the antennas at separate locations may occupy an excessive amount of the limited space within device10. In order to reduce the amount of space required within device10for covering both the first and second frequency bands, the first antenna may be co-located with the second antenna in device10. First and second antennas40may be considered to be co-located within device10when at least some of the antenna resonating element104of the first antenna overlaps the outline or footprint of the antenna resonating element104in the second antenna. Co-locating the antennas in this way may optimize the amount of space required by the antennas in device10for covering both the first and second communications bands.

FIG. 7is a cross-sectional side view showing how a first antenna for covering the first communications band between 10 GHz and 300 GHz may be co-located with a second antenna for covering the second communications band between 10 GHz and 300 GHz. As shown inFIG. 7, antenna structures70may include a first antenna40such as antenna40A and a second antenna40such as antenna40B. Antenna40A may cover the first communications band whereas antenna40B covers the second communications band. Antenna structures70may collectively cover both the first and second communications bands. The second communications band covered by antenna40B may include higher frequencies (e.g., frequencies between 57 GHz and 71 GHz) than the first communications band covered by antenna40A (e.g., frequencies between 27.5 GHz and 28.5 GHz), for example.

In the example ofFIG. 7, antenna40A is a patch antenna such as the single-polarization patch antenna shown inFIG. 5or the dual-polarization patch antenna shown inFIG. 6. Similarly, antenna40B is a patch antenna such as the single-polarization patch antenna shown inFIG. 5or the dual-polarization patch antenna shown inFIG. 6. This is merely illustrative and, if desired, antennas40A and40B may be formed using other antenna structures. Antenna structures70may sometimes be referred to herein as antenna system70, multi-band antenna system70, dual-band antenna system70, multi-band antenna structures70, patch antenna structures70, multi-band patch antenna structures70, co-located patch antenna structures70, or co-located antenna structures70. Antennas40A and40B may sometimes be referred to collectively herein as co-located antennas or co-located patch antennas40A and40B.

As shown inFIG. 7, patch antenna40A may include patch antenna resonating element104A, ground plane92, and an antenna feed that includes a positive antenna feed terminal96A coupled to patch antenna resonating element104A and a corresponding ground antenna feed terminal coupled to ground plane92. Patch antenna40B may include patch antenna resonating element104B, ground plane92, and an antenna feed that includes a positive antenna feed terminal96B coupled to patch antenna resonating element104B and a corresponding ground antenna feed terminal coupled to ground plane92.

Patch element104A may have a lateral surface extending in the X-Y plane ofFIG. 7and may be separated from antenna ground plane92by distance H (e.g., the lateral surface of patch104A may extend parallel to the lateral surface of ground plane92). Patch element104B may have a lateral surface extending in the X-Y plane and may be separated from patch element104A by distance H′ (e.g., the lateral surface of patch104B may extend parallel to the lateral surface of ground plane92and patch104A). Distance H′ may be the same as distance H, less than distance H, or greater than distance H (e.g., patch104B may be separated from ground plane92by distance H+H′). Patch element104B may, for example, serve to reflect some of the antenna signals radiated by patch104A if desired. Distances H and H′ may be between 0.1 mm and 10 mm, as examples. In general, adjusting distances H and H′ may serve to adjust the bandwidth of antennas40A and40B, respectively.

Antennas40A and40B may be formed on a dielectric substrate such as substrate120. Substrate120may be, for example, a rigid or printed circuit board or other dielectric substrate. Substrate120may include multiple dielectric layers122(e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy) such as a first dielectric layer122-1, a second dielectric layer122-2over the first dielectric layer, a third dielectric layer122-3over the second dielectric layer, a fourth dielectric layer122-4over the third dielectric layer, and a fifth dielectric layer122-5over the fourth dielectric layer. Additional dielectric layers122may be stacked within substrate120if desired.

