PATENT DOCUMENT

Publication Number: US-8350761-B2
Application Number: US-65018707-A
Country: US
Kind Code: B2

Title: Antennas for handheld electronic devices

Abstract:
Handheld electronic devices are provided that contain wireless communications circuitry having at least one antenna. The antenna may have a planar ground element and a planar resonating element. The planar ground element may have a rectangular shape that matches a rectangular housing shape for a handheld electronic device. A dielectric-filled slot may be formed in one end of the planar ground element. The planar resonating element may be located above the slot. The antenna may be a hybrid antenna that contains both a slot antenna structure formed from the slot and a planar inverted-F structure formed from the planar resonating element and the planar ground element. The antenna may be fed using a single transmission line or two transmission lines. With two transmission lines, one transmission line may be associated with the slot antenna structure and one transmission line may be associated with the planar inverted-F antenna structure.

Claims:
1. A handheld electronic device antenna comprising:
 a ground plane that surrounds and encloses a dielectric-filled slot; 
 a planar resonating element located above the slot, wherein the handheld electronic antenna comprises a hybrid antenna in which the slot is used in forming a slot antenna portion of the hybrid antenna and in which the planar resonating element is used in forming a planar-inverted-F antenna portion of the hybrid antenna; 
 a first signal terminal that is electrically coupled to the planar resonating element; 
 a first ground terminal that is electrically connected to the ground plane, wherein the first signal terminal and first ground terminal serve as antenna feed points for the planar-inverted-F antenna portion of the hybrid antenna; 
 a second signal terminal that is electrically connected to the ground plane adjacent to the slot; and 
 a second ground terminal that is electrically connected to the ground plane adjacent to the slot, wherein the second signal terminal is different than the first signal terminal, wherein the second ground terminal is different than the first ground terminal, and wherein the second signal terminal and the second ground terminal serve as antenna feed points for the slot antenna portion of the hybrid antenna. 
 
     
     
       2. The handheld electronic device antenna defined in  claim 1  wherein the slot comprises a rectangular slot having lateral dimensions, wherein the planar resonating element has at least one lateral dimension larger than the lateral dimensions of the slot, and wherein the planar resonating element is located less than 10 mm above the slot. 
     
     
       3. The handheld electronic device antenna defined in  claim 1  wherein the planar resonating element comprises a conductor formed on a flex circuit substrate. 
     
     
       4. A hybrid handheld electronic device antenna with characteristics of both a planar inverted-F antenna structure and a slot antenna structure, comprising:
 a ground plane antenna element, wherein portions of the ground plane antenna element define a closed dielectric-filled slot associated with the slot antenna structure and wherein the ground plane antenna element surrounds and encloses the closed slot; 
 a planar antenna resonating element that is located above the closed slot and that is associated with the planar inverted-F antenna structure; and 
 a first pair of antenna terminals through which a first transmission line conveys radio-frequency signals for the slot antenna structure; and 
 a second pair of antenna terminals through which a second transmission line that is different than the first transmission line conveys radio-frequency signals for the planar inverted-F antenna structure. 
 
     
     
       5. The hybrid handheld electronic device antenna defined in  claim 4  wherein the planar resonating element comprises at least two arms and wherein at least one of the arms has a bend. 
     
     
       6. The hybrid handheld electronic device antenna defined in  claim 4  wherein the planar resonating element comprises two arms and wherein each of the two arms has at least a 180° bend. 
     
     
       7. A wireless handheld electronic device comprising:
 storage that stores data; 
 processing circuitry coupled to the storage that generates data for wireless transmission and that processes wirelessly received data; and 
 wireless communications circuitry, wherein the wireless communications circuitry comprises transceiver circuitry, an antenna, and a transmission line, wherein the transmission line has a ground conductor and a signal conductor and conveys radio-frequency signals for the antenna between the transceiver circuitry and the antenna, wherein the antenna comprises a ground plane with a dielectric-filled slot and a planar resonating element located above the slot, and wherein the planar resonating element comprises a conductor formed on a flex circuit substrate, wherein the antenna comprises a hybrid antenna in which the slot in the ground plane is used in forming a slot antenna portion of the hybrid antenna and in which the planar resonating element is used in forming a planar-inverted-F antenna portion of the hybrid antenna, and wherein the hybrid antenna comprises:
 a first terminal connected to the signal conductor; 
 a ground terminal that is electrically connected to the ground plane and the ground conductor; 
 a first antenna conductive path that electrically connects the first terminal to the planar resonating element so that the first terminal and the ground terminal serve as antenna feed points for the planar-inverted-F portion of the hybrid antenna; 
 a second terminal that is connected to the ground plane at a location different from the ground terminal; and 
 a second antenna conductive path that is electrically connected to the second terminal, wherein the first antenna conductive path and the second antenna conductive path convey signals between the signal conductor and the second terminal so that the ground terminal and the second terminal serve as antenna feed points for the slot antenna portion of the hybrid antenna. 
 
 
     
     
       8. The wireless handheld electronic device defined in  claim 7  wherein the planar resonating element comprises a first resonating element arm and a second resonating element arm, wherein the first resonating element arm has a length, and wherein the second resonating element arm has a length that is different than the length of the first resonating element arm. 
     
