PATENT DOCUMENT

Publication Number: US-9761927-B2
Application Number: US-201514848034-A
Country: US
Kind Code: B2

Title: Battery case with supplemental antenna features for cellular telephone

Abstract:
A removable case may receive an electronic device. A male connector in the case may mate with a female connector in the device. A battery in the case may supply power to the device through the male connector. The electronic device may have an antenna. The case may have a supplemental antenna that compensates for variations in performance in the antenna when the device is received within the case. The supplemental antenna may be a parasitic antenna resonating element that is formed from metal traces on a flexible printed circuit. The flexible printed circuit, a metal trim structure, and a plastic support structure may form portions of a connector support structure in the case.

Claims:
What is claimed is: 
     
       1. A removable electronic device case that is configured to mate with an electronic device that has an antenna and a connector port, comprising:
 a body; 
 a chin structure mounted at an end of the body, wherein the body and chin structure are configured to receive the electronic device; 
 a connector that is supported by the chin structure and that mates with the connector port; and 
 a supplemental antenna element mounted on a printed circuit in the chin structure. 
 
     
     
       2. The removable electronic device case defined in  claim 1  wherein the chin structure comprises an assembly that includes the connector and the printed circuit. 
     
     
       3. The removable electronic device case defined in  claim 2  wherein the chin structure comprises a plastic structure to which the assembly is attached. 
     
     
       4. The removable electronic device case defined in  claim 3  wherein the plastic structure has an opening through which the connector passes. 
     
     
       5. The removable electronic device case defined in  claim 4  further comprising at least one fastener that attaches the assembly to the plastic structure. 
     
     
       6. The removable electronic device case defined in  claim 5  wherein the printed circuit comprises a metal trace that forms the supplemental antenna element, wherein the fastener comprises a screw, and wherein the metal trace is electrically coupled to the screw. 
     
     
       7. The removable electronic device case defined in  claim 6  wherein the assembly comprises a metal trim member that is electrically coupled to the screw. 
     
     
       8. The removable electronic device case defined in  claim 6  wherein the connector in the assembly has a signal path that is electrically coupled to the screw. 
     
     
       9. The removable electronic device case defined in  claim 6  wherein the printed circuit comprises a flexible printed circuit with a protruding portion having a hole. 
     
     
       10. The removable electronic device case defined in  claim 9  wherein the screw passes through the hole and is coupled to a portion of the metal trace on the protruding portion. 
     
     
       11. The removable electronic device case defined in  claim 6  wherein the plastic structure has an audio jack opening that is aligned with an audio jack in the electronic device when the electronic device is received with electronic device case. 
     
     
       12. The removable electronic device case defined in  claim 1  further comprising a tunable circuit that tunes the supplemental antenna element. 
     
     
       13. The removable electronic device case defined in  claim 12  wherein the connector comprises a metal tongue member that is supported by the chin structure and contacts supported by the metal tongue member, wherein the metal tongue member has a recessed portion that is located between the contacts and the chin structure and that is filled with dielectric to reduce capacitive coupling between the connector and the electronic device. 
     
     
       14. A removable electronic device case that is configured to mate with an electronic device that has an antenna and a connector port, comprising:
 a body that has first and second ends; 
 a connector support structure at the first end that is configured to receive an end of the electronic device; 
 a male connector that is supported by the connector support structure and that is configured to mate with the connector port of the electronic device when the end of the electronic device is received within the connector support structure; 
 a battery mounted in the body that supplies power to the electronic device via the male connector; and 
 a flexible printed circuit coupled to the connector support structure, wherein the flexible printed circuit includes metal traces that form a parasitic antenna element for the antenna that helps compensate for variations in performance of the antenna when the end of the electronic device is received within the connector support structure. 
 
     
     
       15. The removable electronic device case defined in  claim 14  further comprising tunable circuitry coupled to the parasitic antenna element that tunes the parasitic antenna element. 
     
     
       16. The removable electronic device case defined in  claim 15  wherein the connector support structure includes a plastic structure and a metal trim structure coupled to the plastic structure. 
     
     
       17. The removable electronic device case defined in  claim 16  wherein the plastic structure comprises an opening through which the male connector passes. 
     
