Patent Publication Number: US-11652511-B2

Title: Inductor coil structures to influence wireless transmission performance

Description:
RELATED APPLICATION 
     This application is a continuation of, and claims priority to, U.S. Non-Provisional application Ser. No. 15/989,793, filed May 25, 2018, and entitled “INDUCTOR COIL STRUCTURES TO INFLUENCE WIRELESS TRANSMISSION PERFORMANCE,” which in turn claims priority to U.S. Provisional Application No. 62/511,688, filed on May 26, 2017, and entitled “MAGNETICALLY COUPLED SYSTEM,” each of which is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to the wireless transmission of electrical energy and data. More specifically, this application relates to various embodiments which enable the transmission of wireless electrical energy by near-field magnetic coupling. 
     BACKGROUND 
     Near field magnetic coupling (NFMC) is a commonly employed technique to wirelessly transfer electrical energy. The electrical energy may be used to directly power a device, charge a battery or both. 
     In NFMC an oscillating magnetic field generated by a transmitting antenna passes through a receiving antenna that is spaced from the transmitting antenna, thereby creating an alternating electrical current that is received by the receiving antenna. 
     However, the oscillating magnetic field radiates in multiple directions from the transmitting antenna. Thus, transmission of electrical energy between opposed transmitting and receiving antennas may be inefficient as some of the transmitted magnetic fields may radiate in a direction away from the receiving antenna. 
     In contrast to the prior art, the subject technology provides a wireless electrical power transmitting and receiving antenna and system thereof that increases transmission of electrical energy therebetween, particularly in the presence of a metallic environment. Furthermore, in contrast to the prior art, the wireless electrical power transmitting system enables multiple electronic devices to be electrically charged or powered by positioning one or more devices in non-limiting orientations with respect to the transmitting antenna. Therefore, multiple devices may be electrically charged or powered simultaneously, regardless of their physical orientation with the transmitting antenna. 
     SUMMARY 
     The present disclosure relates to the transfer of wireless electrical energy and/or data between a transmitting antenna and a receiving antenna. In one or more embodiments, at least one of a transmitting antenna and a receiving antenna comprising an inductor coil having a figure eight configuration is disclosed. In one or more embodiments, a “figure eight” coil confirmation comprises at least one filar, forming the coil, crosses over itself thereby forming a “figure-eight” coil configuration. Such an inductor coil configuration improves the efficiency of wireless electrical energy transmission by focusing the radiating magnetic field in a uniform direction, towards the receiving antenna. In one or more embodiments the figure eight coil configuration minimizes coupling of magnetic fields with the surrounding environment thereby improving the magnitude and efficiency of wireless electrical energy transmission. 
     In one or more embodiments, a wireless electrical power system comprising at least one transmitting and receiving antenna is disclosed. In one or more embodiments the at least one transmitting and receiving antenna of the electrical system comprises at least one inductor coil with a figure eight configuration. In one or more embodiments, at least one of the transmitting and receiving antennas of the wireless electrical power system may be configured within an electronic device. Such electronic devices may include, but are not limited to, consumer electronics, medical devices, and devices used in industrial and military applications. 
     In one or more embodiments at least one of the wireless electrical power transmitting and receiving antennas is configured with one or more magnetic field shielding embodiments that increase the quantity of the magnetic field within a given volume of space, i.e., density of the magnetic field that emanates from the antenna. In one or more embodiments the wireless electrical power transmitting antenna is configured with one or more magnetic field shielding embodiments that control the direction in which the magnetic field emanates from the antenna. Furthermore, the transmitting and/or the receiving antenna is configured with one or more embodiments that increase the efficiency, reduces form factor and minimizes cost in which electrical energy and/or data is wirelessly transmitted. As a result, the subject technology provides a wireless electrical energy transmission transmitting and/or receiving antenna and system thereof that enables increased efficiency of wireless electrical energy transmission. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application. 
         FIG.  1 A  is a magnified view of the figure eight configuration illustrated in  FIG.  1   . 
         FIG.  2    shows an embodiment of an inductor coil that does not have a figure eight configuration. 
         FIG.  3    is a cross-sectional view showing an embodiment of the transmission of a magnetic field between a transmitting antenna having an inductor coil that is not of a figure eight configuration and a receiving antenna. 
         FIG.  4    is a cross-sectional view showing an embodiment of the transmission of a magnetic field between a transmitting antenna having an inductor coil with a figure eight configuration and a receiving antenna having an inductor coil with a figure eight configuration. 
         FIG.  5    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application. 
         FIG.  5 A  is a magnified view of the figure eight configuration illustrated in  FIG.  5   . 
         FIG.  6    illustrates an embodiment of an inductor coil of a multiple figure eight configuration of the present application. 
         FIG.  7    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application. 
         FIG.  7 A  shows an embodiment of an equivalent circuit of the inductor coil illustrated in  FIG.  7   . 
         FIG.  8    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application. 
         FIG.  8 A  shows an embodiment of an equivalent circuit of the inductor coil illustrated in  FIG.  8   . 
         FIG.  9    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application. 
         FIG.  9 A  shows an embodiment of an equivalent circuit of the inductor coil illustrated in  FIG.  9   . 
         FIG.  10    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application supported on a substrate. 
         FIGS.  10 A- 10 E  are cross-sectional views of embodiments of inductor coils comprising a figure eight configuration with various magnetic field shielding configurations. 
         FIGS.  11  and  12    show embodiments of spiral inductor coils that do not have a figure eight configuration. 
         FIG.  13    is a cross-sectional view showing an embodiment of a transmitting antenna spaced from a receiving antenna used for electrical performance testing. 
         FIG.  14    illustrates an embodiment of an inductor coil with a figure eight configuration of the present application. 
         FIG.  15    shows an embodiment of a parallel plate capacitor that may be electrically incorporated with an inductor coil of the present application. 
         FIGS.  16 A- 16 C  illustrate embodiments of an interdigitated capacitor that may be electrically incorporated with an inductor coil of the present application. 
         FIG.  17    is a cross-sectional view showing an embodiment of a transmitting or receiving antenna of the present application. 
         FIG.  18    illustrates an embodiment of a transmitting antenna positioned opposed from a receiving antenna, both the transmitting and receiving antennas comprise magnetic field shielding material. 
         FIGS.  19 ,  20 , and  21    show embodiments of an antenna array of the present application. 
         FIG.  22    illustrates an embodiment of an electrical energy transmitting cradle comprising the inductor coil of the present application. 
         FIGS.  23 A- 23 D  illustrate embodiments of an electronic device positioned on the electrical energy transmitting cradle of the present application. 
         FIG.  24    illustrates an embodiment of an electrical energy transmitting base comprising the inductor coil of the present application. 
         FIG.  24 A  illustrates an embodiment of an electronic device positioned on the electrical energy transmitting base of the present application shown in  FIG.  24   . 
         FIGS.  25  and  26    show partially broken views of the electrical energy transmitting base of the present application shown in  FIG.  24   . 
         FIG.  27    illustrates an embodiment of an electrical energy transmitting base comprising the inductor coil of the present application. 
         FIGS.  28 A- 28 G  illustrates an embodiment of a process of assembling a transmitting or receiving antenna of the present application. 
         FIGS.  29 A- 29 C  illustrates an embodiment of a process of assembling a transmitting or receiving antenna of the present application. 
         FIG.  30    is an exploded view of an embodiment of a transmitting or receiving antenna of the present application. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings. 
     The various embodiments illustrated in the present disclosure provide for the wireless transfer of electrical energy and/or data. More specifically, the various embodiments of the present disclosure provide for the wireless transmission of electrical energy and/or data via near field magnetic coupling between a transmitting antenna and a receiving antenna. 
