Terminal antenna and electronic device

Abstract

Embodiments of the present application relate to the technical field of antennas, and provide a terminal antenna and an electronic device. The solution can significantly improve radiation performance of an NFC antenna in a limited space. The terminal antenna at least comprises a first coil and a second coil. The first coil comprises at least one feed point, and the at least one feed point is used for accessing a near field communication (NFC) feed signal. The second coil comprises at least one tuning device, and the at least one tuning device is used for adjusting a resonant frequency corresponding to the second coil. A current flow direction in the first coil comprises a first direction, a current flow direction in the second coil comprises a second direction, and the first direction and the second direction are both clockwise or counterclockwise. Alternatively, the first direction and the second direction are opposite, and the plane in which the first coil is located and the plane where the second coil is located intersect.

Description

A terminal antenna and electronic device

[0001] This application claims priority to Chinese Patent Application No. 202410933530.5, filed on July 11, 2024, entitled "A Terminal Antenna and Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of antenna technology, and more particularly to a terminal antenna and electronic device. Background Technology

[0003] Near Field Communication (NFC) systems can be configured in electronic devices to implement NFC-related functions. An NFC system may include an NFC antenna for transmitting and receiving NFC signals.

[0004] Typical NFC antennas can be implemented using metal coils or similar methods. However, due to the limited space in electronic devices and the increasing complexity of their functions, more and more components are required. This results in a shrinking space for NFC antennas within electronic devices, leading to a decrease in NFC performance. Summary of the Invention

[0005] This application provides a terminal antenna and an electronic device. The terminal antenna can be an NFC antenna. This solution can significantly improve the radiation performance of the NFC antenna within a limited space. For example, it can increase the magnetic field strength of the NFC antenna in its original direction. Furthermore, it can improve the radiation capability of the NFC antenna in different directions.

[0006] To achieve the above technical objectives, this application adopts the following technical solution:

[0007] In a first aspect, a terminal antenna is provided, applied to an electronic device, the terminal antenna including at least a first coil and a second coil. The first coil includes at least one feed point for receiving a near-field communication (NFC) feed signal. The second coil includes at least one tuning device for adjusting the resonant frequency corresponding to the second coil. The current flow direction in the first coil includes a first direction, and the current flow direction in the second coil includes a second direction, both the first and second directions being either clockwise or counterclockwise. Alternatively, the first and second directions are opposite, and the planes containing the first and second coils intersect.

[0008] In this way, by setting up a second coil and making the induced current in the second coil in the same direction as the first coil, the magnetic field of the first coil can be strengthened, thereby improving the NFC radiation performance.

[0009] Optionally, the relationship between the resonant frequency of the second coil and the operating frequency of the first coil corresponds to the positional relationship between the first and second coils. In this application, when the positional relationship between the first and second coils is different, the corresponding resonant frequency and operating frequency can be configured accordingly. For example, the operating frequency of the first coil can be 13.56MHz.

[0010] Optionally, the positional relationship between the first coil and the second coil is a first positional relationship. The at least one tuning device is used to adjust the resonant frequency to be below the operating frequency. In this example, the first positional relationship corresponds to configuring the resonant frequency to be below the operating frequency.

[0011] Optionally, the first positional relationship includes at least one of the following: the planes containing the first coil and the second coil do not intersect; the projections of the first coil and the second coil onto the first plane do not coincide; the planes containing the first coil and the second coil do not intersect; the projections of the first coil and the second coil onto the first plane include an overlapping first region, the area of ​​which is smaller than a second region, which is the portion of the projection region of the second coil onto the first plane that differs from the first region; or the planes containing the first coil and the second coil intersect. Wherein, the first plane is either the plane containing the first coil or the plane containing the second coil.

[0012] Optionally, when the positional relationship between the first coil and the second coil is a first positional relationship, the net magnetic flux direction of the region surrounded by the first coil is opposite to the net magnetic flux direction of the region surrounded by the second coil.

[0013] Optionally, the positional relationship between the first coil and the second coil is a second positional relationship. The at least one tuning device is used to adjust the resonant frequency to be higher than the operating frequency. In this example, the first positional relationship corresponds to configuring the resonant frequency to be higher than the operating frequency.

[0014] Optionally, the second positional relationship includes at least one of the following: the planes containing the first coil and the second coil do not intersect; the projection of the first coil onto the first plane covers the projection of the second coil onto the first plane; the planes containing the first coil and the second coil do not intersect; the projection of the second coil onto the first plane covers the projection of the first coil onto the first plane; the planes containing the first coil and the second coil do not intersect; and the projections of the first coil and the second coil onto the first plane include an overlapping third region, the area of ​​which is larger than a fourth region, which is a region of the projection area of ​​the second coil onto the first plane, but different from the third region; the planes containing the first coil and the second coil intersect. Wherein, the first plane is the plane containing either the first coil or the second coil.

[0015] Optionally, when the positional relationship between the first coil and the second coil is a second positional relationship, the net magnetic flux direction of the region surrounded by the first coil is the same as the net magnetic flux direction of the region surrounded by the second coil.

[0016] In this way, by flexibly configuring the first and second coils according to their optional positions in different implementations, the configuration of the NFC antenna provided in this application embodiment can be realized in different complex environments.

[0017] In other embodiments of this application, the resonant frequency can be adjusted to be near the operating frequency. For example, the resonant frequency can be within a range of 10MHz above and below the operating frequency. In this way, when the first coil radiates normally, the radiation generated by the second coil can cover the frequency range near the operating frequency in the frequency domain, thereby achieving a parasitic coupling effect relative to the operating frequency and improving the overall radiation performance of the terminal antenna at the operating frequency.

[0018] Optionally, the tuning device includes at least one of the following: a lumped capacitor; a distributed capacitor; or a tuning circuit including an inductor and / or a capacitor, the tuning circuit being equivalent to a capacitor at the operating frequency of the first coil.

[0019] Optionally, the second coil is provided with a first electrical connection point. At least one tuning device on the second coil includes a first tuning device. One end of the first tuning device is coupled to the first electrical connection point, and the other end of the first tuning device is grounded.

[0020] Optionally, the second coil is provided with a second electrical connection point and a third electrical connection point, and at least one tuning device on the second coil includes a second tuning device. One end of the second tuning device is coupled to the second electrical connection point, and the other end of the second tuning device is coupled to the third electrical connection point.

[0021] Optionally, the electronic device is also equipped with an NFC chip that is coupled to at least one feed point of the first coil.

[0022] Optionally, the electronic device is further configured with a matching circuit, which includes an input port and a first output port. The NFC chip is coupled to the input of the matching circuit, and the first output port of the matching circuit is coupled to a first power supply point, which is included in the at least one power supply point.

[0023] Optionally, the first coil may also be provided with a first grounding point, which is grounded.

[0024] This allows for the configuration of a single-port power supply system.

[0025] Optionally, the at least one power supply point includes a second power supply point and a third power supply point. The NFC chip is coupled to the second power supply point and the third power supply point, respectively.

[0026] Optionally, the signals input to the first feed point and the second feed point are differential mode signals.

[0027] This allows for the configuration of a dual-port power supply system.

[0028] Optionally, the first coil and / or the second coil are disposed in the electronic device by at least one of the following forms: FPC metal coil; metal frame of the electronic device; metal decorative element (Deco).

[0029] In other embodiments, at least a portion of the first coil and / or the second coil may reuse other pre-configured metallic materials, such as steel sheets. In other embodiments, at least a portion of the first coil and / or the second coil may also be configured using other related processes, such as LDS, MDA, etc.

