PATENT DOCUMENT

Publication Number: US-9379445-B2
Application Number: US-201414180866-A
Country: US
Kind Code: B2

Title: Electronic device with satellite navigation system slot antennas

Abstract:
An electronic device may be provided with a satellite positioning system slot antenna. The slot antenna may include a slot in a metal housing. The slot may be directly fed or indirectly fed. In indirectly fed configurations, the antenna may include a near-field-coupled antenna feed structure that is near-field coupled to the slot. The near-field-coupled antenna feed structure may be formed from a planar metal structure. The planar metal structure may be a metal patch that overlaps the slot and that has a leg that protrudes towards the metal housing. A positive antenna feed terminal may be coupled to the leg and a ground antenna feed terminal may be coupled to the metal housing.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a satellite navigation system receiver; 
 a metal housing in which the satellite navigation system receiver is housed; 
 a slot antenna formed from a slot in the metal housing wherein the slot antenna is an indirectly fed slot antenna having a near-field-coupled antenna feed structure that is near-field coupled to the slot, wherein the antenna feed structure comprises a planar metal structure and a leg that extends from the planar metal structure towards a rear wall of the metal housing; and 
 a transmission line that conveys antenna signals from the slot antenna to the satellite navigation system receiver. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the metal housing forms a ground plane, wherein the slot is formed in the ground plane, and wherein the slot has at least one bend. 
     
     
       3. The electronic device defined in  claim 1  wherein the slot antenna has at least one bend and the slot is an open slot having an open end at an edge of the metal housing. 
     
     
       4. An electronic device, comprising:
 a satellite navigation system receiver; 
 a metal housing in which the satellite navigation system receiver is housed; 
 a slot antenna formed from a slot in the metal housing, wherein the metal housing has a rear housing wall and a sidewall, the slot has first and second segments, the first segment is formed in the rear housing wall, the second segment is formed in the sidewall, and the slot antenna is a directly fed slot antenna having a positive antenna feed terminal coupled to the metal housing on one side of the first segment and having a ground antenna feed terminal coupled to the metal housing on an opposing side of the first segment; and 
 a transmission line that conveys antenna signals from the slot antenna to the satellite navigation system receiver. 
 
     
     
       5. An electronic device, comprising:
 a satellite navigation system receiver; 
 a metal housing in which the satellite navigation system receiver is housed; 
 a slot antenna formed from a slot in the metal housing wherein the metal housing has a rear housing wall and has a sidewall, wherein the slot has a first segment in the rear housing wall, a second segment in the rear housing wall, and a third segment in the sidewall and the slot has a first bend between the first and second segments and has a second bend between the second and third segments; and 
 a transmission line that conveys antenna signals from the slot antenna to the satellite navigation system receiver. 
 
     
     
       6. The electronic device defined in  claim 5  wherein the slot antenna comprises a near-field-coupled antenna feed structure that is near-field coupled to the slot. 
     
     
       7. The electronic device defined in  claim 6  wherein the near-field-coupled antenna feed structure comprises a planar metal structure. 
     
     
       8. The electronic device defined in  claim 7  wherein the planar metal structure overlaps the second segment. 
     
     
       9. The electronic device defined in  claim 7  wherein the near-field-coupled antenna feed structure comprises a leg that extends from the planar metal structure. 
     
     
       10. The electronic device defined in  claim 9  wherein a positive antenna feed terminal is coupled to the leg, a ground antenna feed terminal is coupled to the metal housing, the transmission line has a positive signal line that is coupled to the positive antenna feed terminal, and the transmission line has a ground antenna signal line that is coupled to the ground antenna feed terminal. 
     
     
       11. The electronic device defined in  claim 10  further comprising an additional antenna. 
     
     
       12. An electronic device, comprising:
 a satellite navigation system receiver; 
 a metal housing; and 
 an indirectly fed slot antenna formed from a slot in the metal housing that provides antenna signals to the satellite navigation system receiver, wherein the metal housing has a rear housing wall and a sidewall, the slot has a segment formed in the sidewall that extends from a first edge of the sidewall to an opposing second edge of the sidewall, the slot serves as an antenna resonating element for the indirectly fed slot antenna, and the indirectly fed slot antenna comprises a near-field-coupled antenna feed structure that is near-field coupled to the slot. 
 
     
     
       13. The electronic device defined in  claim 12  wherein the near-field-coupled antenna feed structure comprises a metal patch. 
     
