PATENT DOCUMENT

Publication Number: US-8138977-B2
Application Number: US-89086507-A
Country: US
Kind Code: B2

Title: Antennas for handheld electronic devices

Abstract:
Handheld electronic devices are provided that contain wireless communications circuitry. The wireless communications circuitry may include antenna structures. An antenna may be located in an upper right corner of the handheld device as the handheld device is operated in a portrait mode. When the handheld device is rotated counterclockwise and operated in a landscape mode, the antenna is located in an unobstructed upper left corner of the device. The antenna may be formed from a strip of conductor. A proximal end of the strip of conductor may be connected to a transmission line. A distal end of the strip of conductor may be routed away from housing surfaces by bends formed in the strip. A printed circuit board in the handheld electronic device may have a hole. The distal end of the strip of conductor may be located adjacent to the hole.

Claims:
What is claimed is: 
     
       1. A handheld electronic device antenna in a handheld electronic device having housing surfaces and a dielectric housing portion in a corner of the handheld electronic device, comprising:
 a ground plane antenna element; 
 a strip antenna resonating element, wherein the strip antenna resonating element has a proximal end that is fed by a transmission line and a distal end that is located at an interior location within the handheld electronic device away from the housing surfaces and under the dielectric housing portion in the corner of the handheld electronic device, wherein the strip antenna resonating element has a first portion at the proximal end that extends upwards from the ground plane antenna element, wherein the strip antenna resonating element has a second portion at the distal end that extends downwards towards the ground plane antenna element, wherein the strip antenna resonating element has at least one right-angle bend between the proximal and distal ends, and wherein the first and second portions are parallel to each other, and wherein the strip antenna resonating element is not grounded along its length; and 
 at least one printed circuit board that surrounds an air-filled hole in which at least a portion of the strip antenna resonating element is located, wherein the at least one printed circuit board has top and bottom surfaces and wherein the at least one printed circuit board does not have any metal on the top and bottom surfaces in contact with a perimeter of the air-filled hole. 
 
     
     
       2. The handheld electronic device antenna defined in  claim 1  further comprising a dielectric antenna resonating element support structure to which the strip antenna resonating element is mounted. 
     
     
       3. The handheld electronic device antenna defined in  claim 1  further comprising a dielectric antenna resonating element support structure to which the strip antenna resonating element is mounted, wherein the dielectric antenna resonating element support structure comprises an air-filled hole adjacent to the strip antenna resonating element. 
     
     
       4. The handheld electronic device antenna defined in  claim 1  further comprising a dielectric antenna resonating element support structure to which the strip antenna resonating element is mounted, wherein the strip antenna resonating element comprises holes and wherein the dielectric antenna resonating element support structure comprises posts that extend through the holes in the strip antenna resonating element. 
     
     
       5. The handheld electronic device antenna defined in  claim 1  wherein the proximal end of the strip antenna resonating element comprises a bent spring portion. 
     
     
       6. The handheld electronic device antenna defined in  claim 1  wherein the distal end of the strip antenna resonating element has a third portion that extends parallel to at least one of the housing surfaces. 
     
     
       7. The handheld electronic device antenna defined in  claim 1  further comprising a contact pad to which the proximal end of the strip antenna resonating element is connected, wherein the strip antenna resonating element comprises a plurality of bends. 
     
     
       8. A handheld electronic device that has a front and a rear and that is operated in a portrait orientation and, when rotated counterclockwise, a landscape orientation, comprising:
 a conductive housing having at least one substantially rectangular conductive housing surface, wherein the rectangular conductive housing surface has an opening, wherein the opening is located in an upper-right corner of the conductive housing surface when the handheld electronic device is viewed from its front operating in its portrait orientation; 
 transceiver and control circuitry mounted within the conductive housing; 
 at least one antenna, wherein the antenna comprises a ground plane element and an antenna resonating element and wherein the antenna resonating element is mounted within the opening in the upper-right corner of the conductive housing; 
 a dielectric cap that covers the antenna resonating element; and 
 at least one printed circuit board that surrounds an air-filled hole in which at least a portion of the antenna resonating element is located, wherein the at least one printed circuit board has top and bottom surfaces and wherein the at least one printed circuit board does not have any metal on the top and bottom surfaces in contact with a perimeter of the air-filled hole. 
 
     
     
       9. The handheld electronic device defined in  claim 8  further comprising a display that displays images in the portrait orientation when the handheld electronic device is operating in the portrait orientation and that displays images in the landscape orientation when the handheld electronic device is operating in the landscape orientation, wherein the dielectric cap comprises portions that lie flush with the rectangular conductive housing surface. 
     
     
       10. The handheld electronic device defined in  claim 8 , wherein the at least one printed circuit board has a transmission line conductor, wherein the antenna resonating element includes a conductive strip having a first end and a second end, wherein the first end is electrically connected to the transmission line conductor on the printed circuit board, and wherein the second end is located adjacent to the hole, the handheld electronic device further comprising:
 a conductive bezel that extends around at least part of the hole. 
 
     
     
       11. The handheld electronic device defined in  claim 8  further comprising:
 a transmission line located on the at least one printed circuit board, wherein the transmission line has a signal conductor and a ground conductor; and 
 a contact pad that is located on the printed circuit board and that is connected to the signal conductor, wherein the transceiver and control circuitry are electrically connected to the transmission line, wherein the antenna resonating element is electrically connected to the contact pad. 
 
     
     
       12. The handheld electronic device defined in  claim 8  further comprising:
 a transmission line located on the at least one printed circuit board, wherein the transmission line has a signal conductor and a ground conductor, wherein the transceiver and control circuitry is electrically connected to the transmission line, wherein the antenna resonating element has a first end and a second end and a plurality of bends between the first end and the second end, wherein the first end of the antenna resonating element is electrically connected to the transmission line, and wherein the second end of the antenna resonating element is located in the air-filled hole. 
 
     
     
       13. The handheld electronic device defined in  claim 8  further comprising:
 a transmission line located on the printed circuit board, wherein the transmission line has a signal conductor and a ground conductor, wherein the transceiver and control circuitry is electrically connected to the transmission line, wherein the antenna resonating element has a first end and a second end, wherein the first end of the antenna resonating element is electrically connected to the transmission line, wherein the second end of the antenna resonating element is located within the air-filled hole, and wherein the antenna resonating element comprises a strip antenna resonating element; and 
 a dielectric antenna resonating element support structure to which the strip antenna resonating element is mounted. 
 