[0030] Optionally, the first coil and the second coil are arranged adjacent to each other.

[0031] Optionally, the electronic device includes a first metal frame and a second metal frame, which are separated by a gap; alternatively, the ends of both the first and second metal frames are connected to a metal mid-frame. The metal mid-frame is disposed within the electronic device, and the first and second metal frames are located around its periphery. The first metal frame is reused as at least a portion of a first radiating coil, and the second metal frame is reused as at least a portion of a second radiating coil. The first radiating coil is the first coil, and the second radiating coil is the second coil. Alternatively, the first radiating coil is the second coil, and the second radiating coil is the first coil.

[0032] Optionally, the first radiating coil is disposed at one of the two apex corners of the electronic device. The second radiating coil is disposed at the top edge of the electronic device.

[0033] Optionally, the first metal frame is L-shaped and located at the top corner of the electronic device. The first metal frame and the metal mid-frame form an L-shaped gap. The second metal frame is straight and located at the top edge of the electronic device. The second metal frame and the metal mid-frame form a straight gap. One end of the second metal frame is separated from the end of the first metal frame located at the top edge by the gap; alternatively, one end of the second metal frame and the end of the first metal frame located at the top edge are both connected to the metal mid-frame.

[0034] Thus, with the first radiating coil being the first coil, the first coil coupled to the feed source can be positioned at the apex corner, and the corresponding second coil can be positioned at the top edge of the electronic device. Therefore, the first coil can provide radiation to the corresponding corner, ensuring card-swiping performance in that corner. By setting the second coil, the card-swiping coverage area can be extended to the top of the electronic device.

[0035] When the first radiating coil is the second coil, the first coil coupled to the feed source can be located at the top edge, and the second coil corresponding to the coupling coil can be located at the top corner of the electronic device. Thus, the first coil can provide radiation from the top edge, ensuring card-swiping performance at the top of the electronic device. By setting the second coil, the card-swiping coverage area can be extended to the top corner or side of the electronic device.

[0036] Both of the above methods can effectively expand the card-swiping coverage area of ​​electronic devices.

[0037] Optionally, the terminal antenna further includes a third coil. At least one tuning device is disposed on the third coil, which is used to adjust the resonant frequency corresponding to the third coil. When the terminal antenna is operating, the current flow direction in the third coil includes a third direction, which is the same as the first direction.

[0038] Optionally, the third coil and the second coil are arranged adjacent to each other.

[0039] Optionally, the electronic device is provided with a third metal frame, and the third metal frame, the second metal frame, and the first metal frame are sequentially arranged around the metal mid-frame. The third metal frame is separated from the second metal frame by a gap, or the ends of the third metal frame and the second metal frame that are close to each other are both connected to the metal mid-frame. The third metal frame is reused as at least a part of the third coil.

[0040] This example provides a configuration example of multi-stage coupled coils. A third coil can serve as a secondary coupled coil to the first coil. A second coil can serve as a primary coupled coil to the first coil. This further enhances the radiation performance of the NFC antenna.

[0041] Optionally, at least a portion of the radiating coil included in the terminal antenna is also used for a second wireless communication, which is different from NFC communication. The radiating coil includes a fourth electrical connection point. This fourth electrical connection point is coupled to an isolation network. The radiating coil includes a first coil and / or a second coil, and the fourth electrical connection point includes a feed point and / or a ground point and / or an electrical connection point coupled to the tuning device.

[0042] Optionally, the second wireless communication includes at least one of the following: cellular communication, WIFI communication, and GPS communication.

[0043] This provides specific configuration constraints when multiple systems share a common radiating coil (or radiator). For example, isolation networks can be set up at locations such as the feed source, grounding point, and electrical connection points of coupling tuning devices to achieve signal isolation between different systems in the frequency or time domain. This ensures that the same radiating coil or radiator (such as a metal frame) radiates normally in different systems.

[0044] Optionally, the terminal antenna is an NFC antenna, and the first coil operates at a frequency of 13.56 MHz.

[0045] Secondly, an NFC communication system is provided. This NFC communication system includes an NFC chip and an NFC antenna. The NFC antenna is implemented using a terminal antenna as provided in the first aspect and any of its possible designs.

[0046] Optionally, the NFC communication system may also include a matching circuit.

[0047] Thirdly, an electronic device is provided, which is configured with a terminal antenna provided in the first aspect and any possible design thereof, or the electronic device is configured with an NFC communication system provided in the second aspect. Attached Figure Description

[0048] Figure 1 is a schematic diagram of an NFC system in an electronic device;

[0049] Figure 2 is a schematic diagram of an NFC antenna scheme;

[0050] Figure 3 is a schematic diagram of an NFC antenna setup;

[0051] Figure 4 is a schematic diagram of an electronic device;

[0052] Figure 5 is a schematic diagram of an NFC antenna scheme;

[0053] Figure 6 is a schematic diagram of an NFC antenna scheme;

[0054] Figure 7 is a schematic diagram of the logical composition of an NFC antenna provided in an embodiment of this application;

[0055] Figure 8 is a schematic diagram of an antenna shape provided in an embodiment of this application;

[0056] Figure 9 is a schematic diagram of an NFC system provided in an embodiment of this application;

[0057] Figure 10 is a schematic diagram of an NFC system provided in an embodiment of this application;

[0058] Figure 11 is a schematic diagram of an inductive and capacitive distribution provided in an embodiment of this application;

[0059] Figure 12 is a schematic diagram showing the relationship between resonant frequency and operating frequency and the relationship between magnetic field and current provided in an embodiment of this application;

[0060] Figure 13 is a schematic diagram of a positional relationship provided in an embodiment of this application;

[0061] Figure 14 is a logic diagram of magnetic field enhancement provided in an embodiment of this application;

[0062] Figure 15 is a schematic diagram showing the correspondence between a positional relationship and a resonant frequency and an operating frequency provided in an embodiment of this application;

[0063] Figure 16 is a schematic diagram showing the correspondence between a positional relationship and a resonant frequency and an operating frequency provided in an embodiment of this application;

[0064] Figure 17 is a schematic diagram of a positional relationship provided in an embodiment of this application;

[0065] Figure 18 is a schematic diagram illustrating a specific implementation of a positional relationship provided in an embodiment of this application;

[0066] Figure 19 is a schematic diagram illustrating a specific implementation of a positional relationship provided in an embodiment of this application;

[0067] Figure 20 is a schematic diagram illustrating a specific implementation of a positional relationship provided in an embodiment of this application;

[0068] Figure 21 is a schematic diagram illustrating a specific implementation of a positional relationship provided in an embodiment of this application;

[0069] Figure 22 is a simulation diagram of S11 provided in an embodiment of this application;

[0070] Figure 23 is a schematic diagram of current simulation provided in an embodiment of this application;

[0071] Figure 24 is a schematic diagram comparing the original Smith image with an embodiment of this application.

