Layered short-range wireless communication antenna

Abstract

A system and device for near-field wireless communication with a receiver. The device may include an antenna and one or more antenna printed circuit boards. The antenna may include a first conductor on a first antenna layer and a second conductor on one or more second antenna layers. A current supplied to the antenna may pass through the first conductor in a direction opposite to the direction in which the current passes through the second conductor. The system may include the device and a receiver, which may have a receiver coil. The opposing directions in which the current passes through the first conductor and the second conductor may be substantially perpendicular to the longitudinal axis of the receiver coil. The antenna may generate a substantial magnetic flux in a direction corresponding to the longitudinal axis of the receiver coil, which may be oriented parallel to the planar surface of the antenna.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 370,808, filed August 9, 2022, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION

[0003] The present invention relates generally to near field communication (NFC) antennas for communication and / or powering a remote receiver. In particular, embodiments of the present invention relate to planar NFC antennas for small cylindrical receivers with the axis and coil oriented parallel to the planar antenna surface. [Background technology]

[0003]

[0004] Background Art Discussion

[0005] magnetic field

[0006] FIG. 1A shows a cross-section of a conductor (e.g., a wire) carrying current in a first direction (e.g., forward or into the page) and the direction of the magnetic field generated by the current. FIG. 1B shows a cross-section of a conductor carrying current in a second direction (e.g., backward or out of the page) and the direction of the magnetic field generated by the current. FIG. 1C and FIG. 1E show cross-sections of a group of conductors each carrying current in a first direction, with FIG. 1C showing the direction of the magnetic field generated by each of the currents carried by the conductors in the group of conductors and FIG. 1E showing the direction of the resultant magnetic field generated by the currents in the group of conductors. FIG. 1D and FIG. 1F show cross-sections of a group of conductors each carrying current in a second direction, with FIG. 1D showing the direction of the magnetic field generated by each of the currents carried by the conductors in the group of conductors and FIG. 1F showing the direction of the resultant magnetic field generated by the currents in the group of conductors. FIG. 1G shows a cross section of a group of conductors that includes both (a) conductors carrying current in a first direction and (b) conductors carrying current in a second direction, as well as the direction of the magnetic field generated by the opposing currents in the group of conductors.

[0004]

[0007] Space-saving NFC antenna design

[0008] An NFC antenna is typically a coil shaped to accomplish a specific task. For example, an NFC antenna may operate at a center frequency of 13.56 MHz, and the size of the NFC antenna may be limited to a range of 0.01 meters (m) to 0.1 m. For many applications, the NFC antenna may communicate with a remote device and / or provide power to the remote device (e.g., for the duration of the communication). Typically, maximizing the magnetic flux linkage between the NFC antenna and the remote device improves power efficiency and communication range. The power delivered to the remote device by the NFC antenna will be proportional to the square of the amplitude of the electromagnetic field (EMF) that may be developed in the receiving coil of the remote device. The EMF is proportional to the time derivative of the magnetic flux linkage, as shown in the following equation:

[0005]

number

[0006] The above equation means that the EMF is proportional to the velocity of the magnetic flux changing through the receiving coil of the remote device and the integral over the surface of the coil of the dot product of the incoming magnetic flux density vector and the normal to the surface of the coil. If the frequency is fixed by regulatory assignment, the flux linkage can be maximized by decreasing the distance and / or increasing the area of the coil that receives the flux with a vector oriented in the same direction relative to the coil normal. This can be done by adding turns to the coil, and as shown below, the flux linkage equation simplifies to a single-loop equation multiplied by N, where N is the number of turns in the coil. λ=NΦ (Equation 3)

[0009] Many antennas are optimized (i) to be large and planar, (ii) to communicate with a remote device that is also large and planar, and (iii) to be similar in size and dimensions to a credit card or public transportation pass. Flux linkage in these cases is maximized by adding turns and ensuring that the transmitter antenna and remote device are properly aligned. In this case, flux linkage is achieved through coaxial magnetic field lines that are perpendicular to the surface of the planar coil and represent the instantaneous magnetic "pole" generated by that coil. A receive coil is then positioned parallel to the transmitter coil to receive most of the field lines before they begin to bend sideways.

[0007]

[0010] In special cases where the remote device is not large and planar and cannot be oriented with its magnetic poles perpendicular to the transmitter surface, different antenna shapes are used. For example, if the receiving device is a long cylinder with a helical coil wound along its axis, and the coil can only be positioned parallel to the antenna, it is no longer possible to use magnetic field lines directly at the magnetic poles. Instead, curved magnetic field lines are used to power the coil. This can be achieved by transforming the transmitter antenna into a coil similar to the receiver coil but longer. The magnetic field lines generated at the magnetic poles are then bent along the receiver coil and aligned with the receiver coil's axis. However, if the transmitter's size and shape are limited (e.g., if it must be made as a printed circuit board (PCB)), it may not be feasible to simply create the transmitter in a cylindrical shape.

[0008]

[0011] Planar NFC antenna structure

[0012] For a typical small NFC antenna (e.g., 0.01 m to 0.1 m with 10 to 20 turns), the number of turns and size of the NFC antenna are intended to ensure that the entire antenna structure is approximately in phase when operated at 13.56 MHz. This is because the wavelength at 13.56 MHz is approximately 22 meters, half the wavelength is 11 meters, and the copper equivalent is only slightly smaller. It can be assumed that most of the phase shift occurs in the matching network leading up to the antenna. Therefore, the antenna can be analyzed in terms of overlapping magnetic fields in space generated by the finite current-carrying conductors in the antenna structure. Conductors that are close to each other and carry current in the same direction will generate parallel magnetic field lines that overlap to create a stronger magnetic flux and improve flux linkage for any receive coils placed perpendicular to those field lines. However, because current must travel through a closed circuit, for every conductor traveling in one direction, there will be a conductor carrying an equal amount of current in the opposite direction. Magnetic field lines from conductors carrying current in the opposite direction will destructively interfere with the leading field lines, potentially canceling them. To mitigate this, various techniques are used, including shielding the return conductor with a ferrimagnetic material (e.g., ferrite), spatially separating conductors carrying current in one direction from conductors carrying current in the opposite direction (as shown in Figure 1G), and / or timing their phase reversals so that their interference is constructive rather than destructive. Timing their phase reversals so that their interference is constructive requires an antenna that is electrically large (e.g., about half a wavelength), which is difficult to achieve at small sizes. This means that for small antennas, a combination of the first two techniques is used.

[0009]

[0013] Planar NFC antennas and their compatibility with small cylindrical receiver coils

[0014] 2A, 2B, 3A, and 3B show a cross section of an existing planar NFC antenna 202 that includes a planar transmitter coil 204, the direction of the current carried by the transmitter coil 204, and the direction of the magnetic field generated by the current carried by the transmitter coil 204. FIG. 2A additionally shows a cross section of a receiver 206a that includes a planar receiver coil 208a and the direction of the current induced in the receiver coil 208a by the magnetic field generated by the current carried by the transmitter coil 204. FIG. 2B additionally shows a cross section of a receiver 206b that includes a cylindrical receiver coil 208b and the direction of the current induced in the receiver coil 208b by the magnetic field generated by the current carried by the transmitter coil 204. As shown in FIGS. 2A and 2B, the existing planar NFC antenna 202 and receiver 206a or 206b use coaxial magnetic flux linkage. That is, the transmitter coil 204 of the NFC antenna 202 and the receiver coil 208a of the receiver 206a or the receiver coil 208b of the receiver 206b are expected to be aligned approximately along the same axis. For receivers 206a or 206b positioned such that their axes are perpendicular to the conductors of the transmitter coil 204 and coaxial with the magnetic field generated by the current carried by the conductors of the transmitter coil 204, existing planar NFC antennas 202 will function in the mid-range.