     
       9. The wireless handheld electronic device defined in  claim 7  further comprising a display coupled to the processing circuitry, wherein the wireless handheld electronic device comprises a device having music player capabilities. 
     
     
       10. A hybrid handheld electronic device antenna with characteristics of both a planar inverted-F antenna structure and a slot antenna structure, comprising:
 a ground plane antenna element, wherein portions of the ground plane antenna element define a dielectric-filled slot associated with the slot antenna structure and wherein the ground plane antenna element completely encloses the slot; and 
 a planar resonating element that is located above the slot and that is associated with the planar inverted-F antenna structure, wherein the planar resonating element comprises a conductor formed on a flex circuit substrate. 
 
     
     
       11. The hybrid handheld electronic device antenna defined in  claim 10  further comprising:
 a pair of antenna terminals through which a single transmission line conveys radio-frequency signals for both the planar inverted-F antenna structure and the slot antenna structure. 
 
     
     
       12. The hybrid handheld electronic device antenna defined in  claim 10  further comprising:
 a first pair of antenna terminals through which a first transmission line conveys radio-frequency signals for the slot antenna structure; and 
 a second pair of antenna terminals through which a second transmission line that is different than the first transmission line conveys radio-frequency signals for the planar inverted-F antenna structure. 
 
     
     
       13. The hybrid handheld electronic device antenna defined in  claim 10  wherein the planar resonating element comprises at least two arms and wherein at least one of the arms has a bend. 
     
     
       14. The hybrid handheld electronic device antenna defined in  claim 10  wherein the planar resonating element comprises two arms and wherein each of the two arms has a 180° bend. 
     
     
       15. Wireless communications circuitry comprising:
 an antenna comprising a ground plane element having portions that define a dielectric-filled slot for a slot antenna and comprising a planar resonating element located above the slot for a planar inverted-F antenna; and 
 a connector having a ground terminal connected to the ground plane element at a first point and having a signal terminal, wherein the antenna comprises:
 a first antenna path located between the signal terminal and the planar resonating element so that the ground terminal and the signal terminal serve as antenna feed terminals for the planar inverted-F antenna; and 
 a second antenna path located between the planar resonating element and a second point on the ground plane element so that the ground terminal and the second point on the ground plane element serve as antenna feed terminals for the slot antenna. 
 
 
     
     
       16. The wireless communications circuitry defined in  claim 15  further comprising:
 a wireless transceiver circuit; and 
 at least one coaxial cable connected between the wireless transceiver circuit and the connector, wherein the coaxial cable has an outer ground conductor connected to the ground terminal and has a signal conductor connected to the signal terminal. 
 
     
     
       17. The wireless communications circuitry defined in  claim 15  further comprising:
 a wireless transceiver circuit; and 
 at least one transmission line connected between the wireless transceiver circuit and the connector, wherein the transmission line has a ground conductor connected to the ground terminal and has a signal conductor connected to the signal terminal. 
 
     
     
       18. The wireless communications circuitry defined in  claim 15  further comprising at least one wireless transceiver circuit that transmits and receives radio-frequency signals through the antenna using a coaxial cable. 
     
     
       19. The wireless communications circuitry defined in  claim 15  further comprising a dielectric antenna support structure having a surface on which at least part of the planar resonating element is mounted, wherein the first antenna path and the second antenna path are supported by the dielectric antenna support structure. 
     
     
       20. The wireless communications circuitry defined in  claim 15  further comprising at least one tuning element, wherein the slot is substantially rectangular, wherein the first antenna path and the second antenna path comprise strips of metal that are connected through the tuning element, and wherein the planar resonating element comprises two arms. 
     
     
       21. An antenna for use in a handheld device, comprising:
 a ground plane, wherein portions of the ground plane define a dielectric-filled slot; 
 a planar resonating element that is located above the slot, wherein the slot forms a slot antenna portion of the antenna and wherein the planar resonating element forms a planar-inverted-F antenna portion of the antenna; 
 positive and ground antenna terminals that convey radio-frequency signals between the antenna and radio-frequency transceiver circuitry; 
 a first antenna path that conveys signals between the positive antenna terminal and the planar resonating element so that the positive and ground antenna terminals form antenna feed terminals for the planar inverted-F antenna portion of the antenna; and 
 a second antenna path that conveys signals between the planar resonating element and the ground plane at a point on the ground plane adjacent to the slot so that the point on the ground plane and the ground antenna terminal serve as antenna feed terminals for the slot antenna portion of the antenna. 
 
     
     
       22. The antenna defined in  claim 21  wherein the ground plane surrounds and encloses the slot. 
     
     
       23. The antenna defined in  claim 21  wherein the planar resonating element comprises a flex circuit, the antenna further comprising a dielectric antenna support structure having a surface on which at least part of the planar resonating element is mounted, wherein the first antenna path and the second antenna path are supported by the dielectric antenna support structure and are formed as part of the flex circuit. 
     