[0072] Figure 25 is a schematic diagram of a multi-stage coupling coil configuration provided in an embodiment of this application;

[0073] Figure 26 is a schematic diagram of current simulation comparison provided in an embodiment of this application;

[0074] Figure 27 is a schematic diagram of current simulation comparison provided in an embodiment of this application;

[0075] Figure 28 is a schematic diagram of a multi-system multiplexing radiator provided in an embodiment of this application;

[0076] Figure 29 is a schematic diagram of an isolation network setup provided in an embodiment of this application;

[0077] Figure 30 is a schematic diagram of a multi-system multiplexing radiator provided in an embodiment of this application;

[0078] Figure 31 is a schematic diagram of a multi-system multiplexing radiator provided in an embodiment of this application;

[0079] Figure 32 is a schematic diagram of an NFC antenna scheme for a dual-port feeding system provided in an embodiment of this application;

[0080] Figure 33 is a schematic diagram of an NFC antenna scheme for a dual-port feeding system provided in an embodiment of this application;

[0081] Figure 34 is a schematic diagram of an NFC antenna scheme for a dual-port feeding system provided in an embodiment of this application;

[0082] Figure 35 is a schematic diagram of an NFC antenna scheme for a dual-port feeding system provided in an embodiment of this application;

[0083] Figure 36 is a schematic diagram of a metal frame configuration in an electronic device provided in an embodiment of this application;

[0084] Figure 37 is a schematic diagram of an NFC antenna scheme for a single-port power supply system provided in an embodiment of this application;

[0085] Figure 38 is a schematic diagram of an NFC antenna scheme for a single-port power supply system provided in an embodiment of this application;

[0086] Figure 39 is a schematic diagram of an NFC antenna scheme provided in an embodiment of this application;

[0087] Figure 40 is a schematic diagram of the coupling relationship between the power connection points of a coupling coil provided in an embodiment of this application;

[0088] Figure 41 is a schematic diagram of an NFC antenna scheme provided in an embodiment of this application;

[0089] Figure 42 is a schematic diagram of an NFC antenna scheme provided in an embodiment of this application;

[0090] Figure 43 is a schematic diagram of an NFC antenna scheme provided in an embodiment of this application;

[0091] Figure 44 is a schematic diagram of an NFC antenna scheme provided in an embodiment of this application;

[0092] Figure 45 is a schematic diagram of an NFC antenna scheme provided in an embodiment of this application. Detailed Implementation

[0093] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this embodiment, unless otherwise stated, "a plurality of" means two or more.

[0094] Currently, electronic devices can provide a variety of wireless communication functions. For example, these various wireless communication functions may include cellular communication, Wi-Fi communication, and Near Field Communication (NFC) communication.

[0095] Take electronic devices that support NFC communication as an example.

[0096] Referring to Figure 1, an NFC system can be incorporated into an electronic device. This NFC system may include components such as an NFC antenna and an NFC chip. In some embodiments, a matching circuit may also be provided between the NFC chip and the NFC antenna.

[0097] NFC communication can be used in various scenarios, including card mode and reader mode. In card mode, electronic devices can communicate with a card reader as the recipient of the data via the NFC system. For example, in card mode, the electronic device can read transportation cards, bank cards, and other similar cards. In reader mode, electronic devices can communicate with other cards via the NFC system as the reader.

[0098] During NFC communication, the NFC chip provides analog signal processing capabilities. The NFC antenna is used to convert between wireless and analog signals during NFC communication.

[0099] As an example, Figure 2 provides a schematic diagram of an NFC antenna.

[0100] In this example, the NFC antenna may include one or more continuous turns of conductive coil. Taking two turns as an example, as shown in Figure 2, one end of the outer conductive coil corresponds to port 1. The other end of the outer conductive coil is electrically connected to one end of the inner conductive coil. The other end of the inner conductive coil corresponds to port 2. Port 1 and port 2 can be coupled to two signal ports of the NFC chip (not shown in Figure 2), respectively.

[0101] In the embodiments of this application, coupling can be used to represent a connection method of electrical connection. Specific implementations may include direct electrical connection, coupled electrical connection, etc. Through coupling, signal transmission between two modules can be realized. For example, port 1 is coupled to a signal port of the NFC chip, which can correspond to port 1 being directly electrically connected to a signal port of the NFC chip, or port 1 being electrically connected to a signal port of the NFC chip through a matching circuit.

[0102] In other embodiments, the NFC antenna may also include three, four, or more consecutive conductive coils.

[0103] In practical implementation, the NFC antenna shown in Figure 2 can be implemented using a flexible printed circuit (FPC). Within the FPC, the NFC coil can be implemented by setting copper wires or applying silver paste. In some implementations, the FPC including the NFC coil can be mounted inside the back cover of the electronic device.

[0104] It should be noted that the NFC communication system shown in Figure 2, in which the NFC antenna is coupled to the two signal ports of the NFC chip through two ports, can be called a dual-port power supply system.

[0105] In this dual-port system, the NFC antenna can be configured with two electrical connection points for receiving NFC feed signals (or NFC signals). The two signal ports of the NFC chip can respectively input the NFC signals into the matching circuit between the NFC chip and the NFC coil (i.e., the NFC antenna). Through processing by the matching circuit, the two NFC signals can be separately input into the NFC antenna for radiation. In some implementations, the two NFC signals can have differential feeding characteristics at the electrical connection points of the NFC antenna.

[0106] In other embodiments, the NFC antenna can also be coupled to the signal port of the NFC chip via a single port. This NFC system may also be referred to as a single-port fed system.

[0107] For example, in this single-port feed system, the NFC antenna can be equipped with an electrical connection point for receiving NFC feed signals (or NFC signals). The two signal ports of the NFC chip can each input the NFC signal into a matching circuit between the NFC chip and the NFC coil (i.e., the NFC antenna). Through processing by the matching circuit, the two NFC signals can be processed into a single NFC feed signal, which is then input into the NFC antenna for radiation. The other port of the NFC antenna can be grounded.

[0108] During the operation of the NFC antenna, a feed signal can be received through the NFC chip. This feed signal can include an AC signal. Correspondingly, under the excitation of the AC signal, the NFC antenna can generate a magnetic field for radiation.

[0109] In the NFC antenna example shown in Figure 2, with other parameters such as line width remaining constant, the larger the area enclosed by the coil of the NFC antenna, the better the NFC antenna performance. Conversely, the smaller the area enclosed by the coil of the NFC antenna, the worse the NFC antenna performance. In this example, the area enclosed by the coil of the NFC antenna can be called the effective magnetic flux area. In this embodiment, NFC antenna performance can include performance such as coverage range and / or reading distance. Taking NFC antenna performance measured by coverage range as an example, the larger the coverage, the better the NFC antenna performance. Taking NFC antenna performance measured by reading distance as an example, the farther the reading distance, the better the NFC antenna performance.

[0110] Furthermore, for NFC antennas, the equivalent inductance of the coil also significantly affects the antenna's performance. This is understandable, considering an NFC antenna installed in a portable mobile terminal (such as a phone). The usable area of ​​an NFC antenna is limited, thus restricting the area covered by the coil. In practical applications, the equivalent inductance (L) of the NFC antenna coil is generally insufficient for the requirements of NFC communication. A longer coil results in a larger equivalent inductance, leading to better NFC antenna performance.

[0111] In summary, the performance of an NFC antenna can be improved by increasing the effective magnetic flux area and / or increasing the equivalent inductance value of the NFC antenna.

[0112] As electronic devices evolve, they can support increasingly more diverse functions. Consequently, the space allocated within these devices for components such as NFC antennas is becoming increasingly limited.

[0113] In some implementations, the NFC antenna can be set up by sharing it with other wireless communication components.

[0114] In some embodiments, taking an electronic device equipped with wireless charging functionality as an example, a wireless charging coil can be included in the electronic device to convert the wireless charging signal into an analog current signal, thereby enabling the charging module in the electronic device to charge the battery or supply power to other electronic devices.

[0115] The wireless charging coil can also be called a Wireless Power Consortium (WPC) coil, or simply WPC.

