PATENT DOCUMENT

Publication Number: US-9647332-B2
Application Number: US-201414476453-A
Country: US
Kind Code: B2

Title: Electronic device antenna with interference mitigation circuitry

Abstract:
An electronic device may be provided with an antenna. The antenna may have an antenna resonating element and an antenna ground. The antenna resonating element may be formed from peripheral conductive housing structures. An audio jack or other connector may be mounted in an opening in the peripheral conductive housing structures. The audio jack may overlap the antenna ground. Contacts in the audio jack may be coupled to an interference mitigation circuit. The interference mitigation circuit may include capacitors coupled to the ground and inductors coupled between the contacts and the capacitors. Radio-frequency signal blocking inductors may be coupled between the interference mitigation circuit and respective ports in an audio circuit.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 an antenna formed from an antenna resonating element and an antenna ground; 
 an electrical connector that has contacts and that is configured to receive a mating connector, wherein the electrical connector is capacitively coupled to the antenna ground; and 
 an interference mitigation circuit coupled between antenna ground and the electrical connector, wherein the interference mitigation circuit includes at least one capacitor and currents from the antenna resonating element flow through the electrical connector and the at least one capacitor to the antenna ground. 
 
     
     
       2. The apparatus defined in  claim 1  wherein the capacitor has a first terminal that is coupled to the antenna ground and a second terminal coupled to a node in the interference mitigation circuit. 
     
     
       3. The apparatus defined in  claim 2  wherein the interference mitigation circuit includes an inductor having a first terminal coupled to the node and a second terminal coupled to one of the contacts. 
     
     
       4. The apparatus defined in  claim 3  further comprising:
 circuitry; and 
 a radio-frequency signal blocking inductor that is coupled between the circuitry and the node. 
 
     
     
       5. The apparatus defined in  claim 4  wherein the circuitry comprises audio circuitry. 
     
     
       6. The apparatus defined in  claim 5  wherein the connector is an audio jack. 
     
     
       7. The apparatus defined in  claim 6  wherein the antenna resonating element comprises peripheral conductive electronic device housing structures. 
     
     
       8. The apparatus defined in  claim 7  wherein the peripheral conductive electronic device housing structures have an opening aligned with the audio jack. 
     
     
       9. The apparatus defined in  claim 8  wherein the antenna resonating element comprises an inverted-F antenna resonating element. 
     
     
       10. The apparatus defined in  claim 9  further comprising an adjustable inductor coupled between the antenna resonating element and the antenna ground. 
     
     
       11. The apparatus defined in  claim 1  wherein the contacts in the connector comprise a first contact and a second contact, the interference mitigation circuit includes at least first and second inductors, and the first inductor is connected to the first contact and the second inductor is connected to the second contact. 
     
     
       12. The apparatus defined in  claim 11  wherein the capacitor is one of a set of first and second capacitors, the first capacitor has a terminal that is connected to the first inductor at a first node, and the second capacitor has a terminal that is connected to the second inductor at a second node. 
     
     
       13. The apparatus defined in  claim 12  further comprising:
 an audio circuit having first and second ports; 
 a third inductor coupled between the first port and the first node; and 
 a fourth inductor coupled between the second port and the second node. 
 
     
     
       14. The apparatus defined in  claim 13  wherein the connector comprises an audio jack having at least three contacts. 
     
     
       15. An electronic device, comprising:
 a conductive housing structure; 
 an antenna formed from an antenna resonating element that includes at least part of the conductive housing structure and from an antenna ground; 
 an audio connector mounted in an opening in the conductive housing structure, wherein the audio connector has a contact and the audio connector is capacitively coupled to the antenna resonating element; 
 an audio circuit having a port; 
 first and second inductors that are connected at a node and that are coupled in series between the port and the contact; and 
 a capacitor coupled to the node, wherein antenna currents from the antenna resonating element flow through the audio connector and the capacitor to the antenna ground. 
 
     
     
       16. The electronic device defined in  claim 15  wherein the capacitor has a first terminal connected to the node and a second terminal connected to the antenna ground. 
     
     
       17. The electronic device defined in  claim 16  wherein the antenna resonating element is an inverted-F antenna resonating element that is separated from the antenna ground by a gap and the electronic device further comprises an adjustable inductor that is coupled across the gap between the inverted-F antenna resonating element and the antenna ground. 
     
