PATENT DOCUMENT

Publication Number: US-9559406-B2
Application Number: US-201514733793-A
Country: US
Kind Code: B2

Title: Electronic device with dual clutch barrel cavity antennas

Abstract:
An electronic device has antennas formed from cavity antenna structures. The electronic device may have a metal housing. The metal housing may have an upper housing in which a component such as a display is mounted and a lower housing in which a component such as a keyboard is mounted. Hinges may be used to mount the upper housing to the lower housing for rotation about a rotational axis. Cavity antennas may be formed in a clutch barrel region located between the hinges and running along the rotational axis. A flexible printed circuit may be formed between the cavity antennas. Each cavity antenna may have a first end that is adjacent to one of the hinges and a second end that is adjacent to the flexible printed circuit. Cavity walls for the cavity antennas may be formed from metal housing structures such as metal portions of the lower housing.

Claims:
What is claimed is: 
     
       1. A portable computer, comprising:
 a metal housing having an upper metal housing portion that contains a display and having a lower metal housing portion that contains a keyboard; 
 hinges that connect the upper metal housing portion to the lower metal housing portion, wherein the upper metal housing portion rotates relative to the lower metal housing portion about a rotational axis between a closed position and an open position, and there is a gap between opposing metal portions of the upper and lower metal housing portions when the upper metal housing portion is in the closed position through which antenna signals pass; 
 first and second antennas in the lower housing portion between the hinges that transmit and receive the antenna signals; 
 control circuitry in the lower housing portion; and 
 a flexible printed circuit that is coupled between the control circuitry and the display and that runs across the gap between the first and second antennas, wherein the flexible printed circuit includes metal traces that are shorted to the upper metal housing portion and the lower metal housing portion, the metal traces are interposed between the first and second antennas, the metal traces divide the gap into a first portion and a second portion, the first antenna transmits and receives the antenna signals through the first portion of the gap, and the second antenna transmits and receives the antenna signals through the second portion of the gap. 
 
     
     
       2. The portable computer defined in  claim 1  wherein the gap has a slot shape that runs parallel to the rotational axis. 
     
     
       3. The portable computer defined in  claim 2  wherein the first and second antennas comprise dual band antennas. 
     
     
       4. The portable computer defined in  claim 3  wherein the first and second antennas transmit and receive the antenna signals in communications bands at 2.4 GHz and 5 GHz. 
     
     
       5. The portable computer defined in  claim 4  wherein the first and second antennas comprise cavity antennas. 
     
     
       6. A portable computer, comprising:
 a display; 
 an upper metal housing in which the display is mounted; 
 a keyboard; 
 a lower metal housing in which the keyboard is mounted; 
 hinges that connect the upper metal housing to the lower metal housing, wherein the upper metal housing rotates relative to the lower metal housing about a rotational axis between a closed position and an open position, and there is a slot between opposing metal portions of the upper and lower metal housing portions that runs parallel to the rotational axis; 
 first and second cavity antennas in the lower metal housing between the hinges that transmit and receive antenna signals through the slot; and 
 control circuitry in the lower housing portion; and 
 a flexible printed circuit that is coupled between the control circuitry and the display and that runs across the slot between the first and second cavity antennas, wherein the flexible printed circuit includes ground traces that are shorted to the upper metal housing and to the lower metal housing, and the flexible printed circuit forms at least part of an end of the first and second cavity antennas. 
 
     
     
       7. The portable computer defined in  claim 6  wherein the flexible printed circuit includes metal traces that are shorted to the upper metal housing and the lower metal housing. 
     
     
       8. The portable computer defined in  claim 7  wherein the first and second antennas transmit and receive the antenna signals in communications bands at 2.4 GHz and 5 GHz. 
     
     
       9. A portable computer, comprising:
 a metal housing having an upper metal housing portion that contains a display and having a lower metal housing portion that contains a keyboard; 
 hinges that connect the upper metal housing portion to the lower metal housing portion, wherein the upper metal housing portion rotates relative to the lower metal housing portion about a rotational axis between a closed position and an open position, and there is a gap between opposing metal portions of the upper and lower metal housing portions when the upper metal housing portion is in the closed position through which antenna signals pass; 
 first and second antennas in the lower housing portion between the hinges that transmit and receive the antenna signals; 
 control circuitry in the lower housing portion; and 
 a flexible printed circuit that is coupled between the control circuitry and the display and that runs across the gap between the first and second antennas, wherein the flexible printed circuit includes metal traces that are shorted to the upper metal housing portion and the lower metal housing portion, the metal traces are interposed between the first and second antennas, the metal traces are shorted to the lower metal housing portion at first and second grounding locations, the first grounding location is interposed between the second grounding location and the first antenna, and the second grounding location is interposed between the first grounding location and the second antenna. 
 