[0116] Referring to Figure 3, an example of a shared WPC scheme is provided. This scheme allows the NFC antenna to be placed near the WPC coil, thereby reducing the additional thickness requirements of the electronic device during NFC antenna assembly.

[0117] As shown in Figure 3, taking the WPC coil being smaller than the NFC antenna as an example, the WPC coil can be placed within the effective magnetic flux area of ​​the NFC antenna. In this way, the NFC antenna and the WPC coil can be respectively mounted inside the back cover of the electronic device.

[0118] In other embodiments, the NFC antenna coil can reuse the WPC coil, thus saving the overhead of separately configuring the NFC antenna coil. For example, the WPC coil may have one or more ports for transmitting charging current. The WPC coil may also have one or more ports for feeding NFC signals (i.e., NFC feed signals). Specifically, these one or more ports for feeding NFC signals can be coupled to the signal ports of the NFC chip. For a specific implementation, refer to the NFC antenna configuration shown in Figure 2 above.

[0119] Generally, the WPC coil can be located within the battery projection area, which facilitates the use of wireless charging. However, in the shared WPC scheme shown in Figure 3, the NFC coil is also located within the battery projection area. This makes the use of NFC inconvenient.

[0120] Understandably, taking the card mode scenario as an example, when using the NFC function, a user can hold their phone close to the card reader to read a card. However, if the NFC antenna is positioned within the battery projection area, it can cause operational difficulties when the user is holding the electronic device and using the NFC function. The card reader mode scenario is similar.

[0121] Therefore, when configuring an NFC antenna in an electronic device, it is necessary to place the NFC antenna as close as possible to the upper part of the electronic device for user convenience.

[0122] The example above illustrates the configuration of an NFC antenna using FPC mounting. In other embodiments, the NFC antenna can be implemented in other ways.

[0123] For example, referring to Figure 4, a schematic diagram of an electronic device is shown. In this example, the electronic device may have an architecture with a metal frame.

[0124] Taking a mobile phone as an example, a continuous or discontinuous metal frame can be provided around the sides of the phone. As shown in Figure 4, the metal frame can be interrupted by one or more gaps running through the inside and outside of the frame, thus presenting multiple unconnected metal frames. In some implementations, the gaps between two adjacent frames can be filled with non-conductive materials such as engineering plastics or plastics.

[0125] In the electronic device with the metal frame architecture shown in Figure 4, one or more frames can currently be used as radiators for cellular antennas, thereby saving the cost of additional cellular antenna radiators.

[0126] Take, for example, reusing the metal frame at the top of an electronic device as a radiator for a cellular antenna. A feed point coupled to a cellular feed source can be provided on this metal frame. In some implementations, one or more grounding points coupled to a reference ground can also be provided on the metal frame. Thus, by feeding a cellular feed signal to the top metal frame through the feed point, the top metal frame can be excited to radiate cellular communication signals.

[0127] In some implementations, the NFC antenna can also be configured through the metal frame of the electronic device.

[0128] Taking a single-port power supply system as an example, referring to Figure 5, a power supply point coupled to the NFC chip can be set on the metal frame. A grounding point coupled to a reference ground can also be set on the metal frame. In this way, the metal frame between the power supply point and the grounding point, along with the reference ground, can equivalently constitute an NFC coil. As shown in Figure 5, this effective magnetic flux region corresponds to the area between the metal frame between the power supply point and the grounding point, and the reference ground.

[0129] Therefore, when an electronic device performs NFC communication, the NFC chip feeds an NFC power signal to the metal frame through a power point, which can then excite the metal frame to perform NFC communication radiation.

[0130] As electronic devices support an increasing number of cellular communication frequency bands, in metal frame architectures, most of the metal frame is fully or partially reused as a cellular antenna radiator. This allows for the configuration of an NFC antenna by reusing the cellular antenna radiator.

[0131] As an example, referring to Figure 6, there is an example of a cellular multiplexing scheme.

[0132] In this implementation, the metal frame can act as a radiator for cellular antenna radiation. Thus, the feed point of the metal frame can be coupled to the cellular feed source to receive the cellular feed signal.

[0133] In addition, the power supply point of the metal frame can also be coupled to the NFC chip to receive NFC power supply signals.

[0134] In some implementations, to avoid interference between cellular signals and NFC signals, an isolation network can be set between the power supply point and the two power supply signals.

[0135] This isolation network can be used to filter cellular signals in the NFC path, which corresponds to the path between the NFC chip and the metal frame. This allows NFC signals to be transmitted normally between the NFC chip and the metal frame, while cellular signals are filtered out.

[0136] This isolation network can be used to filter out NFC signals on the cellular path. This cellular path corresponds to the path between the cellular chip (or cellular RF module) and the metal frame. This allows cellular signals to be transmitted normally between the cellular chip and the metal frame, while NFC signals are filtered out.

[0137] Understandably, this cellular multiplexing scheme, as shown in Figure 6, eliminates the need for an additional coil for the NFC antenna, saving on associated costs. Furthermore, by reusing the top bezel, the effective magnetic flux area of ​​the NFC antenna is located in the upper half of the electronic device, making the use of NFC communication functions more convenient.

[0138] In current cellular multiplexing schemes, the electrical length of the metal frame is becoming increasingly smaller due to the requirements of cellular communication. This results in a decrease in the equivalent inductance and effective magnetic flux area of ​​the NFC antenna when configuring it using the cellular multiplexing scheme shown in Figure 6. This significantly impacts the performance of the NFC antenna.

[0139] Based on this, the NFC antenna solution provided in this application embodiment configures a second coil near the first coil. The first coil has a feed point for feeding in the NFC feed signal. The second coil is a closed or open coupled coil. Through the various feature limitations provided in this application embodiment, when the first coil is working, the magnetic field corresponding to the induced current generated by the second coil can be superimposed with the magnetic field generated by the first coil, thereby improving the performance of the NFC antenna. In some implementations, multiple coils can also be configured near the first coil, and these multiple coils can improve the performance of the NFC antenna based on a similar mechanism to the second coil.

[0140] The magnetic fields of the first coil and the second coil can be superimposed in the same direction or in orthogonal directions. When the magnetic fields of the two coils are superimposed in orthogonal directions, taking the effective magnetic flux region of the first coil as an example where the magnetic field direction is perpendicular to the plane where the electronic device's display screen is located, the magnetic field generated by the second coil can improve the NFC communication performance in the plane parallel to the display screen.

[0141] In some embodiments, additional coupling coils may be disposed near the first coil or the second coil. For example, a third coil may be disposed near the second coil on the side away from the first coil. The third coil may be configured to operate with a current in the same direction as that on the first coil (e.g., both are clockwise or both are counterclockwise). This creates a multi-stage coupling effect, expanding the NFC radiation area while improving the radiation performance of the NFC antenna. The specific configuration of the third coil can be referenced to that of the second coil.

[0142] The NFC antenna solution provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0143] Referring to Figure 7, it is a schematic diagram of the logical composition of an NFC antenna provided in an embodiment of this application.

[0144] As shown in Figure 7, this NFC antenna scheme may include two or more radiating components.

[0145] It should be noted that each of the two or more radiating components can correspond to a logic coil.

[0146] A logic coil can provide a complete current loop. For example, this complete current loop may include: an NFC signal being emitted from the feed source, passing through the logic coil and returning to ground; or an NFC signal being emitted from one signal port of an NFC chip, passing through the logic coil and returning to another signal port of the NFC chip; or, at any given time, current being emitted from one point on the logic coil, passing through the logic coil and returning to the same point.