     
       18. The electronic device defined in  claim 15  wherein the first and second inductors are tunable inductors. 
     
     
       19. An electronic device, comprising:
 peripheral conductive housing structures having an opening; 
 an audio jack aligned with the opening, wherein the audio jack has first and second contacts; 
 a hybrid inverted-F slot antenna, wherein the hybrid inverted-F slot antenna has an inverted-F antenna portion formed from an inverted-F antenna resonating element and an antenna ground, the inverted-F antenna resonating element is formed from the peripheral conductive housing structures, the hybrid inverted-F slot antenna has a slot antenna portion formed from an opening between the inverted-F antenna resonating element and the antenna ground, and the hybrid inverted-F antenna has an antenna feed that feeds both the inverted-F antenna portion and the slot antenna portion; 
 a first capacitor having a first terminal directly coupled to the antenna ground and having a second terminal; 
 a first inductor having a first terminal directly coupled to the first contact and having a second terminal directly coupled to the second terminal of the first capacitor; 
 a second capacitor having a first terminal directly coupled to the antenna ground and having a second terminal; and 
 a second inductor having a first terminal directly coupled to the second contact and having a second terminal directly coupled to the second terminal of the second capacitor. 
 
     
     
       20. The electronic device defined in  claim 19  further comprising:
 audio circuitry having first and second ports; 
 a third inductor coupled between the first port and the second terminal of the first capacitor; and 
 a fourth inductor coupled between the second port and the second terminal of the second capacitor. 
 
     
     