     
       24. The antenna defined in  claim 21  further comprising at least one capacitor in the first antenna path.

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 (e.g., the main Global System for Mobile Communications or GSM cellular telephone bands). 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. 
     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. Many devices use planar inverted-F antennas (PIFAs). Planar inverted-F antennas are formed by locating a planar resonating element above a ground plane. These techniques can be used to produce antennas that fit within the tight confines of a compact handheld device. 
     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 functions satisfactorily over a wide frequency range with satisfactory performance levels. For example, when the vertical size of conventional planar inverted-F antennas is made too small in an attempt to minimize antenna size, the bandwidth and gain of the antenna are adversely affected. 
     It would therefore be desirable to be able to provide improved antennas and wireless handheld electronic devices. 
     SUMMARY 
     In accordance with an embodiment of the present invention, a handheld electronic device with wireless communications circuitry is provided. The handheld electronic device may have cellular telephone, music player, or handheld computer functionality. The wireless communications circuitry may have at least one antenna. 
     The handheld electronic device may have lateral dimensions that define a rectangular housing. The antenna may have a ground plane element and a resonating element. The ground plane element of the antenna may be rectangular and may have lateral dimensions that match those of the handheld electronic device. A rectangular slot may be formed in one end of the ground plane element. The resonating element may be located directly above the slot. Because the slot reduces electromagnetic near-field coupling between the resonating element and the ground plane, the height of the antenna above the ground plane may be reduced without adversely affecting antenna performance, thereby allowing the thickness of the handheld electronic device to be minimized. 
     The antenna may operate in a hybrid mode in which the antenna displays characteristics of both a slot antenna and a planar inverted-F antenna. The planar inverted-F antenna characteristics of the antenna may be obtained by using an antenna feed arrangement in which an antenna ground terminal is connected to the ground plane and an antenna signal terminal is connected to the resonating element through a feed conductor or other suitable feed path. The slot antenna characteristics of the antenna may be obtained using an antenna feed arrangement having a ground terminal connected to the ground plane in the vicinity of the slot and a signal terminal connected to the ground plane in the vicinity of the slot. The ground terminal used for driving the antenna so that it exhibits planar inverted-F antenna characteristics need not be the same as the ground terminal used for driving the antenna so that it exhibits slot antenna characteristics. 
     With one feed arrangement, separate coaxial cables or other suitable transmission lines are used to convey signals to the slot antenna portion and the planar inverted-F antenna portion of the antenna. In this type of arrangement, a first transmission line has a ground conductor and a signal conductor that are connected to the ground plane and the resonating element, respectively. The first transmission line is associated with the planar inverted-F antenna operating characteristics of the antenna. A second transmission line has a ground conductor that is connected to the ground plane at a location that is different than the location at which the ground conductor of the first transmission line is connected. The second transmission line also has a signal conductor that is connected to the ground plane. The second transmission line is associated with the slot antenna operating characteristics of the antenna. 
     With another feed arrangement, a single coaxial cable or other suitable transmission line is used to convey signals simultaneously to the slot antenna portion and the planar inverted-F antenna portion of the antenna. In this type of arrangement, the transmission line has a ground conductor and a signal conductor that are connected to the ground plane and the resonating element, respectively. A conductive path connects the signal conductor to the ground plane at a location that is different than the location at which the ground conductor is connected to the ground plane. 
     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. 3  is a cross-sectional side view of an illustrative handheld electronic device with an antenna in accordance with an embodiment of the present invention. 
         FIG. 4  is a perspective view of an illustrative planar inverted-F antenna in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative planar inverted-F antenna (PIFA) in accordance with an embodiment of the present invention. 
         FIG. 6  is an illustrative antenna performance graph for an antenna of the type shown in  FIGS. 4 and 5  in which standing-wave-ratio (SWR) values are plotted as a function of operating frequency. 
         FIG. 7  is a perspective view of an illustrative planar inverted-F antenna in which a portion of the antenna&#39;s ground plane underneath the antenna&#39;s resonating element has been removed in accordance with an embodiment of the present invention. 
         FIG. 8  is a top view of an illustrative slot antenna in accordance with an embodiment of the present invention. 
         FIG. 9  is an illustrative antenna performance graph for an antenna of the type shown in  FIG. 8  in which standing-wave-ratio (SWR) values are plotted as a function of operating frequency. 
         FIG. 10  is a perspective view of an illustrative planar inverted-F antenna in which a portion of the antenna&#39;s ground plane underneath the antenna&#39;s resonating element has been removed and in which the antenna is shown as being fed by two coaxial cable feeds in accordance with an embodiment of the present invention. 