     
     
       10. A portable computer, comprising:
 a metal housing having an upper metal housing portion that contains a display and having a lower metal housing portion that contains a keyboard; 
 hinges that connect the upper metal housing portion to the lower metal housing portion, wherein the upper metal housing portion rotates relative to the lower metal housing portion about a rotational axis between a closed position and an open position, and there is a gap between opposing metal portions of the upper and lower metal housing portions when the upper metal housing portion is in the closed position through which antenna signals pass; 
 first and second antennas in the lower housing portion between the hinges that transmit and receive the antenna signals; 
 control circuitry in the lower housing portion; and 
 a flexible printed circuit that is coupled between the control circuitry and the display and that runs across the gap between the first and second antennas, wherein the flexible printed circuit includes metal traces that are shorted to the upper metal housing portion and the lower metal housing portion, the metal traces are interposed between the first and second antennas, the lower metal housing portion has opposing first and second conductive surfaces, the first antenna comprises a first antenna resonating element, the second antenna comprises a second antenna resonating element, an entirety of the first antenna resonating element is interposed between the first and second conductive surfaces of the lower metal housing portion, and an entirety of the second antenna resonating element is interposed between the first and second conductive surfaces of the lower metal housing portion.

Description:
This application is a continuation of patent application Ser. No. 14/202,860, filed Mar. 10, 2014, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with antennas. 
     Electronic devices often include antennas. For example, cellular telephones, computers, and other devices often contain antennas for supporting wireless communications. 
     It can be challenging to form electronic device antenna structures with desired attributes. In some wireless devices, the presence of conductive housing structures can influence antenna performance. Antenna performance may not be satisfactory if the housing structures are not configured properly and interfere with antenna operation. Device size can also affect performance. It can be difficult to achieve desired performance levels in a compact device, particularly when the compact device has conductive housing structures. 
     It would therefore be desirable to be able to provide improved wireless circuitry for electronic devices such as electronic devices that include conductive housing structures. 
     SUMMARY 
     An electronic device such as a portable computer may be provided with antennas. The antennas may be cavity antennas. Each cavity antenna may have a metal cavity structure that defines an antenna cavity and may have an antenna resonating element that is mounted within the cavity. 
     The electronic device may have a metal housing. The metal housing may have an upper housing in which a component such as a display is mounted and a lower housing in which a component such as a keyboard is mounted. Hinges may be used to mount the upper housing to the lower housing. Cavity antennas may be formed in a clutch barrel region located between the hinges. Cavity structures may be formed from metal portions of the housing such as portions of the lower housing. 
     A flexible printed circuit may be formed between first and second cavity antennas. Each cavity antenna may have an outer end that is adjacent to one of the hinges and an inner end that is adjacent to the flexible printed circuit. 
     Components such as speakers may be mounted within antenna cavities. The speakers may be isolated from the antennas using inductors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a laptop computer in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device with wireless circuitry in accordance with an embodiment. 
         FIG. 3  is a perspective view of an illustrative hinge of the type that may be used in an electronic device with housing portions that rotate relative to each other in accordance with an embodiment. 
         FIG. 4  is a perspective view of an illustrative electronic device such as a portable computer showing how the electronic device may have a clutch barrel region in which antennas can be formed in accordance with an embodiment. 
         FIG. 5  is a diagram of an illustrative inverted-F antenna in accordance with an embodiment. 
         FIG. 6  is a perspective view of an illustrative cavity antenna in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative cavity antenna such as the cavity antenna of  FIG. 6  in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative electronic device such as a portable computer having a lid in a closed position and having antenna structures in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of an illustrative electronic device such as a portable computer having a lid in an open position and having antenna structures in accordance with an embodiment. 
