PATENT DOCUMENT

Publication Number: US-7804453-B2
Application Number: US-10435908-A
Country: US
Kind Code: B2

Title: Antennas for wireless electronic devices

Abstract:
Antenna window structures and antennas are provided for electronic devices. The electronic devices may be laptop computers or other devices that have conductive housings. Antenna windows can be formed from dielectric members. The dielectric members can have elastomeric properties. An antenna may be mounted inside a conductive housing beneath a dielectric member. The antenna can be formed from a parallel plate waveguide structure. The parallel plate waveguide structure may have a ground plate and a radiator plate and may have dielectric material between the ground and radiator plates. The ground plate can have a primary ground plate portion and a ground strip. The ground strip may reflect radio-frequency signals so that they travel through the dielectric member. The antenna may handle radio-frequency antenna signals in one or more communications bands. The radio-frequency antenna signals pass through the dielectric member.

Claims:
1. A portable electronic device, comprising:
 a device housing having a first housing portion with a first surface and a second housing portion with a second surface, wherein the first and second housing portions are hinged together; 
 a dielectric member on the first surface that has portions that define a path for radio-frequency signals from an interior portion of the first housing portion to an exterior edge of the device housing, wherein the dielectric member forms a channel between the first surface and the second surface through which the radio-frequency signals pass; and 
 an antenna mounted within the first housing portion adjacent to the dielectric member so that radio-frequency signals for the antenna pass along the path. 
 
   
   
     2. The portable electronic device defined in  claim 1  wherein the portable electronic device comprises a laptop computer, wherein the laptop computer is in a closed position when the first and second surfaces are parallel to each other and are facing each other, and wherein the radio-frequency signals for the antenna pass along the path between the exterior edge of the device housing and the antenna when the laptop computer is in the closed position and when the laptop computer is in an open position. 
   
   
     3. The portable electronic device defined in  claim 2  wherein the dielectric member comprises a spacer that is attached to the first housing portion, that extends above the first surface, and that prevents the first and second surfaces from directly contacting each other when the laptop computer is in the closed position. 
   
   
     4. The portable electronic device defined in  claim 3  wherein the spacer comprises a strip of elastomeric material that lines a perimeter of the first surface. 
   
   
     5. The portable electronic device defined in  claim 2  wherein the dielectric member comprises a spacer formed from at least one strip of elastomeric material and wherein the at least one strip of elastomeric material lines at least a portion of a perimeter of the first surface. 
   
   
     6. The portable electronic device defined in  claim 5  further comprising an additional spacer formed from at least one strip of elastomeric material that lines at least a portion of a perimeter of the second surface and that mates with the first spacer when the laptop computer is in the closed position. 
   
   
     7. The portable electronic device defined in  claim 1  wherein the antenna comprises a parallel plate wave guide antenna with a radiator plate and a ground plate. 
   
   
     8. The portable electronic device defined in  claim 7  wherein the ground plate comprises a ground strip that reflects radio-frequency signals generated by the antenna that are traveling away from the dielectric member. 
   
   
     9. A portable electronic device, comprising:
 a device housing having a first housing portion with a first surface and a second housing portion with a second surface, wherein the first and second housing portions are hinged together; 
 a dielectric member on the first surface that has portions that define a path for radio-frequency signals from an interior portion of the first housing portion to an exterior edge of the device housing; and 
 an antenna mounted within the first housing portion adjacent to the dielectric member so that radio-frequency signals for the antenna pass along the path, wherein the dielectric member forms a channel having a given dimension along which the radio-frequency signals propagate at an operating frequency and having lateral dimensions perpendicular to the given dimension that are greater than one half of a wavelength in the dielectric member at the operating frequency. 
 
   
   
     10. The portable electronic device defined in  claim 9  wherein the antenna comprises a parallel plate wave guide antenna with a radiator plate and a ground plate and wherein the ground plate comprises a ground strip that reflects radio-frequency signals generated by the antenna that are traveling away from the dielectric member. 
   
   
     11. A laptop computer, comprising:
 a conductive housing having top and bottom conductive housing portions that are hinged together; 
 a dielectric member, wherein portions of the dielectric member define an antenna window on the top conductive housing portion through which antenna signals pass between interior and exterior regions of the top conductive housing portion; and 
 an antenna that handles radio-frequency antenna signals, wherein the antenna is contained within the top conductive housing portion adjacent to the dielectric member, wherein when the top and bottom housing portions are parallel to each other and are facing each other, the laptop computer is in a closed position, and wherein the antenna is oriented relative to the dielectric member so that the antenna signals pass through the dielectric member to the exterior region of the top conductive housing portion when the laptop computer is in the closed position and when the laptop computer is in an open position, wherein the dielectric member comprises an elastomeric member on the top conductive housing portion that prevents the top and bottom conductive housing portions from directly contacting each other. 
 
   
   
     12. The laptop computer defined in  claim 11  wherein the antenna window comprises a path for the antenna signals from the interior region of the top conductive housing portion to the exterior region of the top conductive housing portion and wherein the elastomeric member comprises a strip of elastomeric material that lines at least a portion of a perimeter of the top conductive housing portions. 
   