     Now turning to the figures,  FIG.  1    illustrates an example of a configuration of an antenna  10  of the present application. The antenna  10  may be configured to either receive or transmit electrical energy and/or data via NFMC. In at least one or more embodiments, the antenna  10  comprises at least one inductor coil  12  having at least one turn formed by at least one filar or wire  14 . In at least one or more embodiments, the inductor coil  12  is arranged in a configuration that resembles a “figure-eight”. In one or more embodiments, the at least one filar  14  forming the inductor coil  12  crosses over itself forming a “figure-eight” coil configuration. As illustrated in  FIG.  1   , the inductor coil  12  comprises at least one filar  14  that continuously extends from a first coil end  16  to a second coil end  18 . In one or more embodiments, the point at which the filar  14  crosses over itself between the first and second ends  16 ,  18  is referred to as a crossover intersection  20 . In one or more embodiments, the filar  14  may have a constant or a variable filar width. 
     As will be discussed in more detail, when configured within a transmitting antenna  22  ( FIG.  4   ), the figure-eight coil configuration of the present application helps to focus magnetic fields  24  ( FIG.  4   ) to emanate toward a receiving antenna  26  from the inductor coil  12  of the transmitting antenna  22 , thereby minimizing interference with a metallic object or objects that may be positioned about the periphery of the transmitting antenna  22 . Furthermore, as a result of the figure-eight coil configuration, coupling decreases between the transmitting antenna and external metallic objects, and in some cases increases between the transmitting antenna  22  and a receiving antenna  26  ( FIG.  4   ) which results in increased efficiency of the wireless transmission of electrical energy and/or data therebetween. 
     As illustrated in  FIGS.  1 ,  1 A,  5 ,  5 A, and  6   , in one or more embodiments, the crossover intersection  20  comprises a first filar portion  28  and a second filar portion  30 . As illustrated in  FIGS.  1 ,  1 A,  5 ,  5 A, and  6   , the first filar portion  28  crosses over the second filar portion  30  at the crossover intersection  20 . Likewise, the second filar portion  30  may crossover the first crossover filar portion  28 . Thus, as a result of the figure eight construction, the inductor coil  12  comprises a first inductor coil loop  32  comprising the first filar portion  28  and a second inductor coil loop  34  comprising the second filar portion  30 .  FIG.  1 A  illustrates a magnified view of an embodiment of the crossover intersection  20  illustrated in  FIG.  1   . 
     In one or more embodiments, the inductor coil  12  comprising the figure eight construction may have an overlap area  36 . As defined herein the overlap area  36  is the area encompassed by the first filar portion  28  and the second filar portion  30  (shown in  FIG.  1 A ) that resides within either of the first or second inductor coil loops  32 ,  34 .  FIG.  1    illustrates an embodiment of the overlap area  36  encompassed by the first and second filar portions  28 ,  30  that resides within the first inductor coil loop  32 . In one or more embodiments, magnetic fields  24  within the overlap area  36  cancel each other. In one or more embodiments, the overlap area  36  may be configured to adjust the inductance exhibited by the inductor coil  12 . In general, increasing the size of the overlap area  36  decreases inductance and coupling exhibited by the inductor coil  12  whereas decreasing the size of the overlap area  36  increases the inductance and coupling exhibited by the inductor coil  12 . 
     In contrast to the figure eight coil configuration of the present application,  FIG.  2    illustrates an example of an inductor coil  38  that does not comprise the figure eight configuration of the present application. As shown the inductor coil  38  of  FIG.  2    is of a spiral configuration in which the first coil end  16  resides at the end of the outer most coil turn and the second coil end  18  resides at the end of the inner most coil turn. 
       FIG.  3    illustrates a cross-sectional view of an embodiment of wireless transmission of electrical energy between a transmitting antenna  22  and a receiving antenna  26  in which both the transmitting and receiving antennas  22 ,  26  comprise a transmitting and receiving coil, respectively, lacking the figure-eight configuration. More specifically, in the embodiment shown in  FIG.  3   , the transmitting antenna  22  comprises an inductor coil  38  that lacks the figure-eight coil configuration. In one or more embodiments, as illustrated in  FIG.  3   , emanating magnetic fields  24  follow a circular path around the current carrying filar  14  of the inductor coil  38 . Further referencing the cross-sectional view of  FIG.  3   , electrical current within the inductor coil  38  at the opposing left and right coil ends shown in the cross-sectional view flows in opposite directions to each other, i.e., electrical current at the left end flows in a left direction and the electrical current at the right end, flows in a right direction. Furthermore, as the current electrical current changes direction, i.e. from flowing in a left direction back towards the right and vice versa within the inductor coil  38 , this causes at least a portion of the emanating magnetic field  24  to follow a path away from the inductor coil  12  of the transmitting antenna  22  and curve around an edge  40  of the transmitting antenna  22 . As a result, efficiency of the wireless transmission of the electrical energy between the transmitting antenna  22 , having the inductor coil  38  not configured with a figure eight configuration, and the receiving antenna  26  decreases as some of the emanating magnetic fields  24  do not contribute to the flux of the receiving antenna  26 . Furthermore, a metallic object (not shown) positioned adjacent to the transmitting antenna  22  may adversely interact with emanating magnetic fields  24  not emanating directly towards the receiving antenna  26  such as the magnetic fields  24  as illustrated travelling in a curved direction around the edge  40  of the transmitting antenna  22  in  FIG.  3   . As a result of this interaction between a portion of the emanating magnetic fields  24  and a metallic object (not shown), the magnitude of transmitted electrical power between the transmitting and receiving antennas  22 ,  26  is reduced. 
     In contrast to the inductor coil  38  illustrated in  FIG.  2   , the inductor coil  12  of the present application comprises a figure eight construction that focuses the direction of the emanating magnetic fields  24  in a uniform direction. Thus, spurious magnetic field emanating directions such as magnetic fields emanating in a curved or circular direction around an edge  40  of the transmitting antenna  22 , as illustrated in  FIG.  3   , is minimized. 
     In one or more embodiments, magnetic fields  24  emanating from the inductor coil  12  of the subject technology having a figure eight configuration exhibit the pattern shown in  FIG.  4   . As illustrated in the embodiment shown in  FIG.  4   , magnetic fields  24  emanating from a transmitting antenna  22  comprising an inductor coil  12  having a figure eight configuration emanate in a direct, straight direction between opposing transmitting and receiving antennas  22 ,  26 . As shown, in the embodiment of  FIG.  4    a significantly reduced quantity of emanating magnetic fields  24 , unlike the quantity of emanating magnetic fields  24  shown in  FIG.  3   , curve around the respective edges  40  of the transmitting antenna  22 . This, therefore, increases efficiency and the magnitude of wireless electrical energy and/or data as an increased amount of magnetic field  24  is directed from the transmitting antenna  22  towards the receiving antenna  26 . In addition, potential interference with a metallic object or objects (not shown) positioned adjacent to the transmitting antenna  22  is minimized. As a result, coupling between the transmitting antenna  22  and the receiving antenna  26  increases relative to each other. 
     In one or more embodiments, the figure eight coil configuration of the present application creates an additional current carrying path at the crossover intersection  20  that bisects the electrical current flowing through either of the first or second filar portions  28 ,  30 . As a result, there are three electrical currents at the crossover intersection  20  instead of two electrical currents if not constructed with the figure eight configuration. In one or more embodiments, the filar  14  comprising the figure eight configuration crosses the intersection  20  twice in the same direction as compared to the electrical current flowing within the inductor coil  12  at the respective first and second inductor coil ends  16 ,  18  which flows in the same direction with respect to each other. Therefore, the electrical current at the crossover intersection  20  has a magnitude that is twice as great as the electrical current at the respective first and second inductor coil ends  16 ,  18 . In one or more embodiments, the electrical current having a greater magnitude flowing through the crossover intersection  20  of the figure eight configuration thus forces the magnetic fields  24  to form opposing loop formations that are offset from the center of the crossover intersection  20 . These opposing magnetic field loop formations that are offset from the center of the crossover intersection  20  thus creates a compact emanating magnetic field  24  that inhibits the magnetic field  24  from emanating in a spurious direction such as following a curved path around the edge  40  of the transmitting antenna  22 . Furthermore, interference of the emanating magnetic field  24  with a metallic object or objects (not shown) that may be positioned adjacent to the transmitting antenna  22  is thus minimized or eliminated. As a result, coupling and efficiency between transmitting and receiving antennas  22 ,  26  is increased. Furthermore, efficiency of wireless electrical energy transfer is increased. 
