Electronic Devices with Multi-Substrate Stacked Patch Antennas

An electronic device may be provided with a phased antenna array with antennas on an antenna module. The module may include a primary substrate and a secondary substrate mounted to the primary substrate by an interconnect. An antenna may include patch elements in the primary substrate and patch elements in the secondary substrate that are fed using conductive vias. Fences of conductive vias may couple the patch elements in the primary substrate to ground to isolate the patch elements in the primary substrate from the patch elements in the secondary substrate. The secondary substrate may be smaller than the primary substrate, allowing the secondary substrate to fit into relatively small portions of the electronic device while locating the patch elements in the secondary substrates closer to free space, thereby maximizing antenna performance.

BACKGROUND

This relates generally to electronic devices and, more particularly, to electronic devices with wireless communications capabilities.

Electronic devices such as portable computers and cellular telephones are often provided with wireless communications capabilities. To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to implement wireless communications circuitry such as antenna components using compact structures. At the same time, there is a desire for antennas to cover as many different frequencies as possible.

It can be challenging to provide antennas that cover wide bandwidths with satisfactory levels of performance while also accommodating the presence of nearby device components.

SUMMARY

An electronic device may be provided with a housing, a display, and wireless circuitry. The housing may include peripheral conductive housing structures that run around a periphery of the device. The display may include a display cover layer mounted to the peripheral conductive housing structures. The housing may include a rear housing wall opposite the display cover layer. The wireless circuitry may include a phased antenna array that conveys radio-frequency signals at centimeter and/or millimeter wave frequencies. The phased antenna array may be aligned with apertures in the peripheral conductive housing structures or elsewhere in the device.

The phased antenna array may include antennas on an antenna module. The antenna module may include a primary substrate and a secondary substrate mounted to the primary substrate. An interconnect may couple the primary substrate to the secondary substrate. An antenna may include one or more patch elements in the primary substrate and one or more patch elements in the secondary substrate and overlapping the patch elements in the primary substrate. The patch elements in the primary and/or secondary substrates may be fed using conductive vias. A patch element in the secondary substrate may be fed using a conductive via that passes through the patch elements in the primary substrate. Fences of conductive vias may couple the patch elements in the primary substrate to ground around the conductive via feeding the secondary substrate to isolate the patch elements in the primary substrate from the patch elements in the secondary substrate.

Each antenna in the phased antenna array may include a different respective secondary substrate or the antennas may share a single secondary substrate. Electrical components may be embedded in the secondary substrate, may be disposed on the primary substrate between different secondary substrates, and/or may be mounted to the secondary substrates. The secondary substrates may be provided with edge metallizations and/or may be embedded in an encapsulation layer. The secondary substrates may be smaller than the primary substrate, which may allow the secondary substrates to fit into relatively small portions of the electronic device while locating the patch elements in the secondary substrates closer to free space, thereby maximizing antenna performance.

DETAILED DESCRIPTION

An electronic device such as electronic device10ofFIG.1may be provided with wireless circuitry that includes antennas. The antennas may be used to transmit and/or receive wireless radio-frequency signals. The antennas may include phased antenna arrays that are used for performing wireless communications and/or spatial ranging operations using millimeter and centimeter wave signals. Millimeter wave signals, which are sometimes referred to as extremely high frequency (EHF) signals, propagate at frequencies above about 30 GHz (e.g., at 60 GHz or other frequencies between about 30 GHz and 300 GHz). Centimeter wave signals propagate at frequencies between about 10 GHz and 30 GHz. If desired, device10may also contain antennas 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.

Device10may be a portable electronic device or other suitable electronic device. For example, device10may be a laptop computer, a tablet computer, a somewhat smaller device such as a wrist-watch device, pendant device, headphone device, earpiece device, headset device, or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, or other small portable device. Device10may also be a set-top box, a desktop computer, a display into which a computer or other processing circuitry has been integrated, a display without an integrated computer, a wireless access point, a wireless base station, an electronic device incorporated into a kiosk, building, or vehicle, or other suitable electronic equipment.

Device10may include a housing such as housing12. Housing12, which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing12may be formed from dielectric or other low-conductivity material (e.g., glass, ceramic, plastic, sapphire, etc.). In other situations, housing12or at least some of the structures that make up housing12may be formed from metal elements.

Device10may, if desired, have a display such as display14. Display14may be mounted on the front face of device10. Display14may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. The rear face of housing12(i.e., the face of device10opposing the front face of device10) may have a substantially planar housing wall such as rear housing wall12R (e.g., a planar housing wall). Rear housing wall12R may have slots that pass entirely through the rear housing wall and that therefore separate portions of housing12from each other. Rear housing wall12R may include conductive portions and/or dielectric portions. If desired, rear housing wall12R may include a planar metal layer covered by a thin layer or coating of dielectric such as glass, plastic, sapphire, or ceramic (e.g., a dielectric cover layer). Housing12may also have shallow grooves that do not pass entirely through housing12. The slots and grooves may be filled with plastic or other dielectric materials. If desired, portions of housing12that have been separated from each other (e.g., by a through slot) may be joined by internal conductive structures (e.g., sheet metal or other metal members that bridge the slot).

Housing12may include peripheral housing structures such as peripheral structures12W. Conductive portions of peripheral structures12W and conductive portions of rear housing wall12R may sometimes be referred to herein collectively as conductive structures of housing12. Peripheral structures12W may run around the periphery of device10and display14. In configurations in which device10and display14have a rectangular shape with four edges, peripheral structures12W may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges and that extend from rear housing wall12R to the front face of device10(as an example). In other words, device10may have a length (e.g., measured parallel to the Y-axis), a width that is less than the length (e.g., measured parallel to the X-axis), and a height (e.g., measured parallel to the Z-axis) that is less than the width. Peripheral structures12W or part of peripheral structures12W may serve as a bezel for display14(e.g., a cosmetic trim that surrounds all four sides of display14and/or that helps hold display14to device10) if desired. Peripheral structures12W may, if desired, form sidewall structures for device10(e.g., by forming a metal band with vertical sidewalls, curved sidewalls, etc.).

Peripheral structures12W may be formed of a conductive material such as metal and may therefore sometimes be referred to as peripheral conductive housing structures, conductive housing structures, peripheral metal structures, peripheral conductive sidewalls, peripheral conductive sidewall structures, conductive housing sidewalls, peripheral conductive housing sidewalls, sidewalls, sidewall structures, or a peripheral conductive housing member (as examples). Peripheral conductive housing structures12W may be formed from a metal such as stainless steel, aluminum, alloys, or other suitable materials. One, two, or more than two separate structures may be used in forming peripheral conductive housing structures12W.

It is not necessary for peripheral conductive housing structures12W to have a uniform cross-section. For example, the top portion of peripheral conductive housing structures12W may, if desired, have an inwardly protruding ledge that helps hold display14in place. The bottom portion of peripheral conductive housing structures12W may also have an enlarged lip (e.g., in the plane of the rear surface of device10). Peripheral conductive housing structures12W may have substantially straight vertical sidewalls, may have sidewalls that are curved, or may have other suitable shapes. In some configurations (e.g., when peripheral conductive housing structures12W serve as a bezel for display14), peripheral conductive housing structures12W may run around the lip of housing12(i.e., peripheral conductive housing structures12W may cover only the edge of housing12that surrounds display14and not the rest of the sidewalls of housing12).

Rear housing wall12R may lie in a plane that is parallel to display14. In configurations for device10in which some or all of rear housing wall12R is formed from metal, it may be desirable to form parts of peripheral conductive housing structures12W as integral portions of the housing structures forming rear housing wall12R. For example, rear housing wall12R of device10may include a planar metal structure and portions of peripheral conductive housing structures12W on the sides of housing12may be formed as flat or curved vertically extending integral metal portions of the planar metal structure (e.g., housing structures12R and12W may be formed from a continuous piece of metal in a unibody configuration). Housing structures such as these may, if desired, be machined from a block of metal and/or may include multiple metal pieces that are assembled together to form housing12. Rear housing wall12R may have one or more, two or more, or three or more portions. Peripheral conductive housing structures12W and/or conductive portions of rear housing wall12R may form one or more exterior surfaces of device10(e.g., surfaces that are visible to a user of device10) and/or may be implemented using internal structures that do not form exterior surfaces of device10(e.g., conductive housing structures that are not visible to a user of device10such as conductive structures that are covered with layers such as thin cosmetic layers, protective coatings, and/or other coating/cover layers that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device10and/or serve to hide peripheral conductive housing structures12W and/or conductive portions of rear housing wall12R from view of the user).

Display14may have an array of pixels that form an active area AA that displays images for a user of device10. For example, active area AA may include an array of display pixels. The array of pixels may be formed from liquid crystal display (LCD) components, an array of electrophoretic pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels or other light-emitting diode pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. If desired, active area AA may include touch sensors such as touch sensor capacitive electrodes, force sensors, or other sensors for gathering a user input.