[0010]

[0015] 3A and 3B show a cross section of a receiver 306 that includes a cylindrical receiver coil 308. As shown in Figures 3A and 3B, the axis of the transmitter coil 204 of the NFC antenna 202 is perpendicular to the axis of the receiver coil 308 of the receiver 306. That is, in Figures 3A and 3B, the axis of the receiver coil 308 of the receiver 306 is oriented horizontally relative to the vertical orientation of the axis of the transmitter coil 204 of the NFC antenna 202.

[0011]

[0016] Figure 3A shows a receiver 306 positioned at the center of the magnetic field generated by the current carried by the conductors of the transmitter coil 204. Figure 3A illustrates the direction of current that the magnetic field generated by the current carried by the transmitter coil 204 attempts to induce in the receiver coil 308 of the receiver 306. However, with the receiver 306 positioned at the center of the magnetic field generated by the current carried by the conductors of the transmitter coil 204, as shown in Figure 3A, the magnetic field generated by the current carried by the conductors of the transmitter coil 204 cannot induce a current in the receiver coil 308 of the receiver 306 (or can only generate a small amount of current if the receiver 306 is not exactly centered).

[0012]

[0017] FIG. 3B illustrates a receiver 306 positioned at a different location, away from the center of the magnetic field generated by the current carried by the conductors of the transmitter coil 204. As shown in FIG. 3B, with the receiver 306 positioned away from the center of the magnetic field generated by the current carried by the conductors of the transmitter coil 204, the magnetic field generated by the current carried by the conductors of the transmitter coil 204 can induce a current in the receiver coil 308 of the receiver 306. FIG. 3B illustrates the direction of the current induced in the receiver coil 308 of the off-center receiver 306 by the magnetic field generated by the current carried by the conductors of the transmitter coil 204. That is, as shown in FIGS. 3A and 3B, the receiver coil 308 of a horizontally oriented receiver 306 cannot be used with the transmitter coil 204 of the NFC antenna 202 unless the receiver 306 is positioned away from the center of the magnetic field generated by the current carried by the conductors of the transmitter coil 204.

[0013]

[0018] The ferrite sheet backing may improve the performance of the NFC antenna 202 and prevent magnetic flux from affecting electronic devices on the other side of the NFC antenna 202.

[0019] 4A and 4C show cross-sectional views of a system including a device 402 and a receiver 306. The device 402 includes an antenna 404, an antenna printed circuit board (PCB) 410, a ferromagnetic layer 416, a circuit component PCB 412, a connector 414 between the antenna PCB 410 and the circuit component PCB 412, and one or more circuit components 418, 420, and 422 mounted on or fabricated in the circuit component PCB 412. The one or more circuit components may include a processor 418 and a computer-readable medium (CRM) 420 (e.g., flash memory). FIG. 4B shows the antenna 404. As shown in FIG. 4B, the antenna 404 includes a first antenna differential feed 424 and a second antenna differential feed 426, through which current is supplied to the antenna 404. 4A-4C, the antenna 404 includes a first conductor 404a and a second conductor 404b that extend substantially perpendicular to the axis of the receiver coil 308 of the receiver 306. As shown in Figure 4B, the antenna 404 additionally includes a third conductor 404c that connects the first conductor 404a and the second conductor 404b and extends substantially parallel to the axis of the receiver coil 308 of the receiver 306. As shown in Figure 4B, the antenna 404 additionally includes wires 428, 430, and 432 (e.g., PCB traces).

[0014]

[0020] As shown in Figures 4A-4C, the antenna 404 includes a first conductor 404a and a second conductor 404b in a single layer. As shown in Figures 4A and 4C, a current supplied to the antenna 404 passes through the first conductor 404a in a direction opposite to the direction in which the current passes through the second conductor 404b. The opposing directions in which the current supplied to the antenna 404 passes through the first conductor 404a and the second conductor 404b are perpendicular to the axis of the receiver coil 308 of the receiver 306. As shown in Figures 4A-4C, the first conductor 404a is located at the center of the antenna 404 between the second conductors 404b at the left and right edges of the antenna 404. As shown in FIG. 4B, first conductors 404a are also disposed between conductors of antenna 404 connecting first conductor 404a and second conductor 404b at the top and bottom edges of antenna 404.

[0015]

[0021] The magnetic field generated by the current carried by the first conductor 404a and the second conductor 404b of the antenna 404 is shown in Figures 4A and 4C. The ferromagnetic layer 416 contributes to optimal performance of the device 402. As shown in Figure 4A, with the receiver 306 positioned at the center of the magnetic field generated by the current carried by the first conductor 404a of the transmitter antenna 404, the receiver 306 receives a good signal, and the magnetic field generated by the current carried by the first conductor 404a of the transmitter antenna 404 can induce a current in the receiver coil 308 of the receiver 306.

[0016]

[0022] 4C , if the receiver coil 308 of the receiver 306 is positioned between the magnetic field generated by the current carried by the first conductor 404 a and the second conductor 404 b of the transmitter antenna 404, the magnetic field generated by the current carried by the first conductor 404 a and the second conductor 404 b of the transmitter antenna 404 cannot induce a current in the receiver coil 308 of the receiver 306. That is, the receiver 306 loses signal if it is shifted a small distance from the center, which makes it easy for the device 402 and the receiver 306 to lose connection. If the receiver coil 308 of the receiver 306 is instead positioned completely within the magnetic field generated by the current carried by the second conductor 404 b of the transmitter antenna 404, as shown in FIG. 4C , the magnetic field generated by the current carried by the first conductor 404 a of the transmitter antenna 404 may be able to induce a small amount of current in the receiver coil 308 of the receiver 306. That is, the receiver 306 receives a weak signal that is far off-center, which can be confusing to a user (eg, trying to center the receiver 306).

[0017]

[0023] Note that the magnetic field generated by the third conductor 404c of the antenna 404, which connects the first conductor 404a and the second conductor 404b and extends in a direction substantially parallel to the axis of the receiver coil 308 of the receiver 306, is not shown in Figures 4A and 4C because it is perpendicular to the axis of the receiver coil 308 of the receiver 306 and does not contribute to generating a current in the receiver coil 308 of the receiver 306. Summary of the Invention

[0018]

[0024] Embodiments of the present invention may improve the coverage area and range of planar near-field communication (NFC) antennas, which may be differentially driven and operate at, for example, but not limited to, 13.56 MHz, by improving flux linkage and area efficiency. Embodiments of the present invention may additionally or alternatively improve the area efficiency of the antenna by covering a larger area with conductors carrying currents with constructively overlapping magnetic fields. Embodiments of the present invention may additionally or alternatively improve antenna range by lowering the resistance of the antenna coil, moving the return current conductor further away from the active area, and / or shrouding the return current wire with one or more ferromagnetic pieces. Embodiments of the present invention may result in significant improvements in antenna performance.