With this type of arrangement, antenna40A may be embedded within the layers of substrate120. For example, ground plane92may be formed on a surface of second layer122-2whereas patch antenna resonating element104A is formed on a surface of third layer122-3. Antenna40A may be fed using a first transmission line such as transmission line64A. Transmission line64A may, for example, be formed from a conductive trace such as conductive trace126A on layer122-1and portions of ground layer92. Conductive trace126A may form the positive signal conductor for transmission line64A, for example. A first hole128A may be formed in ground layer92. First transmission line64A may include a vertical conductor124A (e.g., a conductive through-via, metal pillar, metal wire, conductive pin, or other vertical conductive interconnect structures) that extends from trace126A through layer122-2, hole128A in ground layer92, and layer122-3to antenna feed terminal96A on patch element104A. 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 antenna40B may be embedded within the layers of substrate120. For example, patch antenna resonating element104B may be formed on a surface of dielectric layer122-4. Some or all of the lateral area of patch antenna resonating element104B may overlap with the outline (footprint) of patch antenna resonating element104A (in the X-Y plane). Antenna40B may be fed using a second transmission line such as transmission line64B. Transmission line64B may, for example, be formed from a conductive trace such as conductive trace126B on layer122-1and portions of ground layer92. Conductive trace126B may form the positive signal conductor for transmission line64B, for example. A second hole128B may be formed in ground layer92. A hole130may be formed in patch antenna resonating element104A. Second transmission line64B may include a vertical conductor124B (e.g., a conductive through-via, metal pillar, metal wire, conductive pin, or other vertical conductive interconnect structures) that extends from trace126B through layer122-2, hole128B in ground layer92, layer122-3, opening130in patch element104A, and layer122-4to antenna feed terminal96B on patch element104B. 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.). Transmission line traces126A and126B may be formed on different layers122if desired. Vertical conductors124A and124B may extend through the same hole in ground plane92if desired. Holes128A and128B may sometimes be referred to herein as notches, gaps, openings, or slots.

In practice, patch element104B alone may have insufficient bandwidth for covering an entirety of the second communications band (e.g., an entirety of the frequency range from 57 GHz to 71 GHz). If desired, antenna40B may include one or more parasitic antenna resonating elements that serve to broaden the bandwidth of antenna40B.

As shown inFIG. 7, antenna40B may include a parasitic antenna resonating element such as parasitic antenna resonating element106. Parasitic antenna resonating element106may be formed on a surface of dielectric layer122-5. Parasitic antenna resonating element106may have a lateral surface area extending in the X-Y plane ofFIG. 7and may be separated from patch element104B by distance H″. Distance H″ may be the same as distance H, less than distance H, or greater than distance H (e.g., parasitic106may be separated from ground plane92by distance H+H′+H″ and may be separated from patch104B by distance H′+H″). Distance H″ may be between 0.1 mm and 10 mm, as an example. In general, adjusting distance H″ may serve to adjust the bandwidth of antenna40B, for example. Some or all of the lateral area of patch antenna resonating element106may overlap with the outline (footprint) of patch antenna resonating element104B (in the X-Y plane).

Parasitic antenna resonating element106may be formed from conductive traces patterned onto a surface of layer122-4, from stamped sheet metal, metal foil, electronic device housing structures, or any other desired conductive structures. Parasitic antenna resonating element106may sometimes be referred to herein as parasitic resonating element106, parasitic antenna element106, parasitic element106, parasitic patch106, parasitic conductor106, parasitic structure106, patch106, or parasitic106. Parasitic element106is not directly fed (e.g., element106is not electrically connected to any transmission lines64), whereas patch antenna resonating element104B is directly fed via transmission line64B and feed terminal96B and patch antenna resonating element104A is directly fed via transmission line64A and feed terminal96A. Parasitic element106may create a constructive perturbation of the electromagnetic field generated by patch antenna resonating element104B, creating a new resonance for antenna40B. This may serve to broaden the overall bandwidth of antenna40B (e.g., to cover the entire frequency band from 57 GHz to 71 GHz).