Display14may have an inactive border region that runs along one or more of the edges of active area AA. Inactive area IA of display14may be free of pixels for displaying images and may overlap circuitry and other internal device structures in housing12. To block these structures from view by a user of device10, the underside of the display cover layer or other layers in display14that overlap inactive area IA may be coated with an opaque masking layer in inactive area IA. The opaque masking layer may have any suitable color. Inactive area IA may include a recessed region or notch that extends into active area AA (e.g., at speaker port16). Active area AA may, for example, be defined by the lateral area of a display module for display14(e.g., a display module that includes pixel circuitry, touch sensor circuitry, etc.). The display module may have a recess or notch in upper region20of device10that is free from active display circuitry (i.e., that forms notch8of inactive area IA). Notch8may be a substantially rectangular region that is surrounded (defined) on three sides by active area AA and on a fourth side by peripheral conductive housing structures12W. Alternatively, notch8may be surrounded on all sides by active area AA (e.g., notch8may be detached from housing12and may form an island of inactive area IA surrounded by active area AA). One or more sensors may be aligned with notch8and may transmit and/or receive light through display14within notch8.

Display14may be protected using a display cover layer such as a layer of transparent glass, clear plastic, transparent ceramic, sapphire, or other transparent crystalline material, or other transparent layer(s). The display cover layer may have a planar shape, a convex curved profile, a shape with planar and curved portions, a layout that includes a planar main area surrounded on one or more edges with a portion that is bent out of the plane of the planar main area, or other suitable shapes. The display cover layer may cover the entire front face of device10. In another suitable arrangement, the display cover layer may cover substantially all of the front face of device10or only a portion of the front face of device10. Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button. An opening may also be formed in the display cover layer to accommodate ports such as speaker port16or a microphone port. Openings may be formed in housing12to form communications ports (e.g., an audio jack port, a digital data port, etc.) and/or audio ports for audio components such as a speaker and/or a microphone if desired.

Display14may include conductive structures such as an array of capacitive electrodes for a touch sensor, conductive lines for addressing pixels, driver circuits, etc. Housing12may include internal conductive structures such as metal frame members and a planar conductive housing member (sometimes referred to as a conductive support plate or backplate) that spans the walls of housing12(e.g., a substantially rectangular sheet formed from one or more metal parts that is welded or otherwise connected between opposing sides of peripheral conductive housing structures12W). The conductive support plate may form an exterior rear surface of device10or may be covered by a dielectric cover layer such as a thin cosmetic layer, protective coating, and/or other coatings that may include dielectric materials such as glass, ceramic, plastic, or other structures that form the exterior surfaces of device10and/or serve to hide the conductive support plate from view of the user (e.g., the conductive support plate may form part of rear housing wall12R). Device10may also include conductive structures such as printed circuit boards, components mounted on printed circuit boards, and other internal conductive structures. These conductive structures, which may be used in forming a ground plane in device10, may extend under active area AA of display14, for example.

In regions22and20, openings may be formed within the conductive structures of device10(e.g., between peripheral conductive housing structures12W and opposing conductive ground structures such as conductive portions of rear housing wall12R, conductive traces on a printed circuit board, conductive electrical components in display14, etc.). These openings, which may sometimes be referred to as gaps, may be filled with air, plastic, and/or other dielectrics and may be used in forming slot antenna resonating elements for one or more antennas in device10, if desired.

Conductive housing structures and other conductive structures in device10may serve as a ground plane for the antennas in device10. The openings in regions22and20may serve as slots in open or closed slot antennas, may serve as a central dielectric region that is surrounded by a conductive path of materials in a loop antenna, may serve as a space that separates an antenna resonating element such as a strip antenna resonating element or an inverted-F antenna resonating element from the ground plane, may contribute to the performance of a parasitic antenna resonating element, or may otherwise serve as part of antenna structures formed in regions22and20. If desired, the ground plane that is under active area AA of display14and/or other metal structures in device10may have portions that extend into parts of the ends of device10(e.g., the ground may extend towards the dielectric-filled openings in regions22and20), thereby narrowing the slots in regions22and20. Region22may sometimes be referred to herein as lower region22or lower end22of device10. Region20may sometimes be referred to herein as upper region20or upper end20of device10.

In general, device10may include any suitable number of antennas (e.g., one or more, two or more, three or more, four or more, etc.). The antennas in device10may be located at opposing first and second ends of an elongated device housing (e.g., at lower region22and/or upper region20of device10ofFIG.1), along one or more edges of a device housing, in the center of a device housing, in other suitable locations, or in one or more of these locations. The arrangement ofFIG.1is merely illustrative.

Portions of peripheral conductive housing structures12W may be provided with peripheral gap structures. For example, peripheral conductive housing structures12W may be provided with one or more dielectric-filled gaps such as gaps18, as shown inFIG.1. The gaps in peripheral conductive housing structures12W may be filled with dielectric such as polymer, ceramic, glass, air, other dielectric materials, or combinations of these materials. Gaps18may divide peripheral conductive housing structures12W into one or more peripheral conductive segments. The conductive segments that are formed in this way may form parts of antennas in device10if desired. Other dielectric openings may be formed in peripheral conductive housing structures12W (e.g., dielectric openings other than gaps18) and may serve as dielectric antenna windows for antennas mounted within the interior of device10. Antennas within device10may be aligned with the dielectric antenna windows for conveying radio-frequency signals through peripheral conductive housing structures12W. Antennas within device10may also be aligned with inactive area IA of display14for conveying radio-frequency signals through display14.

To provide an end user of device10with as large of a display as possible (e.g., to maximize an area of the device used for displaying media, running applications, etc.), it may be desirable to increase the amount of area at the front face of device10that is covered by active area AA of display14. Increasing the size of active area AA may reduce the size of inactive area IA within device10. This may reduce the area behind display14that is available for antennas within device10. For example, active area AA of display14may include conductive structures that serve to block radio-frequency signals handled by antennas mounted behind active area AA from radiating through the front face of device10. It would therefore be desirable to be able to provide antennas that occupy a small amount of space within device10(e.g., to allow for as large of a display active area AA as possible) while still allowing the antennas to communicate with wireless equipment external to device10with satisfactory efficiency bandwidth.

In some implementations, device10may have one or more upper antennas and one or more lower antennas. An upper antenna may, for example, be formed in upper region20of device10. A lower antenna may, for example, be formed in lower region22of device10. Additional antennas may be formed along the edges of housing12extending between regions20and22if desired. An example in which device10includes three or four upper antennas and five lower antennas is described herein as an example. The antennas may be used separately to cover identical communications bands, overlapping communications bands, or separate communications bands. The antennas may be used to implement an antenna diversity scheme or a multiple-input-multiple-output (MIMO) antenna scheme. Other antennas for covering any other desired frequencies may also be mounted at any desired locations within the interior of device10. The example ofFIG.1is merely illustrative. If desired, housing12may have other shapes (e.g., a square shape, cylindrical shape, spherical shape, combinations of these and/or different shapes, etc.).

A schematic diagram of illustrative components that may be used in device10is shown inFIG.2. As shown inFIG.2, device10may include control circuitry28. Control circuitry28may include storage such as storage circuitry30. Storage circuitry30may include 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.

Control circuitry28may include processing circuitry such as processing circuitry32. Processing circuitry32may be used to control the operation of device10. Processing circuitry32may include one or more processors such as microprocessors, microcontrollers, digital signal processors, host processors, baseband processor integrated circuits, application specific integrated circuits, graphics processing units, central processing units (CPUs), etc. Control circuitry28may be configured to perform operations in device10using hardware (e.g., dedicated hardware or circuitry), firmware, and/or software. Software code for performing operations in device10may be stored on storage circuitry30(e.g., storage circuitry30may include non-transitory (tangible) computer readable storage media that stores the software code). The software code may sometimes be referred to as program instructions, software, data, instructions, or code. Software code stored on storage circuitry30may be executed by processing circuitry32.

Control circuitry28may be used to run software on device10such 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 circuitry28may be used in implementing communications protocols. Communications protocols that may be implemented using control circuitry28include 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, antenna-based spatial ranging protocols (e.g., radio detection and ranging (RADAR) protocols or other desired range detection protocols for signals conveyed at millimeter and centimeter wave frequencies), etc. Each communication protocol may be associated with a corresponding radio access technology (RAT) that specifies the physical connection methodology used in implementing the protocol.

Device10may include input-output circuitry24. Input-output circuitry24may include input-output devices26. Input-output devices26may be used to allow data to be supplied to device10and to allow data to be provided from device10to external devices. Input-output devices26may include user interface devices, data port devices, sensors, 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, gyroscopes, 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 circuitry24may include wireless circuitry such as wireless circuitry34for wirelessly conveying radio-frequency signals. While control circuitry28is shown separately from wireless circuitry34in the example ofFIG.2for the sake of clarity, wireless circuitry34may include processing circuitry that forms a part of processing circuitry32and/or storage circuitry that forms a part of storage circuitry30of control circuitry28(e.g., portions of control circuitry28may be implemented on wireless circuitry34). As an example, control circuitry28may include baseband processor circuitry or other control components that form a part of wireless circuitry34.