     
       18. The removable electronic device case defined in  claim 17  wherein the flexible printed circuit has a bent tab portion that is coupled to the metal trim structure. 
     
     
       19. The removable electronic device case defined in  claim 18  wherein the bent tab portion has an opening, wherein the removable electronic device case further comprises a screw that passes through the opening, and wherein the metal trim structure has an opening through which the screw passes. 
     
     
       20. A removable electronic device case that is configured to mate with an electronic device that has an antenna and a connector port, comprising:
 a body having first and second ends; 
 a connector support structure at the first end that is configured to receive an end of the electronic device, wherein the connector support structure has a plastic structure with an opening and has a metal trim structure with an opening; 
 a male connector that is supported by the connector support structure, that passes through the opening in the plastic structure, and that is configured to mate with the connector port of the electronic device when the end of the electronic device is received within the connector support structure; 
 a female connector coupled to the male connector; 
 a battery mounted in the body that supplies power to the electronic device via the male connector; 
 a flexible printed circuit coupled to the connector support structure, wherein the flexible printed circuit forms a parasitic antenna element that helps compensate for variations in performance of the antenna when the end of the electronic device is received within the connector support structure and wherein the flexible printed circuit includes an opening; and 
 a fastener that passes through the opening in the flexible printed circuit and that passes through the opening in the metal trim structure.

Description:
BACKGROUND 
     This relates generally to removable cases for electronic devices and, more particularly, to removable cases for wireless electronic devices. 
     Electronic devices often include wireless circuitry. For example, cellular telephones, computers, and other devices often contain antennas for supporting wireless communications with external equipment. Removable cases are sometimes used with electronic devices. Some cases are passive plastic sleeves that help protect the outer surface of an electronic device from scratches. Other cases contain supplemental batteries. When a case with a supplemental battery is attached to an electronic device, a user can perform more functions without running out of battery power. 
     It can be challenging to ensure that an electronic device antenna operates properly in the presence of an external case. The materials of the case may affect antenna operation. For example, metal structures associated with a battery of other components may interfere with the normal operation of an electronic device antenna and dielectric materials may load an antenna. If care is not taken, wireless performance for an electronic device may be degraded in the presence of a removable case or undesired amounts of radiated spurious emissions may arise. 
     It would therefore be desirable to be able to provide improved removable cases for electronic devices such as electronic devices with antennas. 
     SUMMARY 
     A removable case for an electronic device such as a cellular telephone may have a body. A male connector in the case may mate with a female connector in the electronic device. The male connector may be supported by a connector support structure located at one of the ends of the body. The connector support structure and the body may be configured to receive the electronic device. 
     A battery in the case may supply power to the electronic device through the male connector. The battery power supplied to the device through the male connector may supplement internal battery power in the electronic device. 
     The electronic device may have an antenna. Due to the presence of external structures such as portions of the case, there is a potential for the antenna of the electronic device to become detuned when the electronic device is received within the body of the case. A supplemental antenna in the case may be used to restore antenna performance to the electronic device, so that the electronic device antenna performs satisfactorily, even when the electronic device is received within the body of the case. The supplemental antenna and other features in the case may be configured to help reduce or eliminate radiated spurious emissions. 
     The supplemental antenna may be formed from an antenna resonating element on a flexible printed circuit that is coupled to the connector support structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device and a mating removable case in accordance with an embodiment. 
         FIG. 2  is a cross-sectional side view of an illustrative electronic device and a mating case with a supplemental antenna in accordance with an embodiment. 
         FIG. 3  is a top view of an illustrative electronic device and a mating case with a supplemental antenna in accordance with an embodiment. 
         FIG. 4  is a schematic diagram of an illustrative electronic device antenna and a supplemental antenna element in a case in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative electronic device into which a plug from a mating case has been inserted in accordance with an embodiment. 
         FIG. 6  is an exploded perspective view of components in an illustrative case in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with removable external cases. The removable external cases may contain supplemental components. For example, a removable electronic device case may include a supplemental battery to extend battery life. An illustrative electronic device and a mating removable case are shown in the exploded perspective view of  FIG. 1 . As shown in  FIG. 1 , electronic device  10  may have a rectangular shape and case  200  may have a body such as body  202  with a corresponding rectangular recess. Rectangular recess  240  of body  202  may be configured to receive a rectangular device such as electronic device  10  of  FIG. 1 . Electronic devices and cases of other shapes may be used, if desired. For example, a case may have a folding cover, may have the shape of a sleeve that slides over an electronic device, may be mounted to only one end of an electronic device, or may have other suitable shapes. The example of  FIG. 1  is merely illustrative. 
     Device  10  may include one or more antennas such as loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. Conductive structures for the antennas may, if desired, be formed from conductive electronic device structures. The conductive electronic device structures may include conductive housing structures and internal structures (e.g., brackets, metal members that are formed using techniques such as stamping, machining, laser cutting, etc.), and other conductive electronic device structures. The housing structures may include peripheral structures such as peripheral conductive structures that run around the periphery of an electronic device. The peripheral conductive structure may serve as a bezel for a planar structure such as a display, may serve as sidewall structures for a device housing, may have portions that extend upwards from an integral planar rear housing (e.g., to form vertical planar sidewalls or curved sidewalls), and/or may form other housing structures. Gaps may be formed in the peripheral conductive structures that divide the peripheral conductive structures into peripheral segments. One or more of the segments may be used in forming one or more antennas for electronic device  10 . Antennas may also be formed using an antenna ground plane formed from conductive housing structures such as metal housing midplate structures and other internal device structures. Rear housing wall structures may be used in forming antenna structures such as an antenna ground. 
     Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a wristwatch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, an electronic stylus, or other small portable device. Device  10  may also be a television, a set-top box, a desktop computer, a computer monitor into which a computer has been integrated, or other suitable electronic equipment. 
     Device  10  may include a housing such as housing  12 . Housing  12  may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     The rear face of housing  12  may have a planar housing wall. The rear housing wall may be formed from metal with one or more regions that are filled with plastic or other dielectric. Portions of the rear housing wall that are separated by dielectric in this way may be coupled together using conductive structures (e.g., internal conductive structures) and/or may be electrically isolated from each other. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be mounted on the opposing front face of device  10  from the rear housing wall. Display  14  may be a touch screen that incorporates capacitive touch electrodes or may be insensitive to touch. 
     Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. A display cover layer such as a layer of clear glass or plastic, a layer of sapphire, a transparent dielectric such as clear ceramic, fused silica, transparent crystalline material, or other materials or combinations of these materials may cover the surface of display  14 . Buttons such as button  24  may pass through openings in the cover layer. The cover layer may also have other openings such as an opening for speaker port  26 . 
     Housing  12  may include peripheral housing structures such as structures  16 . Structures  16  may run around the periphery of device  10  and display  14 . In configurations in which device  10  and display  14  have a rectangular shape with four edges, structures  16  may be implemented using peripheral housing structures that have a rectangular ring shape with four corresponding edges (as an example). Peripheral structures  16  or part of peripheral structures  16  may serve as a bezel for display  14  (e.g., a cosmetic trim that surrounds all four sides of display  14  and/or that helps hold display  14  to device  10 ). Peripheral structures  16  may also, if desired, form sidewall structures for device  10  (e.g., by forming a metal band with vertical sidewalls, by forming curved sidewalls that extend upwards as integral portions of a rear housing wall, etc.). 
     Peripheral housing structures  16  may be formed of a conductive material such as metal and may therefore sometimes be referred to as peripheral conductive housing structures, conductive housing structures, peripheral metal structures, or a peripheral conductive housing member (as examples). Peripheral housing structures  16  may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, or more than two separate structures may be used in forming peripheral housing structures  16 . 
     If desired, housing  12  may have a conductive rear surface. For example, housing  12  may be formed from a metal such as stainless steel or aluminum. The rear surface of housing  12  may lie in a plane that is parallel to display  14 . In configurations for device  10  in which the rear surface of housing  12  is formed from metal, it may be desirable to form parts of peripheral conductive housing structures  16  as integral portions of the housing structures forming the rear surface of housing  12 . For example, a rear housing wall of device  10  may be formed from a planar metal structure and portions of peripheral housing structures  16  on the sides of housing  12  may be formed as vertically extending integral metal portions of the planar metal structure. Housing structures such as these may, if desired, be machined from a block of metal and/or may include multiple metal pieces that are assembled together to form housing  12 . The planar rear wall of housing  12  may have one or more, two or more, or three or more portions. 
     Display  14  may include conductive structures such as an array of capacitive electrodes, conductive lines for addressing pixel elements, driver circuits, etc. Housing  12  may include internal structures such as metal frame members, a planar housing member (sometimes referred to as a midplate) that spans the walls of housing  12  (i.e., a substantially rectangular sheet formed from one or more parts that is welded or otherwise connected between opposing sides of member  16 ), printed circuit boards, and other internal conductive structures. These conductive structures, which may be used in forming a ground plane in device  10 , may be located in the center of housing  12  under active area AA of display  14  (e.g., the portion of display  14  that contains a display module for displaying images). 
     In regions such as regions  22  and  20 , openings may be formed within the conductive structures of device  10  (e.g., between peripheral conductive housing structures  16  and opposing conductive ground structures such as conductive housing midplate or rear housing wall structures, a printed circuit board, and conductive electrical components in display  14  and device  10 ). These openings, which may sometimes be referred to as gaps, may be filled with air and/or solid dielectrics such as plastic, glass, ceramic, polymers with fiber filler material (e.g., fiber composites), sapphire, etc. 
     Conductive housing structures and other conductive structures in device  10  such as a midplate, traces on a printed circuit board, display  14 , and conductive electronic components may serve as a ground plane for the antennas in device  10 . The openings in regions  20  and  22  may serve as slots in open or closed slot antennas, may serve as a central dielectric region that is surrounded by a conductive path of materials in a loop antenna, may serve as a space that separates an antenna resonating element such as a strip antenna resonating element or an inverted-F antenna resonating element from the ground plane, may contribute to the performance of a parasitic antenna resonating element, or may otherwise serve as part of antenna structures formed in regions  20  and  22 . If desired, the ground plane that is under active area AA of display  14  and/or other metal structures in device  10  may have portions that extend into parts of the ends of device  10  (e.g., the ground may extend towards the dielectric-filled openings in regions  20  and  22 ). 
     In general, device  10  may include any suitable number of antennas (e.g., one or more, two or more, three or more, four or more, etc.). The antennas in device  10  may be located at opposing first and second ends of an elongated device housing (e.g., at ends  20  and  22  of device  10  of  FIG. 1 ), along one or more edges of a device housing, in the center of a device housing, in other suitable locations, or in one or more of these locations. The arrangement of  FIG. 1  is merely illustrative. 
     Portions of peripheral housing structures  16  may be provided with gap structures. For example, peripheral housing structures  16  may be provided with one or more peripheral gaps such as gaps  18 , as shown in  FIG. 1 . The gaps in peripheral housing structures  16  may be filled with dielectric such as polymer, ceramic, glass, air, other dielectric materials, or combinations of these materials. Gaps  18  may divide peripheral housing structures  16  into one or more peripheral conductive segments. There may be, for example, two peripheral conductive segments in peripheral housing structures  16  (e.g., in an arrangement with two gaps), three peripheral conductive segments (e.g., in an arrangement with three gaps), four peripheral conductive segments (e.g., in an arrangement with four gaps, etc.). The segments of peripheral conductive housing structures  16  that are formed in this way may form parts of antennas in device  10  (e.g., a resonating element arm in an inverted-F antenna and/or part of the periphery of a slot antenna, etc.). If desired, gaps may extend across the width of the rear wall of housing  12  and may penetrate through the rear wall of housing  12  to divide the rear wall into different portions. Polymer or other dielectric may fill these housing gaps (grooves). 
     In a typical scenario, device  10  may have upper and lower antennas (as an example). An upper antenna may, for example, be formed at the upper end of device  10  in region  22 . A lower antenna may, for example, be formed at the lower end of device  10  in region  20 . The antennas may be used separately to cover identical communications bands, overlapping communications bands, or separate communications bands. The antennas may be used to implement an antenna diversity scheme or a multiple-input-multiple-output (MIMO) antenna scheme. 
     Antennas in device  10  may be used to support any communications bands of interest. For example, device  10  may include antenna structures for supporting local area network communications, voice and data cellular telephone communications, global positioning system (GPS) communications or other satellite navigation system communications, Bluetooth® communications, etc. 
     Case  200  may have a body such as body  202 . Body  202  may be formed from plastic and/or other materials. For example, body  202  of case  200  may be formed from injection molded plastic. Other insulating and/or conductive materials may be used in forming body structures such as body  202  if desired. Rectangular recess  240  may be shaped to receive electronic device  10 . If desired, other shapes may be formed in body  202  to receive device  10 . The configuration of  FIG. 1  is illustrative. 
     A battery and other components may be mounted within body  202  of case  200 . Device  10  may have a connector port with a connector such as female connector  130 . Connector  130  may have signal pins and power pins (sometimes referred to as contacts, signal paths, or signal lines). For example, connector  130  may have 5-20 contacts, 16 contacts, 8 contacts, more than 3 contacts, or fewer than 32 contacts. Case  200  may have a mating connector such as male connector  204 . When device  10  is mounted in case  200 , connector  204  and connector  130  may be coupled to each other (i.e., the contacts of connector  204  may mate with corresponding contacts in connector  130 ). The battery in case  200  may supply supplemental power to device  10  by routing power signals to the circuitry of device  10  through power pins in connectors  204  and  130 . 
     Connector  204  may be coupled to female connector  206 . When it is desired to use an accessory or other external equipment with device  10 , an external plug (e.g., a plug on the end of an accessory cable or a plug in a dock) may be inserted into connector  206 . Internal wiring in case  200  may route signals from contacts in the plug coupled to connector  206  to corresponding contacts in connector  204 . Because connector  204  is coupled to connector  130 , this routes the signals from the accessory or other external equipment to device  10  (i.e., plugs  204  and  206  serve as a port replicator). 
     A cross-sectional side view of device  10  and case  200  is shown in  FIG. 2 . In the illustrative configuration of  FIG. 2 , device  10  is shown in a configuration in which housing  12  of device  10  has been partly inserted into recess  240  of body  202  of case  200 . In this configuration, connector  204  of case  200  is positioned for insertion into connector  130 . Device  10  may be powered by an internal power source such as a battery. External power may also be supplied to device  10  through connector  130 . For example, power may be received from battery  210  in case  200  via path  212  and connector  204  when device  10  has been mounted in case  200  so that connector  204  mates with connector  130 . 
     Connector  204  and other circuitry in case  200  may be mounted in a connector support structure (sometimes referred to as a chin structure) such as structure  220  at the end of case body  202 . Chin structure  220  may include a hollow plastic structure that receives the end of housing  12  of device  10 . A structure such as flexible printed circuit  222  or other structure may be included on the lower portion of chin structure  220 . Flexible printed circuit  222  may include a metal trace that forms a supplemental antenna element. 
     The supplemental antenna element may be coupled to the antenna in device  10  via near-field coupling and/or by coupling portions of the antenna in device  10  (e.g., an antenna ground) to portion of the supplemental antenna element (e.g., via a signal path in connectors  204  and  130 , etc.). 
     In the absence of the supplemental antenna element, there may be a risk that an antenna in device  10  (e.g., an antenna at lower end  20  of device  10 ) may be detuned when device  10  is installed in body  202  of case  200 . The supplemental antenna element may be coupled to the antenna of device  10  (e.g., through a signal path in connectors  130  and  204  or other suitable path and/or via near-field electromagnetic coupling) and may be used to restore a desired level of antenna performance and reduce or eliminate radiated spurious emissions when device  10  is installed in case  200 . If desired, the supplemental antenna element may include tunable circuitry that can be adjusted using control circuitry in case  200  and/or control circuitry in device  10 . 
       FIG. 3  is a top view of a portion of case  200  and device  10  at lower end  20  of device  10 . As shown in  FIG. 3 , device  10  may include radio-frequency transceiver circuitry  90  for handling various radio-frequency communications bands. For example, circuitry  90  may include transceiver circuitry that handles 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band, cellular telephone transceiver circuitry 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), and/or circuitry for handling wireless communications at other frequencies. 
     Radio-frequency transceiver circuitry  90  may be coupled to antenna  40  using a signal path such as transmission line  92 . Antenna  40  may be formed using any suitable antenna type. For example, antenna  40  may include one or more 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, antenna  40  may include antenna structures for one type of antenna for forming a local wireless link antenna such as a wireless local area network link and may include antenna structures for another type of antenna for forming a remote wireless link antenna (e.g., a cellular telephone antenna). 
     Case  200  may have a supplemental antenna structure such as supplemental antenna element  222 . Element  222  may help ensure that device  10  operates properly, even in the presence of the structures of case  200 . 
     Transmission line  92  may include positive signal line (path)  94  and ground signal line (path)  96 . Transmission line  92  may be coupled to an antenna feed for antenna  40  that is formed from positive antenna feed terminal  98  and ground antenna feed terminal  100 . Positive signal line  94  may be coupled to positive antenna feed terminal  98  and ground signal line  96  may be coupled to ground antenna feed terminal  100 . If desired, impedance matching circuitry, switching circuitry, filter circuitry, and other circuits may be interposed in the path between transceiver circuitry  90  and antenna  40 . 
       FIG. 4  shows an illustrative antenna for device  10  and an illustrative associated supplemental antenna element for case  200 . In the example of  FIG. 4 , antenna  40  is an inverted-F antenna. This is merely illustrative. Antenna  40  may be an inverted-F antenna, a slot antenna, an antenna that includes slot and inverted-F structures, etc. 
     As shown in  FIG. 4 , antenna  40  may include inverted-F antenna resonating element  108  and antenna ground  104 . Ground  104  may be formed from metal portions of housing  12  (e.g., portions of the rear wall of housing  12 , a housing midplate, etc.), conductive structures such as display components and other electrical components, ground traces in printed circuits, etc. For example, ground  104  may include portions that are formed from metal housing walls, a metal band or bezel, or other peripheral conductive housing structures. 
     Antenna resonating element  108  may be formed from peripheral conductive housing structure in device  10  (e.g., a segment of structures  16  of  FIG. 1 ) or other conductive structures. Structure  108  may form a main resonating element arm for the inverted-F antenna resonating element and may have one or more branches (e.g., branches that are terminated at gaps  18  at the ends of a segment of structures  16 , etc.). 
     Dielectric  114  may form a gap that separates structure  108  from ground  104 . The shape of the dielectric gap associated with dielectric  114  may form a slot antenna resonating element (i.e., the conductive structures surrounding dielectric  114  may form a slot antenna). The slot antenna resonating element may support an antenna resonance at higher frequencies (e.g., a high band resonance). Higher frequency antenna performance may also be supported by harmonics of the lower-frequency resonances associated with longer and shorter branches of structure  108 . 