     
       14. The electronic device defined in  claim 13  wherein the metal patch overlaps the slot. 
     
     
       15. The electronic device defined in  claim 14  wherein the slot comprises a closed slot having two closed ends. 
     
     
       16. A satellite navigation system slot antenna configured to receive satellite navigation system signals in an electronic device, comprising:
 a slot antenna resonating element formed from a plastic-filled slot in a metal housing for the electronic device, wherein the metal housing has a rear housing wall and a sidewall, the slot has first and second segments, the first segment is formed in the rear housing wall, and the second segment is formed in the sidewall; and 
 a near-field-coupled antenna feed structure that is near-field coupled to the slot antenna resonating element, wherein the near-field coupled antenna feed structure comprises a metal patch that overlaps the slot.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with antennas. 
     Electronic devices often include antennas. For example, cellular telephones, computers, and other devices often contain antennas for supporting wireless communications. 
     It can be challenging to form electronic device antenna structures with desired attributes. In some wireless devices, the presence of conductive housing structures can influence antenna performance. Antenna performance may not be satisfactory if the housing structures are not configured properly and interfere with antenna operation. Device size can also affect performance. It can be difficult to achieve desired performance levels in a compact device, particularly when the compact device has conductive housing structures. 
     It would therefore be desirable to be able to provide improved wireless circuitry for electronic devices such as electronic devices that include conductive housing structures. 
     SUMMARY 
     An electronic device may be provided with antennas. The antennas may include a satellite navigation system antenna that provides satellite navigation system signals to a satellite navigation system receiver. 
     The satellite navigation system antenna may be a slot antenna. The electronic device may have a housing such as a metal housing. The slot antenna may include a slot antenna resonating element formed from a slot in the metal housing. The slot in the metal housing may be filled with a dielectric such as plastic. 
     The slot may extend across a planar rear housing wall and may extend up a sidewall of the housing. The slot may have no bends or may have one or more bends. The slot may be an open slot having an open end or may be a closed slot that is enclosed and surrounded by portions of the metal housing. 
     The slot may be directly fed or indirectly fed. In directly fed configurations, a positive antenna feed may be coupled to the metal housing on one side of the slot and a ground antenna feed may be coupled to the metal housing on another side of the slot. 
     In indirectly fed configurations, the antenna may include a near-field-coupled antenna feed structure that is near-field coupled to the slot. The near-field-coupled antenna feed structure may be formed from a planar metal structure. The planar metal structure may be a metal patch that overlaps the slot and that has a leg that protrudes towards the metal housing. A positive antenna feed terminal may be coupled to the leg and a ground antenna feed terminal may be coupled to the metal housing. 
     A satellite navigation system slot antenna may be coupled to a satellite navigation system receiver using a transmission line coupled between the antenna feed terminals and the satellite navigation system receiver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a laptop computer in accordance with an embodiment. 
         FIG. 2  is a perspective view of an illustrative electronic device such as a handheld electronic device in accordance with an embodiment. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer in accordance with an embodiment. 
         FIG. 4  is a perspective view of an illustrative electronic device such as a display for a computer or television in accordance with an embodiment. 
         FIG. 5  is a schematic diagram of illustrative circuitry in an electronic device in accordance with an embodiment. 
         FIG. 6  is a schematic diagram of illustrative wireless circuitry in accordance with an embodiment. 
         FIG. 7  is a diagram of an illustrative antenna that is being fed using near-field coupling in accordance with an embodiment. 
         FIG. 8  is a schematic diagram of an illustrative electronic device that includes a satellite navigation system antenna such as a Global Positioning System antenna and that includes additional antennas in accordance with an embodiment. 
         FIG. 9  is a top view of an illustrative ground plane in an electronic device that has been provided with an antenna based on an open-ended slot running parallel to the longer of two lateral dimensions associated with the ground plane in accordance with an embodiment. 
         FIG. 10  is a top view of an illustrative ground plane in an electronic device that has an antenna based on an open-ended slot having at least one bend and having an opening on a short edge of the ground plane in accordance with an embodiment. 
         FIG. 11  is a top view of an illustrative ground plane in an electronic device that has been provided with an antenna based on an open-ended slot having an opening on a long edge of the ground plane in accordance with an embodiment. 