   
     13. The laptop computer defined in  claim 12  wherein the top conductive housing portion has opposing surfaces that define a lateral dimension for the path and wherein the antenna is oriented with the top conductive housing portion so that an electric field component in the radio-frequency antenna signals is parallel to the lateral dimension. 
   
   
     14. The laptop computer defined in  claim 13  wherein the top conductive housing portion comprises an exterior housing structure that at least partially surrounds the interior region of the top conductive housing portion and that has a first surface that faces the interior region, wherein the top conductive housing portion comprises a housing member in the interior region of the top conductive housing portion that has a second surface that is adjacent to the dielectric member, wherein the dielectric member is located between the housing member and the exterior housing structure, and wherein the opposing surfaces of the top conductive housing portion comprise the first and second surfaces.

Description:
BACKGROUND 
   This invention relates to antennas, and more particularly, to dielectric antenna windows that allow antennas to operate from within electronic devices such as laptop computers. 
   Due in part to their mobile nature, portable electronic devices are often provided with wireless communications capabilities. Portable electronic devices may use wireless communications to communicate with wireless base stations. For example, portable electronic devices such as laptop computers can communicate using the Wi-Fi® (IEEE 802.11) bands at 2.4 GHz and 5 GHz and the Bluetooth® band at 2.4 GHz. Communications are also possible in data service bands such as the 3G data communications band at 2100 MHz band (commonly referred to as UMTS or Universal Mobile Telecommunications System). 
   To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to reduce the size of components that are used in these devices. For example, manufacturers have made attempts to miniaturize the antennas used in portable electronic devices. 
   A typical antenna may be fabricated by patterning a metal layer on a circuit board substrate or may be formed from a sheet of thin metal using a foil stamping process. These techniques can be used to produce antennas that fit within the tight confines of a compact portable device. With conventional portable electronic devices, however, design compromises are made to accommodate compact antennas. These design compromises can include, for example, compromises related to antenna efficiency and antenna bandwidth and comprises related to the visual appearance and structural integrity of the electronic devices. 
   It would therefore be desirable to be able to provide improved antennas for electronic devices such as portable electronic devices. 
   SUMMARY 
   Wireless communications structures for laptop computers or other electronic devices are provided. The wireless communications structures may include antennas and antenna window structures formed from dielectric members such as elastomeric spacers, as an example. 
   The electronic devices can have housings in which electrical components are mounted. The housings can be used, for example, to house components such as processors, memory, and input-output devices. Wireless transceiver circuitry, antennas, and other electrical components can be contained within a device housing. 
   The housing of a device may be formed from metal, metal alloys, or other conductive materials. An antenna may be housed within the housing. To allow radio-frequency antenna signals to pass through the conductive housing, an antenna window may be formed in the conductive housing. 
   The antenna windows can be formed from members such as dielectric spacers and dielectric gaskets, as an example. The antenna windows can be formed from materials with elastomeric properties in addition to dielectric properties. For example, the electronic device may be a laptop computer with two conductive housing portions that are hinged together and that open and close in a clamshell motion. In this type of arrangement, there may be one or more dielectric members (e.g., trim beads) along the perimeter (or along a portion of the perimeter) of at least one of the conductive housing portions. The dielectric members can be used to protect the laptop computer from damage when the laptop is closed (e.g., by preventing the two housing portions from directly contacting each other). 
   The antennas may be mounted inside the electronic device housing. For example, the antennas can be mounted beneath the dielectric members. The radio-frequency signals may be conveyed between the exterior of the electronic device housing and the antennas through the dielectric members. In embodiments in which the electronic devices are laptop computers with two housing portions that open and close in a clamshell motion, the dielectric members may convey radio-frequency signals between the exterior environment and the antennas even when the laptop computer is closed. The housing can form a channel that helps to guide these signals. 
   An antenna may be formed from one or more parallel plate waveguides, as an example. A parallel plate antenna structure of this type may have a ground plate and a radiator plate. The antenna can also have a reflector such as a copper sheet that serves to direct radio-frequency signals generated by the antenna towards the dielectric member. The gap between the ground plate and the radiator plate can be filled with a dielectric. The dielectric in the antenna may be selected to match the dielectric in the dielectric member so that radio-frequency signals pass between the antenna and the member with minimal reflection and attenuation. 
   The ground plate in the antenna can be split into multiple sections. In one example, the ground plate can be split into a primary ground plate portion and a ground strip. The ground strip may reflect radio-frequency signals generated by the antenna that are traveling away from the dielectric member. By reflecting signals that are traveling away from the member, the ground strip may increase antenna efficiency. 