     In one or more embodiments, the first and second inductor loops  32 ,  34  may be electrically connected in series, parallel, or a combination thereof. In general, connecting the inductor loops in electrical series increases inductance and series resistance. Connecting the inductor loops electrically in parallel generally decreases series resistance and inductance. In addition, in one or more embodiments, the first and second inductor coil loops  32 ,  34  may be positioned in opposition to each other. In one or more embodiments, the first and second inductor coil loops  32 ,  34  may be positioned diametrically opposed from each other. In one or more embodiments, a crossover angle θ is created between the first and second filar portions  28 ,  30 . As defined herein, the crossover angle θ is the angle that extends between the first or second filar portion  28 ,  30  that extends over the other of the first or second filar portion  28 ,  30  at the crossover intersection  20 . In one or more embodiments, the crossover angle θ may be about 90°. In one or more embodiments, the crossover angle θ may be greater than 0° and less than 90°. In one or more embodiments, the crossover angle θ may be greater than 90° and less than 180°. 
     In this application, the subject technology concepts particularly pertain to NFMC. NFMC enables the transfer of electrical energy and/or data wirelessly through magnetic induction between a transmitting antenna  22  and a corresponding receiving antenna  26  ( FIG.  13   ). The NFMC standard, based on near-field communication interface and protocol modes, is defined by ISO/IEC standard 18092. Furthermore, as defined herein “inductive charging” is a wireless charging technique that utilizes an alternating electromagnetic field to transfer electrical energy between two antennas. “Resonant inductive coupling” is defined herein as the near field wireless transmission of electrical energy between two magnetically coupled coils that are tuned to resonate at a similar frequency. As defined herein, “mutual inductance” is the production of an electromotive force in a circuit by a change in current in a second circuit magnetically coupled to the first circuit. 
     As defined herein a “shielding material” is a material that captures a magnetic field. Examples of shielding material include, but are not limited to ferrite materials such as zinc comprising ferrite materials such as manganese-zinc, nickel-zinc, copper-zinc, magnesium-zinc, and combinations thereof. A shielding material thus may be used to direct a magnetic field to or away from an object, such as a parasitic metal, depending on the position of the shielding material within or nearby an electrical circuit. Furthermore, a shielding material can be used to modify the shape and directionality of a magnetic field. As defined herein a parasitic material, such as a parasitic metal, is a material that induces eddy current losses in the inductor antenna. This is typically characterized by a decrease in inductance and an increase in resistance of the antenna, i.e., a decrease in the quality factor. An “antenna” is defined herein as a structure that wirelessly receives or transmits electrical energy or data. An antenna comprises a resonator that may comprise an inductor coil or a structure of alternating electrical conductors and electrical insulators. Inductor coils are preferably composed of an electrically conductive material such as a wire, which may include, but is not limited to, a conductive trace, a filar, a filament, a wire, or combinations thereof. 
     It is noted that throughout this specification the terms, “wire”, “trace”, “filament” and “filar” may be used interchangeably to describe a conductor. As defined herein, the word “wire” is a length of electrically conductive material that may either be of a two-dimensional conductive line or track that may extend along a surface or alternatively, a wire may be of a three-dimensional conductive line or track that is contactable to a surface. A wire may comprise a trace, a filar, a filament or combinations thereof. These elements may be a single element or a multitude of elements such as a multifilar element or a multifilament element. Further, the multitude of wires, traces, filars, and filaments may be woven, twisted or coiled together such as in a cable form. The wire as defined herein may comprise a bare metallic surface or alternatively, may comprise a layer of electrically insulating material, such as a dielectric material that contacts and surrounds the metallic surface of the wire. The wire (conductor) and dielectric (insulator) may be repeated to form a multilayer assembly. A multilayer assembly may use strategically located vias as a means of connecting layers and/or as a means of creating a number of coil turns in order to form customized multilayer multiturn assemblies. A “trace” is an electrically conductive line or track that may extend along a surface of a substrate. The trace may be of a two-dimensional line that may extend along a surface or alternatively, the trace may be of a three-dimensional conductive line that is contactable to a surface. A “filar” is an electrically conductive line or track that extends along a surface of a substrate. A filar may be of a two-dimensional line that may extend along a surface or alternatively, the filar may be a three-dimensional conductive line that is contactable to a surface. A “filament” is an electrically conductive thread or threadlike structure that is contactable to a surface. “Operating frequency” is defined as the frequency at which the receiving and transmitting antennas operate. “Self-resonating frequency” is the frequency at which the resonator of the transmitting or receiving antenna resonates. 
     In one or more embodiments, the inductor coils  12  of either the transmitting antenna  22  or the receiving antenna  26  are strategically positioned to facilitate reception and/or transmission of wirelessly transferred electrical power or data through near field magnetic induction. Antenna operating frequencies may comprise all operating frequency ranges, examples of which may include, but are not limited to, about 100 kHz to about 200 kHz (Qi interface standard), 100 kHz to about 350 kHz (PMA interface standard), 6.78 MHz (Rezence interface standard), or alternatively at an operating frequency of a proprietary operating mode. In addition, the transmitting antenna  22  and/or the receiving antenna  26  of the present disclosure may be designed to transmit or receive, respectively, over a wide range of operating frequencies on the order of about 1 kHz to about 1 GHz or greater, in addition to the Qi and Rezence interfaces standards. In addition, the transmitting antenna  22  and the receiving antenna  26  of the present disclosure may be configured to transmit and/or receive electrical power having a magnitude that ranges from about 100 mW to about 100 W. In one or more embodiments the inductor coil  12  of the transmitting antenna  22  is configured to resonate at a transmitting antenna resonant frequency or within a transmitting antenna resonant frequency band. In one or more embodiments the transmitting antenna resonant frequency is at least 1 kHz. In one or more embodiments the transmitting antenna resonant frequency band extends from about 1 kHz to about 100 MHz. In one or more embodiments the inductor coil  12  of the receiving antenna  26  is configured to resonate at a receiving antenna resonant frequency or within a receiving antenna resonant frequency band. In one or more embodiments the receiving antenna resonant frequency is at least 1 kHz. In one or more embodiments the receiving antenna resonant frequency band extends from about 1 kHz to about 100 MHz. 
       FIG.  5    illustrates an embodiment of a “digital” figure eight coil construction. As shown, the inductor coil  12  comprises a crossover intersection  20  forming the first and second coil loops  32 ,  34 .  FIG.  5 A  illustrates a magnified view of an embodiment of the crossover intersection  20  shown in  FIG.  5   . In one or more embodiments, the inductor coil  12  is constructed such that adjacent segments of the first and second filar portions  28 ,  30  are positioned about parallel to each other. A digital figure eight gap  42  separates the adjacent segments of the first and second inductor coil loops  32 ,  34 . As shown, a first segment  44  of the first inductor coil loop  32  is positioned parallel to a second segment  46  of the second inductor coil loop  34 . Furthermore, the crossover can be used to modify the shape and directionality of a magnetic field for wireless power transfer. 
     In one or more embodiments, magnetic fields  24  typically combine according to the following mathematical relationship: I(R 1 )+cos ϕ X I(R 2 ) where ϕ is the angle between the electrical current directions R 1  and R 2  within each of the two inductor coil loops  32 ,  34 . As illustrated in  FIG.  5   , since the inductor coil  12  comprises a digital figure eight configuration, the angle between the first and second inductor coil loops  32 ,  34  is 90°. Since the cosine of 90° is 0, the direction of the magnetic field  24  within the digital figure eight inductor coil configuration is in the same direction, I (R 1 ). 
       FIG.  6    illustrates an embodiment of an inductor coil  12  with a multiple figure-eight configuration. As shown in the embodiment of  FIG.  6   , the inductor coil  12  comprises two cross over intersections  20  thereby forming three inductor coil loops, a first coil loop  32 , a second coil loop  34 , and a third coil loop  48 . In an embodiment, constructing the inductor coil  12  with a multiple figure eight construction further focuses the emitting magnetic field  24  and further strengthens coupling between the transmitting and receiving antennas  22 ,  26 . 