         FIG. 11  is a graph of an illustrative antenna performance graph for an antenna of the type shown in  FIG. 10  in which standing-wave-ratio (SWR) values are plotted as a function of operating frequency. 
         FIG. 12  is a perspective view of an illustrative antenna that has both PIFA and slot antenna characteristics in accordance with an embodiment of the present invention. 
         FIGS. 13 ,  14 , and  15  are top views of illustrative multi-arm PIFA resonating element portions for a hybrid PIFA-slot antenna 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 antennas may be small form factor antennas that exhibit wide bandwidths and large gains. 
     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, the portable electronic devices are handheld electronic devices. Space is at a premium in handheld electronics devices, so high-performance compact antennas can be particularly advantageous in such devices. The use of handheld devices is therefore generally described herein as an example, although any suitable electronic device may be used with the high-performance compact antennas of the invention if desired. 
     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, 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  includes housing  12  and includes at least one antenna for handling wireless communications. 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, case  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 case  12  is not disrupted. In other situations, case  12  may be formed from metal elements. In scenarios in which case  12  is formed from metal elements, one or more of the metal elements may be used as part of the antenna(s) in device  10 . For example, the rear of case  12  may be shorted to an internal ground plane in device  10  to create an effectively larger ground plane element for that device  10 . 
     Handheld electronic device  10  may have input-output devices such as a display screen  16 , buttons such as button  23 , user input control devices  18  such as button  19 , and input-output components such as port  20  and input-output jack  21 . 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. As shown in the example of  FIG. 1 , display screens such as display screen  16  can be mounted on front face  22  of handheld electronic device  10 . If desired, displays such as display  16  can 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  18 . User input interface  18  may 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 touch screen (e.g., a touch screen implemented as part of screen  16 ), or any other suitable interface for controlling device  10 . Although shown schematically as being formed on the top face  22  of handheld electronic device  10  in the example of  FIG. 1 , user input interface  18  may generally be formed on any suitable portion of handheld electronic device  10 . For example, a button such as button  23  (which may be considered to be part of input interface  18 ) 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 bus connector  20  and jack  21  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, 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  18 . 
     Components such as display  16  and user input interface  18  may cover most of the available surface area on the front face  22  of device  10  (as shown in the example of  FIG. 1 ) or may occupy only a small portion of the front face  22 . 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 antenna of handheld electronic device  10  to function properly without being disrupted by the electronic components. With one suitable arrangement, the antenna of device  10  is located in the lower end of device  10 , in the proximity of port  20 . An advantage of locating antenna in the lower portion of housing  12  and device  10  is that this places the antenna 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 and minimizes 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, 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  and user input interface  18  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, 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, 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(s) 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, the Bluetooth® band at 2.4 GHz, and the global positioning system (GPS) band at 1550 MHz. These are merely illustrative communications bands over which devices  44  may operate. Additional local and remote communications bands are expected to be deployed in the future as new wireless services are made available. Wireless devices  44  may be configured to operate over any suitable band or bands to cover any existing or new services of interest. If desired, multiple antennas and/or a broadband antenna may be provided in wireless devices  44  to allow coverage of more bands. 
     A cross-sectional view of an illustrative handheld electronic device is shown in  FIG. 3 . In the example of  FIG. 3 , device  10  has a housing that is formed of a conductive portion  12 - 1  and a plastic portion  12 - 2 . Conductive portion  12 - 1  may be any suitable conductor. With one suitable arrangement, case portion  12 - 1  is formed from stamped  304  stainless steel. Stainless steel has a high conductivity and can be polished to a high-gloss finish so that it has an attractive appearance. If desired, other metals can be used for case portion  12 - 1  such as aluminum, magnesium, alloys of these metals and other metals, etc. 
     Housing portion  12 - 2  may be formed from a dielectric. An advantage of using dielectric for housing portion  12 - 2  is that this allows a 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 portion  12 - 2  is a plastic cap 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 one or more circuit boards in device  10 . Typical components 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). 
     The circuit board(s) in device  10  may be formed from any suitable materials. With one suitable arrangement, device  10  is provided with a multilayer printed circuit board. At least one of the layers has large uninterrupted planar regions of conductor that form ground plane  54 - 2 . In a typical scenario, ground plane  54 - 2  is a rectangle that conforms to the generally rectangular shape of housing  12  and device  10  and matches the rectangular lateral dimensions of housing  12 . Ground plane  54 - 2  may, if desired, be electrically connected to conductive housing portion  12 - 1 . Suitable circuit board materials for the multilayer printed circuit board 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 . 
