Patent Grant
9793616
This relates generally to electronic devices, and more particularly, to antennas for electronic devices with wireless communications circuitry.
Electronic devices such as portable computers and cellular telephones are often provided with wireless communications capabilities. For example, electronic devices may use long-range wireless communications circuitry such as cellular telephone circuitry to communicate using cellular telephone bands. Electronic devices may use short-range wireless communications circuitry such as wireless local area network communications circuitry to handle communications with nearby equipment. Electronic devices may also be provided with satellite navigation system receivers and other wireless circuitry such as near field communications circuitry. Near field communications schemes involve electromagnetically coupled communications over short distances, typically 20 cm or less.
To satisfy consumer demand for small form factor wireless devices, manufacturers are continually striving to implement wireless communications circuitry such as antenna components using compact structures. At the same time, there is a desire for wireless devices to cover a growing number of communications bands. For example, it may be desirable for a wireless device to cover a near field communications band while simultaneously covering additional non-near-field (far field) bands such cellular telephone bands, wireless local area network bands, and satellite navigation system bands.
Because antennas have the potential to interfere with each other and with components in a wireless device, care must be taken when incorporating antennas into an electronic device. Moreover, care must be taken to ensure that the antennas and wireless circuitry in a device are able to exhibit satisfactory performance over a range of operating frequencies.
It would therefore be desirable to be able to provide improved wireless communications circuitry for wireless electronic devices.
Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The radio-frequency transceiver circuitry may include near field communications circuitry that operates in a near field communications band. The radio-frequency transceiver circuitry may also include non-near-field-communications circuitry (far field communications circuitry) such as such as cellular telephone, satellite navigation system, or wireless local area network transceiver circuitry. The non-near-field communications circuitry may operate in one or more non-near-field communications bands.
The antenna structures may include conductive housing structures such as a peripheral conductive housing member. The antenna structures may be based on an inverted-F antenna resonating element or may have other types of antenna resonating element. The antenna structures may be configured to handle signals associated with the non-near-field communications circuitry such as cellular telephone signals, satellite navigation system signals, or wireless local area network signals. The antenna structures may also be used to form a near field communications loop antenna. The near field communications loop antenna may handle signals associated with the near field communications circuitry. Sharing the antenna structures between near field and non-near-field applications allows device size to be minimized.
Antenna structures may be provided with paths that form multiple loops for the loop antenna. The loops may be formed at different locations within an inverted-F antenna resonating element or may be concentric.
Antenna structures may be formed at opposing ends of an electronic device. Combining circuitry may allow the near field communications circuitry and the non-near-field communications circuitry to be coupled to common antenna structures. In configurations for an electronic device that include antenna structures at opposing ends of the device, near field communications signals may be transmitted and received at both ends of the device. Near field communications signals may also be transmitted from front and rear faces of an electronic device.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
Electronic devices such as electronic device 10 of
Antenna structures 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 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 and/or may form vertical sidewalls for the device.
The antenna structures may be configured to handle both near field communications (e.g., communications in a near field communications band such as a 13.56 MHz band) and non-near-field communications (sometimes referred to as far field communications) such as cellular telephone communications, wireless local area network communications, and satellite navigation system communications. Near field communications typically involve communication distances of less than about 20 cm. Far field communications typically involved communication distances of multiple meters or miles.
Signal combining circuitry such as a duplexer or switching circuitry may be used to allow a near field communications transceiver and non-near-field-communications transceiver circuitry to share the antenna structures. By reducing or eliminating the need for separate near field communications antenna structures to handle near field communications signals, antenna structures that are shared between near field communication and non-near-field-communications circuitry can help minimize device size.
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 cellular telephone, or a media player. Device 10 may also be a television, a set-top box, a desktop computer, a computer monitor into which a computer has been integrated, a television, a computer monitor, 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 cover glass layer or a layer of clear plastic may cover the surface of display 14. Buttons such as button 19 may pass through openings in the display cover layer or other outer layer in display 14. The cover glass may also have other openings such as an opening for speaker port 26.
Housing 12 may include a peripheral member such as member 16. Member 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, member 16 may have a rectangular ring shape (as an example). Member 16 or part of member 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). Member 16 may also, if desired, form sidewall structures for device 10 (e.g., by forming a band with vertical sidewalls, by forming a band with rounded sidewalls, etc.).
Member 16 may be formed of a conductive material and may therefore sometimes be referred to as a peripheral conductive member or conductive housing structures. Member 16 may be formed from a metal such as stainless steel, aluminum, or other suitable materials. One, two, three, or more than three separate structures may be used in forming member 16.