       FIG.  7    illustrates an embodiment of an edge feed inductor coil  50  comprising a figure eight configuration. As defined herein an edge feed inductor coil is an inductor coil configured to either transmit or receive electrical energy via near field communication (NFC) in which the first and second ends  16 ,  18  of the inductor coil  50  are positioned at a side edge of the transmitting or receiving antenna  22 ,  26 .  FIG.  7 A  shows an embodiment of an equivalent electrical circuit  52  of the inductor coil  50  shown in  FIG.  7   . As illustrated in  FIG.  7 A , the equivalent electrical circuit  52  comprises an inductor L 1  electrically connected between the first and second terminals  54 ,  56 . In one or more embodiments, as illustrated in  FIG.  8   , the inductor coil  12  may be configured in a center feed inductor coil  58  configuration.  FIG.  8 A  shows an embodiment of an equivalent electrical circuit  60  of the inductor coil  58  shown in  FIG.  8   . As illustrated in  FIG.  8 A , the equivalent electrical circuit  60  comprises an inductor L 2  electrically connected between the first and second terminals  54 ,  56 . As defined herein a center feed coil is an inductor coil configured to either transmit or receive electrical energy via NFC in which the first and second ends  16 ,  18  of the inductor coil  58  are positioned at about the center of the inductor coil  58 . In either of the edge feed or center feed inductor coil constructions  50 ,  58 , electrical current flows through the filars  14  of the inductor coils  50 ,  58  having a parallel orientation in the same direction. In one or more embodiments, the edge feed  50  and/or the center feed  58  inductor coil configurations have two inductor coil loops, a first inductor coil loop  32  and a second inductor coil loop  34  respectively, that carry electrical current in opposite directions to each other. Thus, the effective instantaneous magnetic field direction through the center of each first and second loops  32 ,  34  of the edge feed inductor coil  50  and the center feed inductor coil  58  is 180° off-phase. 
       FIG.  9    illustrates an embodiment of a parallel feed inductor coil  62 . In this embodiment, a portion of the filar  14  that comprises the parallel feed inductor coil  62  splits the inductor coil  62  into two inductor coil loops. Similar to the center and edge feed coil configurations  58 ,  50 , electrical current travels in a parallel direction through the two loops of the parallel feed inductor coil configuration  62  shown in  FIG.  9   . In one or more embodiments, the parallel feed inductor coil configuration  62  helps to reduce the inductance exhibited by the inductor coil  62 .  FIG.  9 A  shows an embodiment of an equivalent electrical circuit  64  of the inductor coil  62  shown in  FIG.  9   . As illustrated in  FIG.  9 A , the equivalent electrical circuit  64  comprises a first inductor L 3  electrically connected in parallel to a second inductor L 4 , the first and second inductors L 3 , L 4  electrically connected to the first and second terminals  54 ,  56 . 
     In one or more embodiments, various materials may be incorporated within the structure of the inductor coils  12 ,  50 ,  58 ,  62  of the present application to shield the inductor coils from magnetic fields and/or electromagnetic interference and, thus, further enhance the electrical performance of the respective transmitting or receiving antenna  22 ,  26 . 
     In one or more embodiments, at least one magnetic field shielding material  66 , such as a ferrite material, may be positioned about the inductor coil  12  or antenna  22 ,  26  structure to either block or absorb magnetic fields  24  that may create undesirable proximity effects and that result in increased electrical impedance within the transmitting or receiving antenna  22 ,  26  and decrease coupling between the transmitting and receiving antennas  22 ,  26 . These proximity effects generally increase electrical impedance within the antenna  22 ,  26  which results in a degradation of the quality factor. In addition, the magnetic field shielding material  66  may be positioned about the antenna structure to increase inductance and/or act as a heat sink within the antenna structure to minimize over heating of the antenna. Furthermore, such materials  66  may be utilized to modify the magnetic field profile of the antenna  22 ,  26 . Modification of the magnetic field(s)  24  exhibited by the antenna  22 ,  26  of the present disclosure may be desirable in applications such as wireless charging. For example, the profile and strength of the magnetic field exhibited by the antenna  22 ,  26  may be modified to facilitate and/or improve the efficiency of wireless power transfer between the antenna and an electric device  68  ( FIG.  22   ) such as a cellular phone. Thus, by modifying the profile and/or strength of the magnetic field about an electronic device being charged, minimizes undesirable interferences which may hinder or prevent transfer of data or an electrical charge therebetween. 
       FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E  are cross-sectional views, referenced from the inductor coil  12  configuration shown in  FIG.  10   , illustrating various embodiments in which magnetic field shielding materials  66  may be positioned about the inductor coil  12 . As shown in the cross-sectional view of  FIG.  10 A , the inductor coil  12  may be positioned on a surface  70  of a substrate  72 . In one or more embodiments, the substrate  72  may comprise the magnetic shielding material  66 .  FIG.  10 B  is a cross-sectional view of an embodiment in which the inductor coil  12  is positioned on a substrate  72  that comprises end tabs  74 . As illustrated, the end tabs  74  upwardly extend from the substrate surface  70  at respective first and second ends  76 ,  78  of the substrate  72 . As illustrated, the end tabs  76 ,  78  have a height  80  that extends at least to a top surface  82  of the inductor coil  12 . As shown, the height  80  of the end tabs  74  extend beyond the top surface  82  of the inductor coil  12 . In one or more embodiments, the end tabs  74  have a thickness  84  that extends from about 0.1 mm to about 100 mm  FIG.  10 C  is a cross-sectional view of an embodiment in which the inductor coil  12  may be positioned on a substrate  72  that comprises spaced apart first and second coil enclosures  86 ,  88 . As illustrated, each enclosure  86 ,  88  extends outwardly from the substrate surface  70  at the respective first and second substrate ends  76 ,  78 . In one or more embodiments, at least a portion of the filar  14  that comprises the inductor coil  12  is positioned within at least one of the enclosures  86 ,  88 . As shown in  FIG.  10 C  the filar  14  forming the outermost segment of the first and second inductor coil loops  32 ,  34  are positioned within the respective enclosures  86 ,  88 .  FIG.  10 D  is a cross-sectional view of an embodiment in which a portion of the inductor coil  12  is positioned on a substrate  72  comprising the magnetic shielding material  66 . As shown, all but the outer most segment of the first and second inductor coil loops  32 ,  34  are shown supported by the substrate  72 .  FIG.  10 E  is a cross-sectional view of an embodiment in which at least a portion of the inductor coil  12  is supported on a substrate  72  comprising the magnetic shielding material  66 . In addition, the filar  14  forming the outermost segment of the first and second inductor coil loops  32 ,  34  are positioned within spaced apart first and second inductor coil enclosures  86 ,  88 . As shown, a gap  90  separates the substrate  72  supporting a portion of the inductor coil  12  from the respective first and second enclosures  86 ,  88  that house outermost segments of the first and second inductor coil loops  32 ,  34 . In an embodiment, the substrate  72 , end tabs  74  and enclosures  86 ,  88  may comprise at least one magnetic field shielding material  66 . It is contemplated that more than one or a plurality of shielding materials may be used in a single structure or on a single layer of a multilayer structure. Examples of the shielding material  66  may include, but are not limited to, zinc comprising ferrite materials such as manganese-zinc, nickel-zinc, nickel-iron, copper-zinc, magnesium-zinc, and combinations thereof. Further examples of shielding material  66  may include, but are not limited to an amorphous metal, a crystalline metal, a soft ferrite material, a hard ferrite material and a polymeric material. As defined herein a soft ferrite material has a coercivity value from about 1 Ampere/m to about 1,000 Ampere/m. As defined herein a hard ferrite material has a coercivity value that is greater than 1,000 Ampere/m. These and other ferrite material formulations may be incorporated within a polymeric material matrix so as to form a flexible ferrite substrate. Examples of such materials may include but are not limited to, FFSR and FFSX series ferrite materials manufactured by Kitagawa Industries America, Inc. of San Jose Calif. and Flux Field Directional RFIC material, manufactured by 3M® Corporation of Minneapolis Minn. 
     The embodiments shown in  FIGS.  10 A- 10 E , illustrate non-limiting configurations that are designed to minimize magnetic fields  24  from moving outward from within the area defined by the inductor coil  12 . These illustrated embodiments are designed to help ensure that an increased amount of magnetic fields  24  emanating from the transmitting antenna  22  reach the receiving antenna  26  and do not interfere with adjacently positioned metallic object(s) (not shown) as previously discussed. In one or more embodiments, the magnetic field shielding material  66 , such as a ferrite material, may have a permeability (mu′) that is greater than 1 at the operating frequency or frequencies of the transmitting antenna  22  and/or the receiving antenna  26 . In one or more embodiments, the permeability of the ferrite material may be as great as 20000 at the operating frequency or frequencies of the respective antenna  22 ,  26 . In one or more embodiments, the magnetic shielding material  66  may also comprise an electrically conductive material. 
     In one or more embodiments, various electrical performance parameters of the wireless electrical energy transmitting and receiving antennas  22 ,  26  of the present application were measured. One electrical parameter is quality factor (Q) defined below. 
     The quality factor of a coil defined as: 
             Q   =       ω   *   L     R           
Where:
         Q is the quality factor of the coil   L is the inductance of the coil   ω is the operating frequency of the coil in radians/s. Alternatively, the operating frequency (Hz) may be ω divided by 2π   R is the equivalent series resistance at the operating frequency       