     Ground plane element  54 - 2  and antenna resonating element  54 - 1  form antenna  54  for device  10 . If desired, other antennas can be provided for device  10  in addition to antenna  54 . Such additional antennas 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 element  54 - 1  in antenna  54 . Examples of suitable conductive materials for antenna  54  include metals, such as copper, brass, silver, and gold. Conductors other than metals may also be used, if desired. The conductive elements in antenna  54  are typically thin (e.g., about 0.2 mm). 
     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). Transceiver circuitry may include one or more transmitter integrated circuits, one or more receiver integrated circuits, switching circuitry, amplifiers, etc. In a typical scenario, the transceiver circuitry contains one or two transceivers, each of which has an associated coaxial cable or other transmission line over which radio frequency signals for antenna  54  are conveyed. In the example of  FIG. 3 , these transmission lines are depicted by dotted line  56 . 
     As shown in  FIG. 3 , the transmission lines  56  may be used to distribute radio-frequency signals that are to be transmitted through the antenna from a transmitter integrated circuit  52  or other transceiver circuit to antenna  54 . Paths  56  are also used to convey radio-frequency signals that have been received by antenna  54  to components  52 . A receiver integrated circuit or other transceiver circuitry may be used to process incoming radio-frequency signals that have been conveyed from antenna  54  over one or more transmission lines  56 . 
     Antenna  54  may be formed in any suitable shape. With one suitable arrangement, antenna  54  is based at least partly on a planar inverted-F antenna (PIFA) structure. An illustrative PIFA structure that may be used for antenna  54  is shown in  FIG. 4 . As shown in  FIG. 4 , PIFA structure  54  has a ground plane portion  54 - 2  and a planar resonating element portion  54 - 1 . Antennas are fed using positive signals and ground signals. The portion of an antenna to which the positive signal is provided is sometimes referred to as the antenna&#39;s positive terminal or feed terminal. This terminal is also sometimes referred to as the signal terminal or the center-conductor terminal. The portion of an antenna to which the ground signal is provided may be referred to as the antenna&#39;s ground, the antenna&#39;s ground terminal, the antenna&#39;s ground plane, etc. In antenna  54  of  FIG. 4 , feed conductor  58  is used to route positive antenna signals from signal terminal  60  into antenna resonating element  54 - 1 . Ground terminal  62  is shorted to ground plane  54 - 2 , which forms the antenna&#39;s ground. 
     The dimensions of antenna  54  are generally sized to conform to the maximum size allowed by housing  12  of device  10 . Antenna ground plane  54 - 2  may be rectangular in shape having width W in lateral dimension  68  and length L in lateral dimension  66 . The length of antenna  54  in dimension  66  affects its frequency of operation. Dimensions  68  and  66  are sometimes referred to as horizontal dimensions. Resonating element  54 - 1  is typically spaced several millimeters from ground plane  54 - 2  along vertical dimension  64 . The size of antenna  54  in dimension  64  is sometimes referred to as height H of antenna  54 . 
     A cross-sectional view of antenna  54  is shown in  FIG. 5 . As shown in  FIG. 5 , radio-frequency signals may be fed to antenna  54  (when transmitting) and may be received from antenna  54  (when receiving) using signal terminal  60  and ground terminal  62 . In a typical arrangement, a coaxial conductor or other transmission line has its center conductor electrically connected to point  60  and its ground conductor electrically connected to point  62 . 
     A graph of the expected performance of antenna  54  of  FIGS. 4 and 5  is shown in  FIG. 6 . Expected standing wave ratio (SWR) values are plotted as a function of frequency. As shown, there is a reduced SWR value at frequency f 1 , indicating that the antenna performs well in the frequency band centered at frequency f 1 . Antenna  54  also operates at harmonic frequencies such as frequency 2f 1 . The dimensions of antenna  54  may be selected so that frequencies f 1  and 2f 1  are aligned with a communication bands of interest. The frequency f 1  (and harmonic frequency 2f 1 ) are related to the length L of antenna  54  in dimension  66  (L is approximately equal to one quarter of a wavelength at frequency f 1 ). 
     The height H of antenna  54  of  FIGS. 4 and 5  in dimension  64  is limited by the amount of near-field coupling between resonating element  54 - 1  and ground plane  54 - 2 . For a specified antenna bandwidth and gain, it is not possible to reduced the height H without adversely affecting performance. All other variables being equal, reducing height H will cause the bandwidth and gain of antenna  54  to be reduced. 
     As shown in  FIG. 7 , the minimum vertical dimension of antenna  54  can be reduced while still satisfying minimum bandwidth and gain constraints by introducing a dielectric region  70  in the area under antenna resonating element portion  54 - 1 . The dielectric region  70  may be filled with air, plastic, or any other suitable dielectric and represents a cut-away or removed portion of ground plane  54 - 2 . Removed or empty region  70  may be formed from one or more holes in ground plane  54 - 2 . These holes may be square, circular, oval, polygonal, etc. and may extend though adjacent conductive structures in the vicinity of ground plane  54 - 2 . With one suitable arrangement, which is shown in  FIG. 7 , the removed region  70  is rectangular and forms a slot. The slot may be any suitable size. For example, the slot may be slightly smaller than the outermost rectangular outline of resonating element  54 - 1 . Typical resonating element lateral dimensions are on the order of 0.5 cm to 10 cm. 