[0147] As one possible implementation, the NFC signal is emitted from the feed source and the current loop returns to ground through the logic coil, which can be achieved by setting the logic coil as a single-port feed system.

[0148] An NFC signal is emitted from one signal port of an NFC chip, and the current loop flows back to the other signal port of the NFC chip through a logic coil. This can be achieved by making the logic coil device a dual-port power supply system.

[0149] It is understood that the signals in both of the aforementioned current loops can be fed into the NFC signal through the feed point set on the logic coil. In this application, the logic coil with the feed point can be referred to as the main coil.

[0150] A current loop that originates from one point on a logic coil, flows through the logic coil, and returns to the same point can correspond to a closed coupled loop. The energy in this loop can be obtained from other coils through coupling.

[0151] It is understood that the signal in the aforementioned current loop can be obtained through coupling. That is, a feed point may not be provided on the logic coil. In this application, the logic coil without a feed point can be referred to as a coupling coil.

[0152] In different implementations, the specific implementation of the logic coil can be different.

[0153] For example, in some embodiments, the logic coil can be composed of a radiating coil. The radiating coil can be rectangular, circular, semi-circular, etc. The NFC antenna shown in Figure 2 provides a rectangular implementation.

[0154] In other embodiments, the logic coil can be composed of a radiating portion and a reference ground. The radiating portion can be L-shaped, U-shaped, or linear, etc. In this way, current can flow from the radiating portion to the nearby reference ground, thereby obtaining a complete current loop. The NFC antenna scheme shown in Figure 5 or Figure 6 provides an implementation where the radiating portion is linear.

[0155] The above explanation focuses on the shape and configuration of the logic coil. However, the specific implementation of the logic coil can vary in practice.

[0156] For example, some or all of the logic coils can be implemented in any one or more of the following ways:

[0157] FPC, printed circuit board (PCB), metal frame, steel sheet, metal components made using direct pad printing (PDS) process, or other metal materials.

[0158] In some implementations, taking logic coils including FPC traces as an example, continuous or discontinuous magnetic material can be placed below the FPC or between the FPC and the metal components of the electronic device. This enhances the magnetic radiation capability of the logic coils, including the FPC traces, by utilizing the magnetic material's ability to concentrate magnetic fields.

[0159] For example, the magnetic material may include at least one of the following: ferrite, nanocrystals, resin composites, etc.

[0160] In the example shown in Figure 7, the two or more radiating components in the NFC antenna may include a first coil and a second coil. The first coil may correspond to a main coil, and the second coil may correspond to a coupling coil. The first and second coils can be implemented using the aforementioned logic coils, thereby providing a complete current loop corresponding to the main coil / coupling coil.

[0161] For example, at least one feed point may be provided on the first coil. The first coil is coupled to the signal port of the NFC chip through the at least one feed point.

[0162] In some embodiments, taking the first coil as an example of implementing a dual-port power supply system, at least one power supply point on the main coil may specifically include a first power supply point and a second power supply point. The first power supply point and the second power supply point may be coupled to two signal ports of the NFC chip, respectively.

[0163] In other embodiments, the first coil is used to implement a single-port power supply system as an example. At least one feed point on the main coil may specifically include a first feed point. This first feed point can be coupled to the signal port of the NFC chip. In this example, the first coil may also be configured with at least one ground point. Thus, current can flow through the first coil, through the ground point, and back to the ground, forming a complete current loop.

[0164] In this application, the NFC antenna may further include a second coil. This second coil may not have a feed source. In some embodiments, the second coil may be positioned close to the first coil.

[0165] In different implementations, the second coil can provide any of the complete current loops mentioned above.

[0166] In some implementations, the second coil can be a closed coil. In other implementations, the second coil can be formed by the radiating portion and a reference ground electrically connected at least two locations, creating a closed current loop.

[0167] When the NFC antenna is operational, the first coil can be fed with an NFC signal from a feed point. For example, the NFC signal can be an AC signal. In this way, the first coil can generate an alternating magnetic field around it when it is operational.

[0168] The second coil is positioned close to the first coil. Because it is in an alternating magnetic field, an induced current can be generated in the second coil. Based on this induced current, the second coil can radiate, thereby generating a magnetic field in the surrounding space.

[0169] In this application, by specifically configuring the first and second coils, the magnetic field generated by the second coil can be positively superimposed on the magnetic field generated by the first coil in at least one direction. This results in a stronger magnetic field distribution in the space surrounding the NFC antenna compared to the first coil operating alone, thus improving the performance of the NFC antenna.

[0170] In some embodiments, the first and second coils in this scheme can be implemented using two adjacent metal frames in the electronic device, respectively. This allows for better NFC communication performance with a smaller equivalent inductance and / or a smaller effective magnetic flux area.

[0171] For example, referring to Figure 8, several different structural forms of the metal materials (such as metal frames, FPCs, etc.) that make up the first coil and / or the second coil are shown.

[0172] As shown in Figure 8, in some embodiments, the metal material constituting the coil can be in a straight line shape. This straight line shape can include rectangular metal material. In some implementations, the two opposite sides of the straight-lined metal material may not be strictly parallel; that is, the lines containing any two opposite sides may intersect.

[0173] In other embodiments, the metallic material comprising the coil may include an L-shaped structure. This L-shaped structure may include two components whose ends are connected. The included angle between the two components can be any angle from 0 to 180 degrees. For example, the included angle between the two components can be 90 degrees.

[0174] In other embodiments, the metal material comprising the coil may include a U-shaped structure. This U-shaped structure may include an open end. The U-shaped structure may be implemented by bending traces on an FPC or PCB, or by slotting in the metal.

[0175] In some embodiments of this application, the entire radiator of the first coil and / or the second coil can be implemented using a metal frame.

[0176] For example, referring to Figure 9, several NFC system logic connection examples are shown in single-port and dual-port power supply systems, where the coils fully reuse the metal frame.

[0177] In the various NFC systems provided in this example, the NFC chip may include two signal ports for inputting or outputting NFC signals.

[0178] The two signal ports of the NFC chip can be electrically connected to the two input terminals of the matching circuit, respectively. The matching circuit is used to tune the port impedance between the NFC antenna and the NFC chip, so that the NFC antenna can efficiently radiate NFC signals.

[0179] As shown in NFC System 1 in Figure 9, a schematic of a single-port power supply system is provided. In this example, the matching circuit may include an output port. Taking an NFC signal transmission scenario as an example, the matching circuit can tune two input NFC signals into a single NFC signal, which is then fed into the metal frame through the output port.

[0180] In this example, the metal frame has two electrical connection points, including a power supply point and a ground point. In some implementations, the power supply point and ground point can be located at opposite ends of the metal frame, thereby increasing the area of ​​the effective magnetic flux region of the NFC antenna. The metal frame can be coupled to the output port of the matching circuit at the power supply point. The metal frame can also be coupled to a reference ground at the power supply point.

[0181] Thus, when the NFC system 1 is working, the NFC chip outputs two NFC signals. Through the processing of the matching circuit, one NFC power supply signal can be output and fed into the metal frame, so that the metal frame can radiate the NFC signal.

[0182] As shown in Figure 9, NFC System 2 and NFC System 3 illustrate two dual-port power supply systems.