     
     
       14. The handheld electronic device defined in  claim 8  further comprising:
 a transmission line located on the at least one printed circuit board, wherein the transmission line has a signal conductor and a ground conductor, wherein the transceiver and control circuitry is electrically connected to the transmission line, wherein the antenna resonating element has a first end and a second end, wherein the first end of the antenna resonating element is electrically connected to the transmission line, wherein the second end of the antenna resonating element is located within the air-filled hole, and wherein the antenna resonating element comprises a strip antenna resonating element; and 
 a dielectric antenna resonating element support structure to which the strip antenna resonating element is mounted, wherein the dielectric antenna resonating element support structure contains at least one air-filled hole adjacent to the strip antenna resonating element. 
 
     
     
       15. The handheld electronic device defined in  claim 8  further comprising an additional antenna resonating element, wherein the rectangular conductive housing surface has an additional opening, wherein the additional opening is located at a lower end of the conductive housing surface when the handheld electronic device is viewed from its front operating in its portrait orientation, and wherein the additional antenna resonating element is mounted within the handheld electronic device within the additional opening. 
     
     
       16. A handheld electronic device, comprising:
 a housing having housing surfaces including a conductive rear surface and having a display mounted to at least part of a front surface; 
 a dielectric housing portion formed in an opening within a corner of the conductive rear surface; 
 at least one printed circuit board having a hole; 
 a transceiver circuit mounted to the at least one printed circuit board; 
 a transmission line connected to the transceiver circuit; 
 an antenna mounted within the housing, wherein the antenna comprises:
 a ground plane; and 
 an antenna resonating element formed from a strip of conductor that is located adjacent to the dielectric housing portion, wherein at least a portion of the dielectric housing portion lies flush with the conductive rear surface of the housing, wherein the antenna resonating element has a plurality of bends and has first and second ends, wherein the first end of the antenna resonating element is coupled to the transmission line adjacent to the at least one printed circuit board, wherein the bends in the antenna resonating element route the strip of conductor so that the second end of the antenna resonating element is not adjacent to the surfaces of the housing, wherein the antenna resonating element has a first portion at the first end that extends upwards from the ground plane, wherein the antenna resonating element has a second portion at the second end that extends downwards towards the ground plane, wherein the plurality of bends includes at least one right-angle bend between the first and second ends, wherein the first and second portions are parallel to each other, wherein the antenna resonating element is not grounded along its length, wherein at least a portion of the antenna resonating element is located in the hole of the at least one printed circuit board, wherein the at least one printed circuit board has top and bottom surfaces, and wherein the at least one printed circuit board does not have any metal on the top and bottom surfaces in contact with a perimeter of the hole. 
 
 
     
     
       17. The handheld electronic device defined in  claim 16  further comprising a dielectric antenna resonating element support structure to which the strip of conductor is attached, wherein the strip of conductor comprises a first portion that is parallel to at least one of the housing surfaces and a second portion that is perpendicular to the first portion and wherein the dielectric antenna resonating element support structure comprises portions defining at least one hole adjacent to the strip of conductor. 
     
     
       18. The handheld electronic device defined in  claim 16  wherein the transceiver circuit is configured to transmit and receive signals through the antenna in a 2.4 GHz communications band, the handheld electronic device further comprising an impedance matching network coupled in the transmission line between the transceiver circuit and the antenna.