As shown inFIG. 7, patch element104A may have a width W. As examples, patch element104A may be a rectangular patch (e.g., as shown inFIGS. 5 and 6) having a side of length W, a square patch having four 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 width W is the maximum lateral dimension of the patch, the length of a side of a polygonal patch, the length of the longest side of a polygonal patch, the length of a side of a rectangular footprint of the patch, etc.). Patch element104B may have a width V. As examples, patch element104B may be a rectangular patch (e.g., as shown inFIGS. 5 and 6) having a side of length V, a square patch having four sides of length V, a circular patch having diameter V, an elliptical patch having a major axis length V, or may have any other desired shape (e.g., where width V is the maximum lateral dimension of the patch, the length of a side of a polygonal patch, the length of the longest side of a polygonal patch, the length of a side of a rectangular footprint of the patch, etc.). Width V may be inversely proportional to the frequency of operation of antenna40B whereas width W is inversely proportional to the frequency of operation of antenna40A.

Because antenna40B is used to cover higher frequencies than antenna40A in the example ofFIG. 7, width W may be greater than width V. As an example, width W may be approximately equal to twice width V (e.g., width W may be between 1.7 and 2.3 times width V, between 1.8 and 2.2 times width V, twice width V, etc.). Width W of patch104A may be approximately equal to half of the wavelength of operation of antenna40A. Width V of patch104B may be approximately equal to half of the wavelength of operation of antenna40B. In practice, widths W and V may depend upon the dielectric constant of dielectric substrate120(e.g., widths W and V may be inversely proportional to the dielectric constant of substrate120). As an example, when antenna40A is configured to cover a first communications band from 27.5 GHz to 28.5 GHz and antenna40B is configured to cover a second communications band from 57 GHz to 71 GHz, width W may be approximately equal to 1.1-2.5 mm for covering the first communications band whereas width V is approximately equal to 0.5-1.25 mm for covering the second communications band.

Parasitic element106may have a width U. As examples, parasitic element106may be a rectangular patch having a side of length U, a square patch having sides of length U, a circular patch having diameter U, an elliptical patch having a major axis length U, a cross-shape having a maximum lateral dimension or a rectangular footprint with a side of length U, or may have any other desired shape (e.g., where width U is the maximum lateral dimension of the patch, the length of a side of a polygonal patch, the length of the longest side of a polygonal patch, the length of a side of a rectangular footprint of the patch, etc.). Width U may be less than, greater than, or equal to width V. In one suitable arrangement, width U is less than or equal to width V (e.g., between 0.05 mm and 1.25 mm).

The example ofFIG. 7is merely illustrative. If desired, additional layers122may be interposed between traces126A and126B and ground layer92, between ground layer92and patch104A, between patch104A and patch104B, and/or between patch104B and parasitic106. In another suitable arrangement, substrate120may be formed from a single dielectric layer (e.g., antennas40A and40B may be embedded within a single dielectric layer such as a molded plastic layer). In yet another suitable arrangement, substrate120may be omitted and antennas40A and40B may be formed on other substrate structures or may be formed without substrates.

In the example ofFIG. 7, antennas40A and40B are shown as having only a single feed for the sake of simplicity. In order to enhance the polarizations covered by antenna structures70, antennas40A and/or40B may be dual-polarized patch antennas that each have two corresponding feeds (e.g., as shown inFIG. 6, such that structures70have a combined total of four antenna feeds), suitable geometry, and suitable phasing of ports P1and P2.

FIG. 8is a top-down view showing how antenna structures70may include patch antennas40A and40B that each have two feeds (e.g., for covering multiple or non-linear polarizations). In the example ofFIG. 8, dielectric122is not shown for the sake of clarity. As shown inFIG. 8, antenna40A may have a first feed at antenna port P1that is coupled to a first transmission line64A-P1and a second feed at antenna port P2that is coupled to a second transmission line64A-P2. The first feed may include a first ground feed terminal coupled to ground plane92and a first positive feed terminal96A-P1coupled to patch antenna resonating element104A at a first location on patch antenna resonating element104A. The second antenna feed may include a second ground feed terminal coupled to ground plane92and a second positive feed terminal96A-P2coupled to patch antenna resonating element104A at a second location on patch antenna resonating element104A. For example, the location of first feed terminal96A-P1may be adjacent to a first side155of patch104A (e.g., approximately halfway across width W of patch104A) whereas the location of second feed terminal96A-P2is adjacent to a second side157of patch104A (e.g., approximately halfway across the length of side157).

