PATENT DOCUMENT

Publication Number: US-8269675-B2
Application Number: US-49028609-A
Country: US
Kind Code: B2

Title: Antennas for electronic devices with conductive housing

Abstract:
An electronic device may be provided with a conductive housing. The conductive housing may be formed from a metal. Slots may be formed in the housing. The slots may serve as an antenna and may be fed using an antenna feed structure within the electronic device housing. The electronic device may have a frame to which housing structures are attached and may have a stand or other support structure. The frame may be used to mount a display, to support housing walls, to support clutch barrel structures, etc. The slots may be formed in the frame or in a space between the frame and the housing walls. The slots or other antenna structures may also be formed in the stand. Multiple slots may be used together to support operations in two or more communications bands. There may be multiple dual slot antennas in the electronic device.

Claims:
1. An electronic device comprising:
 a conductive housing; 
 a conductive internal frame connected to the conductive housing, wherein the conductive internal frame is mounted within the conductive housing; and 
 an antenna having an antenna resonating element formed from a gap between the conductive internal frame and the conductive housing. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the antenna further comprises first and second feed terminals, wherein the first feed terminal is located on the conductive housing and wherein the second feed terminal is located on the conductive internal frame. 
     
     
       3. The electronic device defined in  claim 1  further comprising a display that is connected to the internal frame. 
     
     
       4. The electronic device defined in  claim 3  wherein a solid dielectric material fills the gap between the conductive internal frame and the conductive housing. 
     
     
       5. The electronic device defined in  claim 1  wherein the gap comprises a closed slot. 
     
     
       6. An electronic device comprising:
 a conductive housing member that forms at least one exterior surface of the electronic device; 
 at least one conductive internal member electrically connected to the conductive housing member, wherein the conductive internal frame member lies inside the conductive housing member; and 
 an antenna having an antenna resonating element formed from a gap between the conductive internal member and the conductive housing member, wherein the antenna comprises a first feed terminal electrically coupled to the exterior surface formed by the conductive housing member and a second feed terminal located on the conductive internal member. 
 
     
     
       7. The electronic device defined in  claim 6  further comprises a solid dielectric material in at least part of the gap between the conductive internal member and the conductive housing member. 
     
     
       8. The electronic device defined in  claim 6  further comprising a display with an associated optically transparent layer, wherein the optically transparent layer has a portion that overlaps the gap between the conductive internal member and the conductive housing member. 
     
     
       9. The electronic device defined in  claim 8  further comprising an opaque material on the portion of the optically transparent layer that overlaps the gap between the conductive internal member and the conductive housing member. 
     
     
       10. The electronic device defined in  claim 8  further comprising an opaque material on the portion of the optically transparent layer that overlaps the gap between the conductive internal member and the conductive housing member, wherein the opaque material is transparent to radio-frequency signals. 
     
     
       11. The electronic device defined in  claim 10  wherein the optically transparent layer comprises glass. 
     
     
       12. The electronic device defined in  claim 11  wherein the conductive internal member comprises a conductive internal frame member that structurally supports the display. 
     
     
       13. An electronic device comprising:
 a conductive housing member that substantially surrounds the electronic device, wherein the conductive housing members forms exterior surface portions of a perimeter of the electric device; 
 at least one conductive internal member electrically connected to the conductive housing member, wherein the conductive internal member is within the conductive housing member; and 
 an antenna having an antenna resonating element formed from a gap between the conductive internal member and the conductive housing member, wherein the antenna comprises a first feed terminal electrically coupled to one of the exterior surface portions formed by the conductive housing member and a second feed terminal located on the conductive internal member. 
 
     
     
       14. The electronic device defined in  claim 13  further comprises a solid dielectric material in at least part of the gap between the conductive internal member and the conductive housing member. 
     
     
       15. The electronic device defined in  claim 13  further comprising a display with an associated optically transparent layer, wherein the optically transparent layer has a portion that overlaps the gap between the conductive internal member and the conductive housing member. 
     
     
       16. The electronic device defined in  claim 15  further comprising an opaque material on the portion of the optically transparent layer that overlaps the gap between the conductive internal member and the conductive housing member. 
     
     
       17. The electronic device defined in  claim 15  further comprising an opaque material on the portion of the optically transparent layer that overlaps the gap between the conductive internal member and the conductive housing member, wherein the opaque material is transparent to radio-frequency signals. 
     
     
       18. The electronic device defined in  claim 17  wherein the optically transparent layer comprises glass. 
     
     
       19. The electronic device defined in  claim 18  wherein the conductive internal member comprises a conductive internal frame member that structurally supports the display. 
     
     
       20. The electronic device defined in  claim 13  wherein the first feed terminal comprises a positive feed terminal located on the conductive housing member.