         FIG. 12  is a top view of an illustrative ground plane in an electronic device that has been provided with an antenna based on an open-ended slot having at least one bend and having an opening on a long edge of the ground plane in accordance with an embodiment. 
         FIG. 13  is a top view of an illustrative ground plane in an electronic device that has been provided with an antenna based on a closed slot in accordance with an embodiment. 
         FIG. 14  is a top view of an illustrative slot antenna that is being directly fed in accordance with an embodiment. 
         FIG. 15  is a perspective view of an illustrative indirectly-fed slot antenna in accordance with an embodiment. 
         FIG. 16  is a perspective view of an illustrative interior portion of an electronic device having an electronic device housing slot for forming an indirectly fed slot antenna in accordance with an embodiment. 
         FIG. 17  is a graph of antenna efficiency for an illustrative slot antenna having a slot segment that exits a ground plane horizontally parallel to an X axis in accordance with an embodiment. 
         FIG. 18  is a graph of antenna efficiency for an illustrative slot antenna having a slot segment that exits a ground plane vertically parallel to a Y axis in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with antennas. The antennas may include slot antennas formed in device structures such as electronic device housing structures. Illustrative electronic devices that have housings that accommodate slot antennas are shown in  FIGS. 1, 2, 3 , and  4 . 
     Electronic device  10  of  FIG. 1  has the shape of a laptop computer and has upper housing  12 A and lower housing  12 B with components such as keyboard  16  and touchpad  18 . Device  10  has hinge structures  20  (sometimes referred to as a clutch barrel) to allow upper housing  12 A to rotate in directions  22  about rotational axis  24  relative to lower housing  12 B. Display  14  is mounted in housing  12 A. Upper housing  12 A, which may sometimes referred to as a display housing or lid, is placed in a closed position by rotating upper housing  12 A towards lower housing  12 B about rotational axis  24 . 
       FIG. 2  shows an illustrative configuration for electronic device  10  based on a handheld device such as a cellular telephone, music player, gaming device, navigation unit, or other compact device. In this type of configuration for device  10 , device  10  has opposing front and rear surfaces. The rear surface of device  10  may be formed from a planar portion of housing  12 . Display  14  forms the front surface of device  10 . Display  14  may have an outermost layer that includes openings for components such as button  26  and speaker port  27 . 
     In the example of  FIG. 3 , electronic device  10  is a tablet computer. In electronic device  10  of  FIG. 3 , device  10  has opposing planar front and rear surfaces. The rear surface of device  10  is formed from a planar rear wall portion of housing  12 . Curved or planar sidewalls may run around the periphery of the planar rear wall and may extend vertically upwards. Display  14  is mounted on the front surface of device  10  in housing  12 . As shown in  FIG. 3 , display  14  has an outermost layer with an opening to accommodate button  26 . 
       FIG. 4  shows an illustrative configuration for electronic device  10  in which device  10  is a computer display, a computer that has an integrated computer display, or a television. Display  14  is mounted on a front face of device  10  in housing  12 . With this type of arrangement, housing  12  for device  10  may be mounted on a wall or may have an optional structure such as support stand  30  to support device  10  on a flat surface such as a table top or desk. 
     An electronic device such as electronic device  10  of  FIGS. 1, 2, 3, and 4 , may, in general, be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. The examples of  FIGS. 1, 2, 3, and 4  are merely illustrative. 
     Device  10  may include a display such as display  14 . Display  14  may be mounted in housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass or clear plastic. Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button, an opening may be formed in the display cover layer to accommodate a speaker port, etc. 
     Housing  12  may be formed from conductive materials and/or insulating materials. In configurations in which housing  12  is formed from plastic or other dielectric materials, antenna signals can pass through housing  12 . Antennas in this type of configuration can be mounted behind a portion of housing  12 . In configurations in which housing  12  is formed from a conductive material (e.g., metal), it may be desirable to provide one or more radio-transparent antenna windows in openings in the housing. As an example, a metal housing may have openings that are filled with plastic antenna windows. Antennas may be mounted behind the antenna windows and may transmit and/or receive antenna signals through the antenna windows. 
       FIG. 5  is a schematic diagram showing illustrative components that may be used in device  10 . As shown in  FIG. 5 , device  10  may include control circuitry such as storage and processing circuitry  28  and input-output circuitry  44 . Storage and processing circuitry  28 , which may sometimes be referred to as control circuitry, and input-output circuitry  44  may be housed within housing  12 . 