     Another performance parameter is resistance of receiving antenna efficiency (RCE) which is coil to coil efficiency. RCE is defined as: 
             RCE   =         k   2     *     Q   Rx     *     Q   Tx         (     1   +     (           (     1   +       k   2     *     Q   rx     *     Q   tx         )     )       2                   
Where:
         RCE is the coil to coil efficiency of the system   k is the coupling of the system   Q rx  is the quality factor of the receiver   Q tx  is the quality factor of the transmitter       

     Another performance parameter is mutual induction (M). “M” is the mutual inductance between two opposing inductor coils of a transmitting and receiving antenna, respectively. Mutual induction (M) is defined as: 
             M   =       V   induced       ω   *     I   Tx               
Where:
         V induced  is induced voltage on the receiver coil   I tx  is the alternating current (AC) flowing through the transmitter coil   ω is the operating frequency multiplied by 2π       

     Mutual inductance can be calculated by the following relationship:
 
 M=k *√{square root over ( L   Tx   *L   Rx )}
 
Where:
         M is the mutual inductance of the system   k is the coupling of the system   L Tx  is the inductance of the transmitter coil   L Rx  is the inductance of the receiver coil       

     Figure of Merit (FOM) can be calculated by the following relationship: 
             FOM   =       M   2     ⁢       ω   2         R   TX     ⁢     R   RX                 
Where:
         FOM is the figure of merit   ω is the operating frequency in radians   R TX  is the AC electrical resistance of the transmitting coil at the operating frequency   R RX  is the AC electrical resistance of the receiving coil at the operating frequency   M is the mutual inductance       

     Coil to Coil Efficiency (C2C) can be calculated by the following relationship: 
               C   ⁢   2   ⁢   C   ⁢         efficiency     =     FOM       (     1   +       1   +   FOM         )     2             
Where:
         FOM is the figure of merit       

     Table I shown below, delineates the inductance (L), electrical resistance (R), and quality factor (Q) of both the transmitting and receiving antennas  22 ,  26  that comprised an inductor coil configured without the figure eight configuration.  FIG.  11    illustrates an embodiment of a transmitting inductor coil  92  that was used in the performance testing detailed in Table I. As shown in  FIG.  11   , the transmitting inductor coil  92  comprised a spiral configuration having an outer diameter of 27 mm and 5 turns.  FIG.  12    illustrates an embodiment of a receiving inductor coil  94  that was used in the performance testing detailed in Table I. As illustrated, the receiving inductor coil  94 , comprised a spiral configuration with an outer diameter of 29.4 mm and 4 turns. It is noted that both the transmitting and receiving inductor coils  92 ,  94  shown in  FIGS.  11  and  12    respectively and used in the performance testing detailed in Table I, did not comprise a figure eight configuration. Furthermore, the transmitting antenna  22  comprising the transmitting inductor coil  92  was positioned about 3.5 mm from the receiving antenna  26  that comprised the receiving inductor coil  94  during the performance testing as illustrated in  FIG.  13   . Configuration 1 comprised the transmitting antenna  22  with only the transmitting inductor coil  92 . Configuration 2 included the transmitting inductor coil  92  supported by a core  95  of magnetic field shielding material  66  comprising for example, but not limited to, Mn—Zn, Ni—Zn, soft ferrites, hard ferrites, Mu-Metals, amorphous metal sheets, nano-crystalline metal sheets, polymer based magnetic shielding, and having a thickness of about 0.3 mm. Configuration 3 comprised the receiving antenna  26  with only the receiving inductor coil  94 . Configuration 4 comprised the receiving inductor coil  94  supported by the core  95  of magnetic field shielding material comprising materials as discussed for Configuration 2, and having a thickness of about 0.1 mm. Configuration 5 was of the receiving inductor coil  94  supported by the core  95  of magnetic field shielding material comprising materials as discussed for Configuration 2, and surrounded by an aluminum ring  96  having a thickness of about 0.2 mm.  FIG.  13    illustrates the performance test configuration with the transmitting antenna  22  configured in configuration 2 and the receiving antenna  26  in configuration 5. The mutual inductance between the transmitting antenna  22  of configuration 2 and the receiving antenna  26  of configuration 4 was about 300.7 nH. The mutual inductance between the transmitting antenna  22  of configuration 2 and the receiving antenna  26  of configuration 5 was about 275 nH. Thus, the metal ring positioned around the circumference of the receiving inductor coil  94  decreased mutual inductance by about 25.7 nH or by about 8.5 percent. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE I 
               
               
                   
                   
               
             
            
               
                   
                 Transmitting 
                 L 
                 R 
                   
               
               
                   
                 Antenna 
                 (nH) 
                 (Ohms) 
                 Q 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Configuration 1 
                 467 
                 nH 
                 0.17 
                 117 
               
               
                   
                 Configuration 2 
                 666.3 
                 nH 
                 0.435 
                 65.22 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Receiving 
                   
                   
                   
               
               
                   
                 Antenna 
                 L 
                 R 
                 Q 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Configuration 3 
                 618 
                 nH 
                 0.2 
                 131.6 
               
               
                   
                 Configuration 4 
                 720.7 
                 nH 
                 0.32 
                 154 
               
               
                   
                 Configuration 5 
                 575 
                 nH 
                 0.51 
                 48 
               
               
                   
                   
               
            
           
         
       
     
     As detailed in the test performance results shown in Table I, inclusion of the magnetic field shielding material  66  increased the inductance of both the transmitting and receiving antennas  22 ,  26 . In addition, inclusion of the magnetic field shielding material  66  increased the quality factor of the receiving antenna  26 . 
     Table II shown below delineates the inductance (L), electrical resistance (R), and quality factor (Q) of both the transmitting and receiving antennas  22 ,  26  that comprised an inductor coil  12  having the figure eight configuration.  FIG.  14    illustrates an embodiment of a transmitting inductor coil  98  and a receiving inductor coil  100  utilized in the performance testing detailed in Table II. The transmitting inductor coil  98  comprised a spiral configuration having an outer diameter of 27 mm, 3 turns and a figure eight configuration. The receiving inductor coil  100  also comprised a spiral configuration with an outer diameter of 27 mm, 3 turns, and a figure eight configuration. The transmitting antenna  22  was positioned about 3.5 mm from the receiving antenna  26 . Configuration 1 comprised the transmitting antenna  22  with only the transmitting inductor coil  98 . Configuration 2 included the transmitting inductor coil  98  supported by a magnetic field shielding material  66  comprising zinc and having a thickness of about 0.3 mm. Configuration 3 was of the receiving antenna  26  comprising only the receiving inductor coil  100 . Configuration 4 comprised the receiving inductor coil  100  supported by the magnetic field shielding material composed of nickel, zinc, copper ferrite having a thickness of about 0.1 mm. Configuration 5 was of the receiving inductor coil  100  supported by the ferrite material that was surrounded by an aluminum ring  96  having a thickness of about 0.2 mm.  FIG.  13    illustrates the test configuration of the transiting antenna  22  in confirmation 2 and the receiving antenna  26  in configuration 5. The mutual inductance between the transmitting antenna  22  of configuration 2 and the receiving antenna  26  of configuration 4 was about 412 nH. The mutual inductance between the transmitting antenna  22  of configuration 2 and the receiving antenna  26  of configuration 5 was about 411 nH. Thus, the metal ring  96  positioned around the circumference of the receiving inductor coil  100  decreased the mutual inductance by about 1 nH or decreased by about 0.2 percent. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE II 
               
               
                   
                   
               
             
            
               
                   
                 Transmitting 
                   
                 R 
                   
               
               
                   
                 Antenna 
                 L 
                 (ohms) 
                 Q 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Configuration 1 
                 805 
                 nH 
                 0.56 
                 61.23 
               
               
                   
                 Configuration 2 
                 1.135 
                 μH 
                 0.66 
                 73.26 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Receiving 
                   
                   
                   
               
               
                   
                 Antenna 
                 L 
                 R 
                 Q 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Configuration 3 
                 805 
                 nH 
                 0.56 
                 61.23 
               
               
                   
                 Configuration 4 
                 1.1 
                 μH 
                 0.72 
                 65 
               
               
                   
                 Configuration 5 
                 1 
                 μH 
                 0.77 
                 55.32 
               
               
                   
                   
               
            
           
         
       