[0019]

[0025] One embodiment of the present invention may provide an apparatus including an antenna. The antenna may include a first conductor and a second conductor. The first conductor may be in a first antenna layer. The second conductor may be in one or more second antenna layers different from the first antenna layer. A current supplied to the antenna may pass through the first conductor in a direction opposite to a direction in which the current passes through the second conductor.

[0020]

[0026] In some aspects, the apparatus may further include an antenna printed circuit board (PCB). In some aspects, the first conductor may be printed on a bottom surface of the antenna PCB. In some aspects, the antenna PCB may include antenna vias, each of which may electrically connect one of the second conductors to one of the first conductors. In some aspects, the first conductor in the first antenna layer, the conductors in the one or more second antenna layers, and the antenna vias may form a coil, and the conductors in the one or more second antenna layers include at least the second conductor.

[0021]

[0027] In some embodiments, the second conductor may be printed on the top surface of the antenna PCB and / or fabricated in one or more layers of the antenna PCB.

[0028] In some embodiments, the second conductor may include a second conductor disposed on a first edge of the antenna PCB and a second conductor disposed on a second edge of the antenna PCB opposite the first edge. In some embodiments, the apparatus may include a first ferromagnetic piece disposed below the second conductor disposed on the first edge of the antenna PCB and a second ferromagnetic piece disposed below the second conductor disposed on the second edge of the antenna PCB.

[0022]

[0029] In some embodiments, the device may further include a ferromagnetic layer above the antenna PCB. In some embodiments, the device may further include a circuit component PCB and one or more circuit components mounted on or fabricated in the circuit component PCB. In some embodiments, the ferromagnetic layer may be between the circuit component PCB and the antenna PCB.

[0023]

[0030] In some embodiments, the second conductor may be disposed on one edge of the antenna PCB. In some embodiments, the apparatus may further include a ferromagnetic piece disposed above the second conductor on one edge of the antenna PCB.

[0024]

[0031] In some embodiments, the antenna may further include a ferromagnetic layer between the first conductor and the second conductor.

[0032] In some embodiments, the antenna PCB may be a first antenna PCB, and the antenna may further include a second antenna PCB, where the first conductor may be printed on or fabricated in the first PCB antenna, and the second conductor may be printed on and / or fabricated in the second PCB antenna. In some embodiments, the apparatus may further include one or more circuit components mounted on or fabricated in the second antenna PCB. In some embodiments, the first antenna PCB and the second antenna PCB may be part of a composite PCB, and the ferromagnetic layer may be an internal layer within the composite PCB.

[0025]

[0033] In some aspects, a cross-sectional area of the first conductor can be larger than a cross-sectional area of the second conductor. In some aspects, the apparatus may further include a first antenna feed and a second antenna feed, a first feed conductor in one of the one or more second antenna layers electrically connecting the first antenna feed to a first outer conductor of the first conductor at a first antenna end of the first outer conductor, and a second feed conductor in one of the one or more second antenna layers electrically connecting the second antenna feed to a second outer conductor of the first conductor at a second antenna end of the second outer conductor, where the first antenna end and the second antenna end can be opposite ends of the antenna.

[0026]

[0034] In some aspects, the current supplied to the antenna may pass through one of the first conductors and then through one of the second conductors before passing through another of the first conductors. In some aspects, the current supplied to the antenna may pass through one of the second conductors and then through one of the first conductors before passing through another of the second conductors.

[0027]

[0035] In some embodiments, current passing through a first conductor can generate a magnetic field that constructively overlaps. In some embodiments, current passing through a second conductor can generate a magnetic field that can destructively interfere with the magnetic field generated by the current passing through the first conductor. In some embodiments, the current passing through the second conductor can be a return current.

[0028]

[0036] In some embodiments, the first antenna layer does not include a conductor through which current supplied to the antenna passes in a direction opposite to the direction in which current supplied to the antenna passes through the first conductor. In some embodiments, the antenna may further include a third conductor in one or more second antenna layers, and the third conductor may connect the first conductor and the second conductor. In some embodiments, the antenna may include two or more second antenna layers, and the second conductor may be in two or more second antenna layers.

[0029]

[0037] Another aspect of the invention may provide a system including the apparatus of any one of the above aspects and a receiver coil.

[0038] In some aspects, the opposing directions in which current passes through the first and second conductors may be substantially perpendicular to the longitudinal axis of the receiver coil. In some aspects, the first and second conductors may extend in a direction substantially perpendicular to the longitudinal axis of the receiver coil. In some aspects, the antenna may further include a third conductor in one or more second antenna layers, which may connect the first and second conductors and extend in a direction substantially parallel to the longitudinal axis of the receiver coil. In some aspects, the longitudinal axis of the receiver coil may be parallel to a planar surface formed by the first conductors in the first antenna layer.

[0030]

[0039] Yet another aspect of the invention may provide a method that includes supplying a current to an antenna, wherein the current supplied to the antenna may pass through a first conductor in a first antenna layer of the antenna in a direction opposite to a direction in which the current passes through a second conductor in one or more second antenna layers of the antenna that are different from the first antenna layer of the antenna.

[0031]

[0040] In some embodiments, the current passing through the first conductor may generate constructively overlapping magnetic fields. In some embodiments, the current passing through the second conductor may be a return current. In some embodiments, the opposing directions in which the current passes through the first conductor and the second conductor may be substantially perpendicular to the longitudinal axis of the receiver coil. In some embodiments, the first conductor and the second conductor may extend in a direction substantially perpendicular to the longitudinal axis of the receiver coil. In some embodiments, the longitudinal axis of the receiver coil may be parallel to a planar surface formed by the first conductor in the first antenna layer. In some embodiments, the current may be an alternating current.

[0032]

[0041] Further variations encompassed by the systems and methods are described below in the detailed description of the invention.

[0042] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate various non-limiting embodiments of the present invention, in which like reference numbers indicate identical or functionally similar elements. [Brief explanation of the drawings]

[0033] [Figure 1A]

[0043] 1 is a cross-sectional view of a conductor carrying a current in a certain direction, showing the direction of the magnetic field generated by the current. [Figure 1B] 1 is a cross-sectional view of conductors carrying currents in opposite directions, showing the direction of the magnetic fields generated by the currents. [Figure 1C]

[0044] 1 is a cross-sectional view of a group of conductors each carrying current in the same direction, showing the direction of the magnetic field generated by the current. [Figure 1D] 1 is a cross-sectional view of a group of conductors each carrying current in the same direction, showing the direction of the magnetic field generated by the current. [Figure 1E]

[0045] 1 is a cross-sectional view of a group of conductors each carrying current in the same direction, illustrating the direction of the resultant magnetic field generated by the currents in the group of conductors. [Figure 1F] 1 is a cross-sectional view of a group of conductors each carrying current in the same direction, illustrating the direction of the resultant magnetic field generated by the currents in the group of conductors. [Figure 1G]