[0183] In both dual-port feeding systems, the matching circuit can include two output ports. Taking an NFC signal transmission scenario as an example, the matching circuit can tune two input NFC signals into two separate NFC signals, which are then fed into the metal frame through their respective output ports. In some implementations, these tuned two NFC signals can exhibit differential feeding characteristics.

[0184] In both NFC systems 2 and NFC system 3, at least two electrical connection points are provided on the metal frame. This includes two power supply points located at both ends of the metal frame. The metal frame can be coupled to two output ports of the matching circuit at each of the two power supply points.

[0185] As shown in Figure 9, in the example of NFC system 2, only two power supply points are provided on the metal frame. In the example of NFC system 3, at least one grounding point can also be provided on the metal frame. In specific implementation, the configuration can be flexibly selected according to the actual situation.

[0186] Thus, when NFC System 2 or NFC System 3 is working, the NFC chip outputs two NFC signals. Through processing by the matching circuit, two NFC feed signals can be output and fed into the metal frame respectively, so that the metal frame can radiate NFC signals.

[0187] In other embodiments of this application, a portion of the radiators of the first and / or second coils can be multiplexed using a metal frame, and the coils may also include other metal components coupled to the metal frame. In this example, the first and / or second coils are constructed from a metal frame and an FPC electrically connected to the metal frame and provided with metal traces. This forms a semi-coherent antenna implementation.

[0188] For example, referring to Figure 10, several NFC system logic connection examples for single-port and dual-port power supply systems are shown in a semi-common scheme.

[0189] In the example shown in Figure 10, NFC system 4 corresponds to a single-port power supply system, while NFC systems 5 and 6 correspond to dual-port power supply systems. The connection relationships and port configurations of the NFC chip and matching circuit in both single-port and dual-port power supply systems can be found in the example in Figure 9, and will not be repeated here.

[0190] In the semi-coherent scheme shown in Figure 10, taking NFC system 4 as an example, the NFC antenna may specifically include a metal frame and an FPC coupled to the metal frame.

[0191] Two electrical connection points can be provided on the metal frame. One electrical connection point is coupled to the output port of the matching circuit. The other electrical connection point on the metal frame is coupled to one end of the FPC trace.

[0192] The other end of the FPC trace is grounded.

[0193] Thus, when the NFC system 4 is operating, the matching circuit can input the NFC signal into the metal frame, allowing the metal frame and FPC to jointly radiate the NFC signal.

[0194] Compared to NFC System 4, in NFC System 5, the ground terminal of the FPC can be replaced by being coupled to another output port of the matching circuit. This enables dual-port feeding of the NFC antenna.

[0195] Compared to NFC System 5, NFC System 6 can also include a grounding point on the metal frame. In some other implementations, this new grounding point in NFC System 6 can also be located on the FPC.

[0196] It is understood that the NFC systems shown in Figures 9 and 10 are merely examples and do not constitute a limitation on the actual application environment of the NFC antenna solutions provided in the embodiments of this application.

[0197] In the embodiments of this application, regardless of whether it is applied to a single-port power supply system or a dual-port power supply system, the targeted configuration of the second coil can achieve better NFC radiation performance compared to the operation of the first coil alone. The implementation mechanism of the NFC antenna in this application will be described in detail below with reference to the accompanying drawings.

[0198] In this application, the operating frequency band of the NFC antenna may include frequency f0. For example, frequency f0 may include 13.56MHz. In the following description, frequency f0 will be referred to as the operating frequency.

[0199] For example, the first coil can be configured to radiate at the operating frequency under the excitation of the feed source. In some implementations, the configuration of the first coil can be based on the requirement that the resonant eigenmode of the equivalent circuit corresponding to the first coil can operate at frequency f0.

[0200] Correspondingly, the second coil can also be configured according to the frequency f0. In this application, the frequency of the resonant eigenmode of the equivalent circuit corresponding to the second coil can be called the resonant frequency of the second coil.

[0201] Referring to Figure 11, for the operating frequency f0, resonances less than f0 in the frequency domain exhibit inductive behavior, while resonances greater than f0 in the frequency domain exhibit capacitive behavior.

[0202] Corresponding to the second coil, if the resonant frequency of the second coil is lower than the operating frequency f0, then the second coil is inductive relative to the first coil. If the resonant frequency of the second coil is higher than the operating frequency f0, then the second coil is capacitive relative to the first coil.

[0203] Referring to Figure 12, the configuration effects of the first coil and the second coil in different scenarios are explained respectively.

[0204] As shown in Figure 12, taking the example where the electrical length of the first coil is less than that of the second coil, the resonant frequency of the second coil is lower than the operating frequency of the first coil. Therefore, the second coil is inductive relative to the first coil.

[0205] As shown in Figure 12, taking the example of the first coil generating a counterclockwise current under the excitation of the feed source, the corresponding magnetic field generated by the first coil can pass through the first coil from left to right within the effective magnetic flux region inside the first coil.

[0206] Correspondingly, the second coil can generate an induced current during the radiation process of the first coil, and radiate based on the induced current.

[0207] When the magnetic field lines in the magnetic field generated by the first coil pass through the second coil from left to right (i.e., the magnetic field lines generated by the first coil pass through the first and second coils in the same direction, or simply, the magnetic fields are in the same direction), a clockwise induced current can be generated in the second coil. In this case, the magnetic fields of the first and second coils are in the same direction, but the induced currents are in opposite directions.

[0208] When the magnetic field lines in the magnetic field generated by the first coil pass through the second coil from right to left (i.e., the magnetic field lines generated by the first coil pass through the first and second coils in opposite directions, or simply, the magnetic fields are reversed), a counterclockwise induced current can be generated in the second coil. In this case, the magnetic fields of the first and second coils are in opposite directions, and the induced currents are in the same direction.

[0209] As shown in Figure 12, taking the example where the electrical length of the first coil is greater than that of the second coil, the resonant frequency of the second coil is higher than the operating frequency of the first coil. Therefore, the second coil is capacitive relative to the first coil.

[0210] As shown in Figure 12, taking the example of the first coil generating a counterclockwise current under the excitation of the feed source, the corresponding magnetic field generated by the first coil can pass through the first coil from left to right within the effective magnetic flux region inside the first coil.

[0211] Correspondingly, the second coil can generate an induced current during the radiation process of the first coil, and radiate based on the induced current.

[0212] When the magnetic field lines in the magnetic field generated by the first coil pass through the second coil from left to right (i.e., the magnetic field lines generated by the first coil pass through the first and second coils in the same direction, or simply, the magnetic fields are in the same direction), a counterclockwise induced current can be generated in the second coil. In this case, the magnetic fields of the first and second coils are in the same direction, and the induced currents are in the same direction.

[0213] When the magnetic field lines in the magnetic field generated by the first coil pass through the second coil from right to left (i.e., the magnetic field lines generated by the first coil pass through the first and second coils in opposite directions, or simply, the magnetic fields are reversed), a clockwise induced current can be generated in the second coil. In this case, the magnetic fields of the first and second coils are reversed, and the induced currents are reversed as well.

[0214] The description shown in Figure 12 can be identified by the correspondence in Table 1 below.

[0215] Table 1

[0216] Based on the above explanation, in the example in Table 1, the magnetic fields being opposite or reversed correspond to the directional relationship between the direction in which the magnetic field generated by the first coil passes through the region surrounded by the first coil and the direction in which the magnetic field generated by the first coil passes through the region surrounded by the second coil.

[0217] Understandably, the inductive-capacitive relationship between the second coil and the first coil can be adjusted by changing the electrical length of the second coil. Whether the direction of the magnetic field passing through the second coil is the same as or opposite to the direction of the magnetic field passing through the first coil depends on the relative positions of the two coils.