   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 perspective view of an illustrative electronic device such as a portable electronic device in accordance with an embodiment of the present invention. 
       FIG. 2  is a schematic diagram of an illustrative electronic device in accordance with an embodiment of the present invention. 
       FIG. 3  is a side view of an illustrative antenna and a portion of an illustrative electronic device that has a dielectric member in accordance with an embodiment of the present invention. 
       FIG. 4  is a side view of the illustrative antenna and the illustrative electronic device portion of  FIG. 3  that shows illustrative electric fields that may be generated by the antenna in accordance with an embodiment of the present invention. 
       FIG. 5  is a side view of a portion of an illustrative electronic device that has a dielectric member, an upper housing portion, and a lower housing portion and of an illustrative antenna that is mounted in the lower housing portion in accordance with an embodiment of the present invention. 
       FIG. 6  is a side view of a portion of an illustrative electronic device that has a dielectric member, an upper housing portion, and a lower housing portion and of an illustrative antenna that is mounted in the upper housing portion in accordance with an embodiment of the present invention. 
       FIG. 7  is a perspective schematic view of an illustrative antenna that has a ground strip that serves as a reflector in accordance with an embodiment of the present invention. 
       FIG. 8  is a side view of an illustrative antenna that may be used in an illustrative electronic device with a dielectric member in accordance with an embodiment of the present invention. 
       FIG. 9  is a top view of the illustrative antenna shown in  FIG. 8  in accordance with an embodiment of the present invention. 
       FIG. 10  is a bottom view the illustrative antenna shown in  FIG. 8  in accordance with an embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   The present invention relates generally to antennas, and more particularly, to antennas for wireless electronic devices such as laptop computers. The wireless electronic devices may have conductive housings and the antennas can be mounted inside the conductive housings. Antenna windows allow the antennas to transmit and receive radio-frequency signals from inside the conductive housings. 
   The wireless electronic devices can be any suitable electronic devices. As an example, the wireless electronic devices can be desktop computers or other computer equipment. The wireless electronic devices may also be portable electronic devices such as portable computers also known as laptop computers or small portable computers of the type that are sometimes referred to as ultraportables. Portable electronic devices may also be somewhat smaller devices. Examples of smaller portable electronic devices include personal accessory devices capable of being worn, carried, or otherwise attached to the body such as arm and wrist band devices, pendant devices, headphone and earpiece devices, and other wearable and miniature devices. In one embodiment, the portable electronic devices are handheld electronic devices. 
   Examples of portable and handheld electronic devices include laptop computers, cellular telephones, media players with wireless communications capabilities, handheld computers (also sometimes called personal digital assistants), remote controls, global positioning system (GPS) devices, and handheld gaming devices. The devices can also be hybrid devices that combine the functionality of multiple conventional devices. Examples of hybrid devices include a cellular telephone that includes media player functionality, a gaming device that includes a wireless communications capability, a cellular telephone that includes game and email functions, and a handheld device that receives email, supports mobile telephone calls, has music player functionality and supports web browsing. These are merely illustrative examples. 
   An illustrative electronic device such as a portable electronic device in accordance with an embodiment of the present invention is shown in  FIG. 1 . Device  10  may be any suitable electronic device. As an example, device  10  can be a laptop computer. 
   Device  10  may handle communications over one or more communications bands. For example, wireless communications circuitry in device  10  may be used to handle cellular telephone communications in one or more frequency bands and data communications in one or more communications bands. Typical data communications bands that can be handled by the wireless communications circuitry in device  10  include the 2.4 GHz band that is sometimes used for Wi-Fi® (IEEE 802.11) and Bluetooth® communications, the 5 GHz band that is sometimes used for Wi-Fi® communications, the 1575 MHz Global Positioning System band, and 3G data bands (e.g., the UMTS band at 1920-2170). These bands can be covered by using single and multiband antennas. For example, cellular telephone communications can be handled using a multiband cellular telephone antenna and local area network data communications can be handled using a multiband wireless local area network antenna. As another example, device  10  can have a single multiband antenna for handling communications in two or more data bands (e.g., at 2.4 GHz and at 5 GHz). 
   Device  10  has housing  12 . Housing  12 , which is sometimes referred to as a case, can be formed of any suitable materials including plastic, glass, ceramics, metal, other suitable materials, or a combination of these materials. In embodiments in which device  10  is a laptop computer with top and bottom halves, housing halves such as housings  30  and  32  can together form housing  12 . For example, housing portion  30  may be a top half of device  10  that houses a display such as display  16  and housing portion  32  may be a bottom half of device  10  that houses circuitry such as circuitry  18 . The housing halves (e.g., housings  30  and  32 ) can be hinged using a hinge such as hinge  9 . Hinged housing halves can open and close in a clamshell motion about hinge axis  11 . 
   Housing  12  or portions of housing  12  may also be formed from conductive materials such as metal. 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. 