[0046] A cross-sectional view of a group of conductors including both (a) conductors carrying current in a first direction and (b) conductors carrying current in a second direction, showing the direction of the magnetic fields generated by the opposing currents in the group of conductors. [Figure 2A]

[0047] FIG. 1 is a cross-sectional view of a system including an NFC antenna and a receiver with a coaxially aligned coil, illustrating the direction of the current carried by the transmitter coil of the NFC antenna, the direction of the magnetic field generated by the current carried by the transmitter coil of the NFC antenna, and the direction of the current induced in the receiver coil of the receiver by the magnetic field. [Figure 2B]FIG. 1 is a cross-sectional view of a system including an NFC antenna and a receiver with a coaxially aligned coil, illustrating the direction of the current carried by the transmitter coil of the NFC antenna, the direction of the magnetic field generated by the current carried by the transmitter coil of the NFC antenna, and the direction of the current induced in the receiver coil of the receiver by the magnetic field. [Figure 3A]

[0048] FIG. 1 is a cross-sectional view of a system including an NFC antenna with a vertically oriented transmitter coil axis and a receiver with a horizontally oriented receiver coil axis, showing the direction of the current carried by the transmitter coil of the NFC antenna, the direction of the magnetic field generated by the current carried by the transmitter coil of the NFC antenna, and the direction of the current induced (or about to be induced) in the receiver coil of the receiver by the magnetic field. [Figure 3B] FIG. 1 is a cross-sectional view of a system including an NFC antenna with a vertically oriented transmitter coil axis and a receiver with a horizontally oriented receiver coil axis, showing the direction of current carried by the transmitter coil of the NFC antenna, the direction of the magnetic field generated by the current carried by the transmitter coil of the NFC antenna, and the direction of current in the receiver coil of the receiver that is induced (or is about to be induced) by the magnetic field. [Figure 4A]

[0049] 1 is a cross-sectional view of a system including a device having a planar NFC antenna with a single-layer transmitter coil and a receiver having a receiver coil. [Figure 4B] FIG. 1 shows a single layer transmitter coil. [Figure 4C] 1 is a cross-sectional view of a system including a device having a planar NFC antenna with a single-layer transmitter coil and a receiver having a receiver coil. [Figure 5A]

[0050] 1 is a cross-sectional view of a system including a device having a planar NFC antenna with a multi-layer transmitter coil and a receiver having a receiver coil, according to some embodiments. [Figure 5B]

[0051] FIG. 1 is a perspective view of a multi-layer transmitter coil, according to some embodiments. [Figure 5C] 1 is an expanded view of a multi-layer transmitter coil, according to some embodiments. [Figure 5D] FIG. 1 is a bottom view of a multi-layer transmitter coil, according to some embodiments. [Figure 5E] FIG. 1 is a bottom view of a multi-layer transmitter coil, according to some embodiments. [Figure 5F]

[0052] FIG. 2 illustrates a first conductor in a first antenna layer of a multi-layer transmitter coil, according to some embodiments. [Figure 5G]

[0053] FIG. 10 illustrates a second conductor in a second antenna layer of a multi-layer transmitter coil, according to some embodiments. [Figure 5H] FIG. 10 illustrates a second conductor in a second antenna layer of a multi-layer transmitter coil, according to some embodiments. [Figure 5I] FIG. 10 illustrates a second conductor in a second antenna layer of a multi-layer transmitter coil, according to some embodiments. [Figure 5J] FIG. 10 illustrates a second conductor in a second antenna layer of a multi-layer transmitter coil, according to some embodiments. [Figure 5K] FIG. 10 illustrates a second conductor in a second antenna layer of a multi-layer transmitter coil, according to some embodiments. [Figure 5L]

[0054] FIG. 1 is a bottom view of a multi-layer transmitter coil, according to some embodiments. [Figure 6]

[0055] 1 is a cross-sectional view of a system including a device having a planar NFC antenna with a multi-layer transmitter coil and a receiver having a receiver coil, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0034]

[0056] 5A is a cross-sectional view illustrating a system including a device 502 and a receiver 306, according to some embodiments. The receiver 306 may include a receiver coil 308. In some embodiments, the device 502 may include an antenna 504, an antenna printed circuit board (PCB) 510, one or more ferromagnetic layers 516, a circuit component PCB 512, a connector 514 between the antenna PCB 510 and the circuit component PCB 512, and / or one or more circuit components 518, 520, and 522 mounted on or fabricated in the circuit component PCB 512. In some embodiments, the one or more circuit components 518, 520, and 522 may include a processor 518 (e.g., a central processing unit (CPU)) and a computer-readable medium (CRM) 520 (e.g., flash memory). 5A, device 502 may additionally or alternatively include one or more ferromagnetic (e.g., ferrite) pieces 534 disposed on one or more of a first (e.g., left) edge and a second (e.g., right) edge of antenna 504. However, one or more ferromagnetic pieces 534 are not required, and in some alternative embodiments, device 502 may not include one or more ferromagnetic pieces 534.

[0035]

[0057] 5B-5E and 5L are perspective, expanded, bottom, and plan views, respectively, of an antenna 504 according to some embodiments. In some embodiments, as shown in FIGS. 5A-5F and 5L, the antenna 504 can include a first conductor 504a in a first antenna layer (shown in red in FIGS. 5B-5D and 5L). FIG. 5F illustrates the first conductor 504a in the first antenna layer according to some embodiments. In some embodiments, as shown in FIGS. 5A-5E and 5G-5L, the antenna 504 can include conductors in one or more second antenna layers (shown in navy blue, mauve, light blue, yellow, and light green in FIGS. 5B-5D and 5L). FIGS. 5G-5K illustrate conductors in a second antenna layer according to some embodiments. In the illustrated embodiment, the antenna 504 includes five second antenna layers. However, this is not required, and in some alternative embodiments, the antenna 504 may include a different number of second antenna layers (e.g., 1, 2, 3, 4, 6, 7, 8, 12, 20, etc.). In some embodiments, as shown in FIGS. 5B-5L, the antenna 504 may include an antenna via 536 that electrically connects a first conductor 504a in a first antenna layer with one or more conductors in one or more second antenna layers. In some embodiments, the antenna via 536 may be a short vertical conductor in the antenna PCB 510. FIG. 5C shows the antenna 504 with the antenna via 536 expanded to show the first conductor 504a in the first antenna layer and the conductors in a different second antenna layer. 5B, 5D, 5E, 5G, and 5L, the antenna 504 may include a first antenna feed 505a and a second antenna feed 505b (e.g., a differential antenna feed) through which the apparatus 502 may provide current (e.g., alternating current) to the antenna 504. In some embodiments, as shown in FIGS. 5B, 5D, 5E, 5G, and 5L, the first antenna feed 505a and the second antenna feed 505b may be disposed at one end (e.g., the front end) of the antenna 504.In some embodiments, the conductors of the first antenna layer and the conductors of the second antenna layer and the antenna vias 536 may form a coil.