Description:
BACKGROUND 
     This invention relates generally to wireless communications circuitry, and more particularly, to wireless communications circuitry for handheld electronic devices. 
     Handheld electronic devices are becoming increasingly popular. Examples of handheld devices include handheld computers, cellular telephones, media players, and hybrid devices that include the functionality of multiple devices of this type. 
     Due in part to their mobile nature, handheld electronic devices are often provided with wireless communications capabilities. Handheld electronic devices may use long-range wireless communications to communicate with wireless base stations. For example, cellular telephones may communicate using cellular telephone bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz. Handheld electronic devices may also use short-range wireless communications links. For example, handheld electronic devices may communicate using the WiFi® (IEEE 802.11) band at 2.4 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 2170 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 handheld 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. Antennas such as planar inverted-F antennas (PIFAs) and antennas based on L-shaped resonating elements can be fabricated in this way. Antennas such as PIFA antennas and antennas with L-shaped resonating elements can be used in handheld devices. 
     Although modern handheld electronic devices often need to function over a number of different communications bands, it is difficult to design a compact antenna that covers all frequency bands of interest. 
     It would therefore be desirable to be able to provide improved antennas and wireless handheld electronic devices. 
     SUMMARY 
     Handheld electronic devices and antennas for handheld electronic devices are provided. A handheld electronic device may have a display. The handheld electronic device may have a conductive housing such as a metal housing. The display may be mounted to the front surface of the housing. 
     An antenna in the device may be formed from a ground plane element and a resonating element. The antenna resonating element may be mounted to a dielectric antenna resonating element support structure. The dielectric antenna resonating element support structure may have air-filled holes adjacent to the antenna resonating element. 
     The handheld electronic device may contain a printed circuit board having an air-filled hole. A transceiver circuit may be mounted to the printed circuit board. A transmission line may be used to connect the transceiver circuit to the antenna. 
     The antenna resonating element may be formed from a strip of conductor. One end of the strip of conductor may be connected to the transmission line. The other end of the strip of conductor may be located adjacent to the hole in the printed circuit board. 
     The handheld electronic device may be operated in a portrait mode and, when rotated a quarter of a turn counterclockwise, may be operated in a landscape mode. An opening may be formed in the upper right corner of the conductive housing of the handheld device when the handheld electronic device is in the portrait mode orientation. The antenna resonating element may be located within the opening. A dielectric cap may cover the antenna resonating element. The dielectric cap may lie flush with the conductive surfaces of the housing. 
     The antenna may be located in the upper right corner of the handheld device as viewed when the handheld device is operated in the portrait mode. When the handheld device is rotated counterclockwise and operated in the landscape mode, the antenna will be located in an unobstructed upper left corner of the device. 
     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 handheld electronic device with an antenna in accordance with an embodiment of the present invention. 
         FIG. 2  is a schematic diagram of an illustrative handheld electronic device with an antenna in accordance with an embodiment of the present invention. 
         FIG. 3A  is a cross-sectional side view of an illustrative handheld electronic device with an antenna structure and an additional antenna in accordance with an embodiment of the present invention. 
         FIG. 3B  is a cross-sectional side view of an illustrative handheld electronic device with an antenna structure in accordance with an embodiment of the present invention. 
         FIG. 4A  is a perspective rear view of an illustrative handheld electronic device with antennas in accordance with an embodiment of the present invention. 
         FIG. 4B  is a perspective rear view of an illustrative handheld electronic device with an antenna in accordance with an embodiment of the present invention. 
         FIG. 5A  is a perspective front view of an illustrative handheld electronic device with antennas in accordance with an embodiment of the present invention. 
         FIG. 5B  is a perspective front view of an illustrative handheld electronic device with an antenna in accordance with an embodiment of the present invention. 
         FIG. 6  is a front view of an illustrative handheld electronic device showing an illustrative antenna location when the handheld electronic device is held in its normal portrait orientation in accordance with an embodiment of the present invention. 
         FIG. 7  is a front view of an illustrative handheld electronic device showing an illustrative antenna location when the handheld electronic device is held in its normal landscape orientation in accordance with an embodiment of the present invention. 
         FIG. 8  is a perspective view of a corner portion of an illustrative handheld electronic device having an antenna in accordance with an embodiment of the present invention. 
         FIG. 9  is a side interior view of a corner portion of an illustrative handheld electronic device in accordance with an embodiment of the present invention. 
         FIG. 10  is a perspective view of a portion of an illustrative antenna in accordance with an embodiment of the present invention shown without a supporting dielectric chassis. 
         FIG. 11  is a cross-sectional view of an illustrative antenna resonating element and printed circuit board structure associated with an antenna in accordance with an embodiment of the present invention. 
         FIGS. 12 ,  13 ,  14 , and  15  are circuit diagrams of illustrative antenna impedance matching networks that may be used for an antenna in a handheld electronic device in accordance with embodiments of the present invention. 
         FIG. 16  is a top view of an antenna chassis and antenna resonating element for an antenna in a handheld electronic device in accordance with the present invention. 
         FIG. 17  is an exploded perspective view of an illustrative antenna chassis and antenna resonating element for an antenna in a handheld electronic device in accordance with an embodiment of the present invention. 
         FIG. 18  is an exploded perspective view of an illustrative printed circuit board portion, an antenna chassis, and an antenna resonating element for an antenna in a handheld electronic device in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention relates generally to wireless communications, and more particularly, to wireless electronic devices and antennas for wireless electronic devices. 
     The wireless electronic devices may be portable electronic devices such 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 wrist-watch devices, pendant devices, headphone and earpiece devices, and other wearable and miniature devices. With one suitable arrangement, which is sometimes described herein as an example, the portable electronic devices are handheld electronic devices. 
     The handheld devices may be, for example, cellular telephones, media players with wireless communications capabilities, handheld computers (also sometimes called personal digital assistants), remote controllers, global positioning system (GPS) devices, and handheld gaming devices. The handheld devices may also be hybrid devices that combine the functionality of multiple conventional devices. Examples of hybrid handheld 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 handheld electronic device in accordance with an embodiment of the present invention is shown in  FIG. 1 . Device  10  may be any suitable portable or handheld electronic device. 
     Device  10  may have housing  12 . Device  10  may include one or more antennas for handling wireless communications. Embodiments of device  10  that contain two antennas are sometimes described herein as an example. 