   Device  10  can have an antenna window formed from portions of housing  12  and a dielectric such as a portion of a dielectric member (e.g., part of members  28 ). Members such as member  28  may also be referred to as gaskets. With one suitable arrangement, each member  28  can be a narrow bead of elastomeric material that lines a perimeter of housing  12 . For example, as illustrated in  FIG. 1 , device  10  can be a laptop computer that has top and bottom housing portions (e.g., housing portion  30  and housing portion  32 , respectively) and that opens and closes in a clamshell motion. Members such as member  28  may be provided on the inside face of one or both of the housing portions. This may help prevent the housing portions from contacting each other when the laptop computer is closed (e.g., by acting as a mechanical spacer between housing portion  30  and housing portion  32 ). By preventing the housing portions from coming into contact, members  28  can protect a display screen or other potentially fragile elements in the laptop computer from damage when the laptop computer. Members  28  may also help keep dust, water, and other debris from entering device  10  (e.g., by acting as a gasket). Members  28  or portions of a member  28  can be formed from dielectric materials such as rubber, epoxy, plastic, fiberglass-filled epoxy (e.g., flame retardant 4, FR4, or epoxy-fiberglass), thermoplastic polyurethane, etc. In arrangements in which members  28  are used as gaskets, the dielectric materials used to form member  28  or portions of member  28  preferably have elastomeric properties (e.g., as with soft rubber or plastic). 
   Members such as members  28  need not line the entire perimeter of housing  12 . For example, a dielectric member on housing  12  may be formed from one or more strips of material on at least one of housing portions  30  and  32 . In this example, the dielectric member may be a single strip of material at the front edge of device  10  (e.g., adjacent to touchpad  26 ). With another suitable arrangement, dielectric members may be formed from one strip along the right side of housing portion  30  (e.g., at the location of antenna  20  in  FIG. 1 ) and one strip along the left side of housing portion  30  (e.g., on the side of housing  20  opposite antenna  20 ). Dielectric members can also be formed from smaller shapes such as small squares of elastomeric and/or dielectric material. For example, dielectric members  28  can be formed from squares of material located at the outside corners of device  10  (e.g., the two corners of housing portion  30  furthest from the hinge joint of a laptop computer). 
   Member  28  need not be used as a physical spacer. For example, member  28  can blend in with surrounding portions of device  10 . In this type of arrangement, member  28  may not extend above the surface of housing  12  and can have an exterior appearance similar to surrounding portions of housing  12  (e.g., similar in texture and color). 
   Device  10  may have one or more keys such as keys  14 . Keys  14  can be formed on any suitable surface of device  10 . In the example of  FIG. 1 , keys  14  have been formed on the top surface of housing portion  32 . With one suitable arrangement, keys  14  may form a keyboard on a laptop computer. Keys such as keys  14  may also be referred to as buttons. 
   If desired, device  10  may have a display such as display  16 . Display  16  may be a liquid crystal diode (LCD) display, an organic light emitting diode (OLED) display, a plasma display, or any other suitable display. The outermost surface of display  16  may be formed from one or more plastic or glass layers. If desired, touch screen functionality can be integrated into display  16 . Device  10  can also have a separate touch pad device such as touch pad  26 . 
   Device  10  can have circuitry  18 . Circuitry  18  may include storage, processing circuitry, and input-output components. Wireless transceiver circuitry in circuitry  18  may be used to transmit and receive radio-frequency (RF) signals. Transmission lines (e.g., communications paths) such as coaxial transmission lines and microstrip transmission lines are used to convey radio-frequency signals between transceiver circuitry and antenna structures in device  10 . As shown in  FIG. 1 , for example, transmission line  22  is used to convey signals between antenna structure  20  and circuitry  18 . Communications path  22  (i.e., transmission line  22 ) can be, for example, a coaxial cable that is connected between an RF transceiver (sometimes called a radio) and a multiband antenna. Antenna structures such as antenna structure  20  may be located beneath a portion of member  28  adjacent to display  16  as shown in  FIG. 1  or in other suitable locations. For example, antenna structures such as antenna structure  20  can be located adjacent to display  16  on the top edge of housing portion  30  or adjacent to keys  14  (e.g., on the side portion of housing portion  32 ) as illustrated by outlines  24 . 
   A schematic diagram of an embodiment of an illustrative electronic device such as a portable electronic device is shown in  FIG. 2 . Portable device  10  may be a laptop computer, 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 combination of such devices, or any other suitable portable or handheld electronic device. 
   As shown in  FIG. 2 , portable device  10  can include storage  34 . Storage  34  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., battery-based static or dynamic random-access-memory), etc. 
   Processing circuitry  36  can be used to control the operation of device  10 . Processing circuitry  36  may be based on a processor such as a microprocessor and other suitable integrated circuits. With one suitable arrangement, processing circuitry  36  and storage  34  are 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. Processing circuitry  36  and storage  34  can be used in implementing suitable communications protocols. Communications protocols that may be implemented using processing circuitry  36  and storage  34  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling 3G data services, cellular telephone communications protocols, etc. 