         FIG. 10  is a top view of an illustrative electronic device such as a portable computer with its lid in an open position showing how a clutch barrel portion of the electronic device can be divided into two antenna cavities by a flexible printed circuit between the antenna cavities in accordance with an embodiment. 
         FIG. 11  is a cross-sectional side view of an illustrative electronic device such as a portable computer showing how components such as electrically isolated speakers may float within an antenna cavity in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may contain wireless circuitry. For example, electronic device  10  may contain wireless communications circuitry that operates in long-range communications bands such as cellular telephone bands and wireless circuitry that operates in short-range communications bands such as the 2.4 GHz Bluetooth® band and the 2.4 GHz and 5 GHz WiFi® wireless local area network bands (sometimes referred to as IEEE 802.11 bands or wireless local area network communications bands). Device  10  may also contain wireless communications circuitry for implementing near-field communications, communications at 60 GHz, light-based wireless communications, satellite navigation system communications, or other wireless communications. 
     Device  10  may be a handheld electronic device such as a cellular telephone, media player, gaming device, or other device, may be a laptop computer, tablet computer, or other portable computer, may be a desktop computer, may be a computer display, may be a display containing an embedded computer, may be a television or set top box, or may be other electronic equipment. Configurations in which device  10  has a rotatable lid as in a portable computer are sometimes described herein as an example. This is, however, merely illustrative. Device  10  may be any suitable electronic equipment. 
     As shown in the example of  FIG. 1 , device  10  may have a housing such as housing  12 . Housing  12  may be formed from plastic, metal (e.g., aluminum), fiber composites such as carbon fiber, glass, ceramic, other materials, and combinations of these materials. Housing  12  or parts of housing  12  may be formed using a unibody construction in which housing structures are formed from an integrated piece of material. Multipart housing constructions may also be used in which housing  12  or parts of housing  12  are formed from frame structures, housing walls, and other components that are attached to each other using fasteners, adhesive, and other attachment mechanisms. 
     Some of the structures in housing  12  may be conductive. For example, metal parts of housing  12  such as metal housing walls may be conductive. Other parts of housing  12  may be formed from dielectric material such as plastic, glass, ceramic, non-conducting composites, etc. To ensure that antenna structures in device  10  function properly, care should be taken when placing the antenna structures relative to the conductive portions of housing  12 . If desired, portions of housing  12  may form part of the antenna structures for device  10 . For example, conductive housing sidewalls may form an antenna ground element. The antenna ground element may be configured to form one or more cavities for cavity-backed antennas. The cavities in the cavity-backed antennas may be formed from portions of housing  12  located between hinges in a portable computer and/or other conductive electronic device structures. 
     As shown in  FIG. 1 , device  10  may have input-output devices such as track pad  18  and keyboard  16 . Camera  26  may be used to gather image data. Device  10  may also have components such as microphones, speakers, buttons, removable storage drives, status indicator lights, buzzers, sensors, and other input-output devices. These devices may be used to gather input for device  10  and may be used to supply a user of device  10  with output. Ports in device  10  such as ports  28  may receive mating connectors (e.g., an audio plug, a connector associated with a data cable such as a Universal Serial Bus cable, a data cable that handles video and audio data such as a cable that connects device  10  to a computer display, television, or other monitor, etc.). 
     Device  10  may include a display such a display  14 . Display  14  may be a liquid crystal display (LCD), a plasma display, an organic light-emitting diode (OLED) display, an electronic ink display, or a display implemented using other display technologies. A touch sensor may be incorporated into display  14  (i.e., display  14  may be a touch screen display). Touch sensors for display  14  may be resistive touch sensors, capacitive touch sensors, acoustic touch sensors, light-based touch sensors, force sensors, or touch sensors implemented using other touch technologies. 