Description:
BACKGROUND 
     This invention relates to electronic device antennas, and more particularly, to antennas for electronic devices with conductive housings. 
     Electronic devices such as portable computers and handheld electronic devices are becoming increasingly popular. Examples of portable devices include handheld computers, cellular telephones, media players, and hybrid devices that include the functionality of multiple devices of this type. 
     Devices such as these are often provided with wireless communications capabilities. For example, electronic devices may use long-range wireless communications circuitry such as cellular telephone circuitry to communicate using cellular telephone bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz (e.g., the main Global System for Mobile Communications or GSM cellular telephone bands). Long-range wireless communications circuitry may also use the 2100 MHz band. Electronic devices may use short-range wireless communications links to handle communications with nearby equipment. For example, electronic devices may communicate using the WiFi® (IEEE 802.11) bands at 2.4 GHz and 5 GHz (sometimes referred to as local area network bands) and the Bluetooth® band at 2.4 GHz. 
     It can be difficult to incorporate antennas successfully into an electronic device. Some electronic devices are manufactured with small form factors, so space for antennas is limited. Antenna operation can also be blocked by intervening metal structures. This can make it difficult to implement an antenna in an electronic device that contains conductive display structures, conductive housing walls, or other conductive structures that can potentially block radio-frequency signals. 
     It would therefore be desirable to be able to provide improved antennas for portable electronic devices that have conductive housings. 
     SUMMARY 
     Antennas are provided for electronic devices such as devices that have conductive housing. The antennas may be slot antennas that are formed from slots in conductive housing structures. The slot antennas may be formed form a dielectric-filled logo structure that is formed in a conductive housing. Slot antennas may also be formed from a slot between a conductive housing and an internal frame or from one or more slots in an internal frame. If desired, slot antennas may be formed in a stand that supports a portable electronic device. Antennas may be fed by antenna feed structures within the conductive housing. 
     The electronic device may be a portable computer or a handheld electronic device such as a cellular telephone. The housing may contain conductive sidewalls. For example, the housing may be formed from a machined block of aluminum or other metals. The walls of the housing may be used to hold conductive components such as displays. The housing may have internal frame members. Integrated circuits and other electronic components may be mounted within the housing. 
     Slot antennas may be formed directly in the conductive housing of the electronic device. Forming antennas directly in electronic device housing may prevent antennas from being shielded by the conductive housing material. Slot antennas may also be formed in the internal frame members of an electronic device. Slot antennas may also be formed in gaps between conductive housing and an internal frame member. Slot antennas may have open or closed slots. Slot antennas may be single-band or dual-band slot antennas. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an illustrative electronic device in accordance with an embodiment of the present invention. 
         FIG. 2  is a rear perspective view of an illustrative electronic device in accordance with an embodiment of the present invention. 
         FIG. 3  is a rear perspective view of an illustrative electronic device with a stand in accordance with an embodiment of the present invention. 
         FIG. 4  is a front perspective view of an illustrative handheld electronic device in accordance with an embodiment of the present invention. 
         FIG. 5  is a rear perspective view of an illustrative handheld electronic device in accordance with an embodiment of the present invention. 
         FIG. 6  is a schematic diagram of an illustrative electronic device with antenna structures in accordance with an embodiment of the present invention. 
         FIG. 7  is a diagram of an illustrative single-slot antenna in accordance with an embodiment of the present invention. 
         FIG. 8  is a diagram of an illustrative dual-slot antenna in accordance with an embodiment of the present invention. 
         FIG. 9  is a diagram of an illustrative antenna having a closed slot and an open slot in accordance with an embodiment of the present invention. 
         FIG. 10  is a diagram of an illustrative inverted-F antenna resonating element for an antenna in accordance with an embodiment of the present invention. 
         FIG. 11  is a diagram of an illustrative monopole antenna resonating element for an antenna in accordance with an embodiment of the present invention. 
         FIG. 12  is a top view of an illustrative patch antenna resonating element for an antenna in accordance with an embodiment of the present invention. 
         FIG. 13  is a diagram of an illustrative multibranch inverted-F antenna resonating element for an antenna in accordance with an embodiment of the present invention. 
         FIG. 14  is a diagram of an electronic device slot antenna formed from a gap between a housing and a frame in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross section of an electronic device antenna formed between a housing and a frame in accordance with an embodiment of the present invention. 