     The presence of slot  70  reduces near-field electromagnetic coupling between resonating element  54 - 1  and ground plane  54 - 2  and allows height H in vertical dimension  64  to be made smaller than would otherwise be possible while satisfying a given set of bandwidth and gain constraints. For example, height H may be in the range of 1-5 mm, may be in the range of 2-5 mm, may be in the range of 2-4 mm, may be in the range of 1-3 mm, may be in the range of 1-4 mm, may be in the range of 1-10 mm, may be lower than 10 mm, may be lower than 4 mm, may be lower than 3 mm, may be lower than 2 mm, or may be in any other suitable range of vertical displacements above ground plane element  54 - 2 . 
     If desired, the portion of antenna  54  that contains slot  70  may be used to form a slot antenna. The slot antenna structure in antenna  54  may be used at the same time as the PIFA structure. Antenna performance can be improved when operating antenna  54  so that both its PIFA operating characteristics and its slot antenna operating characteristics are obtained. 
     A top view of a slot antenna  72  is shown in  FIG. 8 . The antenna  72  of  FIG. 8  is typically thin in the dimension into the page (i.e., antenna  72  is planar with its plane lying in the page). A slot  70  is formed in the center of antenna  72 . A coaxial cable  56  or other transmission line path may be used to feed antenna  72 . In the example of  FIG. 8 , antenna  72  is fed so that the center conductor  82  of coaxial cable  56  is connected to signal terminal  80  (i.e., the positive or feed terminal of antenna  72 ) and the outer braid of coaxial cable  56 , which forms the ground conductor for cable  56 , is connected to ground terminal  78 . 
     When antenna  72  is fed using the arrangement of  FIG. 8 , the antenna&#39;s performance is given by the graph of  FIG. 9 . As shown in  FIG. 9 , antenna  72  operates in a frequency band that is centered about center frequency f r . The center frequency f r  is determined by the dimensions of slot  70 . Slot  70  has an inner perimeter P that is equal to two times dimension X plus two times dimension Y (i.e., P=2X+2Y). At center frequency f r , perimeter P is equal to one wavelength. The position of terminals  80  and  78  is selected for impedance matching. If desired, terminals such as terminals  84  and  86 , which extend around one of the corners of slot  70  may be used to feed antenna  72 , provided that the distance between terminals  84  and  86  is chosen to properly adjust the impedance of antenna  72 . In the illustrative arrangement of  FIG. 8 , terminals  84  and  86  are shown as being respectively configured as a slot antenna ground terminal and a slot antenna signal terminal, as an example. If desired, terminal  84  could be used as a ground terminal and terminal  86  could be used as a signal terminal. Slot  70  is typically air-filled, but may, in general, by filled with any suitable dielectric. 
     An illustrative configuration in which antenna  54  is fed using two coaxial cables (or other transmission lines) is shown in  FIG. 10 . When antenna  54  is fed as shown in  FIG. 10 , both the PIFA and slot antenna portions of antenna  54  are active. As a result, antenna  54  of  FIG. 10  operates in a hybrid PIFA/slot mode. Coaxial cables  56 - 1  and  56 - 2  have inner conductors  82 - 1  and  82 - 2 , respectively. Coaxial cables  56 - 1  and  56 - 2  also each have a conductive outer braid ground conductor. The outer braid conductor of coaxial cable  56 - 1  is electrically shorted to ground plane  54 - 2  at ground terminal  88 . The ground portion of cable  56 - 2  is shorted to ground plane  54 - 2  at ground terminal  92 . The signal connections from coaxial cables  56 - 1  and  56 - 2  are made at signal terminals  90  and  94 , respectively. 
     With the arrangement of  FIG. 10 , two separate sets of antenna terminals are used. Coaxial cable  56 - 1  feeds the PIFA portion of antenna  54 - 1  using ground terminal  88  and signal terminal  90  and coaxial cable  56 - 2  feeds the slot antenna portion of antenna  54  using ground terminal  92  and signal terminal  94 . Each set of antenna terminals therefore operates as a separate feed for the antenna. Signal terminal  90  and ground terminal  88  serve as antenna feed points for the PIFA portion of antenna  54 , whereas signal terminal  94  and ground terminal  92  serve as antenna feed points for the slot portion of antenna  54 . These two separate antenna feeds allow the antenna  54  to function simultaneously using both its PIFA and its slot characteristics. If desired, the orientation of the feeds can be changed. For example, coaxial cable  56 - 2  may be connected to slot  70  using point  94  as a ground terminal and point  92  as a signal terminal or using ground and signal terminals located at other points along the periphery of slot  70 . 
     Each coaxial cable or other transmission line may terminate at a respective transceiver circuit (also sometimes referred to as a radio) or coaxial cables  56 - 1  and  56 - 2  (or other transmission lines) may be connected to switching circuitry that, in turn is connected to one or more radios. When antenna  54  is operated in hybrid PIFA/slot antenna mode, the frequency coverage of antenna  54  and/or its gain at particular frequencies can be enhanced. 
     With one suitable arrangement, the additional response provided by the slot antenna portion of antenna  54  is used to cover one or more additional frequency bands. By proper selection of the dimensions of slot  70  and length L of ground plane  54 - 2  in dimension  66 , antenna  54  can cover the GSM cellular telephone bands at 850 and 900 MHz and at 1800 and 1900 MHz and can cover an additional band centered at frequency f n  (as an example). A graph showing the performance of antenna  54  of  FIG. 10  is shown in  FIG. 11 . In the example of  FIG. 11 , the PIFA operating characteristics of antenna  54  are used to cover the 850/900 and the 1800/1900 GSM cellular telephone bands, whereas the slot antenna operating characteristics of antenna  54  are used to cover the frequency band centered at f n . This arrangement provides more coverage than would otherwise be possible, while minimizing the size of antenna  54 . The frequency f n  may be adjusted to coincide with any suitable frequency band of interest (e.g., 2.4 GHz for Bluetooth/WiFi, 2170 MHz for UMTS, or 1550 MHz for GPS). 