     Device  10  may have a one-piece housing or a multi-piece housing. As shown in  FIG. 1 , for example, electronic device  10  may be a device such as a portable computer or other device that has a two-part housing formed from upper housing  12 A and lower housing  12 B. Upper housing  12 A may include display  14  and may sometimes be referred to as a display housing or lid. Lower housing  12 B may sometimes be referred to as a base or main housing. Housings  12 A and  12 B may be connected to each other using a hinge (e.g., a hinge located in region  20  along the upper edge of lower housing  12 B and the lower edge of upper housing  12 A). The hinge may allow upper housing  12 A to rotate about axis  22  in directions  24  relative to lower housing  12 B. The plane of lid (upper housing)  12 A and the plane of lower housing  12 B may be separated by an angle that varies between 0° when the lid is closed to 90°, 140°, or more when the lid is fully opened. 
     A schematic diagram showing illustrative components that may be used in device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry such as storage and processing circuitry  30 . Storage and processing circuitry  30  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  30  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, etc. 
     Storage and processing circuitry  30  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  30  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  30  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, MIMO protocols, antenna diversity protocols, etc. 
     Input-output circuitry  44  may include input-output devices  32 . Input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include user interface devices, data port devices, and other input-output components. For example, input-output devices may include touch screens, displays without touch sensor capabilities, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, motion sensors (accelerometers), capacitance sensors, proximity sensors, etc. 
     Input-output circuitry  44  may include wireless communications circuitry  34  for communicating wirelessly with external equipment. Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless communications circuitry  34  may include radio-frequency transceiver circuitry  90  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  36 ,  38 , and  42 . Transceiver circuitry  36  may be wireless local area network transceiver circuitry that may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and that may handle the 2.4 GHz Bluetooth® communications band. Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in frequency ranges such as a low communications band from 700 to 960 MHz, a midband from 1710 to 2170 MHz, and a high band from 2300 to 2700 MHz or other communications bands between 700 MHz and 2700 MHz or other suitable frequencies (as examples). Circuitry  38  may handle voice data and non-voice data. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. Wireless communications circuitry  34  may include satellite navigation system circuitry such as global positioning system (GPS) receiver circuitry  42  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless communications circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, hybrids of these designs, etc. If desired, one or more of antennas  40  may be cavity-backed antennas. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. 
     Transmission line paths may be used to couple antenna structures  40  to transceiver circuitry  90 . Transmission lines in device  10  may include coaxial cable paths, microstrip transmission lines, stripline transmission lines, edge-coupled microstrip transmission lines, edge-coupled stripline transmission lines, transmission lines formed from combinations of transmission lines of these types, etc. Filter circuitry, switching circuitry, impedance matching circuitry, and other circuitry may be interposed within the transmission lines, if desired. 
     Hinges may be used to allow portions of an electronic device to rotate relative to each other. Hinges may, for example, be used to allow upper housing  12 A of  FIG. 1  to rotate relative to lower housing  12 B about rotational axis  22 . The hinge structures that are used to attach housings  12 A and  12 B together are sometimes referred to as clutch structures or clutches. An illustrative clutch (hinge) is shown in  FIG. 3 . As shown in  FIG. 3 , clutch (hinge)  56  may have a structure such as structure  54  and a structure such as structure  46  that rotate relative to each other about axis  22 . Structure  54  may have holes such as holes  58  that receive screws. The screws may be used to attach structure  54  to frame structure  12 A- 1  or other structures in upper housing  12 A. Structure  46  may be attached to housing  12 B using screws that pass through holes  48 . If desired, other attachment techniques may be used to mount structure  54  to housing  12 A and to mount structure  46  to housing  12 B. The use of screws is merely illustrative. 