       21. The electronic device defined in  claim 20  wherein the audio jack has a portion that overlaps the antenna ground.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with antenna structures that prevent accessory interference. 
     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. Challenges also arise when attempting to accommodate accessories that operate in conjunction with an electronic device. Antenna performance can be adversely affected due to coupling between the antenna and an accessory plug and cable or other conductive structures in the vicinity of the device. 
     It would therefore be desirable to be able to provide improved wireless circuitry for electronic devices such as electronic devices that can be coupled to accessories. 
     SUMMARY 
     An electronic device may be provided with an antenna. The antenna may have an antenna resonating element and an antenna ground. The antenna resonating element may be formed from peripheral conductive housing structures. An audio jack or other connector may be mounted in an opening in the peripheral conductive housing structures. The audio jack may overlap the antenna ground. 
     To ensure that the antenna performs satisfactorily both when an audio plug is present in the audio jack and when the audio plug is not present, an interference mitigation circuit may be coupled to contacts in the audio jack. The interference mitigation circuit may include capacitors coupled to the ground and inductors coupled between the contacts and the capacitors. Radio-frequency signal blocking inductors may be coupled between the interference mitigation circuit and respective ports in an audio circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with wireless circuitry in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of illustrative circuitry in an electronic device in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of illustrative wireless circuitry in accordance with an embodiment. 
         FIG. 4  is a schematic diagram of an illustrative inverted-F antenna in accordance with an embodiment. 
         FIG. 5  is a schematic diagram of an illustrative inverted-F antenna with an inductor to tune the antenna to cover desired operating frequencies in accordance with an embodiment. 
         FIG. 6  is a schematic diagram of an illustrative inverted-F antenna with a capacitor to tune the antenna to cover desired operating frequencies in accordance with an embodiment. 
         FIG. 7  is a diagram of an illustrative slot antenna in accordance with an embodiment of the present invention. 
         FIG. 8  is a diagram of an illustrative hybrid inverted-F slot antenna in accordance with an embodiment. 
         FIG. 9  is a diagram of an illustrative accessory having a cable with a plug that is being received within a mating connector in an electronic device in accordance with an embodiment. 
         FIG. 10  is a diagram of illustrative circuitry in an electronic device that may be used to ensure that an antenna within the device performs satisfactorily in the presence of an accessory plug in accordance with an embodiment. 
         FIG. 11  is a diagram of a portion of an electronic device containing an antenna and interference mitigation circuitry of the type shown in  FIG. 10  in accordance with an embodiment. 
         FIG. 12  is a graph in which antenna performance (antenna efficiency) has been plotted as a function of operating frequency for various operating conditions and antenna configurations for an illustrative antenna in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands. The wireless communications circuitry may include one or more antennas. 
     The antennas can include 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. The housing structures may include peripheral structures such as a peripheral conductive member that runs around the periphery of an electronic device. The peripheral conductive member may serve as a bezel for a planar structure such as a display, may serve as sidewall structures for a device housing, and/or may form other housing structures. Gaps may be formed in the peripheral conductive member that divide the peripheral conductive member into segments. One or more of the segments may be used in forming one or more antennas for electronic device  10 . 
     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 wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a handheld device such as a cellular telephone, a media player, 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 , which may sometimes be referred to as a case, 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. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may, for example, be a touch screen that incorporates capacitive touch electrodes. 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 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 a peripheral housing member 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 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, 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 . 
     It is not necessary for peripheral housing structures  16  to have a uniform cross-section. For example, the top portion of peripheral housing structures  16  may, if desired, have an inwardly protruding lip that helps hold display  14  in place. If desired, the bottom portion of peripheral housing structures  16  may also have an enlarged lip (e.g., in the plane of the rear surface of device  10 ). In the example of  FIG. 1 , peripheral housing structures  16  have substantially straight vertical sidewalls. This is merely illustrative. The sidewalls formed by peripheral housing structures  16  may be curved or may have other suitable shapes. In some configurations (e.g., when peripheral housing structures  16  serve as a bezel for display  14 ), peripheral housing structures  16  may run around the lip of housing  12  (i.e., peripheral housing structures  16  may cover only the edge of housing  12  that surrounds display  14  and not the rest of the sidewalls of housing  12 ). 
     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 left and right 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. 
     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 circuitry and other structures for displaying images). 
     In 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, plastic, and other dielectrics. 