     
     As detailed in the test performance results shown in Table II, inclusion of the magnetic field shielding material  66  increased the inductance of both the transmitting and receiving antennas  22 ,  26 . In addition, inclusion of the magnetic field shielding material  66  increased the quality factor of the transmitting and receiving antennas  22 ,  26 . 
     In one or more embodiments a capacitor such as a surface mount capacitor may be electrically connected to the inductor coil  12 . In one or more embodiments, a capacitor can be electrically connected to the inductor coil  12  of the transmitting antenna  22  and/or the receiving antenna  26  to adjust the inductance of the inductor coil  12 . The capacitor may comprise a parallel plate capacitor  102  and/or an interdigitated capacitor  104 . In one or more embodiments, the capacitor, such as a parallel plate capacitor  102  or an interdigitated capacitor  104  may be fabricated on or incorporated within a substrate that supports the inductor coil  12 . For example, a parallel plate capacitor  102  or an interdigitated capacitor  104  may be fabricated on or within a printed circuit board (PCB) or flexible circuit board (FCB) to impart a desired capacitance to the transmitting or receiving antenna  22 ,  26 .  FIG.  15    illustrates examples of a parallel plate capacitor  102  and an interdigitated capacitor  104 . The benefit of utilizing a parallel plate capacitor  102  or an interdigitated capacitor  104  configuration is that they provide a robust thinner design that is generally of a lower cost. 
     In one or more embodiments, the parallel plate capacitor  102 , as shown in  FIG.  15   , comprises a dielectric material  106  positioned between two opposing electrically conducting plates  108  positioned in parallel to each other. 
     Non-limiting examples of an interdigitated capacitor  104  are shown in  FIGS.  15  and  16 A- 16 C . In one or more embodiments, as illustrated in  FIGS.  15  and  16 A- 16 C  interdigitated capacitors  104  typically have a finger-like shape. In one or more embodiments, the interdigitated capacitor  104  comprises a plurality of micro-strip lines  110  that produce high pass characteristics. The value of the capacitance produced by the interdigitated capacitor  104  generally depends on various construction parameters. These include, a length  112  of the micro-strip line  110 , a width  114  of the micro-strip line  110 , a horizontal gap  116  between two adjacent micro-strip lines  110 , and a vertical gap  118  between two adjacent micro-strip lines  110  ( FIG.  16 A ). In one or more embodiments, the length  112  and width  114  of the micro-strip line  110  can be from about 10 mm to about 600 mm, the horizontal gap  116  can be between about 0.1 mm to about 100 mm, and the vertical gap  118  can be between about 0.0001 mm to about 2 mm. 
     In one or more embodiments, the inter-digitated capacitor  104  can be integrated within a substrate  120  such as a PCB. In one or more embodiments, the inductor coil  12  may be positioned on the surface of the interdigitated capacitor  104 . Alternatively, the inductor coil  12  may be positioned surrounding the interdigitated capacitor  104 . In one or more embodiments, the interdigitated capacitor  104  may be positioned within an opening or cavity (not shown) within a substrate  72  supporting the inductor coil  12 . In one or more embodiments, the interdigitated capacitor  104  provides a cost-effective means to add capacitance to the inductor coil  12 . In addition, the interdigitated capacitor  104  is mechanically durable and may be used to connect a tuned inductor coil  12  directly to a circuit board. In one or more embodiments, interdigitated capacitors  104  can also be useful in applications where relatively thin form factors are preferred. For example, an interdigitated capacitor  104  may be used to tune the inductor coil  12  in lieu of a surface mount capacitor because of the mechanical robustness, relatively thin design, and reduced cost of the interdigitated capacitor  104 . 
       FIG.  17    illustrates a cross-sectional view of one or more embodiments of an inductor coil  12  supported on the surface  70  of a substrate  72 . As shown in the embodiment, three sections of filar  14  are illustrated on the surface  70  of the substrate  72 . In one or more embodiments, an air gap  122  extends between adjacently positioned sections of filar  14 . As shown each of the sections of filar  14  comprises a filar section width  124  that extends about parallel to the surface  70  of the substrate  72  between filar section sidewalls  126 . In addition, each of the sections of filar  14  comprise a thickness  128  that extends from the surface  70  of the substrate  72  to a top surface  130  of the filar. In addition, an electrically conductive via  132  is shown electrically connected to the filar  14  extending through the thickness of the substrate  72 . 
     In one or more embodiments, the width of the air gap  122  that extends between sidewalls  126  of adjacently positioned filars  14  is minimized. In one or more embodiments, decreasing the width of the air gap  122  may increase the amount of electrically conductive material that comprises the filar  14  within a defined area. Thus, the amount of electrical current and magnitude of electrical power able to be carried by the inductor coil  12  within a specific area is increased. For example, decreasing the air gap  122  between adjacent filars  14  would enable an increased number of coil turns within a specified area. In one or more embodiments, the width of the air gap  122  may range from about 10 μm to about 50 μm. In one or more embodiments, the width of the air gap  122  may range from about 15 μm to about 40 μm. 
     In one or more embodiments, the thickness  128  of the filar that extends from the surface  70  of the substrate  72  is maximized. In one or more embodiments, increasing the thickness  128  of the filar  14  increases the amount of electrically conductive material that comprises the filar within a defined area. Thus, the amount of electrical current and magnitude of electrical power able to be carried by the inductor coil  12  is increased within a specific area. In one or more embodiments, the thickness  128  of the filar  14  may vary or be constant along the inductor coil  12 . In one or more embodiments, the thickness  128  of the filar  14  may range from about 12 μm to about 150 μm. In one or more embodiments, the width  124  of the filar  14  may vary or be constant along the inductor coil  12 . In one or more embodiments, the width  124  of the filar  14  may range from about 10 μm to about 100,000 μm. 
     In one or more embodiments, the ratio of the width of the air gap  122  to the filar thickness  128  is minimized. In one or more embodiments, the ratio of the width of the air gap  122  to the filar thickness may range from about 0.10 to about 0.50. In one or more embodiments, the ratio of the width of the air gap to the filar thickness may range from about 0.30 to about 0.40. 
     In one or more embodiments, the sidewall  126  of the filar  14  is oriented about perpendicular to the surface  70  of the substrate  72 . In one or more embodiments, the sidewall  126  of the filar  14  may be oriented at a sidewall angle τ with respect to the surface  70  of the substrate  72 . As defined herein, the sidewall angle c is the angle between the exterior surface of the filar sidewall  126  and the surface  70  of the substrate  72  on which the filar  14  is supported. In one or more embodiments, the sidewall angle τ may range from about 75° to about 90°. 
     
       
         
           
               
               
             
               
                 TABLE III 
               
             
            
               
                   
               
               
                 Parameter 1 
                 Parameter 2 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Antenna 
                 Inductance 
                 ESR 
                   
                 Inductance 
                 ESR 
                   
               
               
                 Config 
                 (μH) 
                 (ohms) 
                 Q 
                 (μH) 
                 (ohms) 
                 Q 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 1 
                 5.77 
                 0.211 
                 17.18 
                 5.72 
                 0.254 
                 14.14 
               
               
                 2 
                 5.91 
                 0.508 
                 7.30 
                 5.34 
                 0.624 
                 5.37 
               
               
                 3 
                 5.08 
                 0.642 
                 4.97 
                 3.69 
                 0.815 
                 2.84 
               
               
                   
               
            
           
         
       
     