     Structure  54 , which may sometimes referred to as a clutch pillar, may include shaft  50 . Structure  46 , which may sometimes be referred to as a clutch band, may have portions  52  that grip shaft  50  with a predetermined amount of friction. During operation, the clutch band holds the clutch pillar with an amount of force that allows upper housing  12 A to rotate relative to lower housing  12 B. Sufficient friction is present to allow a user to place upper housing  12 A at a desired angle relative to lower housing  12 B without slipping. Structure  12 A- 1  may be attached to other structures in housing  12 A such as display  14 , housing wall structures (e.g., metal housing structures), etc. The portions of housing  12 B that are attached to structure  46  may include housing structures such as a metal frame, metal sidewalls, and other housing structures. 
     A pair of hinge structures such as hinge  56  of  FIG. 3  may be mounted within portions of housing  12  to form a hinge for device  10 . As shown in  FIG. 4 , for example, hinge structures  56  may be mounted at either end of a region in housing  12  such as clutch barrel region  60  (i.e., a hinge for device  10  may be formed by placing a structure such as hinge  56  of  FIG. 3  at each of the two opposing ends of clutch barrel  60 ). Clutch barrel  60  may have a cylindrical shape as shown in  FIG. 4  or may have other shapes. Clutch barrel  60  may have a dielectric cover portion and/or may be formed form metal. For example, in configurations in which housing  12  is formed from metal, clutch barrel  60  may be part of housing  12 A, may be part of housing  12 B, may contain metal parts that are integral to both housing  12 A and  12 B, and/or may be formed from metal structures that are separate from housing  12 A and  12 B. 
     The portions of housing  12  surrounding clutch barrel  60  may be configured to form one or more cavities for cavity backed antennas. For example, a pair of cavity antennas may be formed in region  60 . The cavities may have elongated shapes that run parallel to axis  22 . One of hinges  56  may be located at the outer end of each cavity antenna. A conductive structure such as a printed circuit may be located between the cavities in the middle of clutch barrel  60 . 
     Antenna structures may also be mounted at other locations within device  10  such as along the upper edge of display  12  (e.g., under the upper bezel of housing  12 A), in lower housing  12 B, under dielectric window structures in housing  12 A or housing  12 B, behind layers of glass or other dielectrics, or elsewhere in housing  12 . An advantage of mounting antenna structures within the clutch barrel is that this location may permit antenna operation both when lid  12 A is open and when lid  12 A is closed. 
     Antenna structures in clutch barrel  60  may include dielectric materials (e.g., a dielectric carrier such as a plastic carrier for supporting patterned conductive antenna structures, a plastic cover or a cover formed from other dielectrics, etc.). Air (which is a dielectric) may also be present within clutch barrel  60  (e.g., in an antenna cavity). Surrounding portions of device  10  may be substantially conductive. For example, structures in upper housing  12 A such as frame  12 A- 1  of  FIG. 3 , display  14  of  FIG. 1 , and housing sidewalls for housing  12  in which display  14  and frame  12 A- 1  are mounted may all be conductive (e.g., metal). Likewise, structures in housing  12 B such as metal housing sidewalls, metal frame structures, ground planes on printed circuit boards, radio-frequency shielding structures, and other device components in housing  12 B may be conductive. 
     The metal structures of housing  12  (e.g., the portions of housing  12  around clutch barrel  60 ) may define antenna cavities and/or slot-shaped features that affect antenna performance. For example, a cavity may be formed that affects how efficiently an antenna may operate at various different wavelengths. To enhance antenna performance, cavities (and associated gaps or slots through which the antennas may operate) may be configured to support antenna resonances at desired frequencies. 
     Cavity-backed antennas (sometimes referred to as cavity antennas) are formed from antenna resonating elements located within an antenna ground plane having the shape of a cavity (e.g., a cavity formed from metal housing  12 ). The antenna resonating element for a cavity antenna may be formed from a patch antenna resonating element, a monopole antenna resonating element, an inverted-F antenna resonating element, a slot antenna resonating element, or other suitable antenna resonating element structures. An illustrative inverted-F antenna of the type that may be used to feed a cavity antenna is shown in  FIG. 5 . Inverted-F antenna  40 F of  FIG. 5  or other suitable antenna structures may be used as an antenna feed for a cavity antenna by placing antenna  40 F within a metal cavity. 
     As shown in  FIG. 5 , inverted-F antenna element  40 F has antenna resonating element  106  and antenna ground (ground plane)  104 . Ground plane  104  may be formed from metal housing  12  (e.g., portions of housing  12  shaped to form an antenna cavity). Antenna resonating element  106  may have a main resonating element arm such as arm  108 . The length of arm  108  may be selected so that antenna element  40 F resonates at desired operating frequencies. For example, if the length of arm  108  may be a quarter of a wavelength at a desired operating frequency for antenna element  40 F. Antenna element  40 F may also exhibit resonances at harmonic frequencies. 