   Input-output devices  38  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. Display screen  16 , keys  14 , and touchpad  26  of  FIG. 1  are examples of input-output devices  38 . 
   Input-output devices  38  can include user input-output devices  40  such as buttons, touch screens, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, speakers, tone generators, vibrating elements, etc. A user can control the operation of device  10  by supplying commands through user input devices  40 . 
   Display and audio devices  42  can include liquid-crystal display (LCD) screens or other screens, light-emitting diodes (LEDs), and other components that present visual information and status data. Display and audio devices  42  may also include audio equipment such as speakers and other devices for creating sound. Display and audio devices  42  may contain audio-video interface equipment such as jacks and other connectors for external headphones, speakers, microphones, monitors, etc. 
   Wireless communications devices  44  can include communications circuitry such as radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, passive RF components, one or more antennas (e.g., antenna structures such as antenna structure  20  of  FIG. 1 ), and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
   Device  10  can communicate with external devices such as accessories  46  and computing equipment  48 , as shown by paths  50 . Paths  50  may include wired and wireless paths. Accessories  46  may include headphones (e.g., a wireless cellular headset or audio headphones) and audio-video equipment (e.g., wireless speakers, a game controller, or other equipment that receives and plays audio and video content). 
   Computing equipment  48  can be any suitable computer. With one suitable arrangement, computing equipment  48  is a computer that has an associated wireless access point or an internal or external wireless card that establishes a wireless connection with device  10 . The computer can be a server (e.g., an internet server), a local area network computer with or without internet access, a user&#39;s own personal computer, a peer device (e.g., another portable electronic device  10 ), or any other suitable computing equipment. 
   The antenna structures and wireless communications devices of device  10  can support communications over any suitable wireless communications bands. For example, wireless communications devices  44  may be used to cover communications frequency bands such as the cellular telephone bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz, data service bands such as the 3G data communications band at 2100 MHz band (commonly referred to as UMTS or Universal Mobile Telecommunications System), Wi-Fi® (IEEE 802.11) bands (also sometimes referred to as wireless local area network or WLAN bands), the Bluetooth® band at 2.4 GHz, and the global positioning system (GPS) band at 1575 MHz. Wi-Fi® bands that can be supported include the 2.4 GHz band and the 5 GHz bands. The 2.4 GHz Wi-Fi® band extends from 2.412 to 2.484 GHz. Commonly-used channels in the 5 GHz Wi-Fi® band extend from 5.15-5.85 GHz, so the 5 GHz band is sometimes referred to by the 5.4 GHz approximate center frequency for this range (i.e., these communications frequencies are sometimes referred to as making up a 5.4 GHz communications band). Device  10  can cover these communications bands and/or other suitable communications bands with proper configuration of the antenna structures in wireless communications circuitry  44 . 
   A side view of an illustrative antenna structure and of a portion of an illustrative electronic device with a dielectric member is shown in  FIG. 3 . As shown in  FIG. 3 , antenna  20  can be formed inside housing  12 . For example, antenna  20  can be formed inside a portion of device  10  such as lower housing portion  32 . Member  28  may extend above a flat portion of housing  12 . For example, as shown in  FIG. 3 , member  28  may extend above an upper planar surface associated with housing portion  32  to prevent housing portions  30  and  32  from coming into contact with each other. 
   In  FIG. 3 , member  28  is shown on only one portion of housing  12  (e.g., housing portion  32 ). This is merely an example. In general, member  28  can be formed on housing portion  30  or on housing portions  30  and  32  (e.g., the top and bottom portions, respectively, of an illustrative laptop computer). 
   As shown in  FIG. 3 , member  28  can help define a channel between conductive housing portions of device  10 . This channel conveys radio-frequency signals from the exterior of device  10  to the interior of housing  12  (e.g., housing portion  30  or housing portion  32 ). The channel formed by member  28  can be substantially rectangular in shape, as an example. As shown in  FIG. 3 , member  28  (and the channel it forms) has an aspect ratio of approximately one to two (e.g., the length of member  28  in  FIG. 3  is approximately twice its height). This is merely an example. In general, member  28  (and the channel it forms) may have any suitable aspect ratio such as one to one, one to two, one to three, more than one to three, etc. For satisfactory performance, member  28  (and the channel it forms) should generally have a depth (e.g., a dimension perpendicular to the page in the orientation of  FIG. 4 ) that is at least one-half of a wavelength at the operating frequency of antenna  20  including the effects of the dielectric material used to form member  28 . In one embodiment, conductive structures such as rivets or braces that are used to hold member  28  in place are spaced at least one-half of a wavelength apart so that member  28  has a depth of at least one-half of a wavelength that is substantially unobstructed by conductive structures. 
   Antenna  20  may be based on a parallel plate waveguide structure. For example, antenna  20  can be formed from a ground plate such as ground plate  52  and a radiator plate such as radiator plate  54 . Ground plate  52  and radiator plate  54  can each have a substantially rectangular shape. Ground plate  52  and radiator plate  54  can be formed from any suitable conductive materials. With one suitable arrangement, plates  52  and  54  are formed primarily from copper. Antenna  20  can be fed by transmission line  22 . In general, any suitable antenna design can be used for antenna  20 . The use of a parallel plate arrangement is presented as an example. 