[0036]

[0058] 5A, the first conductor 504a of the first antenna layer may be on the bottom surface of the antenna PCB 510. In some embodiments, the first conductor 504a may be mounted or printed on the bottom surface of the antenna PCB 510. In some alternative embodiments, the first conductor 504a of the first antenna layer may be on (e.g., fabricated on) the bottom layer of the antenna PCB 510. In some embodiments, the first conductor 504a may be the only conductor on (or in) the bottom surface of the antenna PCB 510. In some embodiments, the longitudinal axis of the receiver coil 308 of the receiver 306 may be substantially parallel to the bottom surface of the planar antenna 504 formed by the first conductor 504a.

[0037]

[0059] 5A-5F and 5L, the first conductor 504a of the first antenna layer can extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, the conductor can extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306 when the conductor is at an angle within a range of 75° to 105° (i.e., 90°±15°) relative to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, the conductor can extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306 when the conductor is at an angle within a range of 80° to 100° (i.e., 90°±10°) relative to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, the conductors may extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306 when the conductors are at an angle within a range of 85° to 95° (i.e., 90°±5°) relative to the longitudinal axis of the receiver coil 308 of the receiver 306.

[0038]

[0060] 5A-5E and 5G-5L, the one or more second antenna layer conductors can include second conductor 504b, third conductor 504c, first feed conductor 504d, and / or second feed conductor 504e. In some embodiments where first conductor 504a is on the bottom surface of antenna PCB 510 as shown in FIG. 5A, one or more second antenna layer conductors (e.g., conductors 504b-504e) can be on the top surface of antenna PCB 510 (e.g., implemented or printed) and / or can be on one or more layers of antenna PCB 510 (e.g., fabricated). In some alternative embodiments in which the first conductor 504a is on the bottom layer of the antenna PCB 510, one or more second antenna layer conductors (e.g., conductors 504b-504e) may be on the top surface of the antenna PCB 510 (e.g., mounted or printed) and / or may be on one or more layers of the antenna PCB 510 other than the bottom layer of the antenna PCB 510 (e.g., fabricated).

[0039]

[0061] 5A-5E and 5G-5L, the second conductor 504b may extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, as shown in FIG. 5A, the second conductor 504b may include a second conductor 504b disposed on a first edge (e.g., the left edge) of the antenna PCB 510 and a second conductor 504b disposed on a second edge (e.g., the right edge) of the antenna PCB 510 opposite the first edge. In some embodiments, as shown in FIGS. 5B-5E and 5G-5L, the third conductor 504c may connect the second conductor 504b to the first conductor 504a (e.g., using an antenna via 536). In some aspects, the second conductor 504b and the third conductor 504c (as well as the antenna via 536) may form a return path for current supplied to the antenna 504. For example, the second conductor 504b and the two third conductors 504c (as well as the two antenna vias 536) in one of the second antenna layers may form a return path for current from one end (e.g., the front end) of one of the first conductors 504a to the opposite end (e.g., the back end) of another one of the first conductors 504a.

[0040]

[0062] 5A-5L, the current supplied to the antenna 504 may pass through one of the first conductors 504a, then through one of the second conductors 504b before passing through another of the first conductors 504a. In some embodiments, the current supplied to the antenna 504 may pass through one of the first conductors 504a, then through one of the second conductors 504b before passing through another of the second conductors 504b.

[0041]

[0063] In some aspects, the first feed conductor 504d may electrically connect the first antenna feed 505a to the first outer conductor of the first conductor 504a at a first antenna end of the first outer conductor (e.g., using an antenna via 536), and the second feed conductor 504e may electrically connect the second antenna feed to the second outer conductor of the first conductor at a second antenna end of the second outer conductor (e.g., using another antenna via 536), where the first antenna end and the second antenna end may be at opposite ends of the antenna 504. For example, the first antenna end may be a front end of the antenna 504, and the second antenna end may be a rear end of the antenna 504. In some aspects, the first feed conductor 504d and the second feed conductor 504e may be in the same layer of one or more second antenna layers. However, this is not required, and in some alternative embodiments, the first feed conductor 504d may be in a different layer of one or more second antenna layers than the second feed conductor 504e.

[0042]

[0064] In some embodiments, as shown in FIGS. 5A-5L, the cross-sectional area of the first conductor 504a on the first antenna layer can be larger than the cross-sectional area of the conductors on one or more second antenna layers (e.g., including the second conductor 504b, the third conductor 504c, and / or the first and second feed conductors 504d and 504e). In some embodiments, as shown in FIGS. 5A-5L, the width of the first conductor 504a on the first antenna layer can be larger than the width of the conductors on one or more second antenna layers. In some embodiments, the first conductor 504a can be the only conductor on the first antenna layer, thus allowing the first conductor 504a to span the entire width of the bottom surface of the antenna PCB 510, thereby enabling a larger cross-sectional area and / or width of the first conductor 504a. However, a larger cross-sectional area and / or width of the first conductor 504a is not required, and in some alternative embodiments, the cross-sectional area and / or width of the first conductor 504a in the first antenna layer may be equal to or smaller than the cross-sectional area and / or width of each of the conductors in one or more second antenna layers.

[0043]

[0065] In some embodiments, the first conductor 504a and the second conductor 504b of the antenna 504 may be wires (e.g., having a round cross-section as shown in FIG. 5A). However, this is not required, and in some alternative embodiments, the first conductor 504a and the second conductor 504b of the antenna 504 may be PCB traces (e.g., planar PCB traces having a rectangular cross-section), as shown in FIGS. 5B-5L.

[0044]

[0066] 5A, the current supplied to the antenna 504 may pass through the first conductor 504a in a direction opposite to the direction in which the current passes through the second conductor 504b. In some embodiments, the opposing directions in which the current supplied to the antenna 504 passes through the first conductor 504a and the second conductor 504b may be substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, the first antenna layer including the first conductor 504a does not include a conductor through which the current supplied to the antenna passes in a direction opposite to the direction in which the current supplied to the antenna passes through the first conductor 504a.

[0045]

[0067] 5A illustrates, according to some embodiments, a magnetic field generated by currents carried by the first conductor 504a and the second conductor 504b of the antenna 504. In some embodiments, as shown in FIG. 5A, a ferromagnetic (e.g., ferrite) layer 516 may be above the antenna PCB 510 (e.g., between the circuit component PCB 512 and the antenna PCB 510), which may contribute to optimal performance of the device 502. 5A, the device 502 may include a first ferromagnetic piece 534 disposed below the second conductor 504b disposed at a first edge (e.g., the left edge) of the antenna PCB 510 and a second ferromagnetic piece 534 disposed below the second conductor 504b disposed at a second edge (e.g., the right edge) of the antenna PCB 510, where the first ferromagnetic piece and the second ferromagnetic piece 534 may further reduce unwanted magnetic field lines (e.g., magnetic field lines generated by current passing through the second conductor 504b). In some embodiments, as shown in FIG. 5A, one or more ferromagnetic pieces 534 may be disposed directly below the second conductor 504b on the bottom of the first conductor 504a of the first antenna layer.

[0046]

[0068] In some embodiments, when receiver 306 is positioned at any of the locations shown in Figure 5A, the magnetic field generated by the current carried by antenna 504 can induce current in receiver coil 308 of receiver 306. In some embodiments, receiver 306 can receive a good signal directly beneath antenna 504. In some embodiments, the connection between device 502 and receiver 306 in the system shown in Figure 5A can be less affected by lateral movement than the connection between device 402 and receiver 306 in the systems shown in Figures 4A and 4C.