     Storage and processing circuitry  28  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VOIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment, storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, cellular telephone protocols, MIMO protocols, antenna diversity protocols, etc. 
     Input-output circuitry  44  may include input-output devices  32 . Input-output devices  32  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  32  may include user interface devices, data port devices, and other input-output components. For example, input-output devices may include touch screens, displays without touch sensor capabilities, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, buttons, speakers, status indicators, light sources, audio jacks and other audio port components, digital data port devices, light sensors, motion sensors (accelerometers), capacitance sensors, proximity sensors, etc. 
     Input-output circuitry  44  may include wireless communications circuitry  34  for communicating wirelessly with external equipment. Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, transmission lines, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
     Wireless communications circuitry  34  may include radio-frequency transceiver circuitry  90  for handling various radio-frequency communications bands. For example, circuitry  34  may include transceiver circuitry  36 ,  38 , and  42 . Transceiver circuitry  36  may be wireless local area network transceiver circuitry that may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and that may handle the 2.4 GHz Bluetooth® communications band. Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in frequency ranges such as a low communications band from 700 to 960 MHz, a midband from 1710 to 2170 MHz, and a high band from 2300 to 2700 MHz or other communications bands between 700 MHz and 2700 MHz or other suitable frequencies (as examples). Circuitry  38  may handle voice data and non-voice data. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry  34  may include 60 GHz transceiver circuitry, circuitry for receiving television and radio signals, paging system transceivers, near field communications (NFC) circuitry, etc. Wireless communications circuitry  34  may include satellite navigation system circuitry such as global positioning system (GPS) receiver circuitry  42  for receiving GPS signals at 1575 MHz or for handling other satellite positioning data. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless communications circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable antenna types. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. 
     As shown in  FIG. 6 , transceiver circuitry  90  in wireless circuitry  34  may be coupled to antenna structures  40  using paths such as path  92 . Wireless circuitry  34  may be coupled to control circuitry  28 . Control circuitry  28  may be coupled to input-output devices  32 . Input-output devices  32  may supply output from device  10  and may receive input from sources that are external to device  10 . 
     To provide antenna structures  40  with the ability to cover communications frequencies of interest, antenna structures  40  may be provided with circuitry such as filter circuitry (e.g., one or more passive filters and/or one or more tunable filter circuits). Discrete components such as capacitors, inductors, and resistors may be incorporated into the filter circuitry. Capacitive structures, inductive structures, and resistive structures may also be formed from patterned metal structures (e.g., part of an antenna). If desired, antenna structures  40  may be provided with adjustable circuits such as tunable components  102  to tune antennas over communications bands of interest. Tunable components  102  may include tunable inductors, tunable capacitors, or other tunable components. Tunable components such as these may be based on switches and networks of fixed components, distributed metal structures that produce associated distributed capacitances and inductances, variable solid state devices for producing variable capacitance and inductance values, tunable filters, or other suitable tunable structures. 
     During operation of device  10 , control circuitry  28  may issue control signals on one or more paths such as path  104  that adjust inductance values, capacitance values, or other parameters associated with tunable components  102 , thereby tuning antenna structures  40  to cover desired communications bands. 
     Path  92  may include one or more transmission lines. As an example, signal path  92  of  FIG. 6  may be a transmission line having a positive signal conductor such as line  94  and a ground signal conductor such as line  96 . Lines  94  and  96  may form parts of a coaxial cable or a microstrip transmission line (as examples). A matching network formed from components such as inductors, resistors, and capacitors may be used in matching the impedance of antenna structures  40  to the impedance of transmission line  92 . Matching network components may be provided as discrete components (e.g., surface mount technology components) or may be formed from housing structures, printed circuit board structures, traces on plastic supports, etc. Components such as these may also be used in forming filter circuitry in antenna structures  40 . 