     Main resonating element arm  108  may be coupled to ground  104  by return path  110 . Antenna feed  112  may include positive antenna feed terminal  98  and ground antenna feed terminal  100  and may run in parallel to return path  110  between arm  108  and ground  104 . If desired, inverted-F antennas such as illustrative antenna  40 F of  FIG. 5  may have more than one resonating arm branch (e.g., to create multiple frequency resonances to support operations in multiple communications bands) or may have other antenna structures (e.g., parasitic antenna resonating elements, tunable components to support antenna tuning, etc.). A planar inverted-F antenna (PIFA) may be formed by implementing arm  108  using planar structures (e.g., a planar metal structure such as a metal patch or strip of metal that extends into the page of  FIG. 5 ). 
       FIG. 6  is a perspective view of an illustrative cavity antenna of the type that may be used in clutch barrel  60  of device  10 . Cavity antenna  40  of  FIG. 6  has cavity structures  200 . Cavity structures  200  are formed from a conductive material such as metal (e.g. portions of metal housing  12  in clutch barrel region  60 ). Cavity structures  200  in the example of  FIG. 6  form an open-front box having rear wall  200 - 5 , upper wall  200 - 4 , lower wall  200 - 2 , right wall  200 - 1 , and left wall  200 - 2 . In device  10 , different cavity shapes may be used (e.g., shapes with curved cavity walls, etc.). Cavity  206  is a recess formed within the interior of cavity structures  200 . Cavity  206  may be characterized by a longer dimension such as length L, a shorter dimension such as height H, and a depth D. The configuration  FIG. 6  is merely illustrative. 
     Antenna feed structure  40 F for cavity antenna  40  may be formed within cavity  206 . A cross-sectional side view of the structures of  FIG. 6  taken along line  202  and viewed in direction  204  is shown in  FIG. 7 . As shown in  FIG. 7 , antenna element  40 F (e.g., an inverted-F antenna resonating element or other suitable antenna resonating element) may be located within cavity  206  in the interior of cavity structures  200 . Antenna element  40 F serves as a feed for cavity antenna  40 . Transmission line  210  may couple antenna element  40 F to radio-frequency transceiver circuitry  90 . 
     Cavity structures  200  may be provided with an opening such as opening  208 . During operation, incoming antenna signals may be received by element  40 F through opening  208  and transmitted antenna signals from element  40 F may be emitted through opening  208 . 
     A cross-sectional side view of device  10  showing how a cavity antenna for device  10  of  FIG. 1  may be implemented in clutch barrel region  60  is shown in  FIG. 8 . As shown in  FIG. 8 , cavity antenna  40  may be formed by placing antenna feed element  40 F within cavity  206 . The walls of cavity  206  may be formed by metal structures in device  10  such as housing  12 . For example, portions of lower housing  12 B may be used to define metal walls for cavity  206 . Housing portion  220  may form upper wall  200 - 4  of  FIG. 7 , housing portion  216  may form lower wall  200 - 2  of  FIG. 7 , and housing portion  222  may form rear wall  200 - 5  of cavity structures  200  (as an example). Antenna element  40 F may be mounted on a plastic carrier such as carrier  214  or may be mounted on other suitable support structures. If desired, antenna element  40 F may be mounted in locations such as locations  40 F′ of  FIG. 8 . 
     Opening  208  of cavity  206  may be formed between portion  220  of housing  12 B and portion  216  of housing  12 B. Portions of housing  12 A may partially block opening  208 , but antenna signals may pass through one or more gaps such as slot-shaped opening  212  (i.e., a gap formed between portion  216  of housing  12 B and opposing housing portion  218  of housing  12 A that runs along the rear edge of housing  12  parallel to axis  22 ). 
     In the configuration of  FIG. 8 , lid  12 A is in its closed position, resting against lower housing  12 B.  FIG. 9  is a cross-sectional side view of the structures of  FIG. 8  when lid  12 A has been placed in its open position by rotating lid  12 A around hinge axis  22 . 
     In the open-lid configuration of  FIG. 9 , cavity antenna  40  can operate through gaps such as upper gap  226  and lower gap  212  (e.g., slot-shaped openings that run parallel to axis  22  and that are formed from opposing metal structures such as portion  220  of housing  12 B and portion  224  of housing  12 A for gap  226  and from opposing metal structures such as portion  216  of housing  12 B and portion  218  of housing  12 A for gap  212 ). Gaps such as gaps  226  and  212  may have widths of about 1.2-1.5 mm, of about 1-3 mm, of less than 4 mm, of more than 2 mm, or other suitable size. If desired, portions of housing  12 A such as portion  228  of  FIG. 9  may be formed from a dielectric such as plastic to help enhance the effective width of gap  226  and thereby enhance antenna efficiency. Dielectric portion  228  is adjacent to rotational axis  222  and when present increases the width of gap  226  (i.e., the spacing between the opposing metal portions of housing  12 A and housing  12 B). When gap  226  is enlarged, the wireless antenna signals being handled by the cavity antennas can pass through gap  226  without being blocked by metal housing structures. 