   Antenna  20 , and in particular the space between ground plate  52  and radiator plate  54 , may be filled with a dielectric insert such as dielectric  56 . Dielectric  56  may be any suitable dielectric such as air, epoxy, polyimide, FR4, epoxy-fiberglass, etc. 
   Solid dielectrics  56  can serve to reduce the size of antenna  20  so that the antenna fits beneath dielectric member  28 . For example, use of a printed circuit board dielectric may reduce the width (e.g., the separation between plates  52  and  54 ) of antenna  20  so that the antenna fits beneath a dielectric member that is similar in size to the spacers that are a part of a laptop computer (e.g., such as spacers for protecting a laptop computer that opens and closes in a clamshell motion). With one suitable arrangement, antenna  20  is small enough to be placed under a conventionally-sized spacer without modification to the spacer (e.g., without enlarging the conventionally-sized spacer or altering its exterior appearance). This may allow radio-communications capabilities to be added to an electronic device without modifying the exterior appearance of the device and without reducing the physical integrity of the device. 
   The dielectric properties of dielectric  56  and dielectric member  28  can be selected to enhance the operation of antenna  20 . For example, by selecting appropriate dielectric materials for dielectric  56  and member  28 , the efficiency of antenna  20  in transmitting and receiving radio-frequency signals to wireless communications equipment such as computing equipment  48  may be maximized. With one suitable arrangement, the dielectric materials in dielectric  56  may be similar to the dielectric materials in member  28  so that radio-frequency signals propagate between dielectric  56  and member  28  with little or no attenuation (e.g., little or no reflection at the interface between member  28  and dielectric  56 ). 
   Antenna  20  can be formed beneath a dielectric member such as member  28  so that the antenna is on the inside of device  10 . An excessive gap between antenna  20  and member  28  might interfere somewhat with the operation of antenna  20  (e.g., by reducing transmission efficiency). For example, in situations in which there is a significant gap between antenna  20  and member  28 , radio-frequency signals that propagate between member  28  and antenna  20  (e.g., dielectric  56 ) may be attenuated. It may therefore be desirable to mount antenna  20  beneath member  28  such that the gap between the antenna and the member is minimized. 
   A reflector such as reflector  58  can optionally be used to enhance the performance of antenna  20 . Optional reflector  58  may be a sheet of copper or other conductor that is located beneath antenna  20  (as an example). Reflector  58  may improve the efficiency of antenna  20  by increasing the proportion of radio-frequency signals generated by antenna  20  that propagate out of device  10  through member  28  (e.g., instead of propagating into the interior of device  10 ). 
   Ground plate  52  and radiator plate  54  can be formed from a printed circuit board, a planar metal structure, conductive electrical components, other suitable conductive structures, or combinations of these structures. 
   Antenna  20  can be used to cover two communications bands. The first band may be (for example) the 2.4 GHz IEEE 802.11 “b” band and the second band may be (for example) the 5 GHz IEEE 802.11 “a” band (sometimes referred to by its approximate center frequency of 5.4 GHz). With another suitable arrangement, device  10  has more than one antenna  20  each of which covers one or more communications band. For example, device  10  may have a first antenna such as antenna  20  that covers the 802.11 “b” band and may have a second antenna such as antenna  20  that covers the 802.11 “a” band. 
   Any suitable feed arrangement can be used to feed antenna  20 . As shown schematically in the example of  FIG. 3 , a transmission line such as transmission line  22  may be used to convey radio-frequency signals between antenna  20  and radio-frequency transceiver circuitry (wireless communications device  44  of  FIG. 2 ). The transceiver circuitry can include one or more transceivers for handling communications in one or more discrete communications bands. The feed arrangement for antenna  20  can include a matching network. The matching network may include a balun (to match an unbalanced transmission line to a balanced antenna) and/or an impedance transformer (to help match the impedance of the transmission line to the impedance of the antenna). 
   Illustrative electric fields that may be generated by antenna  20  are shown in  FIG. 4 . As shown in  FIG. 4 , antenna  20  may generate electric fields such as the electric fields illustrated by field lines  60 . The electric fields illustrated in  FIG. 4  may correspond to the electric field component of electromagnetic radiation (e.g., radio-frequency signals) that is generated by antenna  20  and that is received by antenna  20 . 
   Antenna  20  may be oriented within device  10  such that electric field lines  60  pass through member  28  with a desired orientation. For example, antenna  20  can be mounted in device  10  such that the electric fields of the radio-frequency signals generated by antenna  20  are orientated across the narrow dimension of member  28 . By orienting electric field lines  60  parallel to the narrow dimension (e.g., the vertical direction in  FIG. 4 ) of member  28 , the efficiency of antenna  20  can be improved relative to the efficiency of antenna  20  in situations in which field lines  60  are oriented perpendicular to the narrow dimension of member  28 . 
   Member  28  can convey radio-frequency signals between antenna  20  and the exterior of device  10 . When device  10  is a laptop computer that opens and closes in a clamshell motion, member  28  convey radio-frequency signals between antenna  20  and the exterior of device  10  both when the laptop computer is open ( FIG. 1 ) and when the laptop computer is closed (e.g., as illustrated in  FIG. 4 ). 