Antenna40B may have a third feed at antenna port P1that is coupled to a third transmission line64B-P1and a fourth feed at antenna port P2that is coupled to a fourth transmission line64B-P2. The third feed may include a third ground feed terminal coupled to ground plane92and a third positive feed terminal96B-P1coupled to patch antenna resonating element104B at a first location on patch antenna resonating element104B (e.g., adjacent to side153of patch104B approximately halfway across the width V of patch104B). The fourth antenna feed may include a fourth ground feed terminal coupled to ground plane92and a fourth positive feed terminal96B-P2coupled to patch antenna resonating element104B at a second location on patch antenna resonating element104B (e.g., adjacent to side159of patch104B approximately halfway across side159).

Parasitic resonating element106may be formed over patch104B. At least some or an entirety of parasitic resonating element106may overlap patch104B. In the example ofFIG. 8, parasitic resonating element106has a cross or “X” shape. In order to form the cross shape, parasitic element106may include notches or slots such as slots143(e.g., slots formed by removing conductive material from the corners of a square or rectangular metal patch). Cross-shaped parasitic106may have a rectangular (e.g., square) footprint. The width U of cross-shaped parasitic element106may be defined by the length of a side of the rectangular footprint of element106, for example.

Cross-shaped parasitic resonating element106may include a first arm140, a second arm142, a third arm144, and a fourth arm146that extend from the center point145of element106. First arm140may oppose third arm144whereas second arm142opposes fourth arm146(e.g., arms140and144may extend in parallel and from opposing sides of center point145of element106and arms142and146may extend in parallel and from opposing sides of center point145). Arms142and146may extend along a first longitudinal axis160whereas arms140and144extend along a second longitudinal axis162. Longitudinal axis160may be oriented at a non-parallel angle with respect to longitudinal axis162(e.g., an angle between 0 degrees and 180 degrees). As an example, axis160may be oriented at approximately 90 degrees with respect to axis162. In the example ofFIG. 8, the combined length of arms140and144is equal to the combined length of arms142and146(e.g., each of arms140,142,144, and146has the same length).

In a single-polarization patch antenna, the distance between the positive antenna feed terminal96and the edge of patch104may be adjusted to ensure that there is a satisfactory impedance match between patch104and the corresponding transmission line64. 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 element106to form notches143may serve to adjust the impedance of patch104B so that the impedance of patch104B is matched to both transmission lines64B-P1and64B-P2, for example. Notches143may therefore sometimes be referred to herein as impedance matching notches, impedance matching slots, or impedance matching structures.

The dimensions of impedance matching notches143may be adjusted (e.g., during manufacture of device10) to ensure that antenna40B is sufficiently matched to both transmission lines64B-P1and64B-P2and to tweak the overall bandwidth of antenna40B. As an example, notches143may have sides with lengths U′ that are equal to between 1% and 45% of dimension U of parasitic106. In an example where width U is between 1.0 mm and 1.2 mm, length U′ may be between 0.3 mm and 0.4 mm, for example. In order for antenna40B to be sufficiently matched to transmission lines64B-P1and64B-P2, feed terminals96B-P1and96B-P2need to overlap with the conductive material of parasitic element106. Notches143may therefore be sufficiently small so as not to uncover feed terminals96B-P1or96B-P2. In other words, each of antenna feed terminals96B-P1and96B-P2may overlap with a respective arm of the cross-shaped parasitic antenna resonating element106. During wireless communications using device10, device10may use ports P1and P2to transmit and/or receive wireless wave signals with two orthogonal linear polarizations or with a circular or elliptical polarization. The example ofFIG. 8is merely illustrative. If desired, parasitic antenna resonating element106may have additional notches143, fewer notches143, may have curved edges, straight edges, combinations of straight and curved edges, or any other desired shape.