     Table III above illustrates how the electrical performance of inductance, equivalent series resistance (ESR), and quality factor (Q) change using an air gap of different widths. As shown in Table III above, computer simulations of three different antenna coil configurations were modeled having two different air gap widths. Antenna coil configuration 1 comprised an inductor coil  12  of a rectangular configuration having a length and width of 40 mm and 12 turns. Antenna coil configuration 2 comprised an inductor coil  12  of a circular configuration having an outer diameter of 17 mm. Configuration 2 further comprised two coils, a first coil having 12 turns supported on a top surface of a substrate comprising an electrically insulative material and a second coil comprising 12 turns supported on an opposed bottom surface of the substrate. Antenna coil configuration 3 comprised an inductor coil of a circular configuration having an outer diameter of 17 mm. Configuration 3 further comprised two coils, a first coil having 14 turns supported on a top surface of a substrate comprised of an electrically insulative material and a second coil comprising 14 turns sported on an opposed bottom surface of the substrate. Each of the three antenna coil configurations was modeled having two different air gap widths. Antenna coil configurations 1-3 of Parameter 1 were modeled comprising an air gap width of 0.020 μm whereas antenna coil configurations 1-3 of Parameter 2 were modeled having an air gap width of 0.160 μm. The antenna coil configurations of each parameter comprised the same number of turns but different air gap widths 0.20 μm (Parameter 1) and 0.160 μm (Parameter 2) between adjacent filars  14 . As detailed in Table III above, reducing the width of the air gap  122  increased inductance, quality factor, and reduced equivalent series resistance. 
       FIG.  18    illustrates one or more embodiments of a transmitting antenna  22  comprising magnetic field shielding materials  66  positioned opposed and spaced apart from a receiving antenna  26  comprising magnetic field shielding material  66 . As illustrated, in the embodiment shown in  FIG.  18   , the transmitting antenna  22  comprises a transmitting inductor coil  98  having the figure eight configuration supported on a substrate  72  comprising the magnetic field shielding material  66 . The receiving antenna  26  positioned spaced from the transmitting antenna  22  comprises a receiving inductor coil  100  with the figure eight configuration. The receiving inductor coil  100  is supported by a substrate  72  comprising the magnetic field shielding material  66 . A ground plane  134  comprising an electrically conductive material supports the magnetic field shielding material  66  and the receiving inductor coil  100 . A metal ring  136  having an inner circumference about equal to an outer diameter of the transmitting inductor coil  98  is positioned in a gap  138  positioned between the transmitting and receiving antennas  22 ,  26 . 
     In one or more embodiments the inductor coil  12  and antenna  22 ,  26  concepts of the present application, may be used to form a multi-antenna array  140  as illustrated in  FIGS.  19  and  20   . In addition to an inductor coil  12  having a figure eight configuration of the present application, the multi-antenna array  140  may also comprise inductor coils  12  having a variety of non-limiting configurations such as a spiral, a solenoid or combination thereof. Further examples of wireless antenna structures that may be incorporated within the multi-antenna array may include but are not limited to antennas disclosed in U.S. Pat. Nos. 9,941,729; 9,941,743; 9,960,628; and Ser. No. 14/821,177; 14/821,236; and 14/821,268 all to Peralta et al.; U.S. Pat. Nos. 9,948,129, 9,985,480 to Singh et al.; U.S. Pat. No. 9,941,590 to Luzinski; and U.S. Pat. No. 9,960,629 to Rajagopalan et al., all of which are assigned to the assignee of the present application and incorporated fully herein. Non-limiting examples of antennas having a multilayer multiturn (MLMT) construction that may be incorporated with the present disclosure may be found in U.S. Pat. Nos. 8,610,530; 8,653,927; 8,680,960; 8,692,641; 8,692,642; 8,698,590; 8,698,591; 8,707,546; 8,710,948; 8,803,649; 8,823,481; 8,823,482; 8,855,786; 8,898,885; 9,208,942; 9,232,893; and 9,300,046 all to Singh et al., and assigned to the assignee of the present application are incorporated fully herein. It is also noted that other antennas such as, but not limited to, an antenna configured to send and receive signals in the UHF radio wave frequency such as the IEEE standard 802.15.1 may be incorporated within the present disclosure. 
     In one or more embodiments, the multi-antenna array  140  of the present application may comprise a multitude of transmitting and/or receiving inductor coils  98 ,  100  that are positioned embedded within a platform  142  ( FIG.  20   ). In one or more embodiments, the multi-antenna array  140  within the platform  142  is configured so that electrical energy and/or data may be wirelessly transmitted or received to or from at least one electronic device  68 , such as a cellular phone. The electrical energy and/or data may be wirelessly transmitted to or received from a respective electronic device  68  by positioning the device  68  on or near the platform  142  in a variety of unlimited positions. For example, an electronic device  68 , i.e., a cellular phone or watch, configured with a wireless NFMC receiving antenna  26  may be electrically charged or directly powered by positioning the device  68  in a multitude of orientations with respect to the multi-coil array  142  of the present application. In one or more embodiments, the multi-antenna array is configured having an inductance ranging from about 50 nH to about 50 μH. Thus, the multi-antenna array  140  of the present application may be configured with a multitude of inductor coils  12  that are specifically tuned to a variety of operating frequencies. These frequencies include but are not limited to between 50 kHz to about 500 kHz as well as from about 6.78 MHz to about 276.12 MHz. This, therefore, enables the wireless transmission of electrical energy and/or data to a multitude of unlimited electronic devices  68 . 
       FIGS.  19  and  20    illustrate non-limiting embodiments of the multi-antenna array  140  of the present application.  FIG.  19    illustrates an embodiment in which three inductor coils  12 ,  98 ,  100  are arranged in a specific pattern. As shown, a first inductor coil  144  and a second inductor coil  146  are positioned parallel and co-planar to each other. A third inductor coil  148  is positioned above the first and second inductor coils  144 ,  146 . As illustrated in the embodiment shown in  FIG.  19    the third inductor coil  148  is positioned perpendicular to the first and second inductor coils  144 ,  146  oriented parallel to each other. In addition, the third inductor coil  148  is positioned extending between and at least partially overlapping the first and second inductor coils  144 ,  146 . An imaginary line A-A extends lengthwise, bisecting the third inductor coil  148 . Furthermore, the embodiment of the multi-antenna array shown in  FIG.  19    is arranged such that the imaginary line A-A extends widthwise and bisects the first and second inductor coils  144 ,  146 . In one or more embodiments, the multi-antenna array  140  of  FIG.  19    may be constructed such that an antenna arrangement distance  150  extends between the bisect of the third inductor coil  148  and either of the bisect of the first or second inductor coils  144 ,  146  is about equal. 
       FIGS.  20  and  21    illustrate one or more embodiments of a multi-antenna array  140 . As shown, three inductor coils  12 ,  98 ,  100  are arranged in a fan-like arrangement. In one or more embodiments as shown in  FIGS.  20  and  21   , a third inductor coil  148  is positioned between first and second inductor coils  144 ,  146 . In the embodiment shown in  FIGS.  20  and  21   , the first and second inductor coils  144 ,  146  are positioned about co-planar to each other. The third inductor coil  148  is positioned in a plane above the first and second inductor coils  144 ,  146 . Alternatively, the third inductor coil  148  may be positioned on a plane below the first and second inductor coils  144 ,  146 . In one or more embodiments, the inductor coils  144 ,  146 ,  148  of the multi-antenna array  140  shown in  FIGS.  20  and  21    are oriented in an angular relationship with respect to each other. As illustrated an imaginary line B-B extends lengthwise and bisects the first inductor coil  144  of the array  140 . A second imaginary line C-C extends lengthwise and bisects the second inductor coil  146  of the array  140 . A third imaginary line D-D extends lengthwise and bisects the third inductor coil  148  of the array  140 . In one or more embodiments, a first inductor coil array angle γ extends between the imaginary line A-A that extends through the first inductor coil  144  and the imaginary line D-D that extends through the third inductor coil  148 . A second inductor coil array angle κ extends between the imaginary line C-C that extends through the second inductor coil  146  and the imaginary line D-D that extends through the third inductor coil  148 . In one or more embodiments, at least one of the first and second inductor coil array angles γ,κ may range from about 1° to about 90°. In one or more embodiments, the first and second inductor coil array angles γ,κ may be about equal to each other. In one or more embodiments, the first and second inductor coil array angles γ,κ may not be about equal to each other. 
     In one or more embodiments, the multi-antenna arrays  140  illustrated in either or both  FIG.  19 ,  20   , or  21  may be embedded within a platform  142  or substrate  72 . In one or more embodiments, the multi-antenna array  140  may be embedded within the platform  142  such that the top surface of at least one of the inductor coils  144 ,  146 ,  148  of the array  140  is positioned flush with the top surface of the platform  142 . In one or more embodiments, a potting compound may be used to embed the multi-antenna array  140  within the platform  142  or substrate  72 . In one or more embodiments, the potting compound may comprise but is not limited to an adhesive, a thermosetting adhesive, a polymeric material, a thermoplastic polymer, a dielectric material, a metal, or a ceramic material. In one or more embodiments, the potting compound may have a thermal conductivity equal to or greater than 1.0 W/(M·K). 
     In one or more embodiments, the multi-antenna array  140  of the present application may be configured in a wireless electrical energy transmitting cradle  152  shown in  FIGS.  22  and  23 A- 23 D . 
     In one or more embodiments, as illustrated in  FIG.  21   , at least one platform  142  comprising the multi-antenna array  140  is electrically configured within the electrical energy transmitting cradle  152 . In one or more embodiments, electrical wiring  154  ( FIG.  21   ) connected to each of the inductor coils  144 ,  146 ,  148  is electrically connected to a micro-control unit (not shown) residing within the electrical energy transmitting cradle  152 . In one or more embodiments, an electrical power source (not shown) is electrically connectable to the micro-control unit and each of the inductor coils  144 ,  146 ,  148  of the multi-antenna array  140 . In one or more embodiments, the micro-control unit may be configured to detect the presence of an electronic device  68  positioned near at least one of the inductor coils of the multi-antenna array  140 . In addition, in one or more embodiments, the micro-control unit is configured to electrically switch between any individual or a combination of inductor coils  144 ,  146 ,  148  to ensure proper wireless transmission or reception of electrical energy between the cradle  152  and at least one electronic device  68 . Examples of such devices include but are limited to a cellular phone, a computer, a radio, or a wearable electronic device. 