     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, extensions of the ground plane under active area AA of display  14  and/or other metal structures in device  10  may have portions that extend into parts of 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 such 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 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 . 
     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. 
     A schematic diagram showing illustrative components that may be used in device  10  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include control circuitry such as storage and processing circuitry  28 . 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  30  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  30  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 handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and 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 global positioning system (GPS) receiver equipment such as 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. 3 , 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  26  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  93  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. 3  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 line  92  may be coupled to antenna feed structures associated with antenna structures  40 . 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  92 . Other types of antenna feed arrangements may be used if desired. The illustrative feeding configuration of  FIG. 3  is merely illustrative. 
       FIG. 4  is a diagram of illustrative inverted-F antenna structures that may be used in implementing antenna  40  for device  10 . Inverted-F antenna  40  of  FIG. 4  has antenna resonating element  106  and antenna ground (ground plane)  104 . Antenna resonating element  106  may have a main resonating element arm such as arm  108 . The length of arm  108  may be selected so that antenna  40  resonates at desired operating frequencies. For example, if the length of arm  108  may be a quarter of a wavelength at a desired operating frequency for antenna  40 . Antenna  40  may also exhibit resonances at harmonic frequencies. 
     Main resonating element arm  108  may be coupled to ground  104  by return path  110 . Antenna feed  112  may include positive antenna feed terminal  98  and ground antenna feed terminal  100  and may run in parallel to return path  110  between arm  108  and ground  104 . If desired, inverted-F antennas such as illustrative antenna  40  of  FIG. 4  may have more than one resonating arm branch (e.g., to create multiple frequency resonances to support operations in multiple communications bands) or may have other antenna structures (e.g., parasitic antenna resonating elements, tunable components to support antenna tuning, etc.). 
       FIG. 5  is a diagram of an illustrative inverted-F antenna configuration of the type that may be used to implement a tunable antenna. As shown in  FIG. 5 , antenna  40  may be provided with an inductor L that couples a portion of antenna resonating element arm  108  (e.g., a tip of arm  108 ) in resonating element  106  to antenna ground  104 . Inductor L may be a variable inductor. For example, inductor L may be an adjustable inductor that is formed from one or more transistor or other switching circuitry and a set of fixed inductors. During operation of device  10 , control circuitry  28  can issue control signals that adjust the switching circuitry (e.g., that open and close transistor switches in the switching circuitry), thereby switching desired patterns of the set of fixed inductors into and out of use to adjust the inductance value of inductor L. Adjustments such as these may be made to vary the inductance of inductor L when it is desired to tune the frequency response of antenna  40  (e.g., when it is desired to tune the low band resonance of antenna  40 , when it is desired to tune a mid-band resonance of antenna  40 , etc.). For example, increases to the value of L may be made to increase the frequency of the communications band(s) in which antenna  40  is operating (e.g., to increase a low-band resonant frequency or a mid-band resonant frequency). One or more inductors such as inductor L may be coupled between arm  108  and ground  104  at one or more locations along the length of arm  108 . The configuration of  FIG. 5  is illustrative. 
       FIG. 6  is a diagram of an illustrative inverted-F antenna structure with a capacitor that may be used to implement a tunable antenna. As shown in  FIG. 6 , antenna  40  may be provided with a capacitor C that couples a tip portion of antenna resonating element arm  108  in resonating element  106  to antenna ground  104 . Capacitors such as capacitor C may also be coupled to arm  108  at other locations. Capacitor C may be a fixed capacitor or may be a variable capacitor. For example, capacitor C may be formed from one or more switches or other switching circuitry and a set of fixed capacitors (e.g., a programmable capacitor) or a varactor. During operation of device  10 , control circuitry  28  can issue control signals that open and close switches in the switching circuitry to switch desired capacitors into and out of use or that otherwise make adjustments to capacitor C, thereby varying the capacitance value exhibited by capacitor C. Adjustments such as these may be made to vary the capacitance of capacitance C when it is desired to tune the frequency response of antenna  40  (e.g., when it is desired to tune the low band resonance of antenna  40 , when it is desired to tune a mid-band resonance of antenna  40 , or when it is desired to tune a high band resonance of antenna  40 ). For example, increases to the value of C may be made to decrease the frequency range of the communications band(s) in which antenna  40  is operating (e.g., to decrease a high-band resonant frequency). Capacitor C need not be located at the tip of arm  108 . For example, the resonant frequency decrease associated with inclusion of capacitor C in antenna  40  can be enhanced by locating capacitor C closer to feed  112 . If desired, antenna  40  can be implemented using a pair of fixed capacitances C (e.g., fixed capacitances associated with gaps  18  at either end of a two-branch inverted-F antenna resonating element formed from a peripheral conductive structure such as a segment of peripheral structure  16 ) and variable capacitors can be omitted (as an example). 