         FIG. 16  is a diagram of an electronic device antenna formed across a logo in a conductive housing that has a narrow portion that forms a slot in accordance with an embodiment of the present invention. 
         FIG. 17  is a cross sectional view of an antenna formed from slots in an internal frame in accordance with an embodiment of the present invention. 
         FIG. 18  is a cross sectional view of an antenna formed from slots in a frame that is integral with a housing in accordance with an embodiment of the present invention. 
         FIG. 19  is a diagram showing an illustrative hinge in accordance with an embodiment of the present invention. 
         FIG. 20  is a perspective view of slot antennas formed in a conductive frame in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative portable device such as a portable computer that may include a slot antenna is shown in  FIG. 1 . As shown in  FIG. 1 , device  10  may be a portable computer having a housing such as housing  12 . Housing  12  may have an upper portion such as upper housing  12 A, which is sometimes referred to as a lid or cover. Housing  12  may also have a lower portion such as lower housing  12 B, which is sometimes referred to as the housing base or main unit. Housing portions  12 A and  12 B may be pivotably attached to each other using hinge structures such as hinges  13  (sometimes referred to as clutch barrel hinges). Housing portion  12 E may surround a section of device  10  between hinges  13 . Housing portion  12 E may be attached to lower housing  12 B or may be integral with lower housing  12 B. Display  14  may be mounted in upper housing  12 A. Other components such as keyboard  18  and touch pad  20  may be mounted in lower housing  12 B. Display  14  may be a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a plasma display, or any other suitable display. The outermost surface of display  14  may be formed from one or more plastic or glass layers. If desired, touch screen functionality may be integrated into display  14 . In  FIG. 1 , display  14  and keyboard  18  are shown mounted on a front face  11  of housing  12 . 
     Housing  12 , which is sometimes referred to as a case, may be formed of any suitable materials including, plastic, wood, glass, ceramics, metal, or other suitable materials, or a combination of these materials. In some situations, housing  12  may be a dielectric or other low-conductivity material, so that the operation of conductive antenna elements that are located in proximity to housing  12  is not disrupted. 
     Housing  12  or portions of housing  12  may also be formed from conductive materials such as metal. An advantage of forming housing  12  from metal or other structurally sound conductive materials is that this may improve device aesthetics and may help improve durability and portability. An illustrative metal housing material that may be used is anodized aluminum. Aluminum is relatively light in weight and, when anodized, has an attractive insulating and scratch-resistant surface. If desired, other metals can be used for the housing of device  10 , such as stainless steel, magnesium, titanium, alloys of these metals and other metals, etc. 
     If desired, internal frames may be mounted within housing  12 . These internal frames may be used for mounting electronic components such as a battery, printed circuit boards containing integrated circuits and other electrical devices, etc. If desired, printed circuit boards (e.g., a motherboard and other printed circuit boards) and other components may be mounted directly to housing  12 . 
     When housing  12  is formed from conductive materials such as metal, housing  12  can act as a conductive shield that impedes the passage of radio-frequency signals from nearby antennas. It may therefore be challenging for an antenna that is located inside conductive housing to transmit and receive radio-frequency signals. 
     In scenarios in which housing  12  is formed from metal elements, one or more of the metal elements may therefore be used as part of the antenna in device  10 . For example, metal portions of housing  12  and metal components in housing  12  may be shorted together to form a ground plane in device  10  or to expand a ground plane structure that is formed from a planar circuit structure such as a printed circuit board structure (e.g., a printed circuit board structure used in forming antenna structures for device  10 ). 
     Moreover, slots in housing  12  may be used in forming an antenna resonating element for an antenna. Slot antennas having slots formed in accessible portions of housing  12  may freely transmit and receive radio-frequency signals that are not blocked by conductive housing  12 . Slots for antenna resonating elements may be located anywhere on housing  12 . These slots may be filled with air, plastic or other suitable dielectric material. As shown in  FIG. 1 , a slot antenna may be formed in dashed region  19 A on housing  12 E if housing  12 E is formed of conductive materials. Slots for antennas may also be formed in an internal frame within housing  12 E (e.g., in the clutch barrel just below region  19 A between hinges  13 ). If slots are formed in an internal frame, housing  12 E may be formed of dielectric materials or may have a dielectric antenna window to allow radio-frequency signals to pass through housing  12 E.  