     If desired, antenna  54  may be fed using a single coaxial cable  56  or other such transmission line. An illustrative configuration for antenna  54  in which a single transmission line is used to simultaneously feed both the PIFA portion and the slot portion of antenna  54  is shown in  FIG. 12 . As shown in  FIG. 12 , antenna  54  has a ground plane  54 - 2 . Ground plane  54 - 2  may be formed from metal (as an example). Edges  96  of ground plane  54 - 2  may be formed by bending the metal of ground plane  54 - 2  upward. When inserted into housing  12 , edges  96  may rest within the sidewalls of metal housing portion  12 - 1  ( FIG. 3 ). If desired, ground plane  54 - 2  may be formed using one or more metal layers in a printed circuit board, metal foil, or other suitable conductive structures. 
     Planar antenna resonating element  54 - 1  is an F-shaped structure having shorter arm  98  and longer arm  100 . The lengths of arms  98  and  100  may be adjusted to tune the frequency coverage of antenna  54 . If desired, antenna  54  of  FIG. 12  could use a planar resonating element structure of the type shown in  FIG. 4  or other suitable resonating element structure. The use of a PIFA antenna resonating element structure that is formed with two arms  98  and  100  is shown as an example. 
     Arms  98  and  100  are mounted on a support structure  102 . Support structure  102  may be formed from plastic (e.g., ABS plastic) or other suitable dielectric. The surfaces of structure  102  may be flat or curved. Arms  98  and  100  may be formed directly on support structure  102  or may be formed on a separate structure such as a flex circuit substrate that is attached to support structure  102  (as examples). 
     With one suitable arrangement, resonating element  54 - 1  is a substantially planar structure that is mounted to an upper surface of support  102 . Resonating element  54 - 1  may be formed by any suitable antenna fabrication technique such as metal stamping, cutting, etching, or milling of conductive tape or other flexible structures, etching metal that has been sputter-deposited on plastic or other suitable substrates, printing from a conducive slurry (e.g., by screen printing techniques), patterning metal such as copper that makes up part of a flex circuit substrate that is attached to support  102  by adhesive, screws, or other suitable fastening mechanisms, etc. 
     A conductive path such as conductive strip  104  may be used electrically connect the resonating element  54 - 1  to ground plane  54 - 2  at terminal  106 . A screw or other fastener at terminal  106  may be used to electrically and mechanically connect strip  104  (and therefore resonating element  54 - 1 ) to edge  96  of ground plane  54 - 2 . Conductive structures such as strip  104  and other such structures in antenna  54  may also be electrically connected to each other using conductive adhesive. 
     A coaxial cable such as cable  56  or other transmission line may be connected to the antenna to transmit and receive radio-frequency signals. The coaxial cable or other transmission line may be connected to the structures of antenna  54  using any suitable electrical and mechanical attachment mechanism. As shown in the illustrative arrangement of  FIG. 12 , mini UFL coaxial connector  110  may be used to connect coaxial cable  56  or other transmission lines to antenna conductor  112 . A center conductor of the coaxial cable or other transmission line is connected to center connector  108  of connector  110 . The outer braid ground conductor of the coaxial cable is electrically connected to ground plane  54 - 2  via connector  110  at point  115  (and, if desired, may be shorted to ground plane  54 - 2  at other attachment points upstream of connector  110 ). 
     Conductor  108  may be electrically connected to antenna conductor  112 . Conductor  112  may be formed from a conductive element such as a strip of metal formed on a sidewall surface of support structure  102 . Conductor  112  may be directly electrically connected to resonating element  54 - 1  (e.g., at portion  116 ) or may be electrically connected to resonating element  54 - 1  through tuning capacitor  114  or other suitable electrical components. The size of tuning capacitor  114  can be selected to tune antenna  54  and ensure that antenna  54  covers the frequency bands of interest for device  10 . 
     Slot  70  may lie beneath resonating element  54 - 1  of  FIG. 12 . The signal from center conductor  108  may be routed to point  106  on ground plane  54 - 2  in the vicinity of slot  70  using a conductive path formed from antenna conductor  112 , optional capacitor  114  or other such tuning components, antenna conductor  117 , and antenna conductor  104 . 
     The configuration of  FIG. 12  allows a single coaxial cable or other transmission line path to simultaneously feed both the PIFA portion and the slot portion of antenna  54 . 
     Grounding point  115  functions as the ground terminal for the slot antenna portion of antenna  54  that is formed by slot  70  in ground plane  54 - 2 . Point  106  serves as the signal terminal for the slot antenna portion of antenna  54 . Signals are fed to point  106  via the path formed by conductive path  112 , tuning element  114 , path  117 , and path  104 . 
     For the PIFA portion of antenna  54 , point  115  serves as antenna ground. Center conductor  108  and its attachment point to conductor  112  serve as the signal terminal for the PIFA. Conductor  112  serves as a feed conductor and feeds signals from signal terminal  108  to PIFA resonating element  54 - 1 . 
     In operation, both the PIFA portion and slot antenna portion of antenna  54  contribute to the performance of antenna  54 . 