     In general, antenna  40  may have one or more adjustable components (adjustable inductors, adjustable capacitors, etc.). The configurations of  FIGS. 5 and 6  are merely illustrative. 
     Antenna  40  may include a slot antenna resonating element. As shown in  FIG. 7 , for example, antenna  40  may be a slot antenna having an opening such as slot  114  that is formed within antenna ground  104 . Slot  114  may be filled with air, plastic, and/or other dielectric. The shape of slot  114  may be straight or may have one or more bends (i.e., slot  114  may have an elongated shape follow a meandering path). The antenna feed for antenna  40  may include positive antenna feed terminal  98  and ground antenna feed terminal  100 . Feed terminals  98  and  100  may, for example, be located on opposing sides of slot  114  (e.g., on opposing long sides). Slot-based antenna resonating elements such as slot antenna resonating element  114  of  FIG. 7  may give rise to an antenna resonance at frequencies in which the wavelength of the antenna signals is equal to the perimeter of the slot. In narrow slots, the resonant frequency of a slot antenna resonating element is associated with signal frequencies at which the slot length is equal to a half of a wavelength. Slot antenna frequency response can be tuned using one or more tunable components such as tunable inductors or tunable capacitors. These components may have terminals that are coupled to opposing sides of the slot (i.e., the tunable components may bridge the slot). If desired, tunable components may have terminals that are coupled to respective locations along the length of one of the sides of slot  114 . Combinations of these arrangements may also be used. 
     If desired, antenna  40  may incorporate conductive device structures such as portions of housing  12 . As an example, peripheral conductive housing structures  16  may include multiple segments such as segments  16 - 1 ,  16 - 2 , and  16 - 3  of  FIG. 8  that are separated from each other by gaps  18  (e.g., spaces between the adjoining ends of the segments that are filled with plastic or other dielectric). In antenna  40  of  FIG. 8 , segment  16 - 1  may be formed from a strip of stainless steel or other metal that forms a segment of a peripheral conductive housing member (e.g., a stainless steel member or other peripheral metal housing structure) that runs around the entire periphery of device  10 . 
     Segment  16 - 1  may form antenna resonating arm  108  for an inverted-F antenna. For example, segment  16 - 1  may form a dual-band inverted-F antenna resonating element having a longer branch that contributes an antenna response in a low frequency communications band (low band LB) and having a shorter branch that contributes an antenna response in a middle frequency communications band (middle band MB). Dual-band inverted-F antenna structures of this type may sometimes be referred to as T-shaped antennas or T-antennas. A return path conductor such as a strip of metal may be used to form return path  110  between peripheral conductive segment  16 - 1  (i.e., the main resonating element arm of the T-antenna resonating element) and antenna ground  104 . 
     Antenna ground  104  may have ground structures such as a substantially rectangular antenna ground plane portion in the center of device  10  (e.g., the portion of device underlying active area AA of display  14  of  FIG. 1 ). Antenna ground  104  may also have a portion such as ground plane extension  104 E that extends outwards from the main antenna ground region in device  10 . Ground plane extension  104 E may protrude into an end region of device  10  such as lower end region  20 . Ground plane extension  104 E of antenna ground  104  may be separated from the main portion of antenna ground  104  and peripheral segment  16 - 1  by an opening that forms antenna slot  114 . Antenna slot  114  may be fed using antenna feed  112  (i.e., using antenna feed terminals on opposing sides of slot  114  such as positive antenna feed terminal  98  and ground antenna feed terminal  100 ). The magnitude of the periphery of antenna slot  114  may determine the frequency at which slot  114  resonances and may therefore be used to produce a desired resonance for antenna  40  (e.g., a high band resonance HB that complements low band resonance LB and midband resonance MB associated with the T-antenna formed from segment  16 - 1 ). 
     When operating antenna  40  in device  10 , both the T-antenna formed from segment  16 - 1  of peripheral conductive housing structures  16  (i.e., the inverted-F antenna) and the slot antenna formed from slot  114  may contribute to the overall response of the antenna. Because two different types of antenna contribute to the operation of antenna  40  (i.e., the inverted-F antenna portion and the slot antenna portion), antenna  40  may sometimes be referred to as a hybrid inverted-F slot antenna or hybrid antenna. 
     If desired, optional electrical components such as inductors and/or capacitors may be coupled to antenna  40 . For example, one or more inductors such as inductors L 1 , L 2 , and L 3  may bridge slot  114  or may be coupled to different locations along the periphery of slot  114  and/or one or more capacitors may bridge slot  114  or may be coupled to different locations along the periphery of slot  114 . Capacitances may be formed by discrete components (capacitors) or may be produced by the metal structures of  FIG. 8 . For example, the metal portions of peripheral conductive structures  16  that are separated by gaps  18  from ground  104  may produce capacitances at the left and right ends of resonating element  108 . Inductor L 1  may bridge the left-hand gap  18  and may help compensate for the capacitance associated with the left-hand gap  18 . Inductor L 3  may bridge the right-hand gap  18  and may help compensate for the capacitance associated with the right-hand gap  18 . Inductor L 2  may be an adjustable inductor that can be adjusted by control circuitry  28  to produce various different inductance values. Adjustments to the value of inductor L 2  may be used, for example, to perform low-band tuning for antenna  40 . 