FIG. 2  shows a rear view of device  10 . Slot antennas for device  10  of  FIG. 2  may be formed in upper housing  12 A as shown by dashed antenna regions  19 B,  19 C, and  19 D. Slot antennas may be formed in a corner of housing  12 A, such as in region  19 B or  19 C, or slot antennas may be formed in the center of housing  12 A, as shown by region  19 D. Device  10  may also have multiple slot antennas formed in different regions of housing  12 . For example, a given device  10  may have slot antennas formed in both regions  19 B and  19 C in housing  12 A. Slot antennas may also be formed in lower housing  12 B. In  FIG. 2 , slot antennas are shown as being formed in regions  19 B,  19 C, and  19 D on a back face  9  of housing  12 . Device  10  may optionally have a dielectric-filled logo structure formed in housing  12  such as in regions  19 B- 19 D of housing  12 . A slot antenna may be formed as part of a dielectric-filled logo structure (e.g., if part of the logo forms a slot). Slot antennas may also be formed adjacent to display  14  or keyboard  18  on front face  11  of housing  12  in  FIG. 1 . Each slot antenna may have one slot, two slots, or more slots. Each slot antenna may be a single band or dual band antenna and may use open or closed slots. Device  10  may have hybrid antennas formed from slot antenna structures merged with other types of antennas. 
       FIG. 3  shows a portable electronic device  10  that has a stand  42 . Device  10  has a housing  12 . Housing  12  may have a main portion  12 C and a stand portion  12 D. Device  10  in  FIG. 3  may be a tablet computer. Stand  42  may be pivotably attached by hinge  13  to back face  9  of device  10 . Housing  12 D of stand  42  may be made of conductive or nonconductive materials. Stand  42  may have an open position so that stand  42  holds device  10  in an upright or inclined position when device  10  is placed on a flat surface. Stand  42  may also have a closed position. When stand  42  is in a closed position, stand  42  may be positioned in a recess  44  in housing  12 . 
     Slot antennas may be formed in stand  42  such as in dashed region  19 E of  FIG. 3 . If housing  12 D of stand  42  is formed from conductive materials, slot antennas may be formed in stand  42  using slots that are formed directly in housing  12 D. These slots may be filled with air, epoxy, plastic, or other suitable dielectric material. A slot antenna formed in stand  42  may be a single band, dual band, or multiple band antenna. Device  10  may have multiple antennas including an antenna formed in stand  42  and other antennas. 
     If housing portion  12 D is formed at least partly from nonconductive materials, antennas may be placed within housing  12 D of stand  42 . Any suitable antenna may be placed inside stand  42 . An antenna positioned inside stand  42  may include antennas structures such as slot antenna structures, inverted-F antenna structures, monopole antenna structures, patch antenna structures or other suitable antenna structures. If main housing portion  12 C is made of conductive materials, housing portion  12 C may form part of a ground plane element for an antenna located in stand  42 . Antennas in stand  42  may be used in conjunction with antennas formed in other parts of device  10 . 
     Another illustrative electronic device arrangement that may be used for device  10  is shown in  FIG. 4 . As shown in  FIG. 4 , device  10  may be a handheld electronic device having a housing such as housing  12  and a planar front surface on which display  14  is mounted. Components such as speaker port  28  and menu button  29  may, if desired, protrude through portions of display  14  (i.e., its associated glass cover). Display  14  may be, for example, a touch sensitive display that contains both light-emitting components and touch sensitive components. With this type of display arrangement, light may be emitted from active central region  40  of display  14 , but not from inactive peripheral regions such as right-hand edge  32 , left-hand edge  38 , upper portion  36 , and lower edge region  34 . These peripheral regions may have an undercoating of an opaque substance such as a black ink (as an example) to help cover underlying structures from view. 
       FIG. 5  shows a rear view of electronic device  10  of  FIG. 4 . Device  10  may have a rear surface  50 , side surfaces  51  and  52 , and a bottom surface  54 . Surfaces  50 ,  51 ,  52 , and  54  need not be flat surfaces (i.e., these surfaces may be curved). Slot antenna  46 A is shown on bottom surface  54  and slot antenna  46 B is shown on side surface  52 . In  FIG. 5 , slot antennas  46 A and  46 B are dual band antennas each having two slots of different lengths. In general, slot antennas may have slots of any suitable lengths. Slot antennas  46 A and  46 B may also be formed using slot antenna resonating elements that have single slots. If desired, slot antennas may also be formed in region  48  or elsewhere on rear surface  50 . A dielectric-filled logo structure for device  10  may also be positioned in region  48 . A slot antenna may be implemented as part of a dielectric-filled logo structure. For example, the logo may be formed from a dielectric-filled logo-shaped opening in housing  12 . The logo-shaped opening may have a narrow portion that forms a slot for a slot antenna. 
       FIG. 6  shows a schematic diagram of electronic device  10 . Electronic device  10  may be a portable device such as a mobile telephone, a mobile telephone with media player capabilities, a handheld computer, a remote control, a game player, a global positioning system (GPS) device, a laptop computer, a tablet computer, an ultraportable computer, a combination of such devices, or any other suitable portable electronic device. 
     As shown in  FIG. 6 , electronic device  10  may include storage and processing circuitry  16 . Storage and processing circuitry  16  may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  16  may be used to control the operation of device  10 . Processing circuitry  16  may be based on a processor such as a microprocessor and other suitable integrated circuits. With one suitable arrangement, storage and processing circuitry  16  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. Storage and processing circuitry  16  may be used in implementing suitable communications protocols. 