Because arms144and146need to overlap feed terminals96B-P1and96B-P2on patch104B, parasitic106may be oriented to align with patch104B such that the ends of parasitic arms142and146are parallel to edge159of patch104B and the ends of parasitic arms140and144are approximately parallel to edge153of patch104B (e.g., longitudinal axis162of parasitic106may be oriented between at an angle between 0 and 10 degrees with respect to edge159of patch104B whereas longitudinal axis160of parasitic106may be oriented at an angle between 0 and 10 degrees with respect to edge153of patch104B). In the example ofFIG. 8, longitudinal axis160of parasitic106and edge153of patch104B are parallel to edge155of patch104A and longitudinal axis162of parasitic106and edge159of patch104B are parallel to edge157of patch104A. However, this is merely illustrative. If desired, parasitic106and patch104B may be rotated with respect to patch104A (e.g., so long as the arms of parasitic106remain parallel to two sides of patch104B so that the polarizations associated with ports P1and P2do not mix). For example, longitudinal axis160and side153may be rotated at any desired angle between 0 degrees and 360 degrees with respect to edge155of patch104A. Similarly, longitudinal axis162and side159may be rotated at any desired angle between 0 degrees and 360 degrees with respect to edge157of patch104A. In this way, antenna40B may have any desired polarization rotated with respect to the polarizations of antenna40A.

One or more openings130may be provided in patch104A to accommodate feed terminals96B-P1and96B-P2on patch104B. In the example ofFIG. 8, a first opening130P1is formed in patch104A for accommodating feed96B-P1(e.g., a corresponding vertical conductor128B as shown inFIG. 7may pass through opening130P1to feed terminal96B-P1) and a second opening130P2is formed in patch104A for accommodating feed96B-P2(e.g., a corresponding vertical conductor128B may pass through opening130P2to feed terminal96B-P2). In another suitable arrangement, a single opening130may be formed in patch104A for accommodating both feed terminals96B-P1and96B-P2(e.g., both vertical conductors128B may pass through the same hole130). As one example, a single cross-shaped opening may be formed in patch104A. The cross-shaped opening may have first and second opposing arms that have a longitudinal axis that runs between feed terminals96A-P2and96A-P1(e.g., oriented at an angle between 0 and 90 degrees such as 45 degrees with respect to axes160and162inFIG. 8). When configured in this way, the cross-shaped opening may serve to enhance isolation between feed terminals96A-P2and96A-P1on patch104A. This is merely illustrative and, in general, opening130may have any desired shape.

In the example ofFIG. 8, patches104A and104B are both square patches oriented in the same direction and centered on the same point. This is merely illustrative and, in other scenarios, patches104A and104B may have other shapes or orientations. Parasitic element106may include fewer or more than four arms if desired. In general, parasitic106may be referred to herein as a cross-shaped parasitic element in any scenario where parasitic106includes at least three arms extending from different sides of a common point on parasitic106, where the arms of parasitic106extend along at least two non-parallel longitudinal axes. Similarly, opening130may be referred to herein as a cross-shaped opening in any scenario where opening130includes at least three arms extending from different sides of a common point within the opening, where the arms of the opening extend along at least two non-parallel longitudinal axes.

FIG. 9is a perspective view of multi-band antenna structures70having a single cross-shaped opening130in patch104A. In the example ofFIG. 9, dielectric122is not shown for the sake of clarity. As shown inFIG. 9, patch element104A may be formed at distance H above ground plane92. Patch element104B may be formed at distance H′ above patch104A. Parasitic element106may be formed at distance H″ above patch104B.

A single cross-shaped opening130may be formed in patch104A. Cross-shaped opening130may have a first arm150, a second arm152, a third arm154, and a fourth arm156that extend from the center of opening130(e.g., from the center of patch104A). Arm154may be interposed between the location of feed terminal96A-P1and the location of feed terminal96A-P2and may serve to isolate terminals96A-P1and96A-P2. Opening130may, for example, be a closed slot that is completely surrounded by the conductive material in patch104A (e.g., the conductive material in patch104A may define all of the edges of opening130). First arm150may oppose third arm154whereas second arm152opposes fourth arm156. Arms150and154may both extend along longitudinal axis163(e.g., from opposing sides of the center of patch104A) whereas arms152and156extend along longitudinal axis167.