     Transmission lines such as transmission line  92  may be directly coupled to an antenna resonating element and ground for an antenna or may be coupled to near-field-coupled antenna feed structures that are used in indirectly feeding a resonating element for an antenna. As an example, antenna structures  40  may form an inverted-F antenna, a slot antenna, a hybrid inverted-F slot antenna or other antenna having an antenna feed with a positive antenna feed terminal such as terminal  98  and a ground antenna feed terminal such as ground antenna feed terminal  100 . Positive transmission line conductor  94  may be coupled to positive antenna feed terminal  98  and ground transmission line conductor  96  may be coupled to ground antenna feed terminal  100 . As another example, antenna structures  40  may include an antenna resonating element such as a slot antenna resonating element or other element that is indirectly fed using near-field coupling. In a near-field coupling arrangement, transmission line  92  is coupled to a near-field-coupled antenna feed structure that is used to indirectly feed antenna structures such as an antenna slot or other antenna resonating element through near-field electromagnetic coupling. 
       FIG. 9  shows how antenna  40  may be indirectly fed using a near-field coupling arrangement. With this type of arrangement, transceiver  90  is connected to near-field-coupled antenna feed structure  202  by transmission line  92 . Antenna  40  may include a resonating element such as a slot or other antenna resonating element structure (antenna element  400 ). Structure  202  may include a strip of metal, a patch of metal, planar metal members with other shapes, a loop of metal, or other structure that is near-field coupled to antenna resonating element  400  by near-field coupled electromagnetic signals  204 . Structure  202  does not produce significant far-field radiation during operation (i.e., structure  202  does not itself form a far-field antenna but rather serves as a coupled feed for a slot antenna structure or other antenna resonating element structure for antenna  40 ). During operation, the indirect feeding of element  400  by structure  202  allows antenna element  400  and therefore antenna  40  to receive and/or transmit far-field wireless signals  205  (i.e., radio-frequency antenna signals for antenna  40 ). 
     As shown in  FIG. 8 , device  10  may have multiple antennas such as satellite navigation system antenna  40  (e.g., a Global Positioning System antenna) and additional antennas  40 A. Satellite navigation system antenna  40  may be coupled to satellite navigation system receiver  42  in transceiver circuitry  90  using a signal path such as transmission line  92 . Antenna  40  may be used to receive satellite navigation system signals for receiver  42  that are provided to receiver  42  by transmission line  92 . Antenna  40  may, if desired, handle additional wireless traffic such as cellular telephone system signals, wireless local area network signals, and other wireless signals using other transceivers  210  (e.g., cellular telephone transceivers, etc.). Additional antennas  40 A may be coupled to transceiver circuitry  90  by signal paths such as transmission line paths  92 A. There may be no additional antennas  40 A in device  10  (i.e., device  10  may contain only antenna  40 ), there may be one additional antenna  40 A, there may be more than one additional antenna  40 A, there may be two or more additional antennas  40 A, or there may be any other suitable number of antennas  40 A in device  10 . 
     Antennas in device  10  such as antenna  40  and additional antenna(s)  40 A may be based on antenna resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, slot antenna structures, planar inverted-F antenna structures, helical antenna structures, hybrids of these designs, or other suitable antenna designs. With one suitable arrangement, antenna  40  (and, if desired, one or more of antennas  40 A) may be slot antennas. 
     An illustrative slot antenna is shown in  FIG. 9 . As shown in  FIG. 9 , device  10  may have a ground plane formed from housing  12  (e.g., a metal housing). Antenna  40  may be formed from a slot in the ground plane such as slot  400 . Slot  400  may have opposing ends such as ends  402  and  404 . End  402  may be surrounded by portions of housing (ground plane)  12  and may therefore be referred to as the closed end of slot  400 . End  404  may be exposed to the environment (air) surrounding device  10  and may therefore be referred to as the open end of slot  400 . Slots such as slot  400  that have an open end are sometimes referred to as open slots (i.e., antenna  40  of  FIG. 9  is an open slot antenna). Opening  404  may be formed in a sidewall of housing  12  or other portion of housing  12  (e.g., along one of the peripheral edges of housing  12  such as edge  406 ). Antenna  40  may be fed using an indirect feeding arrangement or may be directly fed using an antenna feed formed from feed terminals coupled to housing  12  on opposing sides of slot  400  such as positive antenna feed terminal  98  and ground antenna feed terminal  100 . Slot  400  may be filled with air, plastic, or other dielectric material and may therefore sometimes be referred to as a dielectric-filled slot. 
     In the illustrative configuration of  FIG. 9 , housing  12  has two opposing short sides  406  and  408  and two opposing long sides  410  and  412 . Housing  12  have a longitudinal axis such as longitudinal axis  414  that runs parallel to the longer edges of housing  12  (i.e., parallel to sides  410  and  412  in the example of  FIG. 9 ). In the  FIG. 9  example, antenna slot  400  runs parallel to longitudinal axis  414 . When a user of device  10  holds device  10  in a portrait orientation, edge  406  may point upwards and edge  408  may point downwards (e.g., towards the Earth). Device  10  may also be used in other orientations. Antenna  40  of  FIG. 9  may be indirectly fed or directly fed. For example, antenna  40  may have an antenna feed formed from feed terminals on opposing sides of slot  400  such as positive antenna feed terminal  98  and ground antenna feed terminal  100 . Slot  400  of  FIG. 9  may be filled with air, plastic, or other dielectric material. 