     Communications protocols that may be implemented using storage and processing circuitry  16  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling 3G communications services (e.g., using wide band code division multiple access techniques), 2G cellular telephone communications protocols, etc. Storage and processing circuitry  16  may have cellular telephone circuitry to communicate using cellular telephone bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz (e.g., the main Global System for Mobile Communications or GSM cellular telephone bands) and may implement protocols for handling 3G communications services. Long-range wireless communications circuitry may also handle the 2100 MHz band. 
     Input-output device circuitry  23  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  18  such as touch screens and other user input interfaces are examples of input-output circuitry  23 . Input-output devices  18  may also include user input-output devices such as buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, etc. A user can control the operation of device  10  by supplying commands through such user input devices. Display and audio devices may be included in devices  18  such as liquid-crystal display (LCD) screens, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), and other components that present visual information and status data. Display and audio components in input-output devices  18  may also include audio equipment such as speakers and other devices for creating sound. If desired, input-output devices  18  may contain audio-video interface equipment such as jacks and other connectors for external headphones and monitors. 
     Wireless communications circuitry  20  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, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). Wireless communications circuitry  20  may include radio-frequency transceiver circuits for handling multiple radio-frequency communications bands. For example, circuitry  20  may include transceiver circuitry  22  that handles 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and the 2.4 GHz Bluetooth communications band. Circuitry  20  may also include cellular telephone transceiver circuitry  24  for handling wireless communications in cellular telephone bands such as the GSM bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz, and the 2100 MHz data band (as examples). Wireless communications circuitry  20  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  20  may include global positioning system (GPS) receiver equipment, wireless circuitry for receiving radio and television signals, paging circuits, etc. 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  20  may include antennas  26 . Device  10  may be provided with any suitable number of antennas. There may be, for example, one antenna, two antennas, three antennas, or more than three antennas, in device  10 . Each antenna may handle communications over a single communications band or multiple communications bands. If desired, a dual band antenna may be used to cover two WiFi bands (e.g., 2.4 GHz and 5 GHz). Different types of antennas may be used for different bands and combinations of bands. For example, it may be desirable to form a dual band antenna for forming a local wireless link antenna, a multiband antenna for handling cellular telephone communications bands, and a single band antenna for forming a global positioning system antenna (as examples). 
     Paths  65  such as transmission line paths may be used to convey radio-frequency signals between transceivers  22  and  24  and antennas  26 . Radio-frequency transceivers such as radio-frequency transceivers  22  and  24  may be implemented using one or more integrated circuits and associated components (e.g., switching circuits, matching network components such as discrete inductors, capacitors, and resistors, and integrated circuit filter networks, etc.). These devices may be mounted on any suitable mounting structures. With one suitable arrangement, transceiver integrated circuits may be mounted on a printed circuit board. Paths  65  may be used to interconnect the transceiver integrated circuits and other components on the printed circuit board with antenna structures in device  10 . Paths  65  may include any suitable conductive pathways over which radio-frequency signals may be conveyed including transmission line path structures such as coaxial cables, microstrip transmission lines, etc. 
       FIG. 7  shows an antenna structure that may be formed in conductive housing of device  10 . As shown in  FIG. 7 , antenna  26  may be formed from a ground plane structure such as ground plane  64 . Ground plane  64  may be formed from conductive housing  12  of device  10  (see, e.g.,  FIGS. 1-5 ). Ground plane  64  may be formed from a printed circuit board, a planar metal structure, conductive electrical components, conductive housing walls, other suitable conductive structures, or combinations of these structures. With one suitable arrangement, ground plane  64  may be formed from one or more conductive layers on a printed circuit board. The printed circuit board may be rigid or flexible. An example of a rigid circuit board substrate is fiberglass-filled epoxy (e.g., FR4). An example of a flexible printed circuit board material is polyimide. Flexible printed circuits are sometimes referred to as flex circuits and may be mounted to dielectric support structures such as plastic supports. 
     An antenna resonating element for antenna  26  may be formed from an opening  56  in ground plane  64 . Opening  56  may be filled with air or with a solid dielectric such as plastic or epoxy. As opening  56  has a length L that is longer than its width W, openings of this type are often referred to as a slots. 