It is not necessary for member 16 to have a uniform cross-section. For example, the top portion of member 16 may, if desired, have an inwardly protruding lip that helps hold display 14 in place. If desired, the bottom portion of member 16 may also have an enlarged lip (e.g., in the plane of the rear surface of device 10). In the example of
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 sheet metal housing structure (sometimes referred to as a midplate) that spans the walls of housing 12 (i.e., a substantially rectangular member that is welded or otherwise connected between opposing sides of member 16), printed circuit boards, and other internal conductive structures. These conductive structures may be located in the center of housing 12 under display 14 (as an example).
In regions 22 and 20, openings (gaps) may be formed within the conductive structures of device 10 (e.g., between peripheral conductive member 16 and opposing conductive structures such as conductive housing structures, a conductive ground plane associated with a printed circuit board, and conductive electrical components in device 10). These openings may be filled with air, plastic, and other dielectrics. Conductive housing structures and other conductive structures in device 10 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 arm from the ground plane, or may otherwise serve as part of antenna structures formed 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, 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
Portions of member 16 may be provided with gap structures. For example, member 16 may be provided with one or more gaps such as gaps 18, as shown in
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 non-near-field-communications such as local area network communications, voice and data cellular telephone communications, global positioning system (GPS) communications or other satellite navigation system communications, Bluetooth® communications, etc. Device 10 may use at least part of the same antenna structures for supporting near field communications (e.g., communications at 13.56 MHz).
A schematic diagram of an illustrative configuration that may be used for electronic device 10 is shown in
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, near field communications protocols, etc.
Circuitry 28 may be configured to implement control algorithms that control the use of antennas in device 10. For example, circuitry 28 may perform signal quality monitoring operations, sensor monitoring operations, and other data gathering operations and may, in response to the gathered data and information on which communications bands are to be used in device 10, control which antenna structures within device 10 are being used to receive and process data and/or may adjust one or more switches, tunable elements, or other adjustable circuits in device 10 to adjust antenna performance. As an example, circuitry 28 may control which of two or more antennas is being used to receive incoming radio-frequency signals, may control which of two or more antennas is being used to transmit radio-frequency signals, may control the process of routing incoming data streams over two or more antennas in device 10 in parallel, may tune an antenna to cover a desired communications band, may perform time-division multiplexing operations to share antenna structures between near field and non-near-field communications circuitry, etc. In performing these control operations, circuitry 28 may open and close switches, may turn on and off receivers and transmitters, may adjust impedance matching circuits, may configure switches in front-end-module (FEM) radio-frequency circuits that are interposed between radio-frequency transceiver circuitry and antenna structures (e.g., filtering and switching circuits used for impedance matching and signal routing), may adjust switches, tunable circuits, and other adjustable circuit elements that are formed as part of an antenna or that are coupled to an antenna or a signal path associated with an antenna, and may otherwise control and adjust the components of device 10.
Input-output circuitry 30 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 circuitry 30 may include input-output devices 32. Input-output devices 32 may include touch screens, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device 10 by supplying commands through input-output devices 32 and may receive status information and other output from device 10 using the output resources of input-output devices 32.
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, 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 satellite navigation system receiver circuitry such as Global Positioning System (GPS) receiver circuitry 35 (e.g., for receiving satellite positioning signals at 1575 MHz) or satellite navigation system receiver circuitry associated with other satellite navigation systems.
Wireless local area network transceiver circuitry 36 in wireless communications circuitry 34 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 cellular telephone bands such as bands in frequency ranges of about 700 MHz to about 2700 MHz or bands at higher or lower frequencies.
Wireless communications circuitry 34 may include near field communications circuitry 42. Near field communications circuitry 42 may handle near field communications at frequencies such as the near field communications frequency of 13.56 MHz or other near field communications frequencies of interest.
Circuitry 44 such as satellite navigation system receiver circuitry 35, wireless local area network transceiver circuitry 36, and cellular telephone transceiver circuitry 38 that does not involve near field communications may sometimes collectively be referred to as non-near-field communications circuitry or far field communications circuitry.
Antenna structures 40 may be shared by non-near-field communications circuitry 44 and near field communications circuitry 42.
If desired, communications circuitry 34 may include circuitry for other short-range and long-range wireless links. For example, wireless communications circuitry 34 may include wireless circuitry for receiving radio and television signals, paging circuits, etc. In near field communications, wireless signals are typically conveyed over distances of less than 20 cm. 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 antenna structures 40. Antenna structures 40 may include one or more antennas. Antennas structures 40 may be formed using any suitable antenna types. For example, antenna structures 40 may include antennas with resonating elements that are formed from loop antenna structure, patch antenna structures, inverted-F antenna structures, closed and open slot antenna structures, planar inverted-F antenna structures, helical antenna structures, strip antennas, monopoles, dipoles, 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.