Wireless circuitry34may include millimeter and centimeter wave transceiver circuitry such as millimeter/centimeter wave transceiver circuitry38. Millimeter/centimeter wave transceiver circuitry38may support communications at frequencies between about 10 GHz and 300 GHz. For example, millimeter/centimeter wave transceiver circuitry38may 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, millimeter/centimeter wave transceiver circuitry38may 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 Kacommunications 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, millimeter/centimeter wave transceiver circuitry38may support IEEE 802.11ad communications at 60 GHZ (e.g., WiGig or 60 GHz Wi-Fi bands around 57-61 GHZ), and/or 5thgeneration mobile networks or 5thgeneration wireless systems (5G) New Radio (NR) Frequency Range 2 (FR2) communications bands between about 24 GHz and 90 GHz. Millimeter/centimeter wave transceiver circuitry38may 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.).

If desired, millimeter/centimeter wave transceiver circuitry38(sometimes referred to herein simply as transceiver circuitry38or millimeter/centimeter wave circuitry38) may perform spatial ranging operations using radio-frequency signals at millimeter and/or centimeter wave frequencies that are transmitted and received by millimeter/centimeter wave transceiver circuitry38. The received signals may be a version of the transmitted signals that have been reflected off of external objects and back towards device10. Control circuitry28may process the transmitted and received signals to detect or estimate a range between device10and one or more external objects in the surroundings of device10(e.g., objects external to device10such as the body of a user or other persons, other devices, animals, furniture, walls, or other objects or obstacles in the vicinity of device10). If desired, control circuitry28may also process the transmitted and received signals to identify a two or three-dimensional spatial location of the external objects relative to device10.

Spatial ranging operations performed by millimeter/centimeter wave transceiver circuitry38are unidirectional. If desired, millimeter/centimeter wave transceiver circuitry38may also perform bidirectional communications with external wireless equipment such as external wireless equipment10(e.g., over a bi-directional millimeter/centimeter wave wireless communications link). The external wireless equipment may include other electronic devices such as electronic device10, a wireless base station, wireless access point, a wireless accessory, or any other desired equipment that transmits and receives millimeter/centimeter wave signals. Bidirectional communications involve both the transmission of wireless data by millimeter/centimeter wave transceiver circuitry38and the reception of wireless data that has been transmitted by external wireless equipment. The wireless data may, for example, include data that has been encoded into corresponding data packets such as wireless data associated with a telephone call, streaming media content, internet browsing, wireless data associated with software applications running on device10, email messages, etc.

If desired, wireless circuitry34may include transceiver circuitry for handling communications at frequencies below 10 GHz such as non-millimeter/centimeter wave transceiver circuitry36. For example, non-millimeter/centimeter wave transceiver circuitry36may handle wireless local area network (WLAN) frequency bands (e.g., Wi-Fi® (IEEE 802.11) or other WLAN communications bands) such as a 2.4 GHZ WLAN band (e.g., from 2400 to 2480 MHZ), a 5 GHZ WLAN band (e.g., from 5180 to 5825 MHz), a Wi-Fi® 6E band (e.g., from 5925-7125 MHZ), and/or other Wi-Fi® bands (e.g., from 1875-5160 MHZ), wireless personal area network (WPAN) frequency bands such as the 2.4 GHz Bluetooth® band or other WPAN communications bands, cellular telephone frequency bands (e.g., bands from about 600 MHz to about 5 GHZ, 3G bands, 4G LTE bands, 5G New Radio Frequency Range 1 (FR1) bands below 10 GHz, etc.), near-field communications frequency bands (e.g., at 13.56 MHZ), satellite navigation frequency bands such as the Global Positioning System (GPS) L1 band (e.g., at 1575 MHz), L2 band (e.g., at 1228 MHZ), L3 band (e.g., at 1381 MHZ), L4 band (e.g., at 1380 MHz), and/or L5 band (e.g., at 1176 MHZ), a Global Navigation Satellite System (GLONASS) band, or a BeiDou Navigation Satellite System (BDS) band, ultra-wideband (UWB) frequency bands that operate under the IEEE 802.15.4 protocol and/or other ultra-wideband communications protocols, communications bands under the family of 3GPP wireless communications standards, communications bands under the IEEE 802.XX family of standards, satellite communications bands such as an L-band, S-band (e.g., from 2-4 GHZ), C-band (e.g., from 4-8 GHZ), X-band, Ku-band (e.g., from 12-18 GHZ), Ka-band (e.g., from 26-40 GHz), etc., industrial, scientific, and medical (ISM) bands such as an ISM band between around 900 MHz and 950 MHz or other ISM bands below or above 1 GHz, one or more unlicensed bands, one or more bands reserved for emergency and/or public services, and/or any other desired frequency bands of interest. The communications bands handled by the radio-frequency transceiver circuitry may sometimes be referred to herein as frequency bands or simply as “bands,” and may span corresponding ranges of frequencies. Non-millimeter/centimeter wave transceiver circuitry36and millimeter/centimeter wave transceiver circuitry38may each include one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive radio-frequency components, switching circuitry, transmission line structures, and other circuitry for handling radio-frequency signals.

If desired, non-millimeter/centimeter wave transceiver circuitry36and millimeter/centimeter wave transceiver circuitry38may be integrated into a single transceiver for handling any desired bands. Radio-frequency transceiver circuitry in wireless circuitry34may include respective transceivers (e.g., transceiver integrated circuits or chips) that handle different frequency bands or any desired number of transceivers that handle two or more frequency bands. In scenarios where different transceivers are coupled to the same antenna, filter circuitry (e.g., duplexer circuitry, diplexer circuitry, low pass filter circuitry, high pass filter circuitry, band pass filter circuitry, band stop filter circuitry, etc.), switching circuitry, multiplexing circuitry, or any other desired circuitry may be used to isolate radio-frequency signals conveyed by each transceiver over the same antenna (e.g., filtering circuitry or multiplexing circuitry may be interposed on a radio-frequency transmission line shared by the transceivers). The radio-frequency transceiver circuitry may include one or more integrated circuits (chips), integrated circuit packages (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.), power amplifier circuitry, up-conversion circuitry, down-conversion circuitry, low-noise input amplifiers, passive radio-frequency components, switching circuitry, transmission line structures, and other circuitry for handling radio-frequency signals and/or for converting signals between radio-frequencies, intermediate frequencies, and/or baseband frequencies.

As shown inFIG.2, wireless circuitry34may include antennas40. The transceiver circuitry may convey radio-frequency signals using one or more antennas40(e.g., antennas40may convey the radio-frequency signals for the transceiver circuitry). The term “convey radio-frequency signals” as used herein means the transmission and/or reception of the radio-frequency signals (e.g., for performing unidirectional and/or bidirectional wireless communications with external wireless communications equipment). Antennas40may transmit the radio-frequency signals by radiating the radio-frequency signals into free space (or to freespace through intervening device structures such as a dielectric cover layer). Antennas40may additionally or alternatively receive the radio-frequency signals from free space (e.g., through intervening devices structures such as a dielectric cover layer). The transmission and reception of radio-frequency signals by antennas40each involve the excitation or resonance of antenna currents on an antenna resonating element in the antenna by the radio-frequency signals within the frequency band(s) of operation of the antenna.

In satellite navigation system links, cellular telephone links, and other long-range links, radio-frequency signals are typically used to convey data over thousands of feet or miles. In Wi-Fi® and Bluetooth® links at 2.4 and 5 GHZ and other short-range wireless links, radio-frequency signals are typically used to convey data over tens or hundreds of feet. Millimeter/centimeter wave transceiver circuitry38may convey radio-frequency signals over short distances that travel over a line-of-sight path. To enhance signal reception for millimeter and centimeter wave communications, phased antenna arrays and beam forming (steering) techniques may be used (e.g., schemes in which antenna signal phase and/or magnitude for each antenna in an array are 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.

Antennas40in wireless circuitry34may be formed using any suitable antenna types. For example, antennas40may include antennas with resonating elements that are formed from stacked patch antenna structures, loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, monopole antenna structures, dipole antenna structures, helical antenna structures, Yagi (Yagi-Uda) antenna structures, hybrids of these designs, etc. In another suitable arrangement, antennas40may include antennas with dielectric resonating elements such as dielectric resonator antennas. 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 non-millimeter/centimeter wave wireless link for non-millimeter/centimeter wave transceiver circuitry36and another type of antenna may be used in conveying radio-frequency signals at millimeter and/or centimeter wave frequencies for millimeter/centimeter wave transceiver circuitry38. Antennas40that are used to convey radio-frequency signals at millimeter and centimeter wave frequencies may be arranged in one or more phased antenna arrays.