     Slot  56  serves as an antenna resonating element for antenna  26 , and ground plane  64  serves as a ground plane element for antenna  26 . The slot and ground plane are sometimes referred to as forming a “pole” for antenna  26 . 
     Any suitable feed arrangement may be used to feed antenna  26 . As shown schematically in the example of  FIG. 7 , a transmission line such as a coaxial transmission line may be used to convey radio-frequency signals between antenna  26  and a radio-frequency transceiver such as WiFi and Bluetooth transceiver circuitry  22  and cellular telephone transceiver circuitry  24  of  FIG. 6 . 
     Transmission line  58  may be coupled to antenna  26  at feed terminals such as feed terminals  60  and  62 . Feed terminal  62  may be referred to as a ground or negative feed terminal and may be shorted to the outer (ground) conductor of transmission line  22 . Feed terminal  60  may be referred to as the positive antenna terminal. The transmission line center conductor may be used to connect transmission line  58  to positive feed terminal  60 . If desired, other types of antenna coupling arrangements may be used (e.g., based on near-field coupling, using impedance matching networks, etc.). 
     Another illustrative slot antenna is shown in  FIG. 8 . Antenna  26  of  FIG. 8  has ground plane  64 . Ground plane  64  may be formed from conductive housing  12  in  FIGS. 1-5  or other conductive structures (e.g., a housing frame member, etc.). Ground plane  64  may also be formed from a rigid or flexible printed circuit board, a planar metal structure, conductive electrical components, or other suitable conductive structures. 
     Antenna resonating elements for antenna  26  may be formed from two openings in ground plane  64 , as shown in  FIG. 8 . These openings, often referred to as slots, may be filled with air or other suitable dielectrics such as plastic. Slots  66  and  68  may have any suitable shapes. Slot  66  may have length L 1  and width W 1 . Slot  68  may have a length L 2  and a width W 2 . In a typical configuration slots  66  and  68  have longitudinal dimensions that significantly exceed their lateral dimensions. Slots  66  and  68  may have different lengths and widths. Slot widths W 1  and W 2  may be, for example, about 0.1 to 0.5 mm, about 100 μm to 0.1 mm, more than 100 μm, more than 0.1 mm, more than 0.5 mm, etc. The length of slots  66  and  68  may be substantially equal to half of a wavelength at the slot&#39;s frequency of operation (e.g., several mm to several cm). Each slot may be configured to provide coverage in a different communications band. 
     Slots  66  and  68  serve as antenna resonating elements for antenna  26 , and ground plane  64  serves as a ground plane element for antenna  26 . A first antenna structure may be formed by slot  66  (which serves as a first of two antenna poles for the first antennas structure) and ground plane  64  (which serves as a second of two antenna poles for the first antenna structure). Similarly, a second antenna structure can be formed from slot  68  (which serves as a first of two antenna poles for the second antenna structure) and ground plane  64  (which serves as a second of two antenna poles for the second antenna structure). Slots  66  and  68  may resonate at different frequencies, so that the antenna that is formed from slots  66  and  68  (and from ground plane  64 ) serves as a multiband antenna. The slot shapes may also be selected so that harmonics from one slot overlap the frequency response of the over slot. The antenna structure formed from slot  66  and ground plane  64  may handle a first communication band, whereas the antenna structure formed from slot  68  and ground plane  64  may handle a second communications band. Communications bands covered by antenna  26  may include cellular telephone bands such as the 850 MHz, 900 MHz, 1800 MHz, 1900 MHz bands, or the 2100 MHz data band or the 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications or the 2.4 GHz Bluetooth communications band (as examples). 
     Any suitable feed arrangement may be used to feed antenna  26 . As shown schematically in  FIG. 8 , a transmission line such as a coaxial transmission line  58  may be coupled to antenna  26  at feed terminals such as feed terminals  60  and  62 . Negative (ground) feed terminal  62  may be shorted to the outer (ground) conductor of transmission line  58 . Positive feed terminal  60  may be shorted to the center conductor of transmission line  58 . If desired, other types of antenna coupling arrangements may be used (e.g., based on near-field coupling, using impedance matching networks, etc.). 
     Antennas  26  may have slots that are open or closed. In the example of  FIG. 9 , antenna  26  has a ground plane  64  with closed slot  80  and open slot  82 . Slots  80  and  82  serve as antenna resonating elements and ground plane  64  serves as a ground plane element. Ground plane  64  may be formed from conductive housing  12  of  FIGS. 1-5 . The antenna formed from structures  64  of  FIG. 9  may be fed using positive antenna feed terminal  60  and ground antenna feed terminal  62 . In this type of arrangement, slot  80  and ground plane  64  may serve as pair of poles for a first antenna resonating structure. Slot  82  and ground plane  64  may serve as a pair of poles for a second antennas resonating structure. Slots  64  and  66  may have any suitable shape. Slots  64  and  66  may be straight or slots  64  and  66  may be angled. In  FIG. 9 , open slot  82  is shown as straight and closed slot  80  is shown as having angles. Any suitable feeding arrangement may be used to feed antenna  26  in  FIG. 9 . For example, a coaxial transmission line may be used to feed antenna  26  in  FIG. 9 . 