To accommodate near field communications within the potentially tight confines of device housing 12, antenna structures 40 may be shared between non-near-field communications circuitry 44 and near field communications circuitry 42. When, for example, it is desired to transmit and receive cellular telephone signals or other non-near-field communications, antenna structures 40 may be used by transceiver circuitry 38. When it is desired to transmit and receive near field communications signals, antenna structures 40 may be used to near field communications circuitry 42.
Combining circuitry 50 allows antenna structures 40 be used by both near field communications circuitry 42 and non-near-field communications circuitry 44. In configurations for combining circuitry that are based on actively switched circuits, control circuitry 28 can make adjustments to circuitry 50 and other circuitry in real time to ensure that near field communications signals and non-near-field communications signals are routed properly. In configurations for combining circuitry 50 that are implemented using passive components (e.g., a network of one or more components such as inductors, capacitors, resistors, etc. to form a duplexer), signals can be routed between antenna structures 40 and near field communications circuitry 42 and non-near-field communications circuitry 44 based on signal frequency (e.g., by routing lower frequency signals such as signals at 13.56 MHz between antenna structures 40 and near field communications circuitry 42 and by routing higher frequency signals such as signals above 700 MHz between antenna structures 40 and non-near-field-communications transceiver circuitry 44).
Paths such as paths 54, 52, and 56 may be used in routing signals between antenna structures 40 and transceiver circuitry 42 and 44.
Paths such paths 54, 52, and 56 may include pairs of signal lines. Each pair of signal lines may form a transmission line or part of a transmission line. Transmission lines in device 10 may be formed from coaxial cables, microstrip transmission lines or other transmission lines that are formed from metal traces on dielectric substrates (e.g., flexible printed circuit substrates formed from flexible layers of polyimide or other sheets of polymer or rigid printed circuit boards formed from fiberglass-filled epoxy), or other suitable transmission line structures.
As shown in the example of
If desired, antenna structures 40 may be provided with multiple antenna feeds and/or components that are actively tuned (e.g., switches that are controlled by control signals from control circuitry 28). Configuration in which antenna structures 40 are formed from passive components and have a single antenna feed are sometimes described herein as an example.
Combining circuitry 50 may include switching circuitry or passive circuitry for multiplexing the near field communications signals associated with near field communications circuitry 42 and the non-near-field communications signals associated with non-near-field communications circuitry 44. In the example of
Duplexer 58 includes duplexing circuitry such as inductor 70 and capacitor 72. This circuitry allows duplexer 58 to route signals between antenna structures 40 and circuits 42 and 44 based on signal frequency. For example, the inductance value for inductor 70 may be selected so that inductor 70 exhibits a low impedance (i.e., a short circuit condition) at relatively low frequencies such as the frequencies associated with near field communications circuitry 42 (e.g., 13.56 MHz). Inductor 70 therefore allows these signals to pass from near field communications circuitry 42 to antenna structures 40 during signal transmission operations and to pass from antenna structures 40 to near field communications circuitry 42 during signal reception operations. The capacitance value for capacitor 72 may be selected so that capacitor 72 exhibits a high impedance (i.e., an open circuit condition) at relatively low frequencies such as the frequencies associated with near field communications circuitry 42 (e.g., 13.56 MHz) and thereby prevents near field communications signals from passing to non-near-field communications circuitry 44 (i.e., capacitor 58 prevents near field communications signals from interfering with the operation of non-near-field communications circuitry 44).
At high frequencies such as frequencies above 700 MHz that are associated with the operation of non-near-field communications circuitry 44, inductor 70 will exhibit a high impedance (i.e., inductor 70 will form an open circuit). This will prevent potentially interfering non-near-field communications signals associated with circuitry 44 from reaching near field communications circuitry 42. At the relatively high frequencies associated with non-near-field communications signals for circuitry 44, capacitor 72 will exhibit a relatively low impedance (i.e., capacitor 72 will form a short circuit), so that circuitry 44 can transmit and receive signals using antenna structures 40.
Antenna structures 40 may include an antenna resonating element and an antenna ground. In the example of
Inverted-F antenna resonating element 62 may, as an example, have a main arm that is formed from a segment of peripheral conductive housing member 16 of
Antenna resonating element 62 may have resonating element arm portions such as low band branch B1, which contributes to an antenna resonance in a lower portion of the 700-2700 MHz cellular telephone spectrum (or other suitable frequency), and high band branch B2, which contributes to an antenna resonance in an upper portion of the 700-2700 MHz spectrum. Antenna resonating element arms B1 and B2 may be configured to exhibit resonances that cover cellular telephone frequencies, satellite navigation system frequencies, wireless local area network frequencies, or other suitable wireless frequencies when antenna structures 40 are operating in an inverted-F antenna mode.