       FIG. 10  shows how antenna slot  400  may have one or more bends such as bend  416 . In the  FIG. 10  example, slot  400  has a first portion such as portion  418  that runs parallel to longitudinal axis  414  and a second portion such as portion  420  that runs perpendicular to longitudinal axis  414 . Open end  404  of slot  400  lies along the upper edge of housing  12 . Antenna  40  of  FIG. 10  may be fed indirectly or may be fed using a direct feed formed from antenna feed terminals such as terminals  98  and  100 . Slot  400  of  FIG. 10  may be filled with air, plastic, or other dielectric material. 
       FIG. 11  shows how antenna slot  400  may extend along a lateral dimension that runs parallel to the shorter edges of housing  12  (i.e., slot  400  may be perpendicular to longitudinal axis  414 ). In the  FIG. 11  example, open end  404  of slot  400  exits housing (ground plane)  12  along right-hand edge  422  of housing  12 . If desired, antenna  40  may be formed from a slot that has open end  404  along opposing left-hand edge  424  of housing  12  or other portion of housing  12 . Slot  400  of  FIG. 11  may be filled with air, plastic, or other dielectric material. Antenna  40  of  FIG. 11  may be fed indirectly or may be fed using a direct feed formed from antenna feed terminals such as terminals  98  and  100  coupled to metal housing  12 . 
     In the illustrative configuration of  FIG. 12 , antenna slot  400  has a bend such as bend  416  between slot segment  418  and slot segment  420 . Slot segment  420  has closed end  402 . Slot segment  418  has open end  404 . Open end  404  exits housing  12  (i.e., the ground plane formed from housing  12 ) along left-hand edge  424 . If desired, open end  404  may exit housing  12  along right-hand edge  222  of housing  12  or elsewhere in housing  12 . In the example of  FIG. 12 , segment  418  runs perpendicular to longitudinal device axis  414  of housing  12  and segment  420  runs parallel to longitudinal axis  414 , but other orientations for segments  418  and segment  420  may be used, if desired. Antenna  40  of  FIG. 12  may be indirectly fed or directly fed (e.g., slot  400  may be fed using antenna feed terminals  98  and  100 ). Slot  400  of  FIG. 12  may be filled with air, plastic, or other dielectric material. 
     If desired, slot antenna  40  in device  10  may be formed from a closed slot (i.e., a slot having two opposing closed ends). This type of configuration is shown in  FIG. 13 . Slot antenna  40  has a closed slot such as slot  400  with opposing ends  426  and  428 . Slot  400  is a closed slot because both ends of slot  400  are surrounded by conductive portions of metal housing (ground)  12  (i.e., ends  426  and  428  are both closed). Antenna slot  400  may run parallel to longitudinal axis  414  (as shown in the example of  FIG. 13 ), may run across housing  12  perpendicular to axis  414 , may have one or more bends such as bend  416  of  FIG. 12 , or may have other configurations. Slot  400  may contain air, plastic, or other dielectric material. An indirect feeding configuration may be used for slot  400  or slot  400  may be fed directly using antenna feed terminals  98  and  100 . 
       FIG. 14  shows how a slot antenna may be directly fed using antenna terminals  98  and  100 . Terminals  98  and  100  may be connected to housing  12  (e.g., the ground plane) on opposing sides of slot  400 . Slot  400  may have segments such as segment  420  and segment  418  that are separate by one or more bends such as bend  416  or may have other shapes. Slot  400  may be an open slot having an open end such as end  404  that exits housing  12  along one of its edges or may be a closed slot of the type shown in  FIG. 13 . 
     In a direct feeding arrangement, radio-frequency transceiver circuitry such as satellite navigation system receiver  42  (e.g., a Global Positioning System receiver or a receiver in another type of satellite navigation system) and/or other transceiver circuitry  90  (e.g., cellular telephone transceiver circuitry  38  and/or wireless local area network transceiver circuitry  36 ) may be coupled to feed terminals  98  and  100  using transmission line path  92 . Transmission line  92  may include positive signal line  94  and ground signal line  96 . Positive signal line  94  may be coupled to positive antenna feed terminal  98 . Ground signal line  96  may be coupled to ground antenna feed terminal  98 . During operation, receiver  42  (or other transceiver circuitry  90 ) may use antenna  40  to receive wireless signals such as satellite navigation system signals. 
     In the illustrative configuration of  FIG. 14 , antenna slot  400  is an open slot having an open end such as end  404  and an opposing closed end  402 . Open end  404  is formed along the upper edge of housing  12 . If desired, open end  404  may be formed on a different edge of housing  12 . In the example of  FIG. 14 , segment  418  extends parallel to longitudinal axis  414  and segment  420  of slot  400  extends perpendicular to longitudinal axis  414 , but segments  418  and  420  may have other orientations and/or slot  400  may be provided with no bends or two or more bends, if desired. Slot  400  may be filled with air, plastic, or other dielectric. 