     As illustrated in  FIGS.  22  and  23 A- 23 D , the electrical transmitting cradle  152  comprises at least one platform  142  comprising the multi-antenna array  140 . In addition, the electrical transmitting cradle  152  may comprise a housing  156  and at least one sidewall  158 . The at least one sidewall  158  is designed to hold the electronic device  68  within the cradle  152  during electrical energy transfer therebetween. In one or more embodiments, the at least one sidewall  158  may comprise at least one multi-antenna array  140  therewithin thereby enabling wireless electrical energy transmission between the cradle  152  and an electronic device  68  positioned therewithin in an unlimited number of orientations with respect to an inductor coil of the array  140 . In one or more embodiments, the at least one sidewall  158 , multi-antenna array platform  142 , and/or housing  156 , may be configured with an angular orientation with respect to each other. Thus, the electrical transmitting cradle  152  is designed to be mechanically sturdy and help prevent an electronic device  68  such as a cellular phone from falling off the cradle  152 .  FIGS.  23 A- 23 D  illustrate various non-limiting orientations within which an electronic device  68 , i.e., a cellular phone may be positioned within the cradle  152  and still enable wireless transmission of electrical energy and/or data therebetween. 
       FIGS.  24 ,  24 A,  25 ,  26 , and  27    illustrate one or more embodiments of a wireless electrical energy transmitting base  160  that comprises the multi-antenna array  140  of the present application. As shown, the wireless transmitting base  160  comprises a base housing  162  and a plurality of wireless transmission surfaces  164  that are positioned about the wireless transmitting base  160 . In one or more embodiments, at least one of the multi-antenna array  140  is positioned within the base housing  162 .  FIG.  23 A  illustrates an example of an electronic device  68 , i.e., a cellular phone, positioned in contact with the transmission surface  164  of the base  160 . In one or more embodiments, the wireless energy transmission base  160  is configured so that at least one electronic device  68  is capable of being electrically charged and/or directly powered from electrical energy wirelessly transmitted from the base  160 . The at least one electronic device may be positioned in contact with at the least one of the transmission surface  164  or alternatively, the at least one electronic device  68  may be positioned adjacent to but not in direct contact with the at least one of the transmission surface  164 . 
     In one or more embodiments as illustrated in  FIGS.  25  and  26   , the wireless transmitting base  160  comprises a circuit board  166  positioned within the base housing  162 . In one or more embodiments, the circuit board  166  comprises at least one micro-control unit  168  that controls the operation of each of the inductor coils that comprise the multi-antenna array  140  positioned within the base housing  162 . In one or more embodiments, the micro-control unit  168  may be configured to switch between each individual or a combination of inductor coils. In one or more embodiments, the micro-control unit  168  may be configured to detect the presence of an electronic device  68  and direct wireless electrical power to the device  68 . In one or more embodiments, the micro control unit  168  is configured to direct electrical power to be wirelessly transmitted by controlling various resistors, inductors, and/or capacitors (not shown) within the wireless electrical energy transmitting base  160  to activate or deactivate specific paths of electrical energy within the base  160 . 
     In one or more embodiments either or both the transmitting inductor coil  98  and the receiving inductor coil  100  of the present application may be fabricated using a laser (not shown). In one or more embodiments, the laser may be used to cut the electrically conductive material, thereby forming the filar or wire  14  of the respective inductor coil  12  and further join components together. In one or more embodiments, the laser may be used to cut the electrically conductive material of the coil filar  14  to exacting tolerances. In one or more embodiments, the laser may also be used to join components of the inductor coil and/or antenna  12 ,  22 ,  26 . 
       FIGS.  28 A- 28 G and  29 A- 29 C  illustrate embodiments of a process of fabricating a transmitting or receiving antenna  22 ,  26  of the present application. In one or more embodiments, a laser (not shown) may be used to fabricate the antenna.  FIG.  28 A  illustrates step one of the process in which at least o first opening  170  is formed through a substrate  172 . In one or more embodiments the substrate  172  is composed of a polymer material.  FIG.  28 B  illustrates an embodiment of step two of the process in which at least one, second opening  174  is formed through an adhesive sheet  176  and placed in contact with either the top or bottom surface of the substrate  172 . In one or more embodiments, at least one adhesive sheet  176  is positioned on both the top and bottom surfaces of the substrate  172 . In one or more embodiments, the adhesive sheet  176  is positioned on the surface of the substrate  172  so that the second openings  174  of the adhesive sheet  176  align with the first openings  170  of the substrate  172 .  FIG.  28 C  illustrates an embodiment of step three of the process in which at least one electrically conductive material  178  such as a metal substrate is positioned on at least the top and bottom surface of the adhesive sheet  176 . As illustrated two copper substrates are adhered to the top and bottom surfaces of the adhesive sheet  176 .  FIG.  28 D  illustrates step four of the process in which the electrically conductive material is cut into wire or filar  14  strands thereby forming the inductor coil  12 . In one or more embodiments, a laser can be used to cut the electrically conductive material into the wire or filar strands  14 .  FIG.  28 E  illustrates step five of the process. In one or more embodiments, at least two of the wires or filars  14  are joined together. In one or more embodiments, at least two of the wires or filars  14  are welded together, for example with a laser forming a weld joint  180  therebetween. In one or more embodiments, a protective substrate  182  such as a polymer film is applied to at least the top and top surfaces of the electrically conductive material  178  that forms the filar  14  of the inductor coil  12 .  FIG.  28 G  illustrates step six of the process in which a metallic substrate  184  is poisoned in contact with at least one of the top and bottom surfaces of the protective substrate  182 . In one or more embodiments, the metallic substrate  184  acts as a barrier to protect the inductor coil  12  from potential damage. 
       FIGS.  29 A- 29 C  illustrate one or more embodiments of a process of fabricating a transmitting or receiving antenna  22 ,  26  of the present application.  FIG.  29 A  illustrates an embodiment of the first step in the process in which an adhesive sheet  176  comprising at least one first opening  170  is applied to at least the top or bottom surface of a substrate  172  such as a polymer substrate. In one or more embodiments, the substrate  172  has at least one, second opening  174 . In one or more embodiments, the first opening  170  of the adhesive sheet  176  aligns with the at least one second opening  174  of the substrate  172 .  FIG.  29 B  illustrates an embodiment of step two of the process in which an electrically conductive material  178  such as a metal substrate is positioned in contact with at least one surface of the adhesive sheet  176 .  FIG.  29 C  illustrates an embodiment of the third step in the process in which the electrically conductive material  178  is cut to form the wires or filars  14  that comprise the inductor coil  12 . 
       FIG.  30    illustrates one or more embodiments of an inductor coil assembly  186  of the present application. As illustrated, the assembly  186  comprises the substrate  172 , such as a substrate composed of a polymeric material. The adhesive sheet  176  having an adhesive material on at least one of the top and bottom surfaces is positioned between the substrate  172  and an inductor coil  12  formed from the electrically conductive material  178 . The first adhesive sheet  176  configured to adhere the inductor coil  12  to the surface of the substrate  172 . A second adhesive sheet  176  is positioned between a second inductor coil  12  and the substrate  172 , on the opposite side of the substrate  172 . 
     It will be appreciated that any of the embodiments described herein can be used with multilayer, multilayer multiturn, multimode and similarly configured structures. The following U.S. patents Nos. and U.S. patent application Ser. Nos. are additionally incorporated herein fully by reference: U.S. Pat. Nos. 8,567,048; 8,860,545; 9,306,358; 9,439,287; 9,444,213; and Ser. No. 15/227,192; 15/240,637. 
     Thus, it is contemplated that the embodiments of inductor coils and antennas that enable wireless electrical energy transfer embodiments of the present disclosure may be configured having a variety of configurations. Furthermore, such configurations of the variety of inductor coils and antennas allow for significantly improved wireless transmission of electrical energy and/or data. It is further contemplated that the various magnetic shielding materials  66  can be strategically positioned adjacent to the transmitting or receiving antennas  22 ,  26  to enhance quality factor and mutual inductance between adjacently positioned transmitting and receiving antennas  22 ,  26 . It is appreciated that various modifications to the subject technology concepts described herein may be apparent to those of ordinary skill in the art without departing from the spirit and scope of the present disclosure as defined by the appended claims. 
     As used herein, the phrase “at least one of” preceding a series of items, with the term “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” does not require selection of at least one of each item listed; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C. 
     The predicate words “configured to”, “operable to”, and “programmed to” do not imply any particular tangible or intangible modification of a subject, but, rather, are intended to be used interchangeably. In one or more embodiments, a processor configured to monitor and control an operation or a component may also mean the processor being programmed to monitor and control the operation or the processor being operable to monitor and control the operation. Likewise, a processor configured to execute code can be construed as a processor programmed to execute code or operable to execute code. 
     A phrase such as “an aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. An aspect may provide one or more examples of the disclosure. A phrase such as an “aspect” may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. An embodiment may provide one or more examples of the disclosure. A phrase such an “embodiment” may refer to one or more embodiments and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A configuration may provide one or more examples of the disclosure. A phrase such as a “configuration” may refer to one or more configurations and vice versa. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” or as an “example” is not necessarily to be construed as preferred or advantageous over other embodiments. Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. 
     All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” 
     Reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure. 
     While this specification contains many specifics, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of particular implementations of the subject matter. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination.