PATENT DOCUMENT

Publication Number: US-10461429-B2
Application Number: US-201715461248-A
Country: US
Kind Code: B2

Title: Switched antenna assembly

Abstract:
A consumer electronic product includes a switchable inductor array coupled to the RF antenna, the switchable inductor array comprising inductive elements and a switch circuit coupled to the inductor array to select at least one of the inductive elements and couple the selected inductive element with the RF antenna. The product can further include an assembly having a mesh that is strengthened by a stiffener. A multi-layer adhesive have a conductive layer that can be used to shield the RF antenna and adhesive layers that can provide adhesion between the stiffener and the housing of the product. The assembly can be covered by a cowling that is made of metal to provide further shielding. To reduce potential coupling between the RF antenna and the cowling, the cowling can have a portion that is formed of plastic to distance its metal portion from the antenna.

Claims:
What is claimed is: 
     
       1. A consumer electronic product, comprising:
 a housing having walls that define an internal volume, wherein a portion of one of the walls is a radio frequency (RF) antenna; 
 a connector electrically coupled to the RF antenna, the connector having a fixed length; 
 a switchable inductor array electrically coupled to the RF antenna via the connector, the switchable inductor array comprising inductive elements that cooperate with the connector to define an inductance of the connector; and 
 a switch circuit coupled to the switchable inductor array and arranged to select at least one of the inductive elements to vary the inductance of the connector. 
 
     
     
       2. The consumer electronic product as recited in  claim 1 , wherein the switchable inductor array and the switch circuit are carried by a mother logic board. 
     
     
       3. The consumer electronic product as recited in  claim 1 , wherein the switchable inductor array and the switch circuit are carried by a flexible circuit. 
     
     
       4. The consumer electronic product as recited in  claim 1 , wherein the switchable inductor array comprises multiple inductors connected in parallel. 
     
     
       5. The consumer electronic product as recited in  claim 1 , wherein the RF antenna is further coupled to a band arm, the band arm comprising:
 an antenna end electrically coupled to the RF antenna; 
 a grounded end electrically coupled to the housing such that the grounded end is grounded by the housing; and 
 a capacitor electrically coupled between the antenna end and the grounded end. 
 
     
     
       6. The consumer electronic product as recited in  claim 5 , wherein the band arm further comprises:
 an inductor electrically coupled between the grounded end and the capacitor; and 
 a switch electrically coupled between the grounded end and the capacitor, the switch being in parallel with the inductor and adapted to selectively provide a shorted path that bypasses the inductor. 
 
     
     
       7. The consumer electronic product as recited in  claim 5 , wherein the capacitor is a variable capacitor. 
     
     
       8. A method for tuning a radio frequency (RF) antenna coupled to a fixed length connector, comprising:
 identifying a RF band for operation; 
 identifying an RF antenna characteristic corresponding to the identified RF band; 
 determining a target inductance of the fixed length connector that resonates with the RF antenna characteristic; and 
 transitioning a state of a switch that is coupled to the fixed length connector to change an inductance of the fixed length connector to the target inductance. 
 
     
     
       9. The method as recited in  claim 8 , wherein the transitioning of the state of the switch comprises selecting multiple inductors connected in parallel. 
     
     
       10. The method as recited in  claim 8 , wherein the fixed length connector is coupled to two inductors in parallel and transitioning the state of the switch comprises opening or closing a circuit associated with one of the two inductors. 
     
     
       11. The method as recited in  claim 8 , wherein the transitioning of the state of the switch comprises shorting a circuit to bypass an inductor. 
     
     
       12. A consumer electronic product, comprising:
 a housing having walls that define an internal cavity, wherein the walls are capable of carrying operational components within the internal cavity that include: 
 a radio frequency (RF) antenna, 
 a connector electrically couple to the RF antenna, 
 a switchable inductor array electrically coupled to the RF antenna via the connector, wherein the switchable inductor array includes inductive elements that cooperate with the connector to define and inductance value, and 
 a switch array that is electrically coupled to the switchable inductor array, wherein the switch array is capable of altering the inductance value. 
 
     
     
       13. The consumer electronic product of  claim 12 , wherein the connector has a fixed length. 
     
     
       14. The consumer electronic product of  claim 12 , wherein the switch array is capable of transitioning between a first state and a second state different than the first state. 
     
     
       15. The consumer electronic product of  claim 12 , wherein the switchable inductor array and the switch array are carried by flexible circuit. 
     
     
       16. The consumer electronic product of  claim 12 , wherein the target inductance value is associated with the connector resonating at a predetermined RF antenna characteristic. 
     
     
       17. The consumer electronic product of  claim 16 , wherein the operational components further include a processor capable of identifying a RF band corresponding to the predetermined RF antenna characteristic. 
     
     
       18. The consumer electronic product of  claim 12 , wherein the switch array is capable of tuning the RF antenna without altering a length of the connector. 
     
     
       19. The consumer electronic product of  claim 12 , wherein the RF antenna is coupled to a parasitic resonating element.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/384,109, filed Sep. 6, 2016, entitled “SWITCHED ANTENNA ASSEMBLY”, which is incorporated by reference herein in its entirety. 
    
    
     FIELD 
     The following description relates to electronic devices. In particular, the following description relates to radio frequency (RF) antennae. In particular, using connector assemblies having adjustable electrical characteristics to tune or otherwise modify RF antenna performance is described. 
     BACKGROUND 
     Portable electronic devices are designed to provide various functions. For example, a portable electronic device can establish wireless communication over various frequency bands that can require different RF antenna configurations for optimal performance. 
     SUMMARY 
     In one aspect, a consumer electronic product can include a housing assembly having walls that define an internal volume. A portion of a wall can be a radio frequency (RF) antenna. The consumer electronic product can also include a connector that is electrically coupled to the RF antenna. The connector has a fixed length. The consumer electronic product can further include a switchable inductor array that is electrically coupled to the RF antenna via the connector. The switchable inductor array can include inductive elements that cooperate with the connector to define an inductance of the connector. The consumer electronic product can further include a switch circuit coupled to the inductor array. The switch circuit is arranged to select at least one of the inductive elements to vary the inductance of the connector. In this way, the inductance of the connector, which can be act as the return path of the RF antenna, can be toned and the optimal frequency of the RF antenna can also be tuned without changing the length of the connector or return path. 
     In another aspect, an assembly carried by an enclosure of a portable electronic device is described. The enclosure of the portable electronic device can include an opening. The assembly can include a mesh fits to the opening such that a side of the mesh is exposed. The assembly can also include a stiffener carried by the enclosure. The stiffener can provide structural support to the receiver and electrically coupling the receiver to a ground to prevent users from receiving accidental electrical shocks. However, the stiffener may interfere with an RF antenna nearby. Hence, the assembly can further include a shield assembly positioned between the stiffener and the enclosure. The shield assembly can include a conductive layer positioned between adhesive layers so that the shield assembly adheres the stiffener to the enclosure and provides shielding to the RF antenna. 
     In yet another aspect, a method for tuning a radio frequency (RF) antenna that is coupled to a fixed length short pin is described. The method can include the steps of identifying a RF band for operation and identifying an RF antenna characteristic corresponding to the identified RF band. The method can also include determining a target inductance of the fixed length short pin that resonates with the RF antenna characteristic. The method can further include transitioning a state of a switch that is coupled to the fixed length short pin to change an inductance of the fixed length short pin to the target inductance. 
     Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the embodiments, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  illustrates a front isometric view of an embodiment of an electronic device, in accordance with some described embodiments; 
         FIG. 2  illustrates a rear isometric view of the electronic device shown in  FIG. 1 , showing various features of the enclosure; 
         FIG. 3A  illustrates an embodiment of a connector assembly that provides a return path having variable properties used to tune an RF antenna; 
         FIG. 3B  is a schematic diagram illustrating a possible circuit arrangement of the embodiment shown in  FIG. 3A . 
         FIG. 4A  illustrates another embodiment of a connector assembly that provides a return path having variable properties used to tune an RF antenna; 
         FIG. 4B  is a schematic diagram illustrating a possible circuit arrangement of the embodiment shown in  FIG. 4A . 
         FIG. 5A  illustrates an embodiment of a flex assembly having variable properties used to tune an RF antenna; 
         FIGS. 5B-5E  are schematic diagrams illustrating different possible circuit arrangements of embodiments shown in  FIG. 5A . 
         FIG. 6A  shows an RF isolation shield in accordance with an embodiment; 
         FIG. 6B  shows a cross-section view of the RF isolation shield arrangement as shown in  FIG. 6A ; 
         FIG. 7A  shows a cowling suitable for use in proximity to an RF antenna in accordance with an embodiment; 
         FIG. 7B  shows a cross-section view of the cowling arrangement as shown in  FIG. 7A ; and 
         FIG. 8  shows a flowchart detailing a process in accordance with an embodiment. 
     
    
    
     Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings can be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting such that other embodiments can be used, and changes can be made without departing from the spirit and scope of the described embodiments. 
     Many modern wireless communication devices include one or more sets of wireless circuitry, which can also be referred to as radios and/or wireless subsystems herein. The multiple radios can be used by a wireless communication device to communicate independently and/or concurrently via multiple wireless communication technologies. The wireless communication technologies can use different radio frequency bands having different bandwidths and can accommodate signals at different receive signal strength levels. The wireless communication device can also include a variety of hardware circuitry to provide additional processing functions that enhance the user&#39;s experience of the wireless communication device. Modern wireless communication devices can be used for voice, video, text, data, media generation and consumption, Internet browsing, gaming, etc. In some instances, one or more different sets of hardware circuitry in the wireless communication device can generate radio frequency energy that can leak into a radio frequency band used by one or more receivers of the wireless circuitry. This energy leakage can raise the noise/interference floor and can cause a problem known as “de-sense.” In many instances, de-sense can negatively impact the use of certain radio frequency bands and, in severe cases, can render certain radio frequency bands unusable. Accordingly, interference that can result in de-sense poses a problem for concurrent operation of wireless circuitry configured to receive low level radio frequency signals and hardware circuitry that generates radio frequency interference that overlaps with the receive radio frequency bands used by the wireless circuitry. 
     Wireless circuitry of the wireless communication device can include transmitters and receivers that provide signal processing of radio frequency wireless signals formatted according to wireless communication protocols, e.g., according to a Wi-Fi wireless communication protocol, a Bluetooth wireless communication protocol, or a cellular wireless communication protocol. In some embodiments, the wireless circuitry can include components such as: processors and/or specific-purpose digital signal processing (DSP) circuitry for implementing functionality such as, but not limited to, baseband signal processing, physical layer processing, data link layer processing, and/or other functionality; one or more digital to analog converters (DACs) for converting digital data to analog signals; one or more analog to digital converters (ADCs) for converting analog signals to digital data; radio frequency (RF) circuitry (e.g., one or more amplifiers, mixers, filters, phase lock loops (PLLs), and/or oscillators); and/or other components. The wireless circuitry can be referred to herein as a radio and can include one or more components as described hereinabove. In some embodiments, the wireless circuitry can include a processor to determine settings for and/or configure operations of the wireless circuitry. The processor of the wireless circuitry, in some embodiments, can also communicate with other processors in the wireless communication device, e.g., a control processor, a host processor, an application processor, and/or a processor in the hardware circuitry. 
     In accordance with various implementations, any one of these consumer electronic devices can relate to: a cellular phone or a smart phone, a tablet computer, a laptop computer, a notebook computer, a personal computer, a netbook computer, a media player device, an electronic book device, a MiFi® device, a wearable computing device, as well as any other type of electronic computing device having wireless communication capability that can include communication via one or more wireless communication protocols such as used for communication on: a wireless wide area network (WWAN), a wireless metro area network (WMAN) a wireless local area network (WLAN), a wireless personal area network (WPAN), a near field communication (NFC), a cellular wireless network, a fourth generation (4G) Long Term Evolution (LTE) network, an LTE Advanced (LTE-A) wireless network, and/or a 5G or other present or future developed advanced cellular wireless network. 
     As consumer electronic devices become smaller and more compact, performance of wireless circuitry can be affected. More specifically, with the advent of multi-band wireless technology (MIMO, for example), the number and placement of antennae in the consumer electronic product are crucial to the overall wireless performance and user experience. In particular, a particular RF antenna can be used to transmit/receive wireless signals over different frequency bands. For example, the consumer electronic product can provide wireless communications in a number of frequency bands that can include, for example, low mid-band (LMB) that can extend from 1400 MHz to 1710 MHz, mid-band (MB) that can extend from about 1710 MHz to about 2170 and high-band (HB) that can extend from about 2300 MHz to about 2700 MHz. Accordingly, in order to improve RF antenna performance, each RF antenna can be tuned so as to provide optimal performance in a particular frequency band. As described in U.S. patent application entitled, Electronic Device Antenna With Switchable Return Paths by Vazquez et. al. filed Jul. 28, 2015 and having U.S. patent application Ser. No. 14/811,714 that is incorporated by reference in its entirety for all purposes, an RF antenna can be coupled to ground by way of a electronic component having electrical characteristics that can be adjusted in such a way so as to optimize the performance of the RF antenna while operating in a particular frequency band. For example, in one embodiment, the electronic component can take the form of an inductive element (or inductor equivalent) characterized as having an adjustable inductance value. The inductance value can be altered in accordance with a wireless operation performed by the consumer electronic product. In one state, the inductance value can be null as the inductive elements can be electrically disconnected from the RF antenna. In another state, the inductance value can be characterized as a combination of inductance values of individual inductors selectively coupled together using a switching element controlled by a processor, for example. In this way, the RF antenna can be tuned in such a way as to provide optimal performance for a selected frequency band. 
     It should be noted that, in addition to using discrete electrical components, performance of an active RF antenna can be optimized using a parasitic antenna resonating element, also referred to as a High Band Arm (HBA). In one embodiment, the HBA can be embedded within a non-conductive medium (such as a plastic filler) in the vicinity of a main RF antenna. The parasitic antenna resonating element (or more simply, the parasitic element) can be grounded to a chassis ground (provided by, for example, metal portions of a housing assembly) and is embedded within the plastic filler. It should be noted that the purpose of the parasitic element is to modify the radiation pattern of the radio waves emitted by the RF antenna by acting as a passive resonator (i.e., absorbing the RF energy from a nearby driven RF antenna and re-radiating the RF energy with a different phase). In this way, the RF energy from different RF antenna elements can interfere to strengthen the antenna&#39;s radiation in the desired direction, and cancelling out the waves in undesired directions. For example, the passive element can be used to direct RF energy from the RF antenna in a beam in one direction thereby increasing the antenna&#39;s gain. 
     In one embodiment, the HBA can be have electrical characteristics that can be modified, or tuned, so as to optimize the overall performance of the nearby main RF antenna in a particular frequency band. For example, the HBA can take the form of a flexible connector (or flex) having electrically conductive traces embedded in a flexible dielectric material. The HBA flex can, in turn, be electrically coupled to a ground plane as well as electrical components (such as a capacitor) that can be used to alter a capacitance value of the HBA flex. By changing the capacitance value of the HBA flex, the overall interaction between the HBA flex and the RF antenna can also be altered in such a way as to optimize the performance characteristics of the RF antenna. In one embodiment, the electrical component connected to the flex can take the form of a switchable inductive element by which it is meant that an inductor (or inductors) can be switchable coupled to the flex in any suitable combination thereby providing the ability to alter performance characteristics of the RF antenna on the fly, so to speak. 
     It should be noted, that metal or metallic objects can have a deleterious effect on the overall performance of an RF antenna. For example, an electrically conductive non-metallic object can mimic a lossy metallic object in that the interaction with a near-by RF antenna can cause loss of gain and overall performance. Therefore, in those situations where such an electrically conductive non-metallic object is present, it can be advantageous to provide a metal interface that can act as a shield to prevent substantial interaction between the RF antenna and the electrically conductive non-metallic object. In one embodiment, the electrically conductive non-metallic object can take the form of a dielectric material (such as plastic) having conductive particles embedded therein. Although the embedded conductive particles imbue the non-metallic object with sufficient conductivity to provide a path to ground, for example, the non-metallic object can interfere with the operation of the RF antenna, thus resulting in a reduced overall performance. In one embodiment, a conductive substrate that can be formed of a layer of a conductive metal (such as copper) can be used to shield, or otherwise, isolate the non-metallic conductive object from the RF antenna. In one embodiment, the conductive metal can take the form of a contiguous layer whereas in another embodiment, the conductive metal can take the form of segments of metal. In any case, the metal can be disposed between layers of adhesive. In this way, the metal (in whichever form is deemed appropriate) can be used as an RF shield that can be placed in any desired location. 
     Accordingly, this paper describes a number of embodiments related to structural elements and housing designs that can be used to provide optimal RF characteristics. The structural elements can include, for example, a connector assembly that can couple an RF antenna to ground or main logic board (MLB) having at least a processor. The connector assembly can act as an RF antenna return path and can include an electrical component having adjustable electrical characteristics coupled to a connector used to electrically connect the RF antenna to a ground plane or an electrical circuit. The electrical circuit can include processing resources used to alter the electrical characteristics of the electrical component. For example, the connector assembly can include a switch (or switches) that can be controlled by the processing resources. The switch can be used to connect one or more discrete electrical components (such as inductors) to the RF antenna in such as way so as to alter the RF performance accordingly. Other structural elements can include a shroud or cowling that can act as an RF shield suitable for isolating an RF antenna from conductive objects that would other degrade the performance of the RF antenna. 
     These and other embodiments are discussed below with reference to  FIGS. 1-8 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  illustrates a front isometric view of an electronic device  100 , in accordance with some described embodiments. In some embodiments, the electronic device  100  is a laptop computer device. In other embodiments, the electronic device  100  is a wearable electronic device designed to secure with an appendage of a user of the electronic device  100 . In the embodiment shown in  FIG. 1 , the electronic device  100  is a consumer electronic device, such as a mobile wireless communication device that takes the form of, for example, a smartphone or a tablet computer device. 
     The electronic device  100  can include an enclosure  102  having several sidewalls and a rear wall that combine to define an internal cavity that receives several internal components (not shown), such as a processor circuit, a memory circuit, an internal power, and speaker module, as non-limiting examples. The enclosure  102  can be formed from a metal, such as aluminum or an alloy that includes aluminum. However, other materials are possible, such as a rigid plastic or ceramic. Also, when the enclosure  102  is formed from a metal that is anodizable, the enclosure  102  can undergo an anodization process that immersing the enclosure  102  in an anodic bath with one or more acidic compounds. The anodization process is designed to provide an aesthetic finish to the enclosure  102  as well as improve the structural rigidity. 
     The electronic device  100  can further include a display assembly  104  (shown as a dotted line) designed to present visual information, such as video or still images, to a user of the electronic device  100 . The electronic device  100  can further include a protective layer  106  that covers the display assembly  104 . The protective layer  106  can include a transparent material, such as glass or sapphire. Further, the display assembly  104  can include a touch-sensitive layer, including capacitive touch-sensitive technology, designed to respond to a touch input to the display assembly  104  (through the protective layer  106 ). The display assembly  104  can respond to the touch input by changing the visual information presented on the display assembly  104 . Although not shown, the electronic device  100  can include a frame that carries the protective layer  106 . The frame is designed to couple or mate with the enclosure  102 . 
     The electronic device  100  can include external controls that provide an input or command to an internal component of the electronic device  100 . For example, the electronic device  100  can include a switch  110  electrically coupled to a processor circuit in the electronic device  100 . The switch  110  can be actuated relative to the enclosure  102  in a direction toward or away from the protective layer  106 . The electronic device  100  can further include a button  112  electrically coupled to a processor circuit in the electronic device  100 . The button  112  can be actuated relative to the enclosure  102  in a direction toward the enclosure  102 . 
     The electronic device  100  can further require additional openings for associated features of the electronic device  100 . For example, the electronic device  100  can include openings  116 , or through holes, formed in the enclosure  102 . The openings  116  can allow acoustical energy, generated by a speaker module (not shown), to exit the electronic device  100 . While a discrete number of openings are shown, additional openings are possible. Moreover, some additional openings can allow airflow into and out of the electronic device  100 , thereby providing an air vent for the electronic device  100 . 
       FIG. 2  illustrates a rear isometric view of the electronic device  100  shown in  FIG. 1 . As shown, the enclosure  102  can be partitioned into multiple regions. For example, the enclosure  102  can include a first housing part  122  and a second housing part  124  separated by a first channel  132 . The enclosure  102  can further include a third housing part  126  separated from the second housing part  124  by a second channel  134 . It should be noted that first housing part  122  and third housing part  126  (or part of first housing part  122  and part of third housing part  126 ) can be operable as upper RF antenna  122  and lower RF antenna  126 , respectively. A cutting operation (not shown), including CNC or milling, as non-limiting examples, applied to the enclosure  102  can form the first channel  132 . Accordingly, the first channel  132  and the second channel  134  define regions of the electronic device  100  void of metal. This can allow an antenna (not shown) to transmit radio frequency (“RF”) communication through the first channel  132  or the second channel  134 , depending upon the location of the antenna in the electronic device  100 . However, the aforementioned housing parts can be interconnected or interlocked together. This will be shown and described below. 
     The first channel  132  and the second channel  134  can be filled with a material (or materials). For example, the first channel  132  includes a material  136  designed to cover a second material (not shown) and provide an aesthetic finish to the electronic device  100 . In some embodiments, the material  136  can include a polymeric material, such as plastic. The material  136  can include a moldable material applied, in liquid form, to the first channel  132  by a molding operation and then cured to solidify. Also, the material  136  can be co-planar, or approximately, co-planar with respect to the first housing part  122  and the second housing part  124 . The second channel  134  can also include a material  138  that can include any feature described for the material  136  in the first channel  132 . 
     The first housing part  122  and the third housing part  126  can provide a rigid cover to protect some components of the electronic device  100 . However, in some instances, each of the first housing part  122  and the third housing part  126  can form part of an antenna used to enable wireless communication. The second housing part  124 , also referred to as a chassis, can provide not only a rigid, protective cover, but also an electrical ground for internal components of the electronic device electrically coupled with the second housing part  124 . 
     Also, the enclosure  102 , and in particular, the second housing part  124 , can include a first opening  150  used by a camera module  152  of the electronic device  100 . Also, the second housing part  124  can include a second opening  154  used by a camera flash  156  of the electronic device  100  to enhance the image capture capabilities of the camera module  152 . 
       FIG. 3A  shows a plan view  300  of electronic device  100  and more particularly upper RF antenna  122 . RF antenna  122  is coupled by way of connector  302  to inductor array  304 . Connector  302  can also be referred as a short pin. Connector  302  can have a fixed length. Inductor array  304  can include any number of discrete inductive components such as inductors L 1 , L 2 , to Ln, each of which is associated with a particular inductance value. Inductor array  304  can be coupled to switch array  306  (that can be incorporated within a control board  310  such as a main logic board, or MLB) arranged to selectively couple individual inductors L of inductor array  304  to system ground  308 , thus forming a return path for RF antenna  122  as shown schematically in  FIG. 3B . Switch array  306  can be triggered by switch signal S that can be provided by control board  310  that can be used to combine any number of inductors L in inductor array  304 . For example, in one state, switch signal S 1  can cause inductor array  304  to provide inductance L 1  corresponding to a first discrete inductor. In another state, switch signal S 2  can cause inductor array  304  to provide inductance L 2  that can correspond to a second discrete inductor, however, inductance L 2  can also correspond to a combination of inductors. For example, switch signal S 2  can cause first and second discrete inductors to be connected in parallel, or in series, depending upon the desired characteristics of RF antenna  122 . It should be noted that in some cases, switching signal S can cause switch array  306  to de-couple all inductive elements within inductor array  304 . 
       FIG. 4A  shows a plan view  400  of electronic device  100  and more particularly lower RF antenna  126 . RF antenna  126  is coupled by way of connector  402  to flex  404  with traces (not shown) that provide inductance represented by inductors  406  and  408  connected in parallel to switch element  410  (represented by schematic diagram of  FIG. 4B ) to housing ground  414 . Inductor  408  is also connected to housing ground  412 . In this way, switch element  410  can de-couple inductance represented by inductor  406  to provide a return path for RF antenna  126  having only inductance represented by inductor  408 . Switch element  410  can also couple inductance represented by inductor  406  to provide a return path for RF antenna  126  having an equivalent inductance represented by inductors  408  and  406  in parallel. 
       FIG. 5A  shows a plan view  500  of electronic device  100  and more particularly upper RF antenna  122  with HBA flex  502  arranged to couple HBA to ground  504 . The HBA can be an elongated structure that has an antenna end being electrically coupled to portion of RF antenna  501  and a grounded end that is electrically coupled to ground  504 . The HBA can include the flex  502  and a metal arm  506  that is connected to ground  504 . Ground  504  can be a chassis ground. HBA flex  502  can include capacitor  508  that can be used to tune the optimal RF characteristic of the HBA. In one case, as shown schematically in  FIG. 5C , capacitor  508  can be a variable capacitor  510  that can be varied to change the coupling between the HBA and the ground, thus having the effect of enabling different HBA lengths. In another case, as shown schematically in  FIG. 5D  and  FIG. 5E , switch  512  can be used to vary the inductance of HBA. For example, in one particular arrangement, switch  512  is connected in between ground  504  and capacitor  508 , providing a path of short circuit when switch  512  is “on.” Inductor L 1  can also be connected with the switch  512  in parallel. When switch  510  is “off”, inductance L 1  is coupled to capacitor  508  as shown in  FIG. 5D  (corresponding to a “long” HBA flex) whereas when switch  510  is “on”, then capacitor  508  is coupled to inductance L 2  (corresponding to a “short” HBA flex) because now a shorted path is provided to bypass the inductor L 1 . 
     While the embodiments shown in  FIGS. 3A and 5A  are described as possible arrangements of upper RF antenna  122  and the embodiment shown in  FIG. 4A  is described as possible arrangement of lower RF antenna  126 , it should be understood the embodiments described in this paper are not limited by the position of any RF antenna. For example, any antenna such as a lower RF antenna can also have the arrangements as shown in  FIG. 3A  and/or  FIG. 5A . 
       FIGS. 6A and 6B  show an assembly  602  carried by an enclosure  604  of electronic device  100  in the upper portion  600 . Enclosure  604  can include metal housing part  124  and cover glass  606  that cooperate to form cavity  608  to receive internal components of electronic device  100 . Cover glass  606  can have opening  610  that provides an outlet for sound of a speaker. Assembly  602  can be carried by the cover glass  606  to cover the opening  610 . Assembly  602  can include mesh  612  that can be used to prevent ingress of contaminants. Mesh  612  can be at shaped to fit opening  610  and be located at least partially within opening  610  so that at least a side of mesh  612  is exposed. As shown in  FIG. 6B , assembly  602  can also include stiffener  614  arranged to provide structural integrity to mesh  612 . In some cases, stiffener  614  can be conductive and be coupled to ground  616  so that mesh  614  is grounded. In one case, stiffener  614  can be formed of a metal. However, in some situations metal is avoided for cosmetic reason because the metal can be visible by the users through cover glass  606 . In other cases, stiffener  614  can be made of a plastic or carbon fiber that is molded with tiny pieces of metals to provide conductivity to the stiffener  614 . In some cases, conductive stiffener  614  can be formed of a lossy material that degrades RF performance (such lossy material may include a carbon fiber filled resin). As metal portion of housing part  124  may partially form an RF antenna, assembly  602  can be positioned in the vicinity of upper RF antenna  122 . In order to avoid interaction between stiffener  614  and RF antenna  122 , RF shield assembly  618  can be used to isolate stiffener  614  from RF antenna  122 . In this way, the performance of RF antenna  122  can be maintained. In one embodiment, (shown in  FIG. 6B ) assembly  602  can include RF seal assembly  618  having conductive layer  620 . In one embodiment, conductive layer  620  can take the form of a sheet of metal such as copper. In one embodiment, conductive layer  620  can take the form of segments spaced apart to preserve the isolation between RF antenna  122  and stiffener  614 . In one embodiment, conductive layer  620  can be positioned between adhesive layers  622 . Adhesive layers  622  can provide adhesion between stiffener  614  and an enclosure such as cover glass  606 . 
       FIGS. 7A and 7B  show receiver cowling  700  in accordance with the described embodiments. Receiver cowling  700  can be used to cowl (or cover) assembly  602  and other components. Receiver cowling  700  can cooperate with the enclosure of electronic device  100  to cover assembly  602 . It should be noted that since receiver cowling  700  is located in close proximity to upper RF antenna  122 , and since it is part of the system ground plane, coupling between receiver cowling  700  and RF antenna  122  can occur. In order to reduce the coupling between receiver cowling  700  and RF antenna  122 , portion  702  of receiver cowling  700  can be formed of plastic and be injection molded to portion  704  that is formed of metal. Hence, plastic portion  702  can be positioned between metal portion  704  and RF antenna  122 . In this way, gap  706  between RF antenna  122  and metal portion  704  of receiver cowling  700  can be increased. 
       FIG. 8  shows a flowchart describing process  800  in accordance with the described embodiments. Process  800  begins at  802  by identifying a radio frequency (RF) band for operation. The identification of an RF band can be based on a SIM card setting, an initiation of a RF protocol such as Wi-Fi or Bluetooth, a processor command based on a user input, a receipt or detection of a wireless network, and/or etc. At  804 , an RF antenna characteristic corresponding to the identified RF band is identified. For example, a particular resonating frequency or wavelength of the RF band is identified. At  806 , a signal is provided corresponding to the identified characteristic. At  808 , the RF antenna characteristic is altered in accordance with the provided signal. Specifically, a processor, such as a central processor on the MLB or a baseband processor, can determine a target inductance that allows a fixed length short pin to resonate with the identified RF antenna characteristic. In turn, the processor can cause a switch to transition so that the inductance of the short pin is changed to the target inductance. For example, a process on the MLB can cause switch array  306  as shown in  FIG. 3A  to select one or more inductors in inductor array  304  to alter the inductance of connector  302  in response to a change of RF band request due to a switching of Wi-Fi network. Likewise, a processor can cause switch  410  as shown in  FIG. 4A  to turn on or off to include or exclude inductor  406  in order to change inductance of connector  402  associated with lower RF antenna  126 . Also, a baseband processor can adjust the RF antenna characteristic of the HBA  502  based on a SIM card by causing switch  512  to close to bypass L 1  as shown in  FIGS. 5D and 5E  to reduce inductance of HBA  502  in response to a change in wireless network. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data that can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20170316
Publication Date: 20191029
Grant Date: 20191029
Priority Date: 20160906
Inventors: DURNING, CHRISTOPHER J.
HU, HONGFEI
IRCI, Erdinc
YARGA, SALIH
CHENG, CHRISTOPHER T.
AYALA VAZQUEZ, ENRIQUE
JIN, NANBO
TONG, ERICA J.
PASCOLINI, MATTIA
LIN, DENIS J.
BAVETTA, SALOME
LEE, SHERRY
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/335", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q5/335", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 61281003