     The sizes of slots  80  and  82  may be configured so that antenna  26  operates in desired communications bands (e.g., 2.4 GHz and 5 GHz, etc.). The length associated with an open slot such as slot  82  may be substantially equal to a quarter of a wavelength at the slot&#39;s frequency of operation. For example, the length L 1  of open-ended slot  82  may be substantially equal to a quarter of a wavelength in a first communications band (i.e., at 2.4 GHz, etc.). The length of a close-ended slot such as closed slot  80  may be substantially equal to half of a wavelength at the slot&#39;s frequency of operation (i.e., its perimeter may be one wavelength in length). For example, the length L 2  of close-ended slot  80  may be substantially equal to half of a wavelength in a second communications band (i.e., at 5 GHz, etc). 
     Other illustrative antenna structures that may be used in forming an antenna for device  10  (e.g., as part of stand  42  of  FIG. 3 ) include inverted-F antenna structures such as the inverted-F antenna structure of  FIG. 10 . Antenna  26  of  FIG. 10  may be fed by radio-frequency source  74  (transceivers  22  and  24  of  FIG. 6 ) at positive antenna feed terminal  60  and ground antenna feed terminal  62 . Positive antenna feed terminal  60  may be coupled to antenna resonating element  70 . Ground antenna feed terminal  62  may be coupled to ground element  80 . Resonating element  70  may have a main arm  76  and a shorting branch  72  that connects main arm  76  to ground  80 . Antenna  26  of  FIG. 10  may be formed in a region such as region  19 E of stand  42  of  FIG. 3 . Ground  80  may be coupled to housing  12 , housing  12 C, or another suitable ground plane element. 
       FIG. 11  shows an illustrative arrangement for antenna  26  that is based on a monopole antenna configuration. In the example of  FIG. 11 , resonating element  70  of antenna  26  has a meandering serpentine path shape. Positive feed terminal  60  may be connected to one end of resonating element  70 . Antenna  26  in  FIG. 11  may be formed in stand  42  of  FIG. 3 . Ground feed terminal  62  may be coupled to housing  12  or another suitable ground plane element. 
     Another possible configuration for antenna  26  is shown in  FIG. 12 . In the arrangement of  FIG. 12 , antenna  26  has a patch antenna resonating element  78 . Antenna  26  of  FIG. 12  may be fed using positive antenna feed terminal  60  and ground antenna feed terminal  62 . Antenna  26  in  FIG. 12  may be formed in stand  42  of  FIG. 3 . Ground  60  may be associated with housing  12  or other suitable ground plane elements in device  10 . 
       FIG. 13  shows another illustrative configuration that may be used for the antenna structures of antenna  26 . In the  FIG. 8  example, antenna resonating element  70  has two main arms. Arm  76 A is shorter than arm  76 B and is therefore associated with higher frequencies of operation than arm  76 A. By using two or more separate resonating element structures of different sizes, antenna resonating element  70  of  FIG. 13  can be configured to cover a wider bandwidth or more than a single communications band of interest. Antenna  26  in  FIG. 13  may be formed in stand  42  of  FIG. 3 . Ground  80  may be associated with housing  12  or other suitable ground plane elements in device  10 . 
     As shown in  FIG. 14 , antenna  26  may be formed from a gap or space between conductive housing  12  and conductive internal frame  15  of electronic device  10 . Device  10  may be any suitable electronic device (e.g., device  10  in  FIGS. 1-5 ) such as a portable computer or handheld electronic device. Housing  12  may be mounted on internal frame  15 . There may be a gap  84  between housing  14  and internal frame  15 . Gap  84  may be filled with air, plastic, epoxy, or other suitable dielectric materials. Housing  12  may be formed from metal or another conductive material. Internal frame  15  may be, for example, a frame that is used to form a structural support for display  14  ( FIG. 1 ) Frame  15  may be formed from aluminum or other suitable conductive materials. Frame  15  may be mounted to the inside surface of housing  12  using welds, adhesive, fasteners, or other suitable attachment mechanisms. Conductive materials  82  may help electrically connect housing  12  to internal frame  15  so that gap  84  forms a closed slot. Antenna  26  may be fed by positive feed terminal  60  and negative feed terminal  62  that are positioned on either side of gap  84  (as an example). One of the feed terminals may be located on housing  12  and the other feed terminal may be positioned on internal frame  15 . Antenna  26  of  FIG. 14  may be fed by a transmission line such as a coaxial transmission line or using any other suitable feeding arrangement. 
       FIG. 15  shows a cross section of an electronic device  10  that has an antenna  26  formed in a gap  84  between housing  12  and frame  15 . Antenna  26  may have a positive feed terminal  60  and a negative feed terminal  62  located on either side of gap  84 , so that one feed terminal is located on housing  12  and the other feed terminal is located on internal frame  15 . The gap between housing  12  and frame  15  may be filled by air or with a solid dielectric  88 . Dielectric  88  may be plastic, epoxy, or any other suitable dielectric material. Frame  15  may form a support for display  14 . Cover glass  86  may be positioned over display  14  and frame  15 , and may optionally be positioned over antenna  26 . The portion of cover glass  86  in region  90  may have an undercoat of an opaque ink such as a black ink, preventing antenna  26  from being viewed by a user of device  10 . The opaque ink in region  90  may be provided in a layer that is sufficiently thin to ensure that the ink layer is transparent to radio-frequency signals. Because glass  86  is a dielectric and because the opaque ink is sufficiently thin, radio-frequency signals for antenna  26  are not blocked by glass  86  or the ink in region  90 . 