A schematic diagram of an antenna40that may be formed in a phased antenna array for conveying radio-frequency signals at millimeter and centimeter wave frequencies is shown inFIG.3. As shown inFIG.3, antenna40may be coupled to millimeter/centimeter (MM/CM) wave transceiver circuitry38. Millimeter/centimeter wave transceiver circuitry38may be coupled to antenna feed44of antenna40using a transmission line path that includes radio-frequency transmission line42. Radio-frequency transmission line42may include a positive signal conductor such as signal conductor46and may include a ground conductor such as ground conductor48. Ground conductor48may be coupled to the antenna ground for antenna40(e.g., over a ground antenna feed terminal of antenna feed44located at the antenna ground). Signal conductor46may be coupled to the antenna resonating element for antenna40. For example, signal conductor46may be coupled to a positive antenna feed terminal of antenna feed44located at the antenna resonating element.

Radio-frequency transmission line42may include a stripline transmission line (sometimes referred to herein simply as a stripline), a coaxial cable, a coaxial probe realized by metalized vias, a microstrip transmission line, an edge-coupled microstrip transmission line, an edge-coupled stripline transmission lines, a waveguide structure, combinations of these, etc. Multiple types of transmission lines may be used to form the transmission line path that couples millimeter/centimeter wave transceiver circuitry38to antenna feed44. Filter circuitry, switching circuitry, impedance matching circuitry, phase shifter circuitry, amplifier circuitry, and/or other circuitry may be interposed on radio-frequency transmission line42, if desired.

Radio-frequency transmission lines in device10may be integrated into ceramic substrates, rigid printed circuit boards, and/or flexible printed circuits. In one suitable arrangement, radio-frequency transmission lines in device10may be integrated within multilayer laminated structures (e.g., layers of a conductive material such as copper and a dielectric material such as a resin that are laminated together without intervening adhesive) that may be folded or bent in multiple dimensions (e.g., two or three dimensions) and that maintain a bent or folded shape after bending (e.g., the multilayer laminated structures may be folded into a particular three-dimensional shape to route around other device components and may be rigid enough to hold its shape after folding without being held in place by stiffeners or other structures). All of the multiple layers of the laminated structures may be batch laminated together (e.g., in a single pressing process) without adhesive (e.g., as opposed to performing multiple pressing processes to laminate multiple layers together with adhesive).

FIG.4shows how antennas40for handling radio-frequency signals at millimeter and centimeter wave frequencies may be formed in a phased antenna array. As shown inFIG.4, phased antenna array54(sometimes referred to herein as array54, antenna array54, or array54of antennas40) may be coupled to radio-frequency transmission lines42. For example, a first antenna40-1in phased antenna array54may be coupled to a first radio-frequency transmission line42-1, a second antenna40-2in phased antenna array54may be coupled to a second radio-frequency transmission line42-2, an Nth antenna40-N in phased antenna array54may be coupled to an Nth radio-frequency transmission line42-N, etc. While antennas40are described herein as forming a phased antenna array, the antennas40in phased antenna array54may sometimes also be referred to as collectively forming a single phased array antenna.

Antennas40in phased antenna array54may 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, radio-frequency transmission lines42may be used to supply signals (e.g., radio-frequency signals such as millimeter wave and/or centimeter wave signals) from millimeter/centimeter wave transceiver circuitry38(FIG.3) to phased antenna array54for wireless transmission. During signal reception operations, radio-frequency transmission lines42may be used to supply signals received at phased antenna array54(e.g., from external wireless equipment or transmitted signals that have been reflected off of external objects) to millimeter/centimeter wave transceiver circuitry38(FIG.3).

The use of multiple antennas40in phased antenna array54allows beam steering arrangements to be implemented by controlling the relative phases and magnitudes (amplitudes) of the radio-frequency signals conveyed by the antennas. In the example ofFIG.4, antennas40each have a corresponding radio-frequency phase and magnitude controller50(e.g., a first phase and magnitude controller50-1interposed on radio-frequency transmission line42-1may control phase and magnitude for radio-frequency signals handled by antenna40-1, a second phase and magnitude controller50-2interposed on radio-frequency transmission line42-2may control phase and magnitude for radio-frequency signals handled by antenna40-2, an Nth phase and magnitude controller50-N interposed on radio-frequency transmission line42-N may control phase and magnitude for radio-frequency signals handled by antenna40-N, etc.).

Phase and magnitude controllers50may each include circuitry for adjusting the phase of the radio-frequency signals on radio-frequency transmission lines42(e.g., phase shifter circuits) and/or circuitry for adjusting the magnitude of the radio-frequency signals on radio-frequency transmission lines42(e.g., power amplifier and/or low noise amplifier circuits). Phase and magnitude controllers50may sometimes be referred to collectively herein as beam steering circuitry (e.g., beam steering circuitry that steers the beam of radio-frequency signals transmitted and/or received by phased antenna array54).

Phase and magnitude controllers50may adjust the relative phases and/or magnitudes of the transmitted signals that are provided to each of the antennas in phased antenna array54and may adjust the relative phases and/or magnitudes of the received signals that are received by phased antenna array54. Phase and magnitude controllers50may, if desired, include phase detection circuitry for detecting the phases of the received signals that are received by phased antenna array54. The term “beam” or “signal beam” may be used herein to collectively refer to wireless signals that are transmitted and received by phased antenna array54in a particular direction. The signal beam may exhibit a peak gain that is oriented in a particular pointing direction at a corresponding pointing angle (e.g., based on constructive and destructive interference from the combination of signals from each antenna in the phased antenna array). The term “transmit beam” may sometimes be used herein to refer to radio-frequency signals that are transmitted in a particular direction whereas the term “receive beam” may sometimes be used herein to refer to radio-frequency signals that are received from a particular direction. If, for example, phase and magnitude controllers50are adjusted to produce a first set of phases and/or magnitudes for transmitted radio-frequency signals, the transmitted signals will form a transmit beam as shown by beam B1 ofFIG.4that is oriented in the direction of point A. If, however, phase and magnitude controllers50are adjusted to produce a second set of phases and/or magnitudes for the transmitted signals, the transmitted signals will form a transmit beam as shown by beam B2 that is oriented in the direction of point B. Similarly, if phase and magnitude controllers50are adjusted to produce the first set of phases and/or magnitudes, radio-frequency signals (e.g., radio-frequency signals in a receive beam) may be received from the direction of point A, as shown by beam B1. If phase and magnitude controllers50are adjusted to produce the second set of phases and/or magnitudes, radio-frequency signals may be received from the direction of point B, as shown by beam B2.

Each phase and magnitude controller50may be controlled to produce a desired phase and/or magnitude based on a corresponding control signal52received from control circuitry28ofFIG.2(e.g., the phase and/or magnitude provided by phase and magnitude controller50-1may be controlled using control signal52-1, the phase and/or magnitude provided by phase and magnitude controller50-2may be controlled using control signal52-2, etc.). If desired, the control circuitry may actively adjust control signals52in real time to steer the transmit or receive beam in different desired directions over time. Phase and magnitude controllers50may provide information identifying the phase of received signals to control circuitry28if desired.

When performing wireless communications using radio-frequency signals at millimeter and centimeter wave frequencies, the radio-frequency signals are conveyed over a line of sight path between phased antenna array54and external communications equipment. If the external object is located at point A ofFIG.4, phase and magnitude controllers50may be adjusted to steer the signal beam towards point A (e.g., to steer the pointing direction of the signal beam towards point A). Phased antenna array54may transmit and receive radio-frequency signals in the direction of point A. Similarly, if the external communications equipment is located at point B, phase and magnitude controllers50may be adjusted to steer the signal beam towards point B (e.g., to steer the pointing direction of the signal beam towards point B). Phased antenna array54may transmit and receive radio-frequency signals in the direction of point B. In the example ofFIG.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 ofFIG.4). However, in practice, the beam may be steered over two or more degrees of freedom (e.g., in three dimensions, into and out of the page and to the left and right on the page ofFIG.4). Phased antenna array54may have a corresponding field of view over which beam steering can be performed (e.g., in a hemisphere or a segment of a hemisphere over the phased antenna array). If desired, device10may include multiple phased antenna arrays that each face a different direction to provide coverage from multiple sides of the device.

Any desired antenna structures may be used for implementing antennas40. In one suitable arrangement that is sometimes described herein as an example, patch antenna structures may be used for implementing antennas40. Antennas40that are implemented using patch antenna structures may sometimes be referred to herein as patch antennas. An illustrative patch antenna that may be used in phased antenna array54ofFIG.4is shown inFIG.5.

As shown inFIG.5, antenna40may have a patch antenna resonating element58that is separated from and parallel to a ground plane such as antenna ground56. Patch antenna resonating element58may lie within a plane such as the A-B plane ofFIG.5(e.g., the lateral surface area of element58may lie in the A-B plane). Patch antenna resonating element58may sometimes be referred to herein as patch58, patch element58, patch resonating element58, antenna resonating element58, or resonating element58. Antenna ground56may lie within a plane that is parallel to the plane of patch element58. Patch element58and antenna ground56may therefore lie in separate parallel planes that are separated by distance65. Patch element58and antenna ground56may be formed from conductive traces patterned on a dielectric substrate such as a rigid or flexible printed circuit board substrate or any other desired conductive structures.