     Device  10  may handle communications over multiple 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. With one suitable arrangement, which is sometimes described herein as an example, the wireless communications circuitry of device  10  uses a first antenna that is configured to handle communications in at least a first communications band and a second antenna that is configured to handle communications in at least a second communications band. The first antenna may, for example, handle communications in a communications band that is centered at 2.4 GHz or 5 GHz (e.g., WiFi and/or Bluetooth frequencies) or may handle Global Positioning Systems (GPS) communications at 1550 MHz or Universal Mobile Telecommunications System (UMTS) 3G data communications band at 2170 MHz (as examples). The second antenna may, for example, handle cellular telephone communications bands. 
     Housing  12 , which is sometimes referred to as a case, may be formed of any suitable materials including, plastic, glass, ceramics, metal, or other suitable materials, or a combination of these materials. In some situations, housing  12  or portions of housing  12  may be formed from 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 illustrative 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. In scenarios in which housing  12  is formed from metal elements, one or more of the metal elements may be used as part of the antenna in device  10 . For example, metal portions of housing  12  may be shorted to an internal ground plane in device  10  to create a larger ground plane element for that device  10 . To facilitate electrical contact between an anodized aluminum housing and other metal components in device  10 , portions of the anodized surface layer of the anodized aluminum housing may be selectively removed during the manufacturing process (e.g., by laser etching). 
     Housing  12  may have a bezel  14 . The bezel  14  may be formed from a conductive material. The conductive material may be a metal (e.g., an elemental metal or an alloy) or other suitable conductive materials. With one suitable arrangement, which is sometimes described herein as an example, bezel  14  may be formed from stainless steel. Stainless steel can be manufactured so that it has an attractive shiny appearance, is structurally strong, and does not corrode easily. If desired, other structures may be used to form bezel  14 . For example, bezel  14  may be formed from plastic that is coated with a shiny coating of metal or other suitable substances. 
     Bezel  14  may serve to hold a display or other device with a planar surface in place on device  10 . As shown in  FIG. 1 , for example, bezel  14  may be used to hold display  16  in place by attaching display  16  to housing  12 . Device  10  may have front and rear planar surfaces. In the example of  FIG. 1 , display  16  is shown as being formed as part of the planar front surface of device  10 . The periphery of the front surface may be surrounded by bezel  14 . If desired, the periphery of the rear surface may be surrounded by a bezel (e.g., in a device with both front and rear displays). 
     Display  16  may be a liquid crystal diode (LCD) display, an organic light emitting diode (OLED) 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 may be integrated into display  16  or may be provided using a separate touch pad device. An advantage of integrating a touch screen into display  16  to make display  16  touch sensitive is that this type of arrangement can save space and reduce visual clutter. 
     In a typical arrangement, bezel  14  may have prongs that are used to secure bezel  14  to housing  12  and that are used to electrically connect bezel  14  to housing  12  and other conductive elements in device  10 . The housing and other conductive elements form a ground plane for the antenna(s) in the handheld electronic device. A gasket (e.g., an o-ring formed from silicone or other compliant material, a polyester film gasket, etc.) may be placed between the underside of bezel  14  and the outermost surface of display  16 . The gasket may help to relieve pressure from localized pressure points that might otherwise place stress on the glass or plastic cover of display  16 . The gasket may also help to visually hide portions of the interior of device  10  and may help to prevent debris from entering device  10 . 
     In addition to serving as a retaining structure for display  16 , bezel  14  may serve as a rigid frame for device  10 . In this capacity, bezel  14  may enhance the structural integrity of device  10 . For example, bezel  14  may make device  10  more rigid along its length than would be possible if no bezel were used. Bezel  14  may also be used to improve the appearance of device  10 . In configurations such as the one shown in  FIG. 1  in which bezel  14  is formed around the periphery of a surface of device  10  (e.g., the periphery of the front face of device  10 ), bezel  14  may help to prevent damage to display  16  (e.g., by shielding display  16  from impact in the event that device  10  is dropped, etc.). 
     Display screen  16  (e.g., a touch screen) is merely one example of an input-output device that may be used with handheld electronic device  10 . If desired, handheld electronic device  10  may have other input-output devices. For example, handheld electronic device  10  may have user input control devices such as button  19 , and input-output components such as port  20  and one or more input-output jacks (e.g., for audio and/or video). Button  19  may be, for example, a menu button. Port  20  may contain a 30-pin data connector (as an example). Openings  24  and  22  may, if desired, form microphone and speaker ports. Display screen  16  may be, for example, a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, a plasma display, or multiple displays that use one or more different display technologies. In the example of  FIG. 1 , display screen  16  is shown as being mounted on the front face of handheld electronic device  10 , but display screen  16  may, if desired, be mounted on the rear face of handheld electronic device  10 , on a side of device  10 , on a flip-up portion of device  10  that is attached to a main body portion of device  10  by a hinge (for example), or using any other suitable mounting arrangement. 
     A user of handheld device  10  may supply input commands using user input interface devices such as button  19  and touch screen  16 . Suitable user input interface devices for handheld electronic device  10  include buttons (e.g., alphanumeric keys, power on-off, power-on, power-off, and other specialized buttons, etc.), a touch pad, pointing stick, or other cursor control device, a microphone for supplying voice commands, or any other suitable interface for controlling device  10 . Although shown schematically as being formed on the top face of handheld electronic device  10  in the example of  FIG. 1 , buttons such as button  19  and other user input interface devices may generally be formed on any suitable portion of handheld electronic device  10 . For example, a button such as button  19  or other user interface control may be formed on the side of handheld electronic device  10 . Buttons and other user interface controls can also be located on the top face, rear face, or other portion of device  10 . If desired, device  10  can be controlled remotely (e.g., using an infrared remote control, a radio-frequency remote control such as a Bluetooth remote control, etc.). 
     Handheld device  10  may have ports such as port  20 . Port  20 , which may sometimes be referred to as a dock connector, 30-pin data port connector, input-output port, or bus connector, may be used as an input-output port (e.g., when connecting device  10  to a mating dock connected to a computer or other electronic device). Device  10  may also have audio and video jacks that allow device  10  to interface with external components. Typical ports include power jacks to recharge a battery within device  10  or to operate device  10  from a direct current (DC) power supply, data ports to exchange data with external components such as a personal computer or peripheral, audio-visual jacks to drive headphones, a monitor, or other external audio-video equipment, a subscriber identity module (SIM) card port to authorize cellular telephone service, a memory card slot, etc. The functions of some or all of these devices and the internal circuitry of handheld electronic device  10  can be controlled using input interface devices such as touch screen display  16 . 