     As shown in  FIG. 16 , slot antenna  26  may be formed as part of a logo. Because a logo carries branding information or other information that is of interest to the user of the electronic device, a logo may serve a useful and accepted information-conveying purpose and need not introduce an undesirable visible design element to the exterior of the electronic device. Housing  12  may be formed of conductive material such as metal. Logo structure  92  may be formed of a dielectric material such as plastic embedded in a corresponding logo-shaped opening in housing  12 . Logo structure  92  may have a slot-shaped narrow region  94 . Antenna  26  may have positive feed terminal  60  and a negative feed terminal  62  on either side of narrow region  94  on logo  92 . All or part of logo structure  92  (e.g., narrow region  94 ) may function as a slot and may serve as an antenna resonating element for antenna  26 . Logo structure  92  may be any logo that has dimensions suitable for an antenna  26 . Logo structure  92  need not have the form depicted in  FIG. 16 . Logo  92  may be formed anywhere on housing  12 . For example, logo  92  may be formed in regions  19 B- 19 D of housing  12  in  FIG. 2 , in region  19 E of  FIG. 3 , or in region  48  of  FIG. 5 . 
     Antennas may also be formed from slots an in internal housing.  FIG. 17  shows a cross section along dashed line  96  of device  10  of  FIG. 1 .  FIG. 17  shows lower housing portion  12 B and housing portion  12 E which surrounds a portion of device  10  that lies between hinges  13  (see, e.g.,  FIG. 1 ). Internal frame  15  may provide support for housing  12 B and for internal components such as circuit boards. Internal frame  15  may be made of conductive materials such as aluminum. One or more slots  98  may be formed in a section of internal frame  15  that lies inside housing portion  12 E. Slots  98  may serve as antenna resonating elements for antenna  26  and may have longitudinal axes that run parallel to the clutch barrel hinges of device  10  (i.e., that run parallel to the back edge of device  10 ). Housing portion  12 E may be formed from dielectric materials so that radio-frequency signals can pass through housing portion  12 E. A dielectric housing portion  12 E may serve as a dielectric window for antenna  26 . 
     There may be one slot  98  so that antenna  26  is a single slot antenna such as in  FIG. 7 . There may also be two slots  98  so that antenna  26  is a dual slot antenna as in  FIG. 8 . Slots  98  may be open or closed slots such as in the example of  FIG. 9 . One or more slot antennas  26  may be formed in internal frame  15 . Any suitable feeding arrangement may be for antenna  26  of  FIG. 17 . For example, a coaxial transmission line may be used to feed antenna  26  of  FIG. 17 . 
       FIG. 18  shows how a housing portion of device  10  may have an integrated frame. Frame  100  in  FIG. 18  is a frame that also serves as a housing portion. Frame  100  may be machined or cast out of a single piece of material such as aluminum. Slots  98  may be formed in frame  100 . Housing portion  12 E surrounding slots  98  may be made of nonconductive or dielectric materials to allow radio-frequency signals to pass through housing  12 E. A dielectric housing portion  12 E may serve as a dielectric window for antenna  26 . Frame  100  may be used conjunction with other housing portions such as housing  12 B. Slots  98  serve as antenna resonating elements for antenna  26  in  FIG. 18 . Slots  98  may be single or double slots and may be open or closed slots. One or more slot antennas  26  may be formed in frame  100 . A coaxial transmission line or any suitable feeding arrangement may be used to feed antenna  26 . 
       FIG. 19  shows an illustrative hinge. Member  102  of hinge  13  may connect to a lower portion of device  10 . For example, member  102  may connect to frame  15  of  FIG. 17  or frame  100  of  FIG. 18 . Hinge  13  may have a member  104  that connects to an upper portion (or cover) of device  10  such as portion  12 A. Parts  102  and  104  may rotate with respect to each other as the upper portion or cover of device  10  opens and closes. Hinge  13  may have a spring  106  that helps to control the motion of hinge  13 . When installed in device  10 , slot antennas formed on the frame of device  10  may be located between a pair of hinges  13  under region  19 A of  FIG. 1 . 
       FIG. 20  shows a perspective view of configuration that may be used for the slot antennas of  FIGS. 17 and 18 . As shown in  FIG. 20 , slot antennas  26  may have antenna resonating elements formed from slots  98  in frame  15 . Antenna  26  may have a single slot, double slots, an open-ended L-shaped slot, or any suitable slot configuration. Antennas  26  may have positive and negative feed terminals. There may be more than one antenna  26  formed in frame  15 . The slot configurations of  FIG. 20  may also be formed in frame  100  of  FIG. 18  that also serves as a housing. 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20090623
Publication Date: 20120918
Grant Date: 20120918
Priority Date: 20090623
Inventors: KOUGH DOUGLAS B.
SPRINGER GREGORY A.
CHIANG BING
AYALA VAZQUEZ ENRIQUE
XU HAO
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/244", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/244", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 43353849