   As illustrated in  FIG. 5 , device  10  can be a laptop computer with two housing portions such as housings  30  and  32 . Housings  30  and  32  can be hinged and can open or close in a clamshell motion. There may be members such as members  28  and  64  in both housings  30  and  32 . Members such as member  28  and  64  can be referred to as trim beads. 
   Housing portion  32  may contain a display such as display  16  that is held in place at least partly by member  66 . Member  66  may be formed from materials similar to housing portion  30  or may be formed using other suitable conductive materials. Member  66  may be considered to be a part of housing portion  30 . Member  66  may be referred to as a display frame (e.g., in arrangements in which member  66  at least partially surrounds a display such as display  16 ). 
   Member  66  and portions of housing portion  30  may together hold member  64  in place. Member  64  may be similar to member  28 . For example, member  64  can act as a spacer that helps prevent housings  30  and  32  from coming into contact with other when the laptop (e.g., device  10 ) is closed. Member  64  can be formed from any suitable material such as the dielectric materials used to form member  28  or other suitable materials. 
   The top face of housing portion  32  (e.g., planar housing member  68 ) can be supported by member  62 . Planar housing member  68  may also be referred to as a housing sub-top. Member  62  may be formed from materials similar to housing portion  30  or may be formed using other suitable conductive materials. Member  62  and other portions of housing portion  32  may be used in holding member  28  in place. For example, member  62  and other portions of housing portion  32  can substantially surround member  28  such that the member cannot be easily removed, as shown in  FIG. 5 . 
   Members such as members  62  and  66  can line the perimeter of housings  32  and  30 , respectively. Alternatively, members  62  and  66  may only be located at certain points along the perimeter of housings  32  and  30 . For example, members  62  and  66  can be located at discrete intervals along the perimeter of housings  30  and  32  or may be located at the corners of housings  30  and  32 . 
   The members illustrated in  FIG. 5  such as members  28  and  64  are merely illustrative examples. If desired, members  28  and  64  may be of similar shape and appearance or may fit together when housings  30  and  32  are brought together (e.g., as shown in  FIG. 5 ). 
   As illustrated in  FIG. 6 , antenna  20  may be located in housing portion  30  rather than housing portion  32 . For example, antenna  20  can be located behind member  64  of upper housing portion  30  rather than underneath (or behind) member  28  as shown in  FIG. 5 . In this type of arrangement, member  64  can convey radio-frequency signals between antenna  20  and the exterior of device  10  in substantially the same manner as member  28  (e.g., as illustrated in  FIG. 4 ). For example, member  64  can convey radio-frequency signals generated by antenna  20  to the exterior of device  10  through gap  70  between housings  30  and  32  (e.g., when device  10  is a laptop in a closed position). 
   As shown in  FIG. 6 , member  64  defines a waveguide-like path for radio-frequency signals from antenna  20 . The channel defined by this path has a narrow lateral dimension such as dimension  61  and a long longitudinal dimension such as dimension  63 . The inner surfaces of the upper housing (i.e., inner surface  65  of upper housing portion  30  and opposing surface  67  of frame member  66 ) are roughly planar and form a waveguide path. By properly orienting antenna  20  so that the parallel plates are at locations  71  and  73 , the electric field polarization of the radio-frequency signals from antenna  20  will be in a low-loss configuration (as shown in  FIG. 6 ) in which electric fields  60  are oriented parallel to lateral dimension  61 . 
   Members such as members  62  and  66  and housing portions such as housing portions  30  and  32  may be formed using any suitable materials. With one suitable arrangement, members such as members  62  and  66  and housing portions such as housing portions  30  and  32  are formed from conductive materials so that the inner surfaces that form the waveguide-like path (i.e., surfaces  65  and  67 ) are conductive and the radio-frequency signals pass through the waveguide-like path with minimal attenuation. With another suitable arrangement, members such as members  62  and  66  and housing portions such as housing portions  30  and  32  may be formed from non-conductive materials such as plastic that are coated with conductive materials (e.g., metal) at least along the inner surfaces that form the waveguide-like path (i.e., surfaces  65  and  67 ). 
   A perspective view of antenna  20  is shown in FIG.  7 . Antenna  20  may be formed from ground plate  52  and radiator plate  54 . The space between plates  52  and  54  may be filled with dielectric  56 . 
     FIG. 7  illustrates that ground plate  52  can be separated into a primary ground plate section (indicated by line  52 ) and a ground strip such as ground strip  53 . Ground strip  53  can be provided to improve the efficiency of antenna  20 . For example, ground strip  53  can improve the efficiency of antenna  20  by increasing the proportion of radio-frequency signals generated by antenna  20  that travel in the direction indicated by arrows  72  (rather than in the opposite direction). Ground strip  53  may serve as a near field reflector that reflects signals traveling in the direction opposite to arrows  72  so that they travel in the direction of arrows  72 . Ground plates with a ground strip such as strip  53  are merely illustrative. If desired, other reflector structures may be used (e.g., a planar reflector) and more than two branches of ground plate  52  can be used (e.g., multiple ground strips can be used). 
   The length of ground strips such as ground strip  53  can be adjusted to enhance the performance of antenna  20 . For example, the length of ground strip  53  may be adjusted such that the radio-frequency signals that reflect off of the ground strip have a phase that is suitable for directing those signals in the direction of arrows  72  and into members such as member  28  and  64 . 