[0047]

[0069] In some aspects, more of the area of device 502 may be used to construct antenna 504 than is used to construct antenna 404 for device 402. In some aspects, the increased area may allow for wider spacing of conductors 504a, and thus a larger operating area for the NFC field.

[0048]

[0070] In some embodiments, the first conductor 504a of the antenna 504 may be wider than the first conductor 404a of the antenna 404 of the device 402. In some embodiments, the first conductor 504a may not be on the same antenna layer as the second conductor 504b, allowing the first conductor 504a to be wider. That is, in some embodiments, the wider first conductor 504a may utilize additional space on the bottom of the antenna PCB 510. In some embodiments, the wider first conductor 504a may provide the advantage of reduced coil resistance.

[0049]

[0071] In some aspects, one or more additional turns may be added to one or more sides of antenna 504 relative to antenna 404 of device 402. In some aspects, the additional turns may offset the reduction in inductance.

[0050]

[0072] In some embodiments, relative to the second conductor 404b of the antenna 404 of the device 402, the second conductor 504b may be further toward the right and left edges of the antenna 504 (e.g., because the second conductors 504b may be distributed across multiple second antenna layers). In some embodiments, the second conductors 504b may be further toward the right and left edges of the antenna 504 to reduce their series resistance and / or reduce their contribution to the magnetic field generated by the current applied to the antenna 504. In some embodiments, relative to the antenna 404 of the device 402, the third conductor 404c may essentially be transformed into the third conductor 504c and the antenna via 536.

[0051]

[0073] 6 is a cross-sectional view illustrating a system including an apparatus 602 and a receiver 306 according to some embodiments. The receiver 306 may include a receiver coil 308. In some embodiments, the apparatus 602 may include an antenna 604, a first antenna printed circuit board (PCB) 610, one or more ferromagnetic layers 616, a second antenna PCB 612, and / or one or more circuit components 618, 620, and 622 mounted on or fabricated in the second antenna PCB 612. In some embodiments, the first antenna PCB 610 and the second antenna PCB 612 may be part of a composite PCB (e.g., a custom PCB), and the ferromagnetic layer 616 may be one or more internal layers within the composite PCB. In some alternative embodiments, the ferromagnetic layer 616 is affixed (e.g., glued) to the top surface of the first antenna PCB 610 and / or the bottom surface of the second antenna PCB 612. In some embodiments, one or more of circuit components 618, 620, and 622 may include a processor 618 (e.g., a CPU) and a CRM 620 (e.g., a flash memory). In some embodiments, as shown in FIG. 6, device 602 may additionally include a ferromagnetic (e.g., ferrite) piece 636 disposed above second conductor 604b of antenna 604 at a first edge (e.g., left or right edge) of antenna 604. However, ferromagnetic piece 636 is not required, and in some alternative embodiments, device 602 may not include ferromagnetic piece 636.

[0052]

[0074] In some aspects, as shown in FIG. 6 , the antenna 604 may include a first conductor 604 a in a first antenna layer. In some aspects, as shown in FIG. 6 , the antenna 604 may include conductors in one or more second antenna layers. In the illustrated embodiment, the antenna 604 includes two second antenna layers. However, this is not required, and in some alternative aspects, the antenna 604 may include a different number of second antenna layers (e.g., 1, 2, 3, 4, 6, 7, 8, 12, 20, etc.). In some aspects, the antenna 604 may include antenna vias that electrically connect the first conductor 604 a in the first antenna layer to one or more conductors in one or more second antenna layers. In some aspects, the antenna vias may be vertical conductors in the first antenna PCB 610 and / or the ferromagnetic layer 616. In some aspects, antenna 604 may additionally or alternatively include vias (e.g., buried vias and / or blind vias) for electronic routing (e.g., routing of one or more of circuit components 618, 620, and 622).

[0053]

[0075] In some aspects, the antenna 604 may include a first antenna feed and a second antenna feed (e.g., a differential antenna feed) through which the device 602 may provide current (e.g., alternating current) to the antenna 604. In some aspects, the first antenna feed and the second antenna feed may be disposed at one end (e.g., the front end) of the antenna 604. In some aspects, the first antenna layer conductors and the second antenna layer conductors and the antenna vias 536 may form a coil.

[0054]

[0076] 6, the first conductor 604a of the first antenna layer may be on the bottom surface of the first antenna PCB 610. In some embodiments, the first conductor 604a may be mounted or printed on the bottom surface of the first antenna PCB 610. In some alternative embodiments, the first conductor 604a of the first antenna layer may be on (e.g., fabricated on) the bottom layer of the first antenna PCB 610. In some embodiments, the first conductor 604a may be the only conductor on (or in) the bottom surface of the first antenna PCB 610. In some embodiments, the longitudinal axis of the receiver coil 308 of the receiver 306 may be substantially parallel to the bottom surface of the antenna 504, which is planar and formed by the first conductor 604a. In some aspects, as shown in FIG. 6, the first conductor 604a of the first antenna layer may extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306.

[0055]

[0077] In some aspects, the one or more second antenna layer conductors may include the second conductor 604b, the third conductor, the first feed conductor, and / or the second feed conductor. In some aspects, as shown in FIG. 6, the one or more second antenna layer conductors (including, for example, the second conductor 604b) may be on (e.g., implemented or printed on) the top surface of the second antenna PCB 612 and / or may be on (e.g., fabricated on) one or more layers of the second antenna PCB 612.

[0056]

[0078] In some embodiments, as shown in FIG. 6, the second conductor 604b may extend substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, as shown in FIG. 6, the second conductor 604b may be disposed at one edge (e.g., the left or right edge) of the second antenna PCB 612. In some embodiments, the ferromagnetic piece 636 may be disposed above the second conductor 604b at one edge (e.g., the left or right edge) of the second antenna PCB 612. In some embodiments, the third conductor may connect the second conductor 604b to the first conductor 504a (e.g., using an antenna via through the second antenna PCB 612, the ferromagnetic layer 616, and / or the first antenna PCB 610). In some embodiments, the second conductor 604b (as well as the third conductor and / or antenna via 536) may form a return path for the current supplied to the antenna 604. For example, the second conductor 604b in one of the second antenna layers (together with two third conductors and / or at least two antenna vias in the second antenna layer) may form part of a return path for the current from one end (e.g., the front end) of one of the first conductors 604a to the opposite end (e.g., the rear end) of another one of the first conductors 604a. In some embodiments, the return paths may all travel around the same edge (e.g., the right or left edge) of the second antenna PCB 612, as shown by the second conductor 604b in FIG. 6 . In some embodiments, the ferromagnetic layer 616 may be disposed between the first conductor 604a and the second conductor 604b.

[0057]

[0079] 6, the current supplied to the antenna 604 may pass through one conductor of the first conductors 604a, then through one conductor of the second conductors 604b before passing through another conductor of the first conductors 604a. In some embodiments, the current supplied to the antenna 604 may pass through one conductor of the first conductors 604a, then through one conductor of the second conductors 604b before passing through another conductor of the second conductors 604b.