Patch104B and parasitic106may be rotated with respect to patch104A. In the example ofFIG. 9, patch104B and parasitic106have been rotated to align with two of the arms of opening130(e.g., so that arm156of opening130overlaps the location of feed terminal96B-P2on patch104B and arm144of parasitic106and arm154of opening130overlaps the location of feed terminal96B-P1on patch104B and arm146of parasitic106). This example is merely illustrative. In general, parasitic106and patch104B may be rotated at any desired angle with respect to patch104A. If desired, cross-shaped opening130may be rotated (misaligned) with respect to cross-shaped parasitic106(e.g., longitudinal axis163may be rotated at an angle between 0 degrees and 90 degrees with respect to axis162and axis167may be rotated at an angle between 0 degrees and 90 degrees with respect to axis160). By rotating parasitic106and patch104B in this way, opening130may serve to isolate feed terminals96A-P1and96A-P2while also accommodating vertical conductors124for both feed terminals96B-P1and96B-P2of patch104B.

A first hole128A-P1, a second hole128B-P1, a third hole128A-P2, and a fourth hole128B-P2may be formed in ground plane92. Transmission line64A-P1(e.g., the corresponding vertical conductor124as shown inFIG. 7) may extend through hole128A-P1to feed terminal96A-P1on patch104A. Transmission line64B-P1(e.g., the corresponding vertical conductor124) may extend through hole128B-P1in ground plane92and through arm154of opening130to feed terminal96B-P1on patch104B. Feed terminal96B-P1may be overlapped by (e.g., may be located directly beneath or within the lateral outline of) arm144of parasitic element106. Transmission line64A-P2(e.g., the corresponding vertical conductor124) may extend through hole128A-P2to feed terminal96A-P2on patch104A. Transmission line64B-P2(e.g., the corresponding vertical conductor124) may extend through hole128B-P2in ground plane92and arm156of opening130to feed terminal96B-P on patch element104B. Feed terminal96B-P2may be overlapped by arm146of parasitic element106.

In this way, cross-shaped opening130, which enhances the isolation between feed terminals96A-P2and96A-P1may allow both transmission lines64B-P2and64B-P1to pass through patch element104A (e.g., without shorting to the conductive material in element104A), while parasitic antenna resonating element106serves to both broaden the bandwidth of antenna40B and impedance match patch104B to both transmission lines64B-P1and64B-P2. By stacking antennas40A and40B in this way, the amount of space required to cover both communications bands may be reduced relative to scenarios where antennas40A and40B are formed at separate locations in device10.

Transmission lines64A-P1,64A-P2,64B-P1, and64B-P2may include conductive traces126formed on a single dielectric layer122(e.g., layer122-1ofFIG. 7) or may be formed on two or more different dielectric layers. If desired, two or more of transmission lines64A-P1,64A-P2,64B-P1, and64B-P2may pass through the same opening in ground plane92. The example ofFIG. 9is merely illustrative. In general, parasitic element106, patch104B, patch104A, and ground92may have any desired shapes, relative placements, and relative orientations. Opening130may have any desired shape having curved and/or straight edges. If desired, separate openings130may be provided in patch104A for accommodating feed terminals96B-P1and96B-P2(e.g., openings130P1and130P2as shown inFIG. 8). Parasitic106and patch104B may be rotated at any desired angle with respect to patch104A.