     Terminals  98  and  100  may be connected to housing  12  using solder, using welds, using conductive adhesive, using an intermediate coupling structure such as a printed circuit with metal traces, or using other coupling techniques. If desired, circuitry such as filter circuitry, switching circuitry, and impedance matching circuitry may be interposed in path  92  between receiver  42  and antenna  40 . 
     Antenna  40  may be implemented using an indirect antenna feeding scheme. This type of approach is shown in  FIG. 15 . As shown in  FIG. 15 , antenna  40  has slot antenna resonating element  400  formed from a slot in metal housing (ground plane)  12  of device  10 . Slot  400  in the example of  FIG. 15  has segments  420  and  418  that are separated by bend  416  (i.e., bend  416  is located between segments  420  and  418 ). Segment  418  has open slot end  404  and segment  420  has opposing closed slot end  402 . If desired, slot  400  may be a closed slot or an open slot with a different configuration. Air, plastic, or other dielectric may fill slot  400 . 
     Radio-frequency transceiver circuitry such as satellite navigation system receiver  42  (e.g., a Global Positioning System receiver or other satellite navigation system receiver) and/or other transceiver circuitry  90  (e.g., cellular telephone transceiver circuitry  38  and/or wireless local area network transceiver circuitry  36 ) may be coupled to terminals  98  and  100  using transmission line path  92 . Transmission line path  92  may have a positive signal line coupled to terminal  98  and may have a ground signal line coupled to ground terminal  100 . 
     In the indirect feeding arrangement of  FIG. 15 , terminals  98  and  100  are used to couple transceiver  42  (e.g., a GPS receiver) to near-field-coupled antenna feed structure  202 . Near-field-coupled antenna feed structure  202 , in turn, is near-field coupled to antenna slot  400  by near-field electromagnetic signals  204  ( FIG. 7 ). During operation, antenna signals (signals  205  of  FIG. 7 ) such as satellite navigation system signals from satellites in orbit around the Earth are received by slot antenna resonating element  400 . Due to the coupling of slot  400  and structure  202 , the received antenna signals are provided to receiver  42  via slot  400 , structure  202 , and transmission line path  92 . 
     In the illustrative configuration of  FIG. 15 , near-field-coupled antenna feed structure  202  is formed from a planar piece of metal such as metal patch  430 . The planar metal of patch  430  may lie in a plane that is parallel to the plane of the rear wall of housing  12 . Patch  430  may overlap slot  400  (e.g., patch  430  may overlap segment  420 ). Leg  432  of near-field-coupled antenna feed structure  202  extends downward towards housing  12  from patch  430  along the vertical Z axis of  FIG. 15 . Positive terminal  98  is connected to tip  434  of leg  432 . Ground terminal  100  is coupled to housing  12  below terminal  98 . A distance D separates terminal  98  and terminal  100  (in the  FIG. 15  example). 
     Patch  430  of near-field-coupled antenna feed structure  202  is separated from ground plane  12  by height H and is characterized by lateral dimensions W 1  and W 2 . The size, shape, and location of patch  430  may be adjusted to optimize antenna performance for antenna  40  (e.g., to enhance coupling between structures  202  and slot  400 , to enhance isolation between antenna  40  and other structures in device  10 , to adjust the directionality of antenna  40 , etc.). 
     In a configuration in which slot antenna  40  is directly fed, electric field intensity in slot antenna  40  may tend to be concentrated, leading to increased antenna directionality. Increased directionality may be desirable in situations in which the orientation of device  10  relative to the satellite navigation system satellites orbiting the earth is known. For example, it may be desirable for antenna  40  to exhibit some directionality in devices that are typically held in a particular portrait orientation during use of satellite navigation system functions. 
     Reduced directionality (i.e., omnidirectional operation or nearly omnidirectional operation) may be desirable in situations in which device  10  is typically used in a number of different orientations. The omnidirectional behavior of antenna  40  may be enhanced (i.e., directionality may be minimized) by using an indirect feeding arrangement for antenna  40 . The ability to independently adjust parameters such as patch size (e.g., dimension W 1  and/or dimension W 2 ), patch location along slot  400 , patch height H, etc. allows characteristics such as capacitance and near-field coupling to be adjusted. By adjusting these attributes of structure  202 , antenna performance can be adjusted. For example, antenna signal phase can be adjusted to reduce coupling between antenna  40  and adjacent additional antennas such as additional antennas  40 A of  FIG. 8 . 
     If desired, slot antenna  40  (e.g., slot antennas of the types shown in  FIGS. 9, 10, 11, 12, 13, 14, and 15 ) may have slots that extend up curved or flat vertical housing sidewalls. As shown in  FIG. 16 , housing  12  may have a planar rear housing wall such as planar rear wall  12 - 1 . The housing surface formed from wall  12 - 1  may lie in the X-Y plane of  FIG. 16 . Housing sidewalls such as top sidewall  12 - 2  may extend vertically upwards (in direction Z) from rear wall  12 - 1 . For example, in a rectangular device with a rectangular housing, housing  12  may have four sidewalls that run around the rectangular periphery of housing  12 . Housings with other shapes may have sidewalls in other configurations. 