     Components such as display  16  and other user input interface devices may cover most of the available surface area on the front face of device  10  (as shown in the example of  FIG. 1 ) or may occupy only a small portion of the front face of device  10 . Because electronic components such as display  16  often contain large amounts of metal (e.g., as radio-frequency shielding), the location of these components relative to the antenna elements in device  10  should generally be taken into consideration. Suitably chosen locations for the antenna elements and electronic components of the device will allow the antennas of handheld electronic device  10  to function properly without being disrupted by the electronic components. 
     With one suitable arrangement, which is sometimes described herein as an example, handheld electronic device has two antennas. A first antenna may be located in the upper right corner of device  10  in region  21 . A second antenna may be located in the lower end of device  10  in region  18 . 
     The first antenna may be (for example), a WiFi antenna, a GPS antenna, a UMTS antenna, etc. The location of the first antenna in region  21  may help to ensure adequate antenna performance in the event that a user of device  10  uses device  10  in a landscape orientation (e.g., a landscape orientation in which button  19  is placed at the user&#39;s right and antenna region  21  is placed at the top of device  10 ). 
     The second antenna may be (for example) a cellular telephone antenna. An advantage of locating antenna resonating element structures for the second antenna in the lower portion of housing  12  and device  10  (i.e., in region  18 ) is that this places radiating portions of the antenna structures away from the user&#39;s head when the device  10  is held to the head (e.g., when talking into a microphone and listening to a speaker in the handheld device as with a cellular telephone). This reduces the amount of radio-frequency radiation that is emitted in the vicinity of the user. Placing the second antenna in region  18  may also help to reduce proximity effects (i.e., influences on the performance of the second antenna due to the proximity of the second antenna to portions of the user&#39;s body). 
     It may also be desirable to minimize proximity effects for the first antenna, particularly when the first antenna is used in a handheld electronic device having a conductive housing. When handheld electronic device  10  has conductive housing walls, it may be necessary to locate the antenna resonating element for the first antenna within a few millimeters of the conductive housing walls. This reduces antenna bandwidth. When an antenna has a narrow bandwidth, it may be particularly sensitive to detuning due to proximity effects. 
     To minimize proximity effects for the first antenna, the resonating element for the first antenna may be configured so that its tail (its distal end), which may be particularly sensitive to proximity effects, is not immediately adjacent to the surface of housing  12 . Routing the tail of the antenna resonating element away from the surfaces of housing  12  in this way helps to prevent situations in which a user&#39;s body (e.g., the user&#39;s fingers, hands, or face) come into close proximity to the tail, thereby reducing or eliminating proximity effects. 
     A schematic diagram of an embodiment of an illustrative handheld electronic device is shown in  FIG. 2 . Handheld device  10  may be 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 electronic device. 
     As shown in  FIG. 2 , handheld device  10  may 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  may 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  may 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 WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling 3G data services such as UMTS, 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 , button  19 , microphone port  24 , speaker port  22 , and dock connector port  20  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, etc. A user can control the operation of device  10  by supplying commands through user input devices  40 . Display and audio devices  42  may 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 and monitors. 
     Wireless communications devices  44  may 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, 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  may be any suitable computer. With one suitable arrangement, computing equipment  48  is a computer that has an associated wireless access point (router) or an internal or external wireless card that establishes a wireless connection with device  10 . The computer may 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 handheld electronic device  10 ), or any other suitable computing equipment. 
     The antenna structures and wireless communications devices of device  10  may 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 2170 MHz band (commonly referred to as UMTS or Universal Mobile Telecommunications System), the WiFi® (IEEE 802.11) bands at 2.4 GHz and 5.0 GHz (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 1550 MHz. The 850 MHz band is sometimes referred to as the Global System for Mobile (GSM) communications band. The 900 MHz communications band is sometimes referred to as the Extended GSM (EGSM) band. The 1800 MHz band is sometimes referred to as the Digital Cellular System (DCS) band. The 1900 MHz band is sometimes referred to as the Personal Communications Service (PCS) 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 cross-sectional view of an illustrative handheld electronic device is shown in  FIG. 3A . In the example of  FIG. 3A , device  10  has a housing that is formed of a conductive portion  12 - 1  and dielectric portions  12 - 2 A and  12 - 2 B (e.g., portions  12 - 2 A and  12 - 2 B that are formed from plastic). Conductive portion  12 - 1  may be any suitable conductor such as aluminum, magnesium, stainless steel, alloys of these metals and other metals, etc. Conductive portion  12 - 1  may include a substantially rectangular conductive rear housing surface and housing side walls. Dielectric portions  12 - 2 A and  12 - 2 B may serve as caps that cover antennas that are mounted within housing  12 . With one suitable arrangement, dielectric portions  12 - 2 A and  12 - 2 B may lie flush with the exterior surfaces of housing  12  (i.e., with the rear surface and sidewall surfaces of conductive housing portion  12 - 1 ). 
     There are two antennas in the example of  FIG. 3A . A first of the two antennas is formed from antenna resonating element  54 - 1 B and antenna ground plane  54 - 2 . A second of the two antennas is formed from antenna resonating element  54 - 1 A and ground plane  54 - 2 . The first antenna (depicted as antenna  54  in  FIG. 3A ) may be formed from an elongated resonating element such as strip of stamped conductor or a trace on a flex circuit. The resonating element of the first antenna may have a first (proximal) end and a second (distal) end. The first end of the first antenna&#39;s resonating element may be fed by an antenna feed terminal in the vicinity of ground plane  54 - 2 . The second end of the first antenna&#39;s resonating element, which is sometimes referred to as its tail, may be positioned in a location that is relatively insensitive to proximity effects. For example, the tail of the first antenna&#39;s resonating element may be mounted in a location in the interior of device  10  so that the tail is not immediately adjacent to the surface of housing portion  12 - 2 B. This helps to minimize proximity effects by ensuring that the tail of the first antenna&#39;s resonating element cannot be contacted by a portion of a user&#39;s body. 
     Housing portions  12 - 2 A and  12 - 2 B may be formed from a dielectric. An advantage of using dielectric for housing portions  12 - 2 A and  12 - 2 B is that this allows resonating element portion  54 - 1  of antenna  54  of device  10  to operate without interference from the metal sidewalls of housing  12 . With one suitable arrangement, housing portions  12 - 2 A and  12 - 2 B are plastic caps formed from a plastic based on acrylonitrile-butadiene-styrene copolymers (sometimes referred to as ABS plastic). These are merely illustrative housing materials for device  10 . For example, the housing of device  10  may be formed substantially from plastic or other dielectrics, substantially from metal or other conductors, or from any other suitable materials or combinations of materials. 