     In general, device  10  may contain one or more antennas  40  and each antenna may include structures of the type shown in  FIG. 8  or other suitable antenna structures (e.g., inverted-F antenna structures, slot antenna structures, hybrid antenna structures, patch antenna structures, etc.). Each antenna  40  in device  10  may include peripheral conductive housing structures such as structures  16 - 1  of  FIG. 8  or other conductive antenna structures (e.g., metal housing structures or other structures for forming antenna resonating elements such as resonating element  108  and/or antenna ground  104 ). The illustrative configuration of antenna  40  that is shown in  FIG. 8  is merely illustrative. 
     It may be desirable to use device  10  in conjunction with one more other electronic devices (sometimes referred to as external electronic devices or accessories). Additional electronic equipment that may be used with device  10  includes base stations, charging stations, headphones, earbuds, speakers, audio equipment, computers, tablet computers, portable devices such as wrist-watch and cellular telephone devices, wearable electronic equipment, and other accessories. 
     Accessories such as headphones (e.g., earbuds, over-the-ear headphones, etc.) may be coupled to electronic device  10  using a cable or other signal path. The cable or other signal path may be terminated with an electrical connector. The electrical connector may be a plug (e.g., a male connector such as an audio plug or data plug) or other suitable connector structure. The connector may be an audio connector, a connector that includes contacts that carry digital signals, a connector that includes contacts that carry audio signals, a connector that includes contacts that carry analog signals, and/or a connector that includes contacts that carry power signals. 
     The plug or other connector may be provided at the end of a cable that is pigtailed to a set of headphones or other accessory, may be part of a stand-alone cable (e.g., an extension cable or a cable that has one end that plugs into an accessory and an opposing end with a connector to be connected to device  10 ), or may be provided as part of an accessory (e.g., as part of a dock). Arrangements in which the external equipment that operates with device  10  is a set of headphones or other accessory having an associated cable terminated with an audio jack may sometimes be described herein as an example. This is, however, merely illustrative. In general, device  10  may operate in cooperation with any suitable external electronic equipment having a connector. 
     When the audio plug or other connector associated with the accessory is plugged into device  10 , antenna structures such as the antenna resonating element structures formed from peripheral conductive structures  16 - 1  may be electromagnetically coupled to the plug, cable, and other conductive portions of the accessory. For example, a headphone cable and audio plug may be coupled to peripheral conductive structures  16 - 1  through capacitive coupling. This gives rise for a potential for interference between the accessory and antenna  40 , because antenna currents from peripheral conductive structures  16 - 1  may flow through the audio plug and other conductive accessory structures. When the accessory is not present, antenna  40  will not be disrupted by the presence of the accessory and will operate normally. When the set of headphones or other accessory is plugged into an audio jack near peripheral conductive structures  16 - 1  in device  10 , however, there is a risk of interference with antenna  40 . 
     To ensure that antenna  40  operates satisfactorily regardless of whether an accessory is plugged into device  10  or not, interference mitigation circuitry may be coupled to the audio jack. This circuitry forms a radio-frequency short circuit path that draws parasitic antenna current to a known ground location whenever an audio plug is inserted into the audio jack. The interference mitigation circuitry may be tuned to ensure that antenna  40  operates satisfactorily in the presence of the audio plug. When the plug is not present, the interference mitigation circuitry will not interfere with the desired operation of the antenna. The interference mitigation circuitry therefore allows antenna  40  to operate satisfactorily both in the presence of the audio plug and in the absence of the audio plug. 
       FIG. 9  is a diagram showing an illustrative system that includes an accessory having a cable and an audio plug. The illustrative system of  FIG. 9  also includes an associated audio jack in device  10  for receiving the audio plug. As shown in  FIG. 9 , device  10  may include a connector such as audio jack connector  134 . Connector  134  may have contacts  138  that mate with corresponding contacts  130  in plug  128  of accessory  120  when plug  128  is inserted in audio jack  134 . Signal lines  136  may be used to distribute signals from connectors such as audio jack  134  to circuitry in device  10  such as audio circuitry and other input-output circuitry  30 . In the example of  FIG. 9 , audio jack  134  has four contacts (pins)  138 . This is merely illustrative. Audio jack  134  may have any suitable number of contacts (e.g., one or more, two or more, three or more, four or more, five or more, six or more, ten or more, etc.). Accessory connectors such as plug  128  may likewise have any suitable number of contacts  130  (e.g., one or more, two or more, three or more, four or more, five or more, six or more, ten or more, etc.). Insulating structures  132  may separate respective contacts  130  from each other. Audio plug  128  may be a ⅛″ audio plug such as a tip-ring-sleeve (TRS) connector, a tip-ring-ring-sleeve (TRRS) connector, or other suitable connector. The audio plug configuration of  FIG. 9  is merely illustrative. 
     Accessory  120  may include a cable such as cable  124 . Cable  124  may include signal paths  126  that couple contacts  130  to corresponding components  122  such as left and right speakers (e.g., earbuds, etc.), buttons (e.g., buttons in a button controller in a headset), microphones (e.g., noise-cancellation microphones and associated control circuitry), integrated circuits, and other electronic components  122  in accessory  120 . Cable  124  may have a connector that plugs into a mating connector in components  122  or may be pigtailed to components  122  (as examples). 