     One or more electrical components may span dielectric gap  114 . These components may include resistors, capacitors, inductors, switches and other structures to provide tuning capabilities, etc. Components in antenna  40  may be used to tune the performance of antenna  40  dynamically during antenna operation and/or may include fixed components. 
     Antenna  40  may have a return path (sometimes referred to as a short circuit path or short pin) such as return path  110 . Return path  110  may be coupled between the main inverted-F resonating element arm formed from structure  108  and antenna ground  104  in parallel with the antenna feed formed by feed terminals  98  and  100 . Return path  110  may be formed from a metal member having opposing first and second ends. In the example of  FIG. 4 , return path  110  is formed from a metal structure that has a first end with a terminal  120  coupled to structure  108  of inverted-F antenna resonating element  106  (e.g., on a housing sidewall or other peripheral conductive structure) and has a second end with a terminal  122  coupled to antenna ground  104 . Return path  110  may have other shapes and sizes, if desired. 
     The presence of case  200  may affect the operation of the structures associated with antenna  40 . Accordingly, case  200  may be provided with supplemental antenna element  222 . Supplemental element  222  may be a parasitic antenna resonating element (e.g., a monopole element, etc.) that helps ensure that antenna  40  operates satisfactorily, regardless of whether or not device  10  is mounted within case  200 . If desired, the performance of element  222  may be tuned (e.g., by using switches, tunable inductors, tunable capacitors, and/or other tunable circuitry  222 T that is coupled to element  222 ). Tunable circuitry  222 T may, as an example, be a switch that can be opened or closed to tune the length of element  222  and thereby adjust the frequency at which element  222  resonates and/or may otherwise be used to tune an antenna resonance associated with element  222 . 
     Element  222  may be near-field coupled to antenna  40  and/or may be coupled to antenna  40  through a signal path. The signal path may include one or more signal lines such as path  250  in connectors  204  and  130 . Signal path  250  may be a ground path, a power path, a data line path, or other signal path. 
     Element  222  may be a parasitic antenna resonating element that can influence the frequency response of antenna  40  by supplementing the response of antenna  40  where antenna  40  has been detuned due to the presence of case  200 . Using tunable circuitry  222 T, the performance of element  222  may be adjusted to suit use of case  200  in different regulatory environments. For example, device  10  can detect the location of device  10  (e.g., by communicating with a wireless network, using global positioning system information, etc.). This location can be conveyed to coupled control circuitry in case  200  and used by the control circuitry in case  200  and/or control circuitry in device  10  to make location-sensitive adjustments to circuitry  222 T. Circuit  222 T may, as an example, be used to tune element  222  (and therefore antenna  40 ) to a first state when case  200  is being used in a first geographical location and may be used to tune element  222  (and therefore antenna  40 ) to a second state when case  200  is being used in a second geographical location. As shown in  FIG. 4 , element  222  may be coupled to antenna  40  by using path  250  to couple element  222  to ground  104  or other portion of antenna  40 . Path  250  may be a connector path formed from paths in connectors  204  and  130  and may be used in addition to or instead of using near-field coupling to couple element  222  to antenna  40 . 
     A cross-sectional side view of device  10  mounted in case  200  is shown in  FIG. 5 . As shown in  FIG. 5 , case  200  includes plastic enclosure (body)  202  from which connector  204  protrudes. Device  10  may have a metal trim structure such as metal trim ring  252  that surrounds the connector port opening in housing  12 . Connector  204  has a protruding support member such as tongue member  254  that is formed from a material such as metal. When connector  204  is mated with connector  130  in device  10 , contacts  256  on connector  204  (i.e., contacts  256  on embedded flexible printed circuit  253 ) mate with corresponding contacts  258  on connector  130 . 
     When connector  204  is inserted in connector  130  as shown in  FIG. 5 , there is a risk of capacitive coupling between trim member  252  and conductive structures in connector  204  such as support member  254 . Member  254  may be formed from machined metal or may be a conductive metal part formed using metal injection molding techniques (e.g., techniques in which powered metal mixed with binder is molded in a mold die to form a conductive part in a desired shape). To increase the distance D between these conductive structures and thereby reduce capacitive coupling, a recessed portion may be formed in support member  254  at a location on support member  254  that lies between connector pins  256  and connector support structure  220 . This recessed portion may be filled with plastic  260  or other dielectric. Plastic  260  may be nylon (e.g., a polyamide), a silicone-based polymer, polyurethane, or other suitable polymer. The recessed portion in member  254  may be, for example, a groove that runs along the exposed upper and lower faces of member  254 . The presence of dielectric  260  in the recessed portion of tongue member  254  helps reduce capacitive coupling between trim member  252  and member  254  that may otherwise reduce wireless bandwidth. 