       FIG. 10  shows how two cavities may be formed within clutch barrel  60 . As shown in  FIG. 10 , flexible printed circuit  230  may run between lower housing  12 B and upper housing  12 A across clutch barrel region  60 . Lower housing  12 B may include control circuitry and other circuitry mounted on one or more printed circuit substrates. This circuitry may be coupled to display  14  using signal paths formed from metal traces  232  on flexible printed circuit  230 . Flexible printed circuit  230  may be formed from a flexible polymer substrate such as a layer of polyimide or a sheet of other polymer material. Ground connections  234  in the middle of clutch barrel  60  may be used to short ground traces on flexible printed circuit  230  to housing  12 A and to housing  12 B. 
     The presence of flexible printed circuit  230  in the middle of clutch barrel  60  divides clutch barrel  60  into two parts (i.e., the metal cavity structures formed from housing  12  in clutch barrel region  60  are separated into two cavities by flexible printed circuit  230 , which is grounded to housing  12 B by ground connections  234  that are adjacent to the two cavities). In this way, the presence of flexible printed circuit  230  forms cavity  206 A and cavity  206 B. Cavity  206 A has an inner end that is formed by flexible printed circuit  230  (i.e., flexible printed circuit  230  forms cavity wall  200 - 3  of  FIG. 6  for cavity  206 A). Cavity  206 A has an opposing outer end (wall  200 - 1  of cavity structures  200  of  FIG. 6 ) that is formed by the left-hand hinge  56  of  FIG. 10  and adjacent portions of housing  12 . Cavity  206 B has an inner end that is formed by flexible printed circuit  230  (i.e., flexible printed circuit  230  forms cavity wall  200 - 1  of  FIG. 6  for cavity  206 B). Cavity  206 B has an opposing outer end (wall  200 - 3  of cavity structures  200  of  FIG. 6 ) that is formed by the right-hand hinge  56  of  FIG. 10  and adjacent portions of housing  12 . Cavities  206 A and  206 B are located between respective hinges  56  and are separated by flexible printed circuit  230 . 
     Cavity  206 A is used in forming first cavity antenna  40 A and cavity  206 B is used in forming second cavity antenna  40 B. Antennas  40 A and  40 B may be cavity antennas such as illustrative cavity antenna  40  of  FIGS. 8 and 9  (as an example). To enhance antenna efficiency, it may be desirable to configure the size of cavities  206 A and  206 B to allow antennas  40 A and  40 B to operate at desired communications frequencies. As an example, it may be desirable for length L (i.e., the length of each cavity and the length of associated slots such as slots  226  and  212 , which is effectively half of the perimeter of the cavities and slots in configurations in which the cavities are elongated) to be equal to one wavelength at a communications band frequency of interest. Other cavity shapes may be used if desired. With one suitable arrangement, antennas  40 A and  40 B may be dual band wireless local area network antennas (e.g., WiFi® antennas) operating at frequencies such as 2.4 GHz and 5 GHz. 
     As shown in the example of  FIG. 11 , an audio component such as speaker  240  may be mounted within cavity  206  of cavity antenna  40 . Inductors  242  may be interposed in the pair of signal paths coupling speaker  240  to audio circuitry  242 . At frequencies associated with the antenna signals handled by antenna  40 , inductors  242  will exhibit high impedances. The configuration of  FIG. 11  therefore allows speaker  240  to electrically float within cavity  206  and prevents speaker  240  from interfering with the operation of antenna  40 . The arrangement for  FIG. 11  may be used for antenna  40 A and for antenna  40 B of  FIG. 10  (i.e., one or more speakers  240  may be mounted in each antenna cavity). 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20150608
Publication Date: 20170131
Grant Date: 20170131
Priority Date: 20140310
Inventors: GUTERMAN JERZY
LI QINGXIANG
PASCOLINI MATTIA
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K1/028", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0054", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0224", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0215", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1683", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0224", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0215", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/028", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0054", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 52474127