     Sidewall  12 - 2  may be formed at the upper end of device  10 , may be formed at the opposing lower end of device  10 , or may run along the left or right side of device  10 . Sidewalls such sidewall  12 - 2  may be flat or may be curved. 
     Slot  400  may have a portion that is formed in housing sidewall  12 - 2 . As shown in  FIG. 16 , slot  400  (e.g., a slot filled with plastic or other solid dielectric material) may have a first segment such as segment  420  that runs perpendicular to axis  414  across the planar rear surface of housing  12 , a second segment such as segment  418  that runs parallel to axis  414  across the planar rear surface of housing  12  towards upper sidewall  12 - 1 , and a third segment such as segment  440 . Segment  440  may extend upwards in dimension Z across sidewall  12 - 2 . 
     Slot  400  may be indirectly fed using near-field-coupled antenna feed structure  202 . Slot  400  may have a closed end such as closed end  438  and an opposing open end such as open end  436 . End  436  may exit sidewall  12 - 2  along housing sidewall edge  442 . Horizontal bend  416  is located between segments  420  and  418 . Vertical bend  442  is located between segments  418  and  440 . 
     The use of a slot resonating element for antenna  40  may impart directionality to antenna  40 . Antenna  40  may therefore operate more efficiently in some directions than in others. When, for example, the slot of antenna  40  exits an edge of a rectangular ground plane such as housing  12 , electric field intensity may peak along the portion of the slot exiting the ground plane and may enhance antenna efficiency for directions running parallel to the slot (i.e., antenna efficiency in this type of arrangement may be greatest in the direction of the slot at its exit from ground plane  12 ). 
     Some electronic devices are frequently used in particular orientations. For example, a user of a handheld electronic device with a longitudinal axis such as axis  414  of  FIG. 10  may tend to operate the device in an upright portrait orientation in which axis  414  is pointed upwards towards GPS satellites (i.e., away from the Earth). Antennas for this type of electronic device that contain vertical segments of slot  400  (see, e.g., slot segment  418  of  FIG. 10 ) can therefore exhibit good efficiency. 
       FIG. 17  is a graph in which antenna efficiency has been plotted as a function of antenna operating direction for an antenna of the type shown in  FIG. 11  in which antenna slot  400  exits ground plane  12  perpendicular to longitudinal axis  414  of device  10 . The Y-axis of  FIG. 17  is aligned with longitudinal axis  414 . Curve  500  represents antenna efficiency for all different possible directions in the X-Y plane (i.e., the plane containing ground plane  12  of  FIG. 11 ). The larger the distance between the origin of the graph of  FIG. 11  and curve  500 , the greater the efficiency of the antenna. The efficiency plot of  FIG. 17  is rotationally symmetric about the Y-axis of  FIG. 11 . As shown in the graph of  FIG. 17 , antenna efficiency is greatest in directions that are roughly orientated along axis X and are lower in directions along axis Y. 
       FIG. 18 , in contrast, is a graph in which antenna efficiency has been plotted for an antenna of the type shown in  FIG. 9  or of the type shown in  FIG. 10  in which the portion of slot  400  that is exiting ground plane  12  (i.e., slot segment  418 ) is oriented along the Y-axis of device  10  (i.e., along longitudinal axis  414 ). Antenna efficiency plot  502  of  FIG. 18  is rotationally symmetric about the X axis of  FIG. 18 . In a usage scenario in which device  10  is held in an upright portrait orientation, axis Y of device  10  (i.e., longitudinal axis  414  of  FIGS. 9 and 10 ) will point upwards towards the GPS satellites orbiting the earth and the efficiency of device  10  in gathering GPS signals will be enhanced. 
     Other types of antennas with vertically extending slot portions at the exit of ground plane  12  may perform similarly. For example, slot  400  of  FIG. 9  may give rise to enhanced antenna efficiency along axis  414  because slot  400  exits ground plane  12  parallel to longitudinal axis  414 . And, as another example, slot segment  418  of slot  400  of  FIG. 12  may give rise to reduced antenna efficiency along axis  414  because slot segment  418  exits ground plane  12  perpendicular to axis  414 . Antennas of the type shown in  FIGS. 9 and 10  will also exhibit satisfactory operation when device  10  is in other orientations (e.g., landscape modes such as a home-button-left mode or home-button-right mode, an orientation in which the flat display surface of device  10  is facing upwards towards earth-orbiting satellites in a satellite navigation system, etc.). 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20140214
Publication Date: 20160628
Grant Date: 20160628
Priority Date: 20140214
Inventors: ZHU JIANG
RAJAGOPALAN HARISH
GOMEZ ANGULO RODNEY A.
LI QINGXIANG
SCHLUB ROBERT W.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/2266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R2201/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/2266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R2201/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 53798946