     Components such as components  52  may be mounted on circuit boards in device  10 . The circuit board structures in device  10  may be formed from any suitable materials. Suitable circuit board materials include paper impregnated with phonolic resin, resins reinforced with glass fibers such as fiberglass mat impregnated with epoxy resin (sometimes referred to as FR-4), plastics, polytetrafluoroethylene, polystyrene, polyimide, and ceramics. Circuit boards fabricated from materials such as FR-4 are commonly available, are not cost-prohibitive, and can be fabricated with multiple layers of metal (e.g., four layers). So-called flex circuits, which are flexible circuit board materials such as polyimide, may also be used in device  10 . 
     Typical components in device  10  include integrated circuits, LCD screens, and user input interface buttons. Device  10  also typically includes a battery, which may be mounted along the rear face of housing  12  (as an example). 
     Because of the conductive nature of components such as these and the printed circuit boards upon which these components are mounted, the components, circuit boards, and conductive housing portions (including bezel  14 ) of device  10  may be grounded together to form antenna ground plane  54 - 2 . With one illustrative arrangement, ground plane  54 - 2  may conform to the generally rectangular shape of housing  12  and device  10  and may match the rectangular lateral dimensions of housing  12 . 
     Ground plane element  54 - 2  and antenna resonating element  54 - 1 B may form first antenna  54  for device  10 . Optional additional antennas such as the antenna formed from antenna resonating element  54 - 1 A and ground plane  54 - 2  may, if desired, be configured to provide additional gain for an overlapping frequency band of interest (i.e., a band at which antenna  54  is operating) or may be used to provide coverage in a different frequency band of interest (i.e., a band outside of the range of antenna  54 ). 
     Any suitable conductive materials may be used to form ground plane element  54 - 2  and resonating elements  54 - 1 A and  54 - 1 B. Examples of suitable conductive materials for the antenna structures in device  10  include elemental metals, such as copper, silver, and gold, and metal alloys (e.g., beryllium copper). Conductors other than metals may also be used, if desired. In a typical scenario, the conductive structures for resonating element  54 - 1 A are formed from copper traces on a flex circuit or other suitable substrate and the conductive structures for resonating element  54 - 1 B are formed from a strip of beryllium copper foil. 
     Components  52  include transceiver circuitry (see, e.g., devices  44  of  FIG. 2 ). The transceiver circuitry may be provided in the form of one or more integrated circuits and associated discrete components (e.g., filtering components). The transceiver circuitry may include one or more transmitter integrated circuits, one or more receiver integrated circuits, switching circuitry, amplifiers, etc. Each transceiver in the transceiver circuitry may have an associated coaxial cable, microstrip transmission line, or other transmission line that is connected to an associated antenna and over which radio frequency signals are conveyed. In the example of  FIG. 3A , transmission lines are depicted by dashed line  56 . 
     As shown in  FIG. 3A , transmission lines  56  may be used to distribute radio-frequency signals that are to be transmitted through the antennas from a transmitter integrated circuit  52 . Paths  56  may also be used to convey radio-frequency signals that have been received by an antenna to components  52 . Components  52  may include one or more receiver integrated circuits for processing incoming radio-frequency signals. 
     As shown in the cross-sectional diagram of  FIG. 3A , it may be advantageous to locate the antennas in device  10  near the extremities of device  10  (i.e., at either end of device  10 ). If desired, the optional additional antenna formed from antenna resonating element  54 - 1 A and ground plane  54 - 2  may be omitted. This type of arrangement is shown in the cross-sectional diagram of  FIG. 3B . As shown in  FIG. 3B , when optional additional antennas are omitted from device  10 , there is additional area available for components  52 . 
     An illustrative arrangement for handheld electronic device  10  in an embodiment with multiple antennas located near the extremities of device  10  is shown in  FIG. 4A . In the arrangement of  FIG. 4A , antennas may be located in locations  18  and  21 .  FIG. 4A  is a perspective view of handheld electronic device  10 . In the orientation of  FIG. 4A , the rear surface of housing  12 - 1  is shown. The first antenna resonating element may be located in region  21  beneath dielectric housing portion  12 - 2 B. 
     The second antenna resonating element may be located in region  18  beneath dielectric housing portion  12 - 2 A. Dielectric housing portions  12 - 2 A and  12 - 2 B may be plastic caps formed from a suitable material such as ABS plastic (as an example). In the illustrative arrangement of  FIG. 4A , cap  12 - 2 A extends across the full width of device  10 , whereas cap  12 - 2 B is located in a corner of device  10 . This type of arrangement may be particularly suitable in situations in which cap  12 - 2 A is used to enclose an antenna that is used for cellular telephone communications and in which cap  12 - 2 B is used to enclose an antenna that is used for higher-frequency data communications (e.g., WiFi communications at 2.4 GHz). Higher frequency communications bands such as the 2.4 GHz and 5 GHz bands are associated with radio frequency signals with shorter wavelengths, so somewhat more compact antenna arrangements may be used. 
     In situations in which housing  12 - 1  is formed from a conductive material (e.g., a metal such as aluminum or stainless steel), it may be desirable to position antenna cap  12 - 2 B in a corner of device  10  (as shown in  FIG. 4A ), rather than positioning antenna cap  12 - 2 B midway along one of the sides of device  10 . This is because an antenna resonating element that is located in a corner position is less likely to be adversely affected by its proximity to conductive housing portions than an antenna resonating element that is located along one of the edges of device  10 . In a central edge location, the antenna resonating element is effectively surrounded by metal on three sides, whereas the antenna resonating element is only surrounded by metal on two sides when the antenna resonating element and cap  12 - 2 B are located on a corner of device  10  as shown in  FIG. 4A . 
     If desired, device  10  may not contain antennas in region  18 . A perspective rear view of handheld electronic device  10  in an embodiment in which there are no antennas in region  18  is shown in  FIG. 4B . 
     A perspective view of the illustrative handheld electronic device of  FIG. 4A  as viewed from the front side of the device is shown in  FIG. 5A . As shown in  FIG. 5A , the first antenna and dielectric cap  12 - 2 B may be located in the upper right corner of device  10  when device  10  is held in a normal portrait orientation. 
     A perspective view of the illustrative handheld electronic device of  FIG. 4B  as viewed from the front side of the device is shown in  FIG. 5B . As with the multiple antenna embodiment of  FIGS. 3A ,  4 A, and  5 A, the single antenna embodiment of  FIGS. 3B ,  4 B, and  5 B may use a configuration in which antenna  54  and dielectric cap  12 - 2 B are located in the upper right corner of device  10  when device  10  is held in a normal portrait orientation. 
     If desired, handheld electronic device  10  may be operated in both portrait and landscape orientations. For example, device  10  may contain position sensors (e.g., motion sensors). The processing circuitry in device  10  can monitor the signals from the position sensors to determine when device  10  is being used in portrait mode and when device  10  is being used in landscape mode. The user may also manually switch between portrait and landscape modes. The portrait mode orientation may be used for some applications (e.g., web browsing), whereas the landscape mode orientation may be used for other applications (e.g., video viewing). 
     In devices  10  that can be operated in either landscape or portrait orientations, it may be particularly advantageous to position antenna  54  and its associated dielectric cover  12 - 2 B in the upper right corner of the device. This is illustrated in connection with  FIGS. 6 and 7 . 