[0058]

[0080] In some aspects, the first feed conductor may electrically connect the first antenna feed to the first outer conductor of the first conductor 604a at a first antenna end of the first outer conductor (e.g., using an antenna via), and the second feed conductor may electrically connect the second antenna feed to the second outer conductor of the first conductor at a second antenna end of the second outer conductor (e.g., using another antenna via), and the first antenna end and the second antenna end may be at opposite ends of the antenna 604. For example, the first antenna end may be at a front end of the antenna 604 and the second antenna end may be at a rear end of the antenna 604. In some aspects, the first feed conductor and the second feed conductor may be in the same layer of one or more second antenna layers. However, this is not required, and in some alternative aspects, the first feed conductor may be in a different layer of one or more second antenna layers from the second feed conductor.

[0059]

[0081] In some embodiments, as shown in Figure 6, the cross-sectional area of the first conductor 604a on the first antenna layer can be larger than the cross-sectional area of the conductors (e.g., second conductor 604b) on one or more second antenna layers. In some embodiments, as shown in Figure 6, the width of the first conductor 604a on the first antenna layer can be larger than the width of the conductors on one or more second antenna layers (e.g., including second conductor 604b). In some embodiments, the first conductor 604a can be the only conductor on the first antenna layer, and thus, a larger cross-sectional area and / or width of the first conductor 604a can be possible because the first conductor 604a can span the entire width of the bottom surface of the first antenna PCB 610. However, a larger cross-sectional area and / or width of the first conductor 604a is not required, and in some alternative embodiments, the cross-sectional area and / or width of the first conductor 604a in the first antenna layer may be equal to or smaller than the cross-sectional area and / or width, respectively, of the conductors in one or more second antenna layers.

[0060]

[0082] 6, the first conductor 604a and the second conductor 604b of the antenna 604 may be wires (e.g., having a round cross-section). However, this is not required, and in some alternative embodiments, the first conductor 604a and the second conductor 604b of the antenna 604 may be PCB traces (e.g., planar PCB traces having a rectangular cross-section).

[0061]

[0083] 6, the current supplied to the antenna 604 may pass through the first conductor 604a in a direction opposite to the direction in which the current passes through the second conductor 604b. In some embodiments, the opposing directions in which the current supplied to the antenna 604 passes through the first conductor 604a and the second conductor 604b may be substantially perpendicular to the longitudinal axis of the receiver coil 308 of the receiver 306. In some embodiments, the first antenna layer including the first conductor 604a does not include a conductor through which the current supplied to the antenna passes in a direction opposite to the direction in which the current supplied to the antenna passes through the first conductor 604a.

[0062]

[0084] 6 illustrates magnetic fields generated by currents carried by the first conductor 604a and the second conductor 604b of the antenna 604, according to some embodiments. In some embodiments, as shown in FIG. 6, a ferromagnetic (e.g., ferrite) layer 616 may be between the first conductor 604a and the second conductor 604b (e.g., between the first antenna PCB 610 and the second antenna PCB 612), and the ferromagnetic layer 616 may contribute to optimal performance of the device 602. In some embodiments, as shown in FIG. 6, the device 602 may include a ferromagnetic piece 636 disposed above the second conductor 604b, which is disposed on one edge (e.g., the left or right edge) of the second antenna PCB 612, and the ferromagnetic piece 636 may further reduce unwanted magnetic field lines (e.g., by keeping magnetic field lines generated by currents passing through the second conductor 604b close to the second antenna PCB 612).

[0063]

[0085] 6, the magnetic field generated by the current carried by the antenna 604 can induce current in the receiver coil 308 of the receiver 306. In some embodiments, the receiver 306 can receive a good signal directly beneath the antenna 604. In some embodiments, the connection between the device 602 and the receiver 306 in the system shown in FIG. 6 can be less affected by lateral movement than the connection between the device 402 and the receiver 306 in the systems shown in FIGS. 4A and 4C.

[0064]

[0086] In some aspects, more of the area of device 602 may be used to construct antenna 604 than is used to construct antenna 404 for device 402. In some aspects, the increased area may allow for wider spacing of conductors 604a, and thus a larger operating area for the NFC field.

[0065]

[0087] In some embodiments, the first conductor 604a of the antenna 604 may be wider than the first conductor 404a of the antenna 404 of the device 402. In some embodiments, the first conductor 604a is not on the same antenna layer as the second conductor 604b, allowing the first conductor 604a to be wider. That is, in some embodiments, the wider first conductor 604a may utilize additional space on the bottom of the first antenna PCB 610. In some embodiments, the wider first conductor 604a may provide the advantage of reduced coil resistance.

[0066]

[0088] In some aspects, one or more additional turns may be added to one or more sides of antenna 604 relative to antenna 404 of device 402. In some aspects, the additional turns may offset the reduction in inductance.

[0067]

[0089] In some aspects, relative to the second conductor 404b of the antenna 404 of the device 402, the second conductor 604b may be at one edge (e.g., the left or right edge) of the antenna 604. In some aspects, the second conductors 604b at one edge of the antenna 604 may reduce their series resistance and / or reduce their contribution to the magnetic field generated by the current applied to the antenna 604. In some aspects, the second conductors 604b at one edge of the antenna 604 may allow for a smaller antenna with the same area efficiency.

[0068]

[0090] In some aspects, for device 402, at least a portion of the top surface of second antenna PCB 612 may be available for one or more circuit components 618, 620, and 622, which may eliminate the need for circuit component PCB 412 in addition to first antenna PCB 610 and second antenna PCB 612. In some aspects, the length of first antenna PCB 610 and second antenna PCB 612 relative to the length of antenna PCB 410 and circuit component PCB 412 may be shorter while maintaining the same NFC coverage area. In some aspects, the overall stackup of device 602 may be thinner relative to the overall stackup of device 402 (and the overall stackup of device 502).

[0069]

[0091] In some aspects, a system including device 502 or 602 and receiver 306 may perform a process in which antenna 504 of device 502 or antenna 604 of device 602 generates a magnetic field that is received by receiver coil 308 of receiver 306. In some aspects, device 502 or 602 (e.g., processor 518 of device 502 or processor 618 of device 602) may perform this process. In some aspects, this process may include device 502 or 602 supplying a current to antenna 504 or 604. In some aspects, the current supplied to antenna 504 or 604 may pass through first conductor 504a or 604a in a first antenna layer of antenna 504 or antenna 604 in a direction opposite to the direction in which the current passes through second conductor 504b or 604b in one or more second antenna layers different from the first antenna layer of antenna 504 or antenna 604. In some aspects, the current may be an alternating current. In some aspects, the device 502 or 602 may supply current to the antenna 504 or 604 through a first antenna feed and a second antenna feed (e.g., a first antenna feed 505a and a second antenna feed 505b), which may be differential antenna feeds.

[0070]

[0092] In some embodiments, the current passing through the first conductor 504a or 604a can generate constructively overlapping magnetic fields. In some embodiments, the current passing through the second conductor 504b or 604b can be a return current. In some embodiments, the opposing directions of the current passing through the first conductor 504a or 604a and the second conductor 504b or 604b can be substantially perpendicular to the longitudinal axis of the receiver coil 308. In some embodiments, the first conductor 504a or 604a and the second conductor 504b or 604b can extend in a direction substantially perpendicular to the longitudinal axis of the receiver coil 308. In some embodiments, the longitudinal axis of the receiver coil 308 can be parallel to a planar surface formed by the first conductor 504a or 604a in the first antenna layer.