FIG. 10is a top-down view showing one example of how antenna structures70ofFIGS. 7-9may be arranged within a phased antenna array. As shown inFIG. 10, multiple antenna structures70(e.g., first multi-band antenna structures70-1including a first co-located pair of antennas40A and40B, second multi-band antenna structures70-2including a second co-located pair of antennas40A and40B, etc.) may be arranged in a grid pattern (e.g., a rectangular grid having rows or columns or in any other desired array pattern). First antenna structures70-1may be located at a distance172with respect to second antenna structures70-2. Distance172may be approximately equal to half of the wavelength of operation of the antennas40A in structures70-1and70-2. As an example, distance172may be between 4 mm and 6 mm (e.g., approximately 5 mm). Separating structures70-1and70-2in this way may allow for array170to perform beam scanning operations without generating grating lobes in the radiation pattern of array170. The presence of excessive grating lobes may result in excessive coupling between structures70-1and70-2and reduce the overall antenna efficiency of array170, for example.

One or more parasitic elements174may be interposed between each pair of antenna structures70in array170to enhance isolation (decoupling) between adjacent structures70if desired. In the example ofFIG. 10, first parasitic element174A and second parasitic element174B are interposed between antenna structures70-1and antenna structures70-2. Parasitic element174A may be an un-fed, non-radiative conductive patch. Parasitic element174A may be, for example, a rectangular conductive patch or a conductive patch having any other desired shape. Parasitic element174A may be located closer to structures70-1than structures70-2in one suitable arrangement. In general, element174A may be formed at any desired location between structures70-1and70-2. If desired, parasitic element174A may be formed from conductive traces, stamped sheet metal, metal foil, metal electronic device housing structures, or other conductive structures on the same dielectric layer of substrate120as patches104A (e.g., layer122-3ofFIG. 7), on a different dielectric layer from patches104A, or may be formed on other dielectric support structures or without dielectric support structures. When configured in this way, wireless signals conveyed by antenna40A in structures70-1may interact with patch174A as if patch174A were an additional ground plane structure for the antenna, for example. Parasitic element174A may serve to reduce electromagnetic coupling between antenna40A in structures70-1and antenna40A in structures70-2, thereby enhancing the overall antenna efficiency of array170.

Parasitic element174B may be formed over parasitic element174A. Parasitic element174B may be an un-fed, non-radiative conductive patch such as a square conductive patch or a conductive patch having any other desired shape. Parasitic element174B may be located at a first distance176from structures70-1and a second distance178from structures70-2. Distance176may, for example, be approximately equal to half of the wavelength of operation of the antennas40B in structures70-1and70-2. As an example, distance176and/or distance178may be between 2 mm and 3 mm. In one suitable arrangement, distance176is approximately equal to distance178. Because parasitic element174A is located closer to structures70-1than structures70-2, parasitic element174B may thereby be located at a first distance180from the edge of parasitic174A closest to structures70-1and a second shorter distance182from the opposing edge of parasitic174A (e.g., parasitic174B may be misaligned with respect to the center of parasitic174A).

If desired, parasitic element174B may be formed from conductive traces, stamped sheet metal, metal foil, metal electronic device housing structures, or other conductive structures on the same dielectric layer of substrate120as patches104B (e.g., layer122-4ofFIG. 7), on a different dielectric layer from patches104B, or may be formed on other dielectric support structures or without dielectric support structures. Parasitic element174B may serve to reduce electromagnetic coupling between antenna40B in structures70-1and antenna40B in structures70-2, thereby enhancing the overall antenna efficiency of array170.

The example ofFIG. 10is merely illustrative. If desired, parasitic elements174A and/or174B may be shorted to ground plane92. In general, any desired parasitic elements having any desired placement, shape, and orientation may be interposed between structures70-1and70-2. In the example ofFIG. 10, the center of structures70-1(e.g., the center of the corresponding patches104A and104B and the center of the corresponding parasitic106) is shown as being located at distance172from center the center of structures70-2. Similarly, the center of structures70-1is shown as being located at distance176from the center of parasitic174B. This is merely illustrative. In general, any desired point within the outline or on the edges of structures70-1(e.g., within the outline or on the edges of patch104A) may be located at distance172from any desired point within the outline or on the edges of structures70-2and may be located at distance176from any desired point within the outline or on the edges of parasitic174B. Array170may include any desired number of structures70(e.g., sixteen structures70and therefore thirty two antennas40, fourteen structures70and therefore twenty-eight antennas40, between ten and fourteen structures70, between three and ten structures70, more than sixteen structures70, five structures70and therefore ten antennas40, six structures70and therefore twelve antennas40, etc.). In general, a greater number of structures70may increase the overall gain of array170(but also the overall manufacturing and operating complexity of array60) relative to scenarios where fewer structures70are formed. Structures70may be arranged in any desired pattern.