     The PIFA functions of antenna  54  are obtained by using point  115  as the PIFA ground terminal (as with terminal  62  of  FIG. 7 ), using point  108  at which the coaxial center conductor connects to conductive structure  112  as the PIFA signal terminal (as with terminal  60  of  FIG. 7 ), and using conductive structure  112  as the PIFA feed conductor (as with feed conductor  58  of  FIG. 7 ). During operation, antenna conductor  112  serves to route radio-frequency signals from terminal  108  to resonating element  54 - 1  in the same way that conductor  58  routes radio-frequency signal from terminal  60  to resonating element  54 - 1  in  FIGS. 4 and 5 , whereas conductive line  104  serves to terminate the resonating element  54 - 1  to ground plane  54 - 2 , as with grounding portion  61  of  FIGS. 4 and 5 . 
     The slot antenna functions of antenna  54  are obtained by using grounding point  115  as the slot antenna ground terminal (as with terminal  86  of  FIG. 8 ), using the conductive path formed of antenna conductor  112 , tuning element  114 , antenna conductor  117 , and antenna conductor  104  as conductor  82  of  FIG. 8  or conductor  82 - 2  of  FIG. 10 , and by using terminal  106  as the slot antenna signal terminal (as with terminal  84  of  FIG. 8 ). 
     The configuration of  FIG. 10  shows that slot antenna ground terminal  92  and PIFA antenna ground terminal  88  may be formed at separate locations on ground plane  54 - 2 . In the configuration of  FIG. 12 , a single coaxial cable may be used to feed both the PIFA portion of the antenna and the slot portion of the antenna. This is because terminal  115  serves as both a PIFA ground terminal for the PIFA portion of antenna  54  and a slot antenna ground terminal for the slot antenna portion of antenna  54 . Because the ground terminals of the PIFA and slot antennas are provided by a common ground terminal structure and because conductive paths  112 ,  117 , and  104  serve to distribute radio-frequency signals to and from the resonating element  54 - 1  and ground plane  54 - 2  as needed for PIFA and slot antenna operations, a single transmission line (e.g., coaxial conductor  56 ) may be used to send and receive radio-frequency signals that are transmitted and received using both the PIFA and slot portions of antenna  54 . 
     If desired, other antenna configurations may be used that support hybrid PIFA/slot operation. For example, the radio-frequency tuning capabilities of tuning capacitor  114  may be provided by a network of other suitable tuning components, such as one or more inductors, one or more resistors, direct shorting metal strip(s), capacitors, or combinations of such components. One or more tuning networks may also be connected to the antenna at different locations in the antenna structure. These configurations may be used with single-feed and multiple-feed transmission line arrangements. 
     Moreover, the location of the signal terminal and ground terminal in antenna  54  may be different from that shown in  FIG. 12 . For example, terminals  115 / 108  and terminal  106  can be moved relative to the locations shown in  FIG. 12 , provided that the connecting conductors  112 ,  117 , and  104  are suitably modified. 
     The PIFA portion of antenna  54  can be provided using a substantially rectangular conductor as shown in  FIG. 10 , or can be provided using other arrangements. For example, resonating element  54 - 1  may be formed from a non-rectangular planar structure, from a planar structure with a rectangular outline that has one or more serpentine conductive structures within the rectangular outline, or from a slotted non-rectangular or slotted rectangular planar structure. If desired, resonating element  54 - 1  may be provided with a substantially F-shaped conductive element having one or more arms such as arms  98  and  100  of  FIG. 12 . Such resonating element arms may be straight, serpentine, curved, or may have any other suitable shape. Use of different shapes for the arms or other portions of resonating element  54 - 1  helps antenna designers to tailor the frequency response of antenna  54  to its desired frequencies of operation and to otherwise optimize antenna performance. The sizes of the structures in resonating element  54 - 1  can be adjusted as needed (e.g., to increase or decrease gain and/or bandwidth for a particular operating band). Arms of dissimilar sizes (lengths) tend to affect the resonance behavior of antenna  54  at different frequencies and may therefore be advantageous when tuning multiple frequency bands of interest. 
     An illustrative resonating element  54 - 1  in which arm  98  is formed from a folded-over structure and arm  100  is formed from a straight strip of conductor is shown in FIG.  FIG. 13 . This type of arrangement may be advantageous when it is desired to place additional structures in region  118 . 
     In the example of  FIG. 14 , both arm  98  and arm  100  are formed without bends. This type of structure may be used for resonating element  54 - 1  when there is sufficient lateral space for forming arms  98  and  100 . 
     Another illustrative configuration for antenna resonating element  54 - 1  is shown in  FIG. 15 . In the example of  FIG. 15 , arm  98 , which is the shorter of the two arms, is formed without any bends. Arm  100 , which is the longer of the two arms, is formed with a single bend. If desired, arms  98  and  100  may be formed with no bends, with one bend, or with more than one bend. The bends may be 180° bends (e.g., where an arm doubles back on itself), may be 90° bends, or may be bends formed at any other suitable angle to the longitudinal axis of the arm. Arrangements of the type shown in  FIGS. 12 ,  13 , and  15  in which the arms contain bends that reverse the direction of the conductive arm element are shown as examples. 
     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: 20070104
Publication Date: 20130108
Grant Date: 20130108
Priority Date: 20070104
Inventors: HILL ROBERT J.
SCHLUB ROBERT W.
ZAVALA JUAN
CABALLERO RUBEN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/371", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q21/29", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/29", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/371", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/40", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 39493701