[0071]

[0093] In some embodiments, by supplying an electric current (e.g., an alternating current) to antenna 504 or 604 to generate a magnetic field, device 502 or 602 may provide power and / or data (e.g., instructions such as analyte measurement instructions and / or measurement data retrieval instructions) to receiver coil 308. In some embodiments, the process may additionally or alternatively include device 502 or 602 receiving data (e.g., measurement data such as light and / or temperature measurements) from receiver coil 308 of receiver 306 using antenna 504 or 604.

[0072]

[0094] While various embodiments have been described herein, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[0073]

[0095] Additionally, while the processes described above and illustrated in the figures are shown as a series of steps, this was done solely for clarity of illustration and, as such, it is contemplated that some steps may be added, some steps may be omitted, the order of steps may be rearranged, and some steps may be performed in parallel.

Claims

1. a first conductor in the first antenna layer; a second conductor in one or more second antenna layers different from the first antenna layer; An antenna comprising: an antenna in which a current supplied to the antenna passes through the first conductor in a direction opposite to the direction in which the current passes through the second conductor; An apparatus comprising:

2. 10. The apparatus of claim 1, further comprising an antenna printed circuit board (PCB).

3. 3. The apparatus of claim 2, wherein the first conductor is printed on a bottom surface of the antenna PCB.

4. 4. The apparatus of claim 2 or 3, wherein the antenna PCB includes antenna vias, each of the antenna vias electrically connecting one of the second conductors to one of the first conductors.

5. 5. The device of claim 4, wherein the first conductor in the first antenna layer, the conductors in the one or more second antenna layers, and the antenna vias form a coil, and the conductors in the one or more second antenna layers include at least the second conductor.

6. 6. The apparatus of claim 2, wherein the second conductor is printed on a top surface of the antenna PCB and / or fabricated in one or more layers of the antenna PCB.

7. 7. The apparatus of claim 2, wherein the second conductor includes a second conductor disposed on a first edge of the antenna PCB and a second conductor disposed on a second edge of the antenna PCB opposite the first edge.

8. 8. The apparatus of claim 7, further comprising: a first ferromagnetic piece disposed below a second conductor disposed at the first edge of the antenna PCB; and a second ferromagnetic piece disposed below a second conductor disposed at the second edge of the antenna PCB.

9. 9. The device of claim 2, further comprising a ferromagnetic layer above the antenna PCB.

10. 10. The apparatus of claim 9, a circuit component PCB; one or more circuit components mounted on or fabricated on said circuit component PCB; The apparatus further comprises:

11. 11. The apparatus of claim 10, wherein the ferromagnetic layer is between the circuitry PCB and the antenna PCB.

12. 7. The apparatus of claim 2, wherein the second conductor is disposed at one edge of the antenna PCB.

13. 13. The apparatus of claim 12, further comprising a ferromagnetic piece disposed above the second conductor at the one edge of the antenna PCB.

14. 14. The apparatus of any one of claims 2 to 5, 12, and 13, wherein the antenna further comprises a ferromagnetic layer between the first conductor and the second conductor.

15. 15. The apparatus of any one of claims 2 to 5 and 12 to 14, wherein the antenna PCB is a first antenna PCB, the antenna further includes a second antenna PCB, the first conductor is printed on or fabricated in the first PCB antenna, and the second conductor is printed on and / or fabricated in the second PCB antenna.

16. 16. The apparatus of claim 15, further comprising one or more circuit components mounted on or fabricated in the second antenna PCB.

17. 17. The apparatus of claim 15 or 16, wherein the first antenna PCB and the second antenna PCB are part of a composite PCB, and the ferromagnetic layer is an internal layer within the composite PCB.

18. 18. The apparatus of claim 1, wherein the cross-sectional area of the first conductor is greater than the cross-sectional area of the second conductor.

19. 19. An apparatus according to any one of claims 1 to 18, comprising: a first antenna feed and a second antenna feed; a first feed conductor in one of the one or more second antenna layers electrically connecting the first antenna feed to a first outer conductor of the first conductor at a first antenna end of the first outer conductor; a second feed conductor in one of the one or more second antenna layers electrically connecting the second antenna feed to a second outer conductor of the first conductor at a second antenna end of the second outer conductor; Furthermore, The apparatus, wherein the first antenna end and the second antenna end are at opposite ends of the antenna.

20. 20. The apparatus of claim 1, wherein the current supplied to the antenna passes through one of the first conductors and then through one of the second conductors before passing through another of the first conductors.

21. 21. The apparatus of claim 1, wherein the current supplied to the antenna passes through one of the first conductors after passing through one of the second conductors and before passing through another of the second conductors.

22. 22. The device of claim 1, wherein the first antenna layer does not include a conductor through which the current supplied to the antenna passes in a direction opposite to the direction in which the current supplied to the antenna passes through the first conductor.

23. 23. The device of claim 1, wherein the antenna further includes a third conductor in the one or more second antenna layers, the third conductor connecting the first conductor and the second conductor.

24. 24. The apparatus of any one of claims 1 to 23, wherein the current passing through the first conductor generates constructively overlapping magnetic fields.

25. 25. The apparatus of any one of claims 1 to 24, wherein the current passing through the second conductor is a return current.

26. 26. The apparatus of claim 1, wherein the antenna includes two or more second antenna layers, and the second conductor is in the two or more second antenna layers.

27. An apparatus according to any one of claims 1 to 26; Receiver coil and A system comprising:

28. 28. The system of claim 27, wherein opposing directions in which the current passes through the first conductor and the second conductor are substantially perpendicular to a longitudinal axis of the receiver coil.

29. 29. The system of claim 27 or 28, wherein the first conductor and the second conductor extend in a direction substantially perpendicular to a longitudinal axis of the receiver coil.

30. 30. The system of claims 27-29, wherein the longitudinal axis of the receiver coil is parallel to a planar surface formed by the first conductor in the first antenna layer.

31. supplying a current to an antenna, the current being passed through a first conductor in the first antenna layer of the antenna in a direction opposite to a direction in which the current passes through a second conductor in one or more second antenna layers different from the first antenna layer of the antenna; A method comprising:

32. 32. The method of claim 31 , wherein the current passing through the first conductor generates constructively overlapping magnetic fields.

33. 33. The method of claim 31 or 32, wherein the current passing through the second conductor is a return current.

34. 34. The method of any one of claims 31 to 33, wherein opposing directions in which the current passes through the first conductor and the second conductor are substantially perpendicular to a longitudinal axis of the receiver coil.

35. 35. The method of any one of claims 31 to 34, wherein the first conductor and the second conductor extend in a direction substantially perpendicular to a longitudinal axis of the receiver coil.

36. 36. The method of any one of claims 31 to 35, wherein a longitudinal axis of the receiver coil is parallel to a planar surface formed by the first conductor in the first antenna layer.

37. 37. The method of any one of claims 31 to 36, wherein the current is an alternating current.

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