Opening 76 is located between the main resonating element arm structure formed from branches B1 and B2 and antenna ground 60. Opening 76 may be filled with a dielectric such as air and/or dielectric such as plastic and other dielectric materials associated with the housing and components of device 10. Short circuit path 64 spans opening 76 and forms a return path between the main resonating element arm of resonating element 62 and antenna ground 60. Antenna feed path 54P spans opening 76 and is coupled to node 74 in duplexer circuitry 58. Node 74 and feed path 54P may form an antenna feed port for combining circuitry 50.
With a sharing configuration of the type shown in
Loop current signals 66 may, for example, circulate in the antenna loop formed by path 54P, segment 80 of resonating element arm B1, short circuit path 64, and antenna ground 60 (which is grounded to ground path 54N in path 54). Loop currents 66 may be induced in antenna structures 40 when antenna structures 40 are exposed to incoming near field communications signals 84 from external equipment 82 and/or may be generated by near field communications circuitry 42. The conductive loop of structures formed by path 54P, segment 80 of resonating element arm B1, short circuit path 64, and antenna ground 60 that supports loop currents 66 serves as a loop antenna for near field communications circuitry 42.
External equipment such as external equipment 82 may communicate with near field communications circuitry 42 via magnetic induction. Equipment 82 may include a loop antenna such as loop antenna 86 that is controlled by control circuitry 88. Loop antenna 86 and the loop antenna formed from antenna structures 40 are electromagnetically coupled, as indicated by near field communications signals 84 of
During operation of non-near-field communications circuitry 44 at frequencies above 700 MHz, path 64-1 forms a short circuit that spans gap 76 and forms a return path between the main antenna resonating element arm in inverted-F antenna resonating element 62 and ground 60 (as with short circuit path 64 of
During operation of near field communications circuitry 42 at frequencies below 700 MHz (e.g., at a frequency below 100 MHz such as in a near field communications band at 13.56 MHz), capacitor 92 exhibits a high impedance so that path 64-1 forms an open circuit and does not participate in the performance of antenna structures 40. Inductor 90 exhibits a low impedance, so that path 64-2 shorts segment 80′ to ground 60 and forms part of a near field communications loop antenna. In this configuration, loop currents flow through the loop antenna structures formed from feed path 54P, segment 80′ of the main resonating element arm of resonating element 62, short circuit path 64-2, and ground 60, as illustrated by loop currents 66 of
In the illustrative configuration of
Paths 64-2A and 64-2B span opposing ends of gap 76. If desired, inductors 90A and 90B may span gaps in housing band 16 such as gaps 18 of
If desired, the conductive structures in antenna structures 40 may be configured to form multiple overlapping loops (i.e., multiple turns in a multi-loop antenna), as shown in
At near field communications frequencies (e.g., frequencies below 700 MHz or below 100 MHz such as frequencies in a near field communications band at 13.56 MHz), capacitor 92 may have a high impedance and path 100 may form an open circuit. Inductors 90′ may exhibit low impedances, so that paths 102 (in conjunction with path 54P, segment 80″ of the main resonating element arm in resonating element 62, and ground 60) form multiple concentric loops. The concentric loops form a near field communications loop antenna portion of antenna structures 40. In the example of
As described in connection with combining circuitry 50, combining circuitry 50A and 50B may be used as multiplexing circuits so that non-near-field communications circuitry 44 can share antenna structures 40A and 40B with near field communications circuitry 42. Switching circuitry 108 may be used to couple non-near-field communications circuitry 44 to antenna structures 40A or antenna structures 40B (e.g., antenna structures 40A or 40B may be switched into use based on signal strength criteria, proximity sensor signals, or other suitable antenna selection criteria).