[0218] For example, referring to Figure 13, two examples of positional relationships between the first coil and the second coil are shown.

[0219] It is understandable that the planes on which the first coil and the second coil are located can coincide (i.e., the two coils are located in the same plane), or the planes on which the first coil and the second coil are located can not coincide.

[0220] Take the example of the first coil and the second coil being located in the same plane.

[0221] In positional relationship 1, the effective magnetic flux regions enclosed by the first coil and the second coil do not overlap. Thus, when a counter-clockwise current is generated in the first coil, the direction of the magnetic field generated by the first coil is perpendicular to the paper and outwards within its effective magnetic flux region. Correspondingly, the direction of the magnetic field generated by the first coil is perpendicular to the paper and inwards within the effective magnetic flux region of the second coil.

[0222] In positional relationship 2, the effective magnetic flux region of the first coil includes the effective magnetic flux region of the second coil. Thus, when a counterclockwise current is generated in the first coil, the direction of the magnetic field generated by the first coil is perpendicular to the paper and outwards within the effective magnetic flux region of the first coil. Correspondingly, the direction of the magnetic field generated by the first coil is also perpendicular to the paper and outwards within the effective magnetic flux region of the second coil.

[0223] It is understandable that in some implementations, where the effective magnetic flux region of the second coil includes the effective magnetic flux region of the first coil, the magnetic field directions of the two coils are also the same. This situation can also be included in positional relationship 2.

[0224] In practical implementation, as shown in Figure 14, taking positional relationship 1 as an example, when the current direction on the second coil is the same as the current direction on the first coil, the first and second coils are treated as a whole, and the counterclockwise current of the NFC antenna is enhanced compared to when only the first coil is configured. Therefore, in positional relationship 1, when the currents in the second and first coils are in the same direction, the radiation performance of the NFC antenna can be enhanced.

[0225] Taking positional relationship 2 as an example, when the current direction on the second coil is the same as the current direction on the first coil, the magnetic field strength in the effective magnetic flux region of the NFC antenna, in addition to the magnetic field generated by the first coil, can also be superimposed with the magnetic field generated by the second coil. Since the current directions of the first and second coils are the same, the magnetic field generated by the first coil is in the same direction as the magnetic field generated by the induced current on the second coil. In this way, the effect of magnetic field superposition can be achieved. Therefore, in positional relationship 2, when the currents of the second and first coils are in the same direction, the radiation performance of the NFC antenna can be enhanced.

[0226] In other words, based on the explanation shown in Figure 14, in positional relationship 1 or positional relationship 2, when the direction of the induced current generated on the second coil is the same as the direction of the current on the first coil, it is possible to obtain the effect of improving the radiation performance of the NFC antenna.

[0227] By combining the correspondence between the inductive / capacitive properties of the second coil and different magnetic field directions and current directions provided in Figure 12 (or Table 1 above); the correspondence between the different positional relationships of the first and second coils and the magnetic field directions provided in Figure 13; and the current requirements for enhancing NFC antenna performance provided in Figure 14, the setting limitations of the first and second coils in this application can be obtained.

[0228] Referring to Figure 15, taking positional relationship 1 between the first and second coils as an example, the second coil can be configured with a resonant frequency lower than the operating frequency. In this way, the second coil is inductive relative to the first coil. In positional relationship 1, the magnetic fields of the second coil and the first coil are opposite, and the induced current generated is in the same direction as the current in the first coil. This improves the performance of the NFC antenna.

[0229] Taking positional relationship 2 between the first and second coils as an example, the second coil can be configured with a resonant frequency higher than the operating frequency. In this way, the second coil is capacitive relative to the first coil. In positional relationship 2, the magnetic fields of the second and first coils are in the same direction, and the induced current generated is in the same direction as the current in the first coil. This improves the performance of the NFC antenna.

[0230] In this application embodiment, the configuration of the first coil and the second coil in the NFC antenna under other possible positional relationships is also provided.

[0231] For example, referring to FIG16, there are two other examples of positional relationships provided in the embodiments of this application.

[0232] As shown in Figure 16, taking the first coil and the second coil as an example with positional relationship 3.

[0233] This positional relationship 3 corresponds to the first coil and the second coil being in the same plane, and the effective magnetic flux regions of the first coil and the second coil including at least partial overlap.

[0234] In this case, for the second coil, the area of ​​the overlapping region is larger than the area of ​​the non-overlapping region. This means that for the overlapping effective magnetic flux region, the magnetic field direction of the second coil is the same as that of the first coil. Conversely, for the non-overlapping effective magnetic flux region, the magnetic field direction of the second coil is opposite to that of the first coil.

[0235] In this example, for the second coil, the magnetic field strength in the same direction is greater than the magnetic field strength in the opposite direction. Thus, the net magnetic flux direction of the second coil is the same as that of the first coil. Therefore, in this positional relationship 3, the resonant frequency of the second coil can be controlled to be higher than the operating frequency, making the second coil capacitive relative to the first coil. This further ensures that the net magnetic flux direction of the second coil is in the same direction as the magnetic field of the first coil, and the induced current generated is in the same direction as the current in the first coil. This improves the performance of the NFC antenna.

[0236] In the embodiments of this application, the net magnetic flux direction can be used to describe the overall situation of the magnetic field direction within the effective magnetic flux region enclosed by any logic coil (such as the first coil or the second coil).

[0237] Taking the example where the magnetic field lines emitted by the first coil after it is energized are oriented in the effective magnetic flux region of the first coil, with the direction being direction 1, this can be described as the net magnetic flux direction of the first coil being direction 1. When the magnetic field lines emitted by the first coil pass through the effective magnetic flux region of the second coil, their direction is direction 2, which can then be described as the net magnetic flux direction of the second coil being direction 2.

[0238] Thus, when direction 1 and direction 2 are the same, the net magnetic flux directions of the first and second coils are the same. Conversely, when direction 1 and direction 2 are opposite, the net magnetic flux directions of the first and second coils are opposite.

[0239] In other embodiments, because the effective magnetic flux regions of the first coil and the second coil partially overlap, the magnetic field lines emitted by the first coil may have two directions simultaneously when passing through the effective magnetic flux region of the second coil.

[0240] For example, in the region where the effective magnetic flux regions of the second coil and the first coil overlap (as referred to as region 1), the direction of the magnetic field lines of the magnetic field emitted by the first coil is the same as the direction passing through the second coil.

[0241] In the region where the effective magnetic flux regions of the second coil and the first coil do not overlap (as referred to as region 2), the direction of the magnetic field lines emitted by the first coil is opposite to the direction passing through the second coil.

[0242] In this case, if the magnetic flux in region 1 is greater than that in region 2, it indicates that the magnetic field direction in region 1 is the dominant magnetic field direction of the second coil. This situation can be described as follows: the net magnetic flux of the second coil is in the same direction as the magnetic field lines in region 1, and the net magnetic flux direction of the second coil is in the same direction as the net magnetic flux direction of the first coil.

[0243] In some implementations, this scenario can correspond to the area of ​​region 1 being larger than the area of ​​region 2.

[0244] Correspondingly, if the magnetic flux in region 1 is less than that in region 2, it indicates that the magnetic field direction in region 2 is the dominant magnetic field direction of the second coil. This situation can be described as follows: the net magnetic flux of the second coil is in the same direction as the magnetic field lines in region 2, and the direction of the net magnetic flux of the second coil is opposite to that of the net magnetic flux of the first coil.