   With one suitable arrangement, antenna  20  can be mounted to a dielectric member such as member  28  or member  64  such that the dielectric member is on the same side of antenna  20  as arrows  72  in  FIG. 7 . When member  28  (or member  64 ) is located on the same side of antenna  20  as arrows  72 , the efficiency of antenna  20  will be increased, because ground strip  53  directs radio-frequency signals in the direction of arrows  72 . 
   A side view of antenna  20  of  FIG. 7  is shown in  FIG. 8 . As illustrated by  FIG. 8 , antenna  20  may be substantially rectangular in shape. Radiator plate  54  is shown as being shorter in length than ground plate  52 . This is merely an example. Antenna  20  can be configured such that the electric fields of the radio-frequency signals generated by the antenna are oriented parallel to lines  60 . 
   The thickness of antenna  20  (e.g., the distance between plates  52  and  54 ) may be approximately 3 millimeters, as an example. 
   Transmission line  22  may be coupled to antenna  20  at feed terminals such as feed terminals  74  and  76 . Feed terminal  74  may be referred to as a ground or negative feed terminal and can be shorted to the outer (ground) conductor of transmission line  22 . Feed terminal  76  may be referred to as the positive antenna terminal. A center conductor to transmission line  22  can connect to positive feed terminal  76 . If desired, other types of antenna coupling arrangements may be used (e.g., based on near-field coupling, using impedance matching networks, etc.). The schematic feed arrangement of  FIG. 8  is merely illustrative. 
   Feed via  80  can convey signals between positive feed terminal  76  (that is itself coupled to a center conductor in line  22 ) and radiator plate  54 . Conductive short circuit vias  78  and feed via  80  may be electrically coupled to feed terminals  74  and  76 , respectively. Vias  78  and  80  can be solder-filled vias (e.g., solder-filled holes in dielectric  56 ). 
   When antenna  20  is being used to transmit or receive radio-frequency communications signals, currents may flow through vias  78  and  80 . Illustrative currents in vias  78  and  80  at a given point in time are shown by lines  82  in  FIG. 8 . With one suitable arrangement, the currents illustrated by line  82  may be the primary mechanism by which antenna  20  generates radio-frequency signals. 
   A top view of antenna  20  is shown in  FIG. 9  (e.g., looking down on ground plate  52 ). From the perspective of  FIG. 9 , the electric fields are oriented vertically as illustrated by line  60 .  FIG. 9  shows ground strip  53  (of  FIG. 7 ) from a straight-on perspective. As illustrated in  FIG. 9 , multiple vias  78  may be spread across the width of ground plate  52  to reduce the resistance of this path. The width of antenna  20  (which is approximately the width of plate  52 ) can be 4 millimeters, as an example. 
   A bottom view of antenna  20  is shown in  FIG. 10 . As shown in  FIG. 10 , radiator plate  54  may be substantially rectangular in shape with a narrow elongated portion that extends most of the length of antenna  20  and a wide shortened portion surrounding and connected to vias  78 . 
   The length of the narrow elongated portion of radiator plate  54  (e.g., the portion of plate  54  from via  80  to the portion of plate  54  opposite vias  78 ) may be related to the resonant frequency of antenna  20 . For example, the length of the elongated portion of plate  54  can be approximately one-quarter of a wavelength at the resonant frequency of antenna  20  including the effects of dielectric  56 . 
   The width of the elongated narrow portion of plate  54  may be related to the bandwidth of antenna  20 . With one suitable arrangement, the bandwidth of antenna  20  may be increased by increasing the width of radiator plate  54 , and in particular by increasing the width of the elongated narrow portion of radiator plate  54 . 
   Any suitable dielectric material can be used to form dielectric portions of device  10  such as dielectric  56  and members  28  and  64 . For example, dielectric portions of device  10  may be formed using a solid dielectric, a porous dielectric, a foam dielectric, a gelatinous dielectric (e.g., a coagulated or viscous liquid), a dielectric with grooves, pores, having a matrix structure, a dielectric having a honeycombed, or lattice structure or having other structural voids, a combination of such dielectrics, etc. Dielectrics such as dielectric  56  can also be formed using a gaseous dielectric. In one embodiment, dielectric portions of device  10  are formed with a nongaseous dielectric (e.g., a dielectric that is not air or another gas). If desired, the dielectric used in dielectric portions of device  10  (e.g., dielectric  56  and members  28  and  64 ) can form a honeycomb structure, a structure with grooved voids, spherical voids, or other hollow shapes. If desired, the dielectric portions of device  10  can be formed from epoxy, epoxy with hollow microspheres or other void-forming structures, etc. Porous dielectric materials used in device  10  can be formed with a closed cell structure (e.g., with isolated voids) or with an open cell structure (e.g., a fibrous structure with interconnected voids). Foams such as foaming glues (e.g., polyurethane adhesive), pieces of expanded polystyrene foam, extruded polystyrene foam, foam rubber, or other manufactured foams can also be used in device  10 . If desired, the dielectric materials in device  10  can include layers or mixtures of different substances such as mixtures including small bodies of lower density material. 
   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: 20080416
Publication Date: 20100928
Grant Date: 20100928
Priority Date: 20080416
Inventors: CHIANG BING
KOUGH DOUGLAS BLAKE
AYALA VAZQUEZ ENRIQUE
CAMACHO EDUARDO LOPEZ
SPRINGER GREGORY ALLEN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0407", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0407", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 40756910