The length of the sides of patch element58may be selected so that antenna40resonates at a desired operating frequency. For example, the sides of patch element58may each have a length68that is approximately equal to half of the wavelength of the signals conveyed by antenna40(e.g., the effective wavelength given the dielectric properties of the materials surrounding patch element58). In one suitable arrangement, length68may be between 0.8 mm and 1.2 mm (e.g., approximately 1.1 mm) for covering a millimeter wave frequency band between 57 GHz and 70 GHz or between 1.6 mm and 2.2 mm (e.g., approximately 1.85 mm) for covering a millimeter wave frequency band between 37 GHz and 41 GHz, as just two examples.

The example ofFIG.5is merely illustrative. Patch element58may have a square shape in which all of the sides of patch element58are the same length or may have a different rectangular shape. Patch element58may be formed in other shapes having any desired number of straight and/or curved edges.

To enhance the polarizations handled by antenna40, antenna40may be provided with multiple feeds. As shown inFIG.5, antenna40may have a first feed at antenna port P1 that is coupled to a first radio-frequency transmission line42such as radio-frequency transmission line42V. Antenna40may have a second feed at antenna port P2 that is coupled to a second radio-frequency transmission line42such as radio-frequency transmission line42H. The first antenna feed may have a first ground feed terminal coupled to antenna ground56(not shown inFIG.5for the sake of clarity) and a first positive antenna feed terminal62V coupled to patch element58. The second antenna feed may have a second ground feed terminal coupled to antenna ground56(not shown inFIG.5for the sake of clarity) and a second positive antenna feed terminal62H on patch element58.

Holes or openings such as openings64and66may be formed in antenna ground56.

Radio-frequency transmission line42V may include a vertical conductor (e.g., a conductive through-via, conductive pin, metal pillar, solder bump, combinations of these, or other vertical conductive interconnect structures) that extends through opening64to positive antenna feed terminal62V on patch element58. Radio-frequency transmission line42H may include a vertical conductor that extends through opening66to positive antenna feed terminal62H on patch element58. This example is merely illustrative and, if desired, other transmission line structures may be used (e.g., coaxial cable structures, stripline transmission line structures, etc.).

When using the first antenna feed associated with port P1, antenna40may transmit and/or receive radio-frequency signals having a first polarization (e.g., the electric field E1 of radio-frequency signals70associated with port P1 may be oriented parallel to the B-axis inFIG.5). When using the antenna feed associated with port P2, antenna40may transmit and/or receive radio-frequency signals having a second polarization (e.g., the electric field E2 of radio-frequency signals70associated with port P2 may be oriented parallel to the A-axis ofFIG.5so that the polarizations associated with ports P1 and P2 are orthogonal to each other).

One of ports P1 and P2 may be used at a given time so that antenna40operates as a single-polarization antenna or both ports may be operated at the same time so that antenna40operates with other polarizations (e.g., as a dual-polarization antenna, a circularly-polarized antenna, an elliptically-polarized antenna, etc.). If desired, the active port may be changed over time so that antenna40can switch between covering vertical or horizontal polarizations at a given time. Ports P1 and P2 may be coupled to different phase and magnitude controllers50(FIG.3) or may both be coupled to the same phase and magnitude controller50. If desired, ports P1 and P2 may both be operated with the same phase and magnitude at a given time (e.g., when antenna40acts as a dual-polarization antenna). If desired, the phases and magnitudes of radio-frequency signals conveyed over ports P1 and P2 may be controlled separately and varied over time so that antenna40exhibits other polarizations (e.g., circular or elliptical polarizations).

If care is not taken, antennas40such as dual-polarization patch antennas of the type shown inFIG.5may have insufficient bandwidth for covering relatively wide ranges of frequencies. It may be desirable for antenna40to be able to cover a first frequency band, a second frequency band at frequencies higher than the first frequency band, and a third frequency higher than the second frequency band. In one suitable arrangement that is described herein as an example, the first frequency band may include frequencies from about 24.5-29.5 GHZ (sometimes referred to herein as a low band), the second frequency band may include frequencies from about 37-43.5 GHz (sometimes referred to herein as a midband), and the third frequency band may include frequencies from about 47-48 GHZ (sometimes referred to herein as a high band). In these scenarios, a single patch element58may not exhibit sufficient bandwidth on its own to cover an entirety of the first, second, and third frequency bands.

While only a single patch element58is shown inFIG.5for the sake of clarity, antenna40may include multiple patch elements58that are vertically stacked and overlapping each other (e.g., along the +C direction). Each patch element58may be directly fed using respective antenna feeds and may be coupled to one or two corresponding positive antenna feed terminals62. Each patch element58may have different dimensions or a different size to cover different frequency bands for antenna40. Additionally or alternatively, antenna40may include one or more additional patch elements60that are stacked over one or more patch elements58.

Patch element60is unfed (e.g., there are no antenna feed terminals on patch elements60). As such, patch element60is a parasitic patch. Patch element60may therefore sometimes be referred to herein as parasitic patch element60, parasitic patch60, or parasitic60. Parasitic patch60may partially or completely overlap an underlying patch element58. If desired, multiple stacked parasitic patches60may be provided over an underlying patch element58and may be excited by the underlying patch element58. A lower-most parasitic patch60may be separated from a corresponding patch element58by distance D, which is selected to provide antenna40with a desired bandwidth without occupying excessive volume within device10. Parasitic patch60may be indirectly fed or excited by the underlying directly fed patch element58. Parasitic patch60may have sides with lengths other than length68, which configure the parasitic patch to radiate at different frequencies than the underlying patch element58, thereby extending the overall bandwidth of antenna40.

The combined resonances of each patch element58and each parasitic patch60in antenna40may configure antenna40to radiate with satisfactory antenna efficiency across an entirety of the first, second, and third frequency bands (e.g., from 24.5-29.5 GHZ, from 37-43.5 GHz, and from 47-48 GHZ). The example ofFIG.5is merely illustrative. Parasitic patches60may be omitted if desired. Parasitic patches60may be rectangular, square, cross-shaped, or any other desired shape having any desired number of straight and/or curved edges. Parasitic patch60may be provided at any desired orientation relative to its underlying patch element58. Antenna40may have any desired number of feeds. Other antenna types may be used if desired (e.g., dipole antennas, monopole antennas, slot antennas, etc.).

If desired, phased antenna array54may be integrated with other circuitry such as a radio-frequency integrated circuit to form an integrated antenna module.FIG.6is a rear perspective view showing one example of integrated antenna module for handling signals at frequencies greater than 10 GHz in device10. As shown inFIG.6, device10may be provided with an integrated antenna module such as integrated antenna module72(sometimes referred to herein as antenna module72or module72).

Antenna module72may include phased antenna array54of antennas40formed on a dielectric substrate such as substrate85. Substrate85may be, for example, a rigid printed circuit board, a flexible printed circuit board, a plastic substrate (e.g., a molded substrate), a polymer substrate, an interposer (e.g., a glass or silicon interposer), or another type of substrate. If desired, substrate85may be a stacked dielectric substrate that includes multiple stacked dielectric layers80(e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy, polymer, silicon, rigid printed circuit board material, ceramic, polyimide, flexible printed circuit board material, plastic, glass, or other dielectrics). Phased antenna array54may include any desired number of antennas40arranged in any desired pattern.

Antennas40in phased antenna array54may include antenna elements such as patch elements91(e.g., patch elements91may form patch element58and/or one or more parasitic patches60ofFIG.5). Ground traces82may be patterned onto substrate85(e.g., conductive traces forming antenna ground56ofFIG.5for each of the antennas40in phased antenna array54). Patch elements91may be patterned on (bottom) surface78of substrate85or may be embedded within dielectric layers80at or adjacent to surface78. Only two patch elements91are shown inFIG.6for the sake of clarity. This is merely illustrative and, in general, antennas40may include any desired number of patch elements91.

One or more electrical components74may be mounted on (top) surface76of substrate85(e.g., the surface of substrate85opposite surface78and patch elements91). Component74may, for example, include an integrated circuit (e.g., an integrated circuit chip) or other circuitry mounted to surface76of substrate85. Component74may include radio-frequency components such as amplifier circuitry, phase shifter circuitry (e.g., phase and magnitude controllers50ofFIG.4), and/or other circuitry that operates on radio-frequency signals. Component74may sometimes be referred to herein as radio-frequency integrated circuit (RFIC)74. However, this is merely illustrative and, in general, the circuitry of RFIC74need not be formed on an integrated circuit. Component74may be embedded within a plastic overmold if desired.

The dielectric layers80in substrate85may include a first set of layers86(sometimes referred to herein as antenna layers86) and a second set of layers84(sometimes referred to herein as transmission line layers84). Ground traces82may separate antenna layers86from transmission line layers84. Conductive traces or other metal layers on transmission line layers84may be used in forming transmission line structures such as radio-frequency transmission lines42ofFIG.4(e.g., radio-frequency transmission lines42V and42H ofFIG.5). For example, conductive traces on transmission line layers84may be used in forming stripline or microstrip transmission lines that are coupled between the antenna feeds for antennas40(e.g., over conductive vias extending through antenna layers86) and RFIC74(e.g., over conductive vias extending through transmission line layers84). A board-to-board connector (not shown) may couple RFIC74to the baseband and/or transceiver circuitry for phased antenna array54(e.g., millimeter/centimeter wave transceiver circuitry38ofFIG.3).