     In  FIG. 6 , device  10  is shown in its normal portrait mode orientation. In this orientation, button  19  is located at the bottom of device  10 . Images that are displayed on display  16  may be oriented so that their upper portions are located at the top of display  16  and their lower portions are located at the bottom of display  16 . The images that are displayed in this way may include text, still images, video, etc. The hands and fingers of a user are typically used to grip device  10  in region  56 . Region  56  is generally located in the lower half or lower third of device  10 . Because contact between the user and device  10  in region  56  may lead to proximity effects, it is desirable to locate antenna  54  in a region of device  10  other than region  56  (i.e., in the upper right corner of device  10 ). 
     When it is desired to use device  10  in its landscape mode, a user can rotate device  10  a quarter of a turn (90°) in the counterclockwise direction, as shown in  FIG. 7 . In this orientation, images that are displayed on display  16  have their upper portions located along right-hand edge  58  of device  10  (which is the top edge of device  10  in its landscape orientation) and have their lower portions located along left-hand edge  60  of device  10  (which is the bottom edge of device  10  in its landscape orientation). Because device  10  has been turned sideways relative to its normal portrait orientation, antenna  54  is located in the upper left corner of device  10  (as viewed in the landscape orientation). During use, a user&#39;s fingers may grip device  10  in regions such as regions  62  and  64 . The normal regions for holding device such as regions  62  and  64  are generally located in the lower half or lower third of device  10  (as viewed in the landscape orientation). 
     As shown in  FIGS. 6 and 7 , it is unlikely that a user will place a finger directly over antenna  54  when holding device  10  during normal operation, because the common regions for holding device  10  in both the portrait and landscape modes (i.e., region  56  of  FIG. 6  and regions  62  and  64  of  FIG. 7 ) do not overlap antenna  54 . As a result, proximity effects that might adversely affect the performance of antenna  54  are generally avoided. Antenna configurations in which the antenna is placed in the upper right corner of the device (as shown in  FIG. 6 ) may be used with any suitable type of antenna. The upper right corner configuration is particularly desirable in situations in which the antenna is sensitive to proximity effects. For example, the upper right corner configuration may be advantageous in arrangements in which a metal case is in close proximity to the antenna resonating element, as this tends to decrease antenna bandwidth and make the antenna more sensitive to proximity effects. 
     A perspective view of structures associated with an antenna in the upper right corner of device  10  is shown in  FIG. 8 . As shown in  FIG. 8 , dielectric cap  12 - 2 B may be used to cover an opening (removed portion) of conductive housing walls  12 - 1 . In the orientation of  FIG. 8 , the front of device  10  faces downwards and the rear of device  10  faces upwards. A circuit board or other mounting structure  66  may be located near the front side of device  10 . Circuit board  66  may, for example, be mounted on a metal frame within housing  12 . Bezel  14  may extend around the outer periphery of device  10 . A hole such as hole  74  may be formed in circuit board  66 . Bezel  14  may extend around the hole  74 . 
     An antenna resonating element for antenna  54  (i.e., antenna resonating element  54 - 1 B) may be located within the area formed by the removed portions of sidewalls  12 - 1  and in the air-filled opening formed by the removed portion of circuit board  66 . Antenna resonating element  54 - 1 B (not shown in  FIG. 8 ) may be formed from a strip of conductor. One end of the strip of conductor may make electrical contact to contact pad  68 . The other end of the strip (which is sometimes referred to as the tail of the resonating element) may be placed in a location within the middle of the opening  72 . The tail of antenna resonating element  54 - 1 B is generally the most sensitive portion of antenna  54  to proximity effects. Accordingly, it is desirable to locate the tail of the antenna away from the surface of housing  12  (i.e., the outer surfaces of dielectric housing member  12 - 2 B). In such outer surface locations, antenna  54  might be detuned if the user touched dielectric cover  12 - 2 B. 
     Transceiver  52  may be electrically connected to contact pad  68  (and therefore antenna resonating element  54 - 1 B) by a transmission line. The transmission line may be formed from a coaxial cable or any other suitable transmission line structure. In the illustrative arrangement shown in  FIG. 8 , the transmission line for connecting transceiver  52  to antenna resonating element  54 - 1 B is a microstrip transmission line. The microstrip transmission line has two conductors. One conductor in the microstrip transmission line is a ground plane conductor (e.g., a conductor formed from a metal layer on the lower surface of printed circuit board  66  as viewed in  FIG. 8 ). The other conductor in the microstrip transmission line is a signal conductor such as signal conductor  70 . 
     A side view of device  10  in the vicinity of antenna  54  is shown in  FIG. 9 . As shown in  FIG. 9 , ground conductor  82  may form one part of the microstrip transmission line and signal conductor  70  may form another part of the microstrip transmission line. The microstrip transmission line may be used to electrically connect transceiver  52  and antenna resonating element  54 - 1 B. 
     Transceiver  52  may be mounted to printed circuit board  66 . Antenna signals associated with antenna  54  may be transmitted and received via ground terminal  86  and positive feed terminal  88 . Feed terminal  88  may be connected to pad  68  using microstrip transmission line signal conductor  70 . Ground terminal  86  may be electrically connected with ground conductor  82  using conductive via  84 . Ground conductor  82  may be, for example, a trace formed from a layer of copper or other conductor on board  66 . 
     Antenna resonating element  54 - 1 B may have first (proximal) end  76  and second (distal) end  80 . Second end  80  is typically referred to as the tail of antenna resonating element  54 - 1 B and is preferably located away from the surface of device  10  to avoid proximity effects. For example, second end  80  may be located within the interior of device  10  away from the surfaces of housing  12  (i.e., the conductive surfaces of housing portions  12 - 1  and the dielectric surfaces of housing portion  12 - 2 B). First end  76  may be electrically connected to contact pad  68  using any suitable contact structure arrangement. With one suitable arrangement, a pogo pin such as pogo pin  78  may be used to form an electrical contact between antenna resonating element end  76  and contact pad  68 . This is merely illustrative. If desired, electrical contact may be made between antenna resonating element  54 - 1 B and contact pad  68  using other suitable structures such as a spring or clip. A spring arrangement may be formed, for example, by bending end  76  to form a spring from resonating element  54 - 1 B in the vicinity of contact pad  68 . 
     Antenna resonating element  54 - 1 B may be formed from a strip of metal (as an example). Antenna resonating element  54 - 1 B may be a free-standing structure, a trace that is patterned on the surface of a substrate such as a flex circuit, or may be attached to other suitable mounting structures. With one illustrative arrangement, which is sometimes described herein as an example, antenna  54  is formed from a strip of metal that is mounted to a dielectric support structure such as support structure  90  (sometimes referred to as a chassis or carrier). 
     Antenna resonating element dielectric support structure  90  may be formed from plastic or any other suitable dielectric. The effective dielectric constant of the support structure  90  may be decreased by forming air-filled regions within the support structure  90 . By forming air-filled openings such as holes and ridges within support structure  90 , the dielectric constant of the support structure in the vicinity of antenna resonating element  54 - 1 B is reduced. For a given desired frequency of operation (e.g., 2.4 GHz), a relatively low dielectric constant for support structure  90  is advantageous, because it allows the length of antenna resonating element  54 - 1 B to be increased, thereby improving antenna efficiency. In a typical scenario (e.g., 2.4 GHz operation with a plastic support structure), the length of antenna resonating element  54 - 1 B may be about 2 cm. The length of resonating element  54 - 1 B is generally about 5-30 mm, depending on the communications frequency band for which coverage is desired. The length of antenna resonating element  54 - 1 B is approximately equal to a quarter of a wavelength at its operating frequency. 