     Audio jack  134  may be mounted in device  10  in a location that allows mating audio plug  128  to be inserted into audio jack  134 . For example, audio jack  134  may be mounted in alignment with a housing opening such as opening  140  in peripheral conductive structures  16 - 1  in housing  12  (i.e., jack  134  may be mounted in an opening in structures  16 - 1  or other structures in housing  12 ). This may give rise to coupling between antenna  40  (which may have antenna currents that flow through structures  16 - 1 ) and audio plug  128  (i.e., when plug  128  is inserted within jack  134 ). The potential of audio plug  128  and cable  124  to carry a portion of the antenna currents associated with operation of antenna  40  gives rise to a risk that the performance of antenna  40  will be adversely affected when audio plug  128  is present in device  10 . 
     This risk can be reduced or eliminated by incorporating interference mitigation circuitry in device  10 . The interference mitigation circuitry may be implemented using circuit components such as inductors and capacitors in the vicinity of audio jack  134 . In particular, the effects of interference can be mitigated using interference mitigation circuitry that is coupled to contacts  138 . The interference mitigation circuitry may, for example, be interposed between contacts  138  and ground. Audio circuitry and other input-output circuitry  30  in device  10  may be coupled to the interference mitigation circuitry (e.g., to allow the audio circuitry to transmit and receive signals through contacts  138 ). 
       FIG. 10  is a diagram of a portion of device  10  in which illustrative interference mitigation circuitry  170  has been coupled to audio jack  134  to prevent the presence of audio plug  128  from disrupting operation of antenna  40 . In the example of  FIG. 10 , interference mitigation circuitry  170  includes inductor(s)  148  and bypass capacitor(s)  146 . 
     As shown in  FIG. 10 , audio jack  134  may be mounted to peripheral conductive structures  16 - 1  in electronic device housing  12  of device  10 . Peripheral conductive structures  16 - 1  may form antenna resonating element  108  or other conductive antenna structures for antenna  40 . When it is desired to couple accessory  120  to device  10 , a user may insert audio plug  128  into audio jack  134  through an opening in peripheral conductive housing structures  16 - 1  (see, e.g., opening  140  of  FIG. 9 ). Insulation  150  (e.g., plastic, glass, ceramic, or other dielectric material) may surround the opening in structures  16 - 1  to ensure that metal portions of audio plug  128  do not short to structures  16 - 1 . There are four contacts  130  in plug  128  of  FIG. 10 , two of which are coupled to contacts  138  and interference mitigation circuitry  170 . This is merely illustrative. Plug  128  may have any suitable number of contacts  130  and any suitable number of contacts  130  may be connected to respective inductors and capacitors an interference mitigation circuit. 
     One or more of the contacts  130  of plug  128  may be electrically connected to one or more corresponding contacts in audio jack  134  such as illustrative contacts  138 . Audio circuitry  142  may be coupled to contacts  138  (and thereby contacts  130 ) through series-coupled inductors  144  and  148 . Each inductor  144  has a terminal coupled to a respective one of inductors  148  at a respective one of nodes N. Bypass capacitors  146  are each coupled between a respective one of nodes N and ground  104 . Due to the close proximity of audio jack  128  and structures  16 - 1 , audio jack  128  (e.g., metal associated with contacts  130  and other signal paths in cable  124  and audio jack  128 ) is capacitively coupled to structures  16 - 1 . As a result, antenna currents I from structures  16 - 1  may flow into audio plug  128  and, via contacts  138  and interference mitigation circuitry  170  to ground  104 . 
     Audio circuitry  142  may be coupled to audio jack  134  by inductors  144  and interference mitigation circuitry  170 . Inductors  144  may serve as radio-frequency signal blocking inductors (chokes) that prevent radio-frequency antenna signals associated with operation of antenna  40  from reaching audio circuitry  142 . At the same time, audio signals associated with audio circuitry  142  may pass through inductors  144  (and through inductors  148 ). Inductors  144  (and the circuitry of inductors  148  and capacitors  146 ) may serve as low pass filters each of which has a cut-off frequency that is above audio signal frequencies (e.g., above 20 kHz) and below radio-frequency signal frequencies (e.g., below 700 MHz, below 1 MHz, etc.). 
     Inductors  144  and inductors  148  are coupled in series between the input-output ports of audio circuitry  142  and respective contacts  138  in audio jack  134 . For example, in each signal path between a respective input-output port in circuitry  142  and a respective contact  138 , an inductor  144  may be coupled to an inductor  148  at a node N. Each inductor  144  may have a first terminal connected to a port of audio circuitry  142  and a second terminal connected to node N. Each inductor  148  may have a first terminal connected to node N and a second terminal coupled to one of contacts  138 . Bypass capacitors  146  are each coupled between a node N and ground  104 . The size of capacitors  146  is preferably sufficiently large to provide a low-impedance path to ground for alternating current signals such as radio-frequency antenna currents I. 
     Interference mitigation circuitry  170  is preferably configured to ensure that antenna  40  will exhibit the same or similar performance both when audio plug  128  is absent from jack  134  and device  10  and when audio plug  128  is present within jack  134  and device  10 . In the absence of plug  128 , antenna currents flow within peripheral conductive structures  16 - 1 . As shown in  FIG. 11 , there may be a distance L associated with the length of structures  16 - 1  between feed terminal  98  (the feed of antenna  40 ) and the end of structures  16 - 1  (e.g., the end of structures  16 - 1  that is on the right-hand side of device  10  in the example of  FIG. 11 ). In the absence of audio plug  128 , antenna currents may flow over distance L between the antenna feed of antenna  40  and the end of antenna resonating element  108 . The length of this branch of antenna resonating element  108  (i.e., length L) affects the frequency response of antenna  40  (e.g., L may be about a quarter of a wavelength at a resonant frequency of interest for antenna  40 ). 