If desired, each antenna40in phased antenna array54may be laterally surrounded by fences of conductive vias88(e.g., conductive vias extending parallel to the X-axis and through antenna layers86ofFIG.6). The fences of conductive vias88for phased antenna array54may be shorted to ground traces82so that the fences of conductive vias88are held at a ground potential. Conductive vias88may extend downwards to surface78or to the same dielectric layer80as the bottom-most conductive patch91in phased antenna array54.

The fences of conductive vias88may be opaque at the frequencies covered by antennas40. Each antenna40may lie within a respective antenna cavity92having conductive cavity walls defined by a corresponding set of fences of conductive vias88in antenna layers86. The fences of conductive vias88may help to ensure that each antenna40in phased antenna array54is suitably isolated, for example. Phased antenna array54may include a number of antenna unit cells90. Each antenna unit cell90may include respective fences of conductive vias88, a respective antenna cavity92defined by (e.g., laterally surrounded by) those fences of conductive vias, and a respective antenna40(e.g., set of patch elements91) within that antenna cavity92. Conductive vias88may be omitted if desired.

If desired, the antennas on antenna module72may radiate through peripheral conductive housing structures12W (FIG.1).FIG.7is a top view of device10showing different illustrative locations for positioning antenna module72to convey radio-frequency signals through peripheral conductive housing structures12W of device10. As shown inFIG.7, device10may include peripheral conductive housing structures12W (e.g., four peripheral conductive housing sidewalls that surround the rectangular periphery of device10). In other words, device10may have a length (parallel to the Y-axis), a width that is less than the length (parallel to the X-axis), and a height that is less than the width (parallel to the Z-axis). Peripheral conductive housing structures12W may extend across the length and the width of device10(e.g., peripheral conductive housing structures12W may include a first conductive sidewall extending along the left edge of device10, a second conductive sidewall extending along the top edge of device10, a third conductive sidewall extending along the right edge of device10, and a fourth conductive sidewall extending along the bottom edge of device10). Peripheral conductive housing structures12W may also extend across the height of device10(e.g., as shown in the perspective view ofFIG.1).

As shown inFIG.7, display14may have a display module such as display module94. Peripheral conductive housing structures12W may run around the periphery of display module94(e.g., along all four sides of device10). Display module94may be covered by a display cover layer (not shown). The display cover layer may extend across the entire length and width of device10and may, if desired, be mounted to or otherwise supported by peripheral conductive housing structures12W.

Display module94(sometimes referred to as a display panel, active display circuitry, or active display structures) may be any desired type of display panel and may include pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable pixel structures. The lateral area of display module94may, for example, determine the size of the active area of display14(e.g., active area AA ofFIG.1). Display module94may include active light emitting components, touch sensor components (e.g., touch sensor electrodes), force sensor components, and/or other active components. Because display module94includes conductive components, display module94may block radio-frequency signals from passing through display14. Antenna module72ofFIG.6may therefore be located within regions96around the periphery of display module94and device10. One or more regions96ofFIG.7may, for example, include a corresponding antenna module72. Apertures may be formed within peripheral conductive housing structures12W within regions96to allow the antennas in antenna module72to convey radio-frequency signals to and/or from the exterior of device10(e.g., through the apertures).

In the example ofFIG.7, each region96is located along a respective side (edge) of device10(e.g., along the top conductive sidewall of device10within region20, along the bottom conductive sidewall of device10within region22, along the left conductive sidewall of device10, and along the right conductive sidewall of device10). Antennas mounted in these regions may provide millimeter and centimeter wave communications coverage for device10around the lateral periphery of device10. When combined with the contribution of antennas that radiate through the front and/or rear faces of device10, the antennas in device10may provide a full sphere of millimeter/centimeter wave coverage around device10. The example ofFIG.7is merely illustrative. Each edge of device10may include multiple regions96and some edges of device10may include no regions96. If desired, additional regions96may be located elsewhere on device10.

FIG.8is a side view showing how apertures may be formed in peripheral conductive housing structures12W to allow the antennas in antenna module72to convey radio-frequency signals to and/or from the exterior of device10(within a given region96ofFIG.7). The example ofFIG.8illustrates apertures that may be formed in the right-most region96ofFIG.7(e.g., along the right conductive sidewall as viewed in the direction of arrow97ofFIG.7). Similar apertures may be formed in any desired conductive sidewall of device10.

As shown inFIG.8, device10may have a first (front) face defined by display14and a second (rear) face defined by rear housing wall12R. Display14may be mounted to peripheral conductive structures12W, which extend from the rear face to the front face and around the periphery of device10. One or more gaps18may extend from the rear face to the front face to divide peripheral conductive housing structures12W into different segments.

One or more antenna apertures such as apertures98may be formed in peripheral conductive housing structures12W. Apertures98(sometimes referred to herein as slots98) may be filled with one or more dielectric materials and may have edges that are defined by the conductive material in peripheral conductive housing structures12W. Antenna module72ofFIG.6may be mounted within the interior of device10(e.g., with the antennas facing apertures98). Each aperture98may be aligned with a respective antenna40in the antenna module. The center of each aperture98may therefore be separated from the center of one or two adjacent apertures98by distance E.

In addition to allowing radio-frequency signals to pass between the antenna module and the exterior of device10, apertures98may also form waveguide radiators for the antennas in the antenna module, if desired. For example, the radio-frequency signals conveyed by the antennas may excite one or more electromagnetic waveguide (cavity) modes within apertures98, which contribute to the overall resonance and frequency response of the antennas in the antenna module.

Apertures98may have any desired shape. In the example ofFIG.8, apertures98are rectangular. Each aperture98may have a corresponding length L2 and width W2. Length L2 and width W2 may be selected establish resonant cavity modes within apertures98(e.g., electromagnetic waveguide modes that contribute to the radiative response of antennas40). Length L2 may, for example, be selected to establish a horizontally-polarized resonant cavity mode for aperture98and width W2 may be selected to establish a vertically-polarized resonant cavity mode for aperture98.

At the same time, if care is not taken, impedance discontinuities between the antennas in the antenna module and free space at the exterior of device10may introduce undesirable signal reflections and losses that limits the overall gain and efficiency for the antennas. Apertures98may therefore also serve as an impedance transition between the antenna module and free space at the exterior of device10that is free from undesirable impedance discontinuities.

In practice, it can be difficult to incorporate antennas40that cover each of a low band, midband, and high band into antenna module72while still allowing the antenna module to be aligned with apertures98without consuming an excessive amount of space within device10. To allow antenna module72to support antennas40that radiate in each of the low band, midband, and high band while also allowing antenna module72be more flexibly placed within device10(such as in alignment with apertures98), antenna module72may include multiple stacked substrates and the antennas40in antenna module may be distributed across the stacked substrates.

FIG.9is a cross-sectional top view showing one example of an antenna40that may radiate in the low band, midband, and high band (e.g., through a corresponding aperture98in peripheral conductive housing structures12W) and that may be distributed across multiple stacked substrates in antenna module72. As shown inFIG.9, antenna module72may include an additional substrate such as substrate100.

Substrate100may be mounted to a lateral (exterior) surface124of substrate85. Substrate100may be different from, external to, and smaller than substrate85. Substrate85may therefore sometimes be referred to herein as primary substrate85whereas substrate100is sometimes referred to herein as secondary substrate100. Secondary substrate100may be, for example, a rigid printed circuit board, a flexible printed circuit board, a plastic substrate (e.g., a molded substrate), a polymer substrate, an interposer (e.g., a glass or silicon interposer), or another type of substrate. If desired, secondary substrate100may be a stacked dielectric substrate that includes multiple stacked dielectric layers102(e.g., multiple layers of printed circuit board substrate such as multiple layers of fiberglass-filled epoxy, polymer, silicon, rigid printed circuit board material, ceramic, polyimide, flexible printed circuit board material, plastic, glass, or other dielectrics).

Primary substrate85may be formed from the same type of material as secondary substrate100or may be formed from a different type of material than secondary substrate100. Secondary substrate100is smaller than primary substrate85and may have a different thickness and/or shape than primary substrate85. This may, for example, allow secondary substrate100to be placed at locations in device10that are nearby other components that would otherwise prevent primary substrate85from fitting at those locations. As one example, secondary substrate100may have a circular, elliptical, or rounded lateral outline (e.g., within the Y-Z plane) whereas primary substrate85has a rectangular or square lateral outline.

If desired, secondary substrate100may be surface-mounted to lateral surface124of primary substrate85using solder (e.g., using an array or grid of solder balls, using surface mount technology (SMT), etc.). As shown in the example ofFIG.9, solder ball120is used to couple a conductive contact pad122on lateral surface126of secondary substrate100to a conductive contact pad118on lateral surface124of primary substrate85. Solder ball120and contact pads122and118may form an interconnect116(e.g., a solder-based interconnection or solder interconnect) between secondary substrate100and primary substrate85. Interconnect116is external to substrates100and85. Interconnect116may serve to mechanically secure secondary substrate100to primary substrate85and may, if desired, be used to convey signals and/or power between components on or within primary substrate85and components on or within secondary substrate100.

While only a single interconnect116is shown inFIG.9for the sake of clarity, any desired number of interconnects116may be used to mount secondary substrate100to primary substrate85(e.g., a grid or array of interconnects116). Some of the interconnects may include solder balls coupled to dummy pads on substrates100and85and/or ground traces on substrates100and85if desired. The example ofFIG.9is merely illustrative. In general, interconnects116may include solder, adhesive, conductive pins, conductive springs, a ball grid array, a conductive bracket, and/or other conductive interconnect structures that serve to mount lateral surface126of secondary substrate100to lateral surface124of primary substrate85. Some or all of the interconnects116may also convey signals and/or power between substrates100and85.

Antenna40may include at least a first patch element58-1and a second patch element58-2overlapping patch element58-1. Antenna40may also include at least one parasitic patch60overlapping patch elements58-1and58-2. Patch elements58-1and58-2and parasitic patch60may each have respective dimensions that configure antenna40to collectively cover, for example, the low band (24.5-29.5 GHZ), the midband (37-43.5 GHZ), and the high band (47-48 GHz). For example, the resonance of patch element58-1may cover some of the low band, parasitic patch60may extend coverage to include all of the low band, and patch element58-2may further extend coverage to include the midband and the high band. This is merely illustrative and, in general, antenna40may cover any desired bands or frequencies.

The components of antenna40may be distributed between primary substrate85and secondary substrate100(e.g., through at least one interconnect116). For example, patch element58-1and parasitic patch60may be disposed in primary substrate85whereas patch element58-2is disposed in secondary substrate100. This is merely illustrative and, if desired, secondary substrate100may include one or more parasitic patches60(e.g., parasitic patch60may be disposed in secondary substrate100over or under patch element58-2instead of in primary substrate85, additional parasitic patches60may be disposed in secondary substrate100, etc.), secondary substrate100may include more than one overlapping patch element58on different dielectric layers102, patch element58-2may be disposed in primary substrate85(e.g., patch elements58-1and58-2may both be disposed in substrate85whereas one or more parasitic patches60are disposed in secondary substrate100), primary substrate85may be free from parasitic patches (e.g., parasitic patch60may be omitted or instead disposed in secondary substrate100), primary substrate85may include more than one patch element58(e.g., in addition to patch element58-2in secondary substrate100) and/or more than one parasitic patch60, and/or the components of antenna40may be distributed across secondary substrate100and primary substrate85in any desired manner.

As shown in the example ofFIG.9, patch element58-1may be formed from a first conductive trace106(e.g., a first layer of one or more conductive traces) on a first dielectric layer80of primary substrate85. Parasitic patch60may be formed from a second conductive trace108(e.g., a second layer of one or more conductive traces) on a second dielectric layer80of primary substrate85(e.g., between patch element58-1and lateral surface124). Alternatively, conductive trace108may be disposed on lateral surface124. Patch element58-2may be formed from a third conductive trace110(e.g., a third layer of one or more conductive traces) on a dielectric layer102of secondary substrate100. Alternatively, patch element58-2may be formed on lateral surface126or lateral surface128of secondary substrate100. Conductive trace110may overlap conductive traces108and106(e.g., when viewed in the −X direction). Conductive trace108may overlap conductive trace106and may be vertically interposed between conductive traces110and106. In this way, antenna40may be embedded within both secondary substrate100and primary substrate85.

Signal traces130and132may be patterned onto one or more of the transmission line layers84of primary substrate85. A conductive via such as conductive via136may extend through an opening144in ground traces82to couple signal trace132to patch element58-1(e.g., at a positive antenna feed terminal for patch element58-1such as positive antenna feed terminals62V or62H ofFIG.5). If desired, impedance matching structures112may be disposed on conductive via114between signal trace132and patch element58-1.

Impedance matching structures112may include one or more layers of conductive traces on one or more dielectric layers102of secondary substrate100and/or one or more conductive vias extending vertically through one or more dielectric layers102. The conductive traces in impedance matching structures112may be coupled together by conductive vias or may be separated by gaps. The conductive traces may, for example, form one or more printed capacitors, inductors, and/or impedance matching segments of a transmission line coupled between signal trace132and patch element58-1. The number, length, and width of the conductive traces and/or conductive vias in impedance matching structures112may be selected to perform impedance matching between patch element58-1and signal trace132at the frequencies of operation for patch element58-1, for example.

Signal trace132and conductive via136may form part of the signal conductor of a radio-frequency transmission line path for patch element58-1(e.g., signal conductor46in radio-frequency transmission line42ofFIG.3, having a ground conductor formed from ground traces82). In other words, patch element58-1may be fed through some of the antenna layers86of primary substrate85. On the other hand, patch element58-2on secondary substrate100may be fed through primary substrate85(e.g., all of the antenna layers86in primary substrate85) and interconnect116.

For example, a conductive via such as conductive via134may couple signal trace130to interconnect116. Conductive via134may extend from signal trace130through opening142in ground traces82, through an opening140in patch element58-1, and through an opening138in parasitic patch60to contact pad118at lateral surface124. Openings140,138,142, and144may sometimes also be referred to herein as slots or holes. Secondary substrate100may include impedance matching structures104that couple interconnect116(e.g., contact pad122) to patch element58-2(e.g., at a positive antenna feed terminal for patch element58-2such as positive antenna feed terminals62V or62H ofFIG.5).

Impedance matching structures104may include one or more conductive vias extending through one or more dielectric layers102of secondary substrate100(e.g., including conductive vias coupled to patch element58-2and contact pad122) and/or one or more layers of conductive traces on one or more dielectric layers102of secondary substrate100. The conductive traces may, for example, form one or more printed capacitors, inductors, and/or impedance matching segments of a transmission line coupled between signal trace130and patch element58-2. The number, length, and width of the conductive traces and/or conductive vias may be selected to perform impedance matching between patch element58-2and signal trace130at the frequencies of operation for patch element58-2, for example. If desired, external impedance matching components (e.g., SMT components) may be mounted to a surface of primary substrate85and/or secondary substrate100and may be coupled to the signal paths for patch elements58-1and/or58-2to perform impedance matching in addition to or instead of embedded impedance matching structures104and112.

Signal trace130, conductive via136, and impedance matching structures104may form part of the signal conductor of a radio-frequency transmission line path for patch element58-1(e.g., signal conductor46in radio-frequency transmission line42ofFIG.3and having a ground conductor formed from ground traces82). If desired, some or all of parasitic patch60and/or patch element58-1may form part of the reference ground (antenna ground) for patch element58-2at the resonant frequencies of patch element58-2. If desired, secondary substrate100may include ground traces (not shown) on one or more dielectric layers102and/or on lateral surface126that additionally or alternatively form the reference ground for patch element58-2.

If desired, one or more conductive vias114may couple patch element58-1and/or parasitic patch60to ground traces82through the antenna layers86of primary substrate85. Conductive vias114may, for example, include a fence of conductive vias that laterally surrounds conductive via134and openings142,140, and138(e.g., in the Y-Z plane). Conductive vias114may serve to shield conductive via134and thus the signal conductor for patch element58-2from interference from low band signals on patch element58-1and parasitic patch60. In this way, the excitation of patch element58-2in the midband and high band may be electrically separated from the excitation of patch element58-1in the low band. This electrical separation may allow for relatively high isolation (e.g., greater than 15 dB) between patch element58-1and parasitic patch60in the low band and patch element58-2in the midband and high band. The electrical separation may also allow the architecture of the low band patches to be optimized independently from that of the midband/high band patch.

If desired, some or all of the active components used to support antenna40may be disposed on or mounted to secondary substrate100instead of primary substrate85(e.g., some or all of the active components of RFIC74ofFIG.6may be distributed between primary substrate85and secondary substrate100). The active components may include, for example, an antenna tuner, a transceiver, phase and magnitude controllers (e.g., beam steering circuitry), an IC that covers baseband to radio frequencies, etc.

The example ofFIG.9shows only a single positive antenna feed terminal on patch elements58-1and58-2for the sake of clarity. If desired, patch element58-1and/or patch element58-2may have two positive antenna feed terminals (e.g., positive antenna feed terminals62H and62V ofFIG.5) for covering multiple polarizations.

FIG.10is a cross-sectional side view showing how antenna module72ofFIG.9may be mounted within device10in alignment with a corresponding aperture98in peripheral conductive housing structures12W (e.g., as taken at the location of a given antenna40in the antenna module). As shown inFIG.10, display14may include a display cover layer150that is mounted to ledge (datum)152of peripheral conductive housing structures12W. Aperture98may be formed in peripheral conductive housing structures12W. Rear housing wall12R may extend from peripheral conductive housing structures12W opposite display cover layer150. Rear housing wall12R may include a dielectric cover layer156if desired. Dielectric cover layer156may be formed from glass, plastic, ceramic, or other materials. Peripheral conductive housing structures12W may include a ledge (datum)154that extends along dielectric cover layer156and/or that forms part of rear housing wall12R.

Aperture98may include a cavity formed in peripheral conductive housing structures12W. A dielectric substrate such as dielectric substrate164may be disposed within the cavity. Dielectric substrate164may be formed from injection molded plastic, as one example. Dielectric cover layer158may also be mounted within the cavity. Dielectric cover layer158may have an inner surface that is coupled to dielectric substrate164by adhesive160. Dielectric cover layer158also has an outer surface at the exterior of device10. The outer surface of dielectric cover layer158may, for example, lie flush with exterior surface of peripheral conductive housing structures12W. Dielectric cover layer158may also sometimes be referred to herein as dielectric antenna window158.

Antenna module72may be aligned with aperture98and may be mounted against dielectric substrate164and peripheral conductive housing structures12W. Some or all of antenna module72(e.g., primary substrate85) may be vertically interposed between ledge152and ledge154. If desired, primary substrate85may be attached to peripheral conductive housing structures12W using adhesive166. When mounted in this way, secondary substrate100may protrude into the cavity of aperture98. If desired, dielectric substrate164may have a cavity or recessed portion that accommodates secondary substrate100(e.g., secondary substrate100may be disposed within the recessed portion of dielectric substrate164). Alternatively, dielectric substrate164may be molded onto secondary substrate100.

The shape and size of secondary substrate100may be selected to fit within the cavity of aperture98. Secondary substrate100may, for example, be smaller than primary substrate85and may have a shape that matches or fits within the recessed portion of dielectric substrate164and/or the cavity of aperture98. This may allow secondary substrate100to protrude farther into aperture98than primary substrate85would otherwise be able to protrude. This places patch element58-2closer to dielectric antenna window158and free space than in implementations where patch element58-2is embedded in primary substrate85. This may serve to boost the performance of antenna40across each of the low band, midband, and high band (e.g., increasing gain by 0.5-2.5 dB across all of the bands).

The example ofFIG.10is merely illustrative. In general, antenna module72may be disposed at other locations in device10. The small size and adaptable form factor of secondary substrate100may allow antenna module72to be placed at a greater number of locations in device10(while exhibiting consistent or improved antenna performance) than in scenarios where antenna module72includes only primary substrate85, given the other components that may be present in device10.

FIG.11is a plot of antenna gain as a function of frequency showing how distributing antenna40across primary substrate85and secondary substrate100in antenna module72may optimize antenna performance. Curves172ofFIG.11plot the gain of antenna40in an implementation where antenna module72includes only primary substrate85(e.g., where patch elements58-1and58-2and parasitic patch60are all disposed in primary substrate85). Curves170ofFIG.11plot the gain of antenna40as distributed across primary substrate85and secondary substrate100(e.g., as shown inFIGS.9and10).

As shown by curves170and172, distributing antenna40across primary substrate85and secondary substrate100may increase the gain of antenna40across multiple bands such as a first band B1 (e.g., the low band), a second band B2 (e.g., the midband), and a third band B3 (e.g., the high band) (e.g., by as much as 0.5-2.5 dB) relative to embedding all of antenna40within a single substrate. The example ofFIG.11is merely illustrative and, in practice, curves170and172may have other shapes. Antenna40may cover any desired frequencies.

In the example ofFIGS.9and10, an entirety of secondary substrate100lies above lateral surface124of primary substrate85. This is merely illustrative. If desired, secondary substrate100may be recessed within primary substrate85.FIG.12is a top view showing one example of how secondary substrate100may be recessed within primary substrate85.

As shown inFIG.12, primary substrate85may have a recess180in lateral surface124. Recess180may sometimes also be referred to herein as cavity180. Secondary substrate100may be mounted to lateral surface124of primary substrate85within recess180(e.g., interconnects116may couple secondary substrate100to primary substrate85within recess180). An entirety of secondary substrate100may lie within recess180or, if desired, some of secondary substrate100may protrude out of recess180.

FIG.13is a bottom view showing an example in which primary substrate85is formed from a rigid material (e.g., as a rigid printed circuit board). As shown inFIG.13, RFIC74and connector184may be disposed on surface76of primary substrate85. A cable or printed circuit182may couple connector184to other components in device10(e.g., a main logic board). Connector184and cable182may carry radio-frequency signals, intermediate frequency signals, baseband signals, control signals, power, or other signals between antenna module72and other components (e.g., a main logic board).

If desired, each antenna40in phased antenna array54may be distributed between primary substrate85and a different respective secondary substrate100mounted to lateral surface124of primary substrate85using different respective interconnects116. For example, the patch element58-2(FIG.9) of each antenna40in phased antenna array54may be disposed in a different respective secondary substrate100.

Alternatively, two or more of the antennas40in phased antenna array54may be distributed between primary substrate85and the same secondary substrate100. For example, all of the antennas40in phased antenna array54may be distributed between primary substrate85and the same secondary substrate100′. Secondary substrate100′ may be smaller than primary substrate85and may have a different shape than primary substrate85, which may allow secondary substrate100′ to fit at locations in device10where primary substrate85would otherwise not fit (e.g., within a single elongated aperture98in peripheral conductive housing structures12W).

FIG.14is a bottom view showing an example in which primary substrate85is formed from a flexible material (e.g., as a flexible printed circuit board). As shown inFIG.14, primary substrate85may be formed from a flexible printed circuit board having a first portion186and a second portion188(e.g., a tail portion) that extends away from first portion186. Portion188may have a first thickness T1 and portion186may have a second thickness T2 that is greater than first thickness T1. Portion188may sometimes be referred to herein as thinner portion188whereas portion186is sometimes referred to herein as thicker portion186or tail186.

Phased antenna array54may be mounted to portion186of primary substrate85. Increasing the thickness of primary substrate85within portion186of primary substrate85in this way may serve to optimize the performance of the antennas in phased antenna array54(e.g., by maximizing antenna bandwidth).

If desired, different antennas in phased antenna array54may be oriented at different angles on a primary substrate85formed from flexible printed circuit material.FIG.15is a bottom view showing an example in which primary substrate85is formed from a flexible material and different antennas in phased antenna array54are oriented at different angles on primary substrate85.

As shown inFIG.15, primary substrate85may include multiple portions186having thickness T2 and multiple thinner portions188having thickness T1. Portions188may be bent or folded to orient thicker portions186in different directions. One or more secondary substrates100from phased antenna array54may be mounted to each portion186of primary substrate85. In this way, different antennas in phased antenna array54may be oriented in different directions. Alternatively, the antennas associated with each secondary substrate100may be independent antennas that are not part of the same phased antenna array, the antennas associated with the secondary substrates100on each portion186may form different respective phased antenna arrays oriented in different directions, etc.

FIG.16is a cross-sectional bottom view showing additional structures that may be formed in antenna module72for supporting phased antenna array54. As shown inFIG.16, an underfill190may be provided over the interconnect structures116between secondary substrates100and primary substrate85if desired. Additionally or alternatively, an edge metallization192may be provided along the vertical edges of secondary substrates100. Edge metallization192may be laterally interposed between a given antenna40and the antenna40of the adjacent secondary substrate100. Edge metallization192may, for example, help to increase isolation between the antennas in phased antenna array54.

Additionally or alternatively, one or more electrical components194may be mounted to lateral surface124of primary substrate85(e.g., using solder). Electrical components194may include some or all of the active components of RFIC74ofFIG.6, impedance matching circuitry for antennas40, tuning circuitry, transceiver circuitry, phase and magnitude controllers, active integrated circuits, passive circuit components, etc. Additionally or alternatively, one or more electrical components194may be embedded within one or more secondary substrates100, such as at location198.

Additionally or alternatively, an encapsulation layer such as encapsulation layer196may be molded over some or all of the secondary substrates100and/or electrical components194on primary substrate85. If desired, secondary substrates100may be omitted and the antennas40in phased antenna array54may be embedded within encapsulation layer196, as shown inFIG.17.

Additionally or alternatively, electrical components194may be mounted to a lateral surface of secondary substrate100. For example, as shown inFIG.18, electrical component194may be mounted to lateral surface126of secondary substrate100using interconnects202(e.g., in a flip-chip configuration). Interconnects202may include solder, adhesive, conductive pins, conductive springs, a ball grid array, a conductive bracket, and/or other conductive interconnect structures that serve to mount lateral surface126of secondary substrate100to electrical component194. If desired, some or all of the interconnects202may also convey signals and/or power between electrical component194and secondary substrate100.

When mounted to lateral surface126, electrical component194may be vertically interposed between primary substrate85and secondary substrate100(e.g., within a cavity200between interconnects116and between substrates85and100). Additionally or alternatively, electrical component194may be mounted to lateral surface128(e.g., at location204). In general, any of the arrangements ofFIGS.12-18may be combined if desired.