FIG. 11is a top-down view showing another example of how antenna structures70ofFIGS. 7-9may be arranged within a phased antenna array170. As shown inFIG. 11, multiple antenna structures70may be arranged in a grid or array (e.g., an array having aligned rows and columns). Each antenna structure70may be located at distance172with respect to the antenna structures70in adjacent rows and columns of the array. Two parasitic elements174A may be interposed between each adjacent pair of antenna structures70. Additional patch elements104B and corresponding cross-shaped antenna resonating elements106may be interposed between each pair of antenna structures70(e.g., between two corresponding parasitic elements174A). The patch element104B and corresponding parasitic106within each antenna structure70may be located at a distance177from the patches104B and parasitic elements106between structures70. Distance177may be, for example, half of the wavelength of operation of antennas40B. When arranged in this way, phased antenna array170may include patches104B and the corresponding parasitic elements106arranged in an array having rows and columns, where patches104B are located in every-other row and column. In this way, the patches104B between structures70may utilize the same ground plane92as patches104A. The example ofFIG. 11is merely illustrative. If desired, patches104B and104A may be arranged in any desired manner. The rows and columns of array170need not be aligned.

FIG. 12is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency F for antenna structures70. As shown inFIG. 12, efficiency curve190illustrates the antenna efficiency of structures70when operated in the absence of parasitic element106. Curve190may have a first peak at within a first communications band BI between frequencies FA and FB and a second peak at frequency F′. Frequency F′ may lie within a second communications BII between frequencies FC and FD. First communications band BI may sometimes be referred to herein as low band BI. Second communications band BII may sometimes be referred to herein as high band BII. The second peak of curve190at frequency F′ may have a bandwidth that is too narrow to cover the entirety of communications band BII. Efficiency curve192illustrates the antenna efficiency of parasitic element106. Curve192may have a peak at frequency F′+ΔF that is offset from frequency F′ by offset value ΔF.

Efficiency curve194illustrates the antenna efficiency of structures70including the contributions of antenna40A and antenna40B having parasitic element106. Efficiency curve194may exhibit a first peak in first communications band BI between frequencies FA and FB (e.g., due to the contribution of antenna40A). Efficiency curve194may exhibit a second peak in second communications band BII between frequencies FC and FD due to the contribution of antenna40B. As shown inFIG. 11, the antenna efficiency of antenna40B in band BII may include contributions from both patch104B and parasitic106such that antenna40B exhibits an extended bandwidth that covers the entirety of band BII between frequencies FC and FD.

In one suitable example, frequency FA is 27.5 GHz, frequency FB is 28.5 GHz, frequency FC is 57 GHz, and frequency FD 71 GHz. This is merely illustrative and, in general, bands BI and BII may be any desired communications bands at frequencies between 10 GHz and 300 GHz. Frequencies FA through FD 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, and frequency FC is less than frequency FD). In this way, co-located antennas40A and40B (i.e., multi-band antenna structure70) may cover multiple frequency bands greater than 10 GHz with satisfactory antenna efficiency in both bands and without occupying as much space within device10as when antennas40A and40B are formed at different locations within device10, for example.

The example ofFIG. 12is merely illustrative. In general, curve194may have any desired shape (e.g., as determined by the arrangement of antennas40A and40B within structure70). If desired, control circuitry14may perform simultaneous communications in bands BI and BII at any given time (e.g., because antenna40A is suitably isolated from antenna40B). If desired, antennas40A or antenna40B may be omitted from structure70(e.g., for only covering one of the first and second communications bands).