     When audio plug  128  is plugged into device  10 , parasitic antenna currents are drawn into plug  128  and jack  134  from structures  16 - 1 . In the absence of interference mitigation circuitry  170 , these currents can flow over an effective distance L′. As shown in  FIG. 11 , a part of audio jack  134  (e.g., the tip of jack  134  or other portion of jack  134 ) may overlap antenna ground  104 . As a result, there may be a coupling capacitance between audio jack  134  (and therefore plug  128 ) and ground  104 . Because of the capacitance between ground  104  and plug  128  due to the overlap of jack  134  and ground  104 , signals from plug  128  can flow to ground  104  from structures  16 - 1  (as illustrated by effective resonating element length L′). The presence of the capacitance in this path electrically increases the effective length of distance L′. The physical length of this current path and increase in the effective length of distance L′ due to the presence of the overlap (coupling) capacitance between ground  104  and plug  128  tends to make length L′ larger in magnitude than length L. As a result, the frequency response of antenna  40  may be undesirably degraded and shifted to a lower resonant frequency than desired in the absence of interference mitigation circuitry  170 . 
     In the presence of interference mitigation circuitry  170 , however, bypass capacitors  146  allow the coupled antenna current in plug  128  to pass to ground  104  directly (i.e., without passing thought the coupling capacitance between ground  104  and overlapping audio plug  128 ). The presence of inductors  148  helps reduce the size of the effective length (length L″) of the antenna current path when plug  128  is in jack  134  and thereby ensures that the antenna resonance is as desired. The magnitude of capacitors  146  may be relatively large (e.g., 56 pF, other values over 20 pF or over 40 pF or values under 70 pF). This relatively large size allows radio-frequency signals to be shorted to ground  104  without having an overly significant impact on effective length L″. The value of inductors  148  (i.e., the values selected to ensure that the effective length L″ of the path for antenna currents that are passing through structures  16 - 1  and plug  128  to ground from the antenna feed is as desired) may be, for example, 20 nH or less, 10 nH or less, etc. 
     Inductors  148  may be fixed inductors (i.e., the sizes of inductors  148  may be selected as part of the design process for device  10 ) and/or may be variable inductors (e.g., inductors that have inductance values that can be adjusted in real time by control circuitry in device  10  to enhance antenna performance under a variety of operating conditions). 
     By appropriate selection of the size of the capacitance of each bypass capacitor  144  and the size of each series inductor  148 , antenna  40  can perform satisfactorily under both plug in and plug out conditions. The performance of antenna  40  under a variety of different operating scenarios is shown in  FIG. 12 . In the graph of  FIG. 12 , antenna performance (i.e., antenna efficiency) has been plotted as a function of operating frequency f for frequencies between low frequency fa and high frequency fb. Frequencies fa and fb may be, for example, 700 MHz and 960 MHz or other frequencies associated with the operation of antenna  40 . 
     In the absence of plug  128 , antenna  40  may exhibit antenna resonance  160 . In this example, the antenna frequency response associated with resonance  160  is the normal desired frequency response for antenna  40  and is the frequency response achieved in device  10  when plug  128  is not present. 
     In the absence of interference mitigation circuitry  170 , the presence of audio plug  128  may create an antenna current path to ground  104  having an effective length L′ that is greater than L due to the location and shape of plug  128  and due to the coupling capacitance associated with the overlap between plug  128  and ground  104 . This increase in effective path length L′ over nominal length L may result in antenna detuning. In particular, desired antenna resonance  160  may be shifted to a lower frequency than desired and may become less efficient, as shown by degraded antenna resonance peak  162  of  FIG. 12 . 
     To avoid undesired performance degradations of the type shown by curve  162 , interference mitigation circuitry  170  may be incorporated into device  10 . In the presence of bypass capacitor(s)  146 , antenna signals will be grounded at ground  104  without passing through the coupling capacitance between plug  128  and overlapped ground  104 . Because the value of capacitors  146  is relatively large, antenna signals will tend to be drawn to ground  104  through bypass capacitors  146  rather than being coupled into wires  126  in cable  124 . Due to the presence of the bypass capacitor and the geometry of the bypass path to ground  104 , however, resonance  160  may tend to shift to higher frequencies (in the absence of inductors  148 ), as illustrated by antenna resonance  164  of  FIG. 12 . 
     To ensure that antenna  40  performs as desired, inductors  148  may be coupled between capacitors  146  and plug  128  (i.e., between capacitors  146  and contacts  138 ), as shown in interference mitigation circuitry  170  of  FIG. 10 . Inductors  148  serve as resonant frequency tuning inductors and shift the resonant frequency of antenna  40  from that shown by resonant curve  164  of  FIG. 12  to that of resonant curve  166  of  FIG. 12 . As shown in  FIG. 12 , antenna resonance  166 , which may be achieved when plug  128  is present in an antenna  40 , may be the same as or nearly the same as normal operation antenna resonance  160 . 
     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: 20140903
Publication Date: 20170509
Grant Date: 20170509
Priority Date: 20140903
Inventors: HAN LIANG
TSAI MING-JU
MOW MATTHEW A.
ZHOU YIJUN
PASCOLINI MATTIA
YARGA SALIH
AYALA VAZQUEZ ENRIQUE
HU HONGFEI
HAN XU
SCHLUB ROBERT W.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/52", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/50", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q21/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q13/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/52", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 54267067