     A perspective view of illustrative structures of the type that may be used in forming chin structure  220  is shown in the exploded perspective view of  FIG. 6 . As shown in  FIG. 6 , chin structures  220  may include chin structures such as chin structure  220 - 1 . Chin structures  220 - 1  may be formed from plastic (e.g., one or more shots of injection molded plastic) and/or other materials. Structure  220 - 1  may have a hollow portion that is configured to receive the end of housing  12  of device  10 . Openings may be formed in structure  220 - 1  to accommodate speaker ports, connectors, audio jacks, etc. For example, opening  300  may be used to allow an audio jack connector from an external set of headphones (earbuds, etc.) to be plugged into audio port  301  in device  10  when device  10  is installed in case  200  and audio port  301  is aligned with opening  300 . When device  10  is installed in case  200 , connector  130  of device  10  will be aligned with opening  318  in chin structure  220 - 1  (or other suitable case body structures). Connector  204  may pass through opening  318  and may be received within connector  130 . 
     Chin structure  220  may include one or more printed circuits. The printed circuits may be rigid printed circuits (e.g., printed circuits formed from rigid printed circuit board material such as fiberglass-filled epoxy) and/or may be flexible printed circuits (e.g., printed circuits formed from flexible polymer substrate materials such as sheets of polyimide or other flexible polymer layers). In the example of  FIG. 6 , chin structure  220  has flexible printed circuit  314  on which circuitry  316  such as discrete components and integrated circuits may be mounted (e.g., tunable component  222 T, control circuitry that adjusts tunable component  222 T to tune supplemental antenna element  222  based on location information signals, control signals, or other signals received from device  10  via connectors  130  and  204 , power management circuitry, etc.). Chin structure  220  also has flexible printed circuit  312 , which is coupled to connector  204 . Flexible printed circuits  312  and  314  may be formed from a common substrate or may be formed from separate substrates that are joined using hot bar soldering techniques, connectors, conductive adhesive, welds, or other coupling techniques. Flexible printed circuit  222  may contain metal traces  223  for forming a supplemental antenna element and may, if desired, be coupled to a signal path in connector  204  (see, e.g., signal path  250  of  FIG. 4 ). The length of metal traces  223  (i.e., the length of the supplemental antenna element) may be selected to reduce undesired spurious radiated emissions and restore a desired level of antenna performance when device  10  is installed in case  200 . The length of traces  223 , the way in which traces  223  are interconnected to ground and/or other signal paths, and other attributes of flexible printed circuit  222  and case  200  may be the same for all cases  200  or cases  200  may have traces of different lengths and other customized features to accommodate different regulations in different parts of the world. 
     Metal structures may be included in chin structures  220 . For example, a metal bracket may be coupled to member  254  of connector  204  and this metal bracket may be attached to structure  310  using fasteners such as screws. Printed circuit  312  may be coupled to the metal bracket, to connector  204 , and to structure  310  to form chin assembly  220 - 2 . Assembly  220 - 2  may mate with structure  220 - 1  to form chin structure  220 . 
     Structure  310  may be formed from stainless steel or other metal and may sometimes be referred to as a metal trim ring structure (e.g., a structure that includes portions that form a trim for the connector port associated with female connector  206 ). Screws such as screw  306  or other fasteners may be used to mechanically secure trim member  310  and therefore assembly  220 - 2  to structure  220 - 1 . Screws such as screw  306  or other fasteners may also form electrical pathways in chin structure  220 . 
     The supplemental antenna element in flexible printed circuit  222  may be coupled to metal traces on bent tab (protruding) portion  222 ′ of circuit  222 . Portion  222 ′ may have an opening such as opening  308 . Screw  306  may pass through opening  304  in trim member  310  and through opening  308  of portion  222 ′ of flexible printed circuit  222 . The shaft of screw  306  may be received within threaded opening  302  in chin structure  220 - 1 . Screw  306  may be formed from metal to help short the antenna trace of flexible printed circuit  222  to the ground path in connector  204  (see, e.g., ground path  250  of  FIG. 4 ). With one suitable arrangement, the supplemental antenna formed from the metal trace in flexible printed circuit  222  may be shorted to metal on portion  222 ′ of flexible printed circuit  222 . This metal may be shorted to trim ring structure  310  when screw  306  is used to secure assembly  220 - 2  to structure  220 - 1 . Trim ring structure  310  may be tied to ground path  250  in connector  204  through traces in flexible printed circuit  312  and/or through other metal structures in assembly  220 - 2  (e.g., through a metal bracket that is laser welded to member  254 , 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: 20150908
Publication Date: 20170912
Grant Date: 20170912
Priority Date: 20150908
Inventors: KASAR DARSHAN R.
KALINICHEV KIRILL
COLAHAN IAN P.
RASMUSSEN TIMOTHY J.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 57704687