[0245] In some implementations, this scenario can correspond to the area of ​​region 1 being smaller than the area of ​​region 2.

[0246] Correspondingly, this positional relationship 4 corresponds to the first coil and the second coil being in the same plane, and the effective magnetic flux regions of the first coil and the second coil including at least partial overlap.

[0247] For the second coil, the area of ​​the overlapping region is smaller than the area of ​​the non-overlapping region.

[0248] In this example, for the second coil, the magnetic field strength in the same direction is less than the magnetic field strength in the opposite direction. Thus, the net magnetic flux direction of the second coil is opposite to that of the first coil. Therefore, in this positional relationship 4, the resonant frequency of the second coil can be controlled to be lower than the operating frequency, making the second coil inductive relative to the first coil. This further causes the net magnetic flux direction of the second coil to be opposite to the magnetic field of the first coil, resulting in an induced current in the same direction as the current in the first coil. This improves the performance of the NFC antenna.

[0249] It should be noted that the positional relationship illustrations provided in Figures 13-16 above are based on the example of the first and second coils being positioned on the same plane. It is understood that when the planes containing the first and second coils are parallel, the magnetic field and current relationships between the first and second coils remain the same as described above. Therefore, when the planes containing the first and second coils are parallel, the first coil can be projected onto the plane containing the second coil, or vice versa. Then, the two coils can be positioned according to positional relationship 1, 2, 3, or 4 as shown in Figures 15 or 16, thereby improving the radiation performance of the NFC antenna.

[0250] Understandably, in some other cases, the planes containing the first and second coils can intersect. Thus, based on the principle of equivalent decomposition, the first and second coils can be projected onto two orthogonal planes respectively. Consequently, in each of the two orthogonal planes, based on the positional relationship between the first and second coils, and in conjunction with the schemes shown in Figures 15 and 16, the configuration conditions for the resonant frequency of the second coil can be determined.

[0251] In some embodiments, the planes containing the first coil and the second coil intersect but are not orthogonal. When it is determined that the resonant frequency of the second coil should be higher or lower than the operating frequency, the second coil can be projected onto the plane containing the first coil. Thus, within the same plane, the configuration conditions of the second coil are determined according to the scheme shown in Figure 15 or Figure 16.

[0252] For example, after projecting the second coil onto the plane where the first coil is located, if the positional relationship between the two coils is positional relationship 1 or positional relationship 4, then the second coil is configured so that its resonant frequency is lower than the operating frequency.

[0253] For example, after projecting the second coil onto the plane where the first coil is located, if the positional relationship between the two coils is positional relationship 2 or positional relationship 3, then the second coil is configured so that its resonant frequency is higher than its operating frequency.

[0254] In the above embodiments, the configuration conditions of the second coil are described in cases where the first coil and the second coil are coplanar, the planes are parallel to each other, and the planes are not parallel and not orthogonal.

[0255] Based on this, in the solution provided by the embodiments of this application, when the net magnetic flux direction in the effective magnetic flux region of the second coil is the same as the net magnetic flux direction in the effective magnetic flux region of the first coil (e.g., position relationship 1 or position relationship 4), the resonant frequency of the second coil can be configured to be lower than the operating frequency (e.g., 13.56MHz), thereby obtaining an induced current in the second coil in the same direction as the first coil, thus improving the performance of the NFC antenna. When the net magnetic flux direction in the effective magnetic flux region of the second coil is opposite to the net magnetic flux direction in the effective magnetic flux region of the first coil (e.g., position relationship 2 or position relationship 3), the resonant frequency of the second coil can be configured to be higher than the operating frequency (e.g., 13.56MHz), thereby obtaining an induced current in the second coil in the same direction as the first coil, thus improving the performance of the NFC antenna.

[0256] Referring to Figure 17, this is a schematic diagram of a scenario where the plane containing the first coil and the plane containing the second coil are orthogonal to each other. This scenario where the first coil and the second coil are orthogonal to each other can be referred to as positional relationship 5.

[0257] It is understandable that the magnetic field generated by the first coil is oriented along the oz-axis within the effective magnetic flux region. This allows for better NFC radiation performance along the oz-axis. For example, consider an xoy plane containing the first coil parallel to the display screen of an electronic device. In card mode, when the user brings the display screen or back cover of the electronic device close to the card reader, the NFC antenna approaches the card reader from the oz-axis, allowing for faster and more sensitive card reading results. However, when the NFC antenna approaches the card reader from the ox or oy axis, card reading is less efficient.

[0258] Correspondingly, in positional relationship 5, after adding the second coil, the induced current generated in the second coil allows it to produce a magnetic field along the ox-axis. Thus, when a user brings the side of their electronic device close to the card reader, the NFC antenna moves closer to the card reader along the ox-axis, allowing for faster and more sensitive card reading results.

[0259] Therefore, in this positional relationship 5, regardless of whether the resonant frequency of the second coil is configured higher or lower than the operating frequency, the effect of extending the NFC magnetic flux direction can be achieved. This improves the omnidirectionality of the NFC antenna and enhances its performance.

[0260] Based on the descriptions in Figures 11 to 17 above, in this application, by rationally configuring the resonant frequency and operating frequency of the second coil according to the relative positional relationship between the second coil and the first coil, the NFC radiation performance can be improved.

[0261] Specifically, the relationship between the resonant frequency and the operating frequency under various positional conditions can be indicated by Table 2 below.

[0262] Table 2

[0263] Based on the above explanation, in the example in Table 1, the magnetic fields being opposite or reversed correspond to the directional relationship between the direction in which the magnetic field generated by the first coil passes through the region surrounded by the first coil and the direction in which the magnetic field generated by the first coil passes through the region surrounded by the second coil.

[0264] For a detailed explanation of the positional relationships, net magnetic flux relationships, and the relationship between the resonant frequency and the operating frequency of the second coil in Table 2 above, please refer to the aforementioned embodiments; they will not be repeated here.

[0265] In some embodiments of this application, when the resonant frequency is higher or lower than the operating frequency, the resonant frequency may be close to the operating frequency in the frequency domain.

[0266] For example, consider a resonant frequency higher than the operating frequency. The resonant frequency can be in the range of the operating frequency plus 10MHz (e.g., 13.56MHz to 23.56MHz).

[0267] For example, consider a resonant frequency lower than the operating frequency. The resonant frequency can be within the range of the operating frequency minus 10MHz (e.g., 3.56MHz to 13.56MHz).

[0268] It should be noted that in the above embodiments, the first coil and the second coil are described as rectangular coils. In other embodiments, the first coil and / or the second coil can be replaced with any possible implementation in the foregoing examples, as long as a complete current loop can be provided.

[0269] Based on the descriptions in the above examples, in this application, the frequency domain relationship between the resonant frequency and the operating frequency of the second coil can be set according to the relative relationship between the net magnetic flux of the first coil and the second coil.

[0270] Understandably, for NFC communication, the operating frequency can include 13.56MHz, corresponding to a wavelength of approximately 22.1m. Due to the size limitations of terminal devices, NFC antennas are typically configured using methods such as reusing metal frames or employing FPC coils, which prevents the antenna's eigenmode (i.e., natural resonance) from covering this 13.56MHz. For example, consider a reusing metal frame. Because the electrical length of the metal frame is too short, the natural resonance of the NFC antenna is much higher in the frequency domain than the operating frequency.

[0271] For example, a resonant circuit can be provided on the first coil to adjust the resonance of the NFC antenna