Antenna structures 40A and 40B may each include structures that form a loop antenna portion for near field communications as described in connection with
As shown in
The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5936583 | Sekine et al. | Aug 1999 | A |
| 6308051 | Atokawa | Oct 2001 | B1 |
| 6556630 | Brinsfield et al. | Apr 2003 | B1 |
| 6600450 | Efanov et al. | Jul 2003 | B1 |
| 6950410 | Brandt | Sep 2005 | B1 |
| 7408515 | Leisten | Aug 2008 | B2 |
| 7423606 | Knadle, Jr. et al. | Sep 2008 | B2 |
| 7450072 | Kim et al. | Nov 2008 | B2 |
| 7505001 | Deavours et al. | Mar 2009 | B2 |
| 7772941 | Yeung et al. | Aug 2010 | B2 |
| 7834813 | Caimi et al. | Nov 2010 | B2 |
| 7843347 | Nikitin et al. | Nov 2010 | B2 |
| 7873385 | Boireau et al. | Jan 2011 | B2 |
| 7973722 | Hill et al. | Jul 2011 | B1 |
| 8041227 | Holcombe et al. | Oct 2011 | B2 |
| 8238825 | Rofougaran et al. | Aug 2012 | B2 |
| 8369959 | Meskens | Feb 2013 | B2 |
| 8417296 | Caballero et al. | Apr 2013 | B2 |
| 8432322 | Amm et al. | Apr 2013 | B2 |
| 8466839 | Schlub et al. | Jun 2013 | B2 |
| 8577289 | Schlub et al. | Nov 2013 | B2 |
| 8606215 | Sharma | Dec 2013 | B2 |
| 8818450 | Caballero et al. | Aug 2014 | B2 |
| 8947305 | Amm et al. | Feb 2015 | B2 |
| 20060055618 | Poilasne et al. | Mar 2006 | A1 |
| 20070279287 | Castaneda et al. | Dec 2007 | A1 |
| 20080081631 | Rofougaran | Apr 2008 | A1 |
| 20090058735 | Hill et al. | Mar 2009 | A1 |
| 20090073070 | Rofougaran | Mar 2009 | A1 |
| 20090143028 | Kim | Jun 2009 | A1 |
| 20090180451 | Alpert et al. | Jul 2009 | A1 |
| 20100007568 | Fear et al. | Jan 2010 | A1 |
| 20100222010 | Ozaki et al. | Sep 2010 | A1 |
| 20100279734 | Karkinen et al. | Nov 2010 | A1 |
| 20110148733 | Fahs et al. | Jun 2011 | A1 |
| 20110241949 | Nickel et al. | Oct 2011 | A1 |
| 20110243120 | Ginsburg et al. | Oct 2011 | A1 |
| 20120258660 | Rajendran et al. | Oct 2012 | A1 |
| 20120299785 | Bevelacqua | Nov 2012 | A1 |
| 20130002511 | Higaki et al. | Jan 2013 | A1 |
| 20130017867 | Lee et al. | Jan 2013 | A1 |
| 20130019413 | Velazquez et al. | Jan 2013 | A1 |
| 20130057446 | Hirobe et al. | Mar 2013 | A1 |
| 20130109433 | Wang et al. | May 2013 | A1 |
| 20130189923 | Lewin | Jul 2013 | A1 |
| 20130194139 | Nickel et al. | Aug 2013 | A1 |
| 20130217342 | Abdul-Gaffoor et al. | Aug 2013 | A1 |
| 20130231046 | Pope et al. | Sep 2013 | A1 |
| 20130241796 | Nagumo et al. | Sep 2013 | A1 |
| 20130300618 | Yarga et al. | Nov 2013 | A1 |
| 20140045442 | Caruana et al. | Feb 2014 | A1 |
| 20140062812 | Smith et al. | Mar 2014 | A1 |
| 20140128032 | Muthukumar | May 2014 | A1 |
| 20140139380 | Ouyang et al. | May 2014 | A1 |
| 20140306857 | Bevelacqua et al. | Oct 2014 | A1 |
| 20140315592 | Schlub et al. | Oct 2014 | A1 |
| 20140328488 | Caballero et al. | Nov 2014 | A1 |
| 20150249292 | Ouyang et al. | Sep 2015 | A1 |
| 20150249485 | Ouyang et al. | Sep 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 2498336 | Sep 2012 | EP |
| 2528165 | Nov 2012 | EP |
| 2618497 | Jul 2013 | EP |
| 10-2012-0084770 | Jul 2012 | KR |
| 10-2012-0102516 | Sep 2012 | KR |
| 2012-0103297 | Sep 2012 | KR |
| 201240379 | Oct 2012 | TW |
| 2012127097 | Sep 2012 | WO |
| 2013147823 | Oct 2013 | WO |
| Entry |
|---|
| “Antenna Theory: A Review,” Balanis, Proc. IEEE vol. 80 No. 1 Jan. 1992. |
| Irci et al., U.S. Appl. No. 14/262,486, filed Apr. 25, 2014. |
| Yarga et al., U.S. Appl. No. 14/254,604, filed Apr. 16, 2014. |
| Number | Date | Country | |
|---|---|---|---|
| 20140139380 A1 | May 2014 | US |