     A perspective view of antenna  54  in which dielectric antenna resonating element support structure  90  of  FIG. 9  is not present is shown in  FIG. 10 . As shown in  FIG. 10 , distal tip  80  of antenna resonating element  54 - 1 B may be located within and adjacent to hole  74  in printed circuit board  66  at a position that is approximately equidistant from the sidewalls of hole  74 . In this location, end  80  is also approximately equidistant from the nearby edges of conductive housing walls  12 - 1  and conductive bezel  14 . 
     Antenna efficiency and bandwidth is improved by ensuring that end  80  (and antenna resonating element  54 - 1 B) is not too close to conductive structures such as bezel  14  and housing walls  12 - 1 . Accordingly, antenna resonating element  54 - 1 B may have a number of bends that help to position end  80  in a suitable location. As shown in  FIG. 9 , a length of antenna resonating element  54 - 1 B such as portion  81  may extend parallel to the walls of housing  12  (i.e., the front and rear surfaces of housing  12  in the present example). Portion  83  extends parallel to portion  81 . Portions such as portions  85  and  87  extend at right angles to portions  81  and  83 . Portion  85  extends upwards from the antenna ground plane, perpendicular to portions  83  and  81 . Portion  87  extends downwards towards the ground plane, perpendicular to portions  81  and  83 . Bend  89  (which may be a single bend or a compound bend formed of two or more individual bends) ensures that the distal end of antenna resonating element  54 - 1 B is located within the interior of housing  12  away from housing surfaces such as the front and rear housing surfaces of device  10 . 
     A cross-sectional view of antenna  54  that is taken along dotted line  94  of  FIG. 10  in direction  96  is shown in  FIG. 11 . As shown in  FIG. 11 , end  80  of antenna resonating element  54 - 1 B may, if desired, lie below upper surface  98  of printed circuit board  66  within hole  74 . Printed circuit board  66  may be a multilevel circuit board (e.g., a circuit board that supports  2 - 8  levels of metal). To ensure that antenna resonating element  54 - 1 B is not adversely affected by conductive materials in its vicinity, the conductive layers of printed circuit board  66  may be patterned so that there is no metal adjacent to hole  74  such as in region  100 . 
     To ensure adequate impedance matching between transceiver  52  and antenna  54 , the path between transceiver  52  and antenna  54  may contain an impedance matching network such as optional impedance matching network  92  of  FIG. 10 . Any suitable circuitry may be used for impedance matching network  92 . Illustrative examples of suitable impedance matching networks are shown in  FIGS. 12 ,  13 ,  14 , and  15 . 
     In the example of  FIG. 12 , impedance matching network  92  is formed from an inductor that is connected in series along signal path  70 . Impedance matching network  92  of  FIG. 13 , which may be preferred, contains an inductor such as a 1.1 nH inductor that is shunted to ground. Impedance matching network  92  of  FIG. 14  has a capacitor connected in series in path  70  between transceiver  52  and contact pad  68 . In the arrangement of  FIG. 15 , impedance matching network  92  contains a capacitor that forms a shunting signal path between signal line  70  and ground. 
       FIG. 16  shows a top view of an illustrative embodiment of dielectric antenna resonating element support structure  90  and antenna resonating element  54 - 1 B. As shown in  FIG. 16 , dielectric antenna resonating element support structure  90  may have cut-away air-filled regions  102  (holes) that help to reduce the effective dielectric constant of the dielectric antenna resonating element support structure. Dielectric antenna resonating element support structure  90  may also have cut-away air-filled regions such as air-filled channels  106 . Dielectric antenna resonating element support structure  90  may be formed from ABS plastic or other suitable dielectric materials. The dielectric constant of the ABS plastic or other dielectric materials may be approximately 2.8 to 3.0. The dielectric constant of air is 1.0. By configuring dielectric resonating element support structure  90  to form air-filled openings such as holes  102  and  106 , the effective dielectric constant for the antenna resonating element may be reduced to a value that is below 2.8 to 3.0. It may be advantageous when at least some of the air-filled holes in support  90  are immediately adjacent to antenna resonating element  54 - 1 B, as shown in  FIG. 16 . Reductions in the dielectric constant for support  90  allow the length of antenna resonating element  54 - 1 B and therefore the efficiency of the antenna to be increased. 
     Dielectric antenna resonating element support structure  90  may have screw holes such as holes  104 . Such holes may be used to attach dielectric antenna resonating element support structure  90  to housing  12  (e.g., with screws, plastic posts, or other fasteners). Dielectric posts (e.g., plastic posts formed from part of antenna resonating element support structure  90 ) such as posts  110  may mate with matching holes in antenna resonating element  54 - 1 B. During assembly, posts  110  and the corresponding holes in antenna resonating element  54 - 1 B may help to align antenna resonating element  54 - 1 B properly with respect to antenna resonating element support structure  90  and may help to attach antenna resonating element  54 - 1 B to antenna resonating element support structure  90 . If desired, the tips of posts  110  may be enlarged slightly (e.g., using heat treatment) to hold antenna resonating element  54 - 1 B in place. 
     Edge  108  of antenna resonating element support structure  90  may be curved (as an example). This may help antenna resonating element support structure  90  to conform to the curved corners of housing  12 . Dielectric cap  12 - 2 B ( FIGS. 4A and 4B ) may be used to cover dielectric antenna resonating element support structure  90  and antenna resonating element  54 - 1 B when mounted in housing  12 . 
     When assembled in device  10 , dielectric antenna resonating element support structure  90  may mate with printed circuit board  66  to form an assembly such as assembly  112  in the exploded perspective view of  FIG. 17 . End  76  of antenna resonating element  54 - 1 B may be bent to form a spring or clip, as shown in  FIG. 17 . The spring that is formed in this way may be biased against contact pad  68  when dielectric antenna resonating element support structure  90  is mounted to printed circuit board  66 . If desired, a pogo pin (i.e., a spring-loaded pin that reciprocates within a pin housing) or other suitable electrical contact structure may be formed at end  76  in place of the illustrative spring structure that is shown in  FIG. 17 .  FIG. 18  is an exploded perspective view of assembly  112  of  FIG. 17  showing an illustrative shape for antenna resonating element  54 - 1 B in more detail. As shown in  FIG. 18 , dielectric antenna resonating element support structure  90  may have a hole  114  or other opening through which end  76  of antenna resonating element  54 - 1 B passes during assembly. Holes  116  in antenna resonating element  54 - 1 B may mate with posts  110  or other suitable registration structures on antenna resonating element support structure  90 . 
     As shown in  FIG. 18 , antenna resonating element  54 - 1 B may be formed from a strip of conductor. The thickness (smallest lateral dimension) of the conductor may be, for example, 0.05 mm to 1 mm. The width (the second smallest lateral dimension) of the strip of conductor may be, for example, 0.5 mm to 5 mm. The length of the strip of conductor may be, for example, 5 mm to 30 mm. 
     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: 20070807
Publication Date: 20120320
Grant Date: 20120320
Priority Date: 20070807
Inventors: ZHANG ZHIJUN
ROTHKOPF FLETCHER R.
SCHLUB ROBERT W.
CABALLERO RUBEN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/36", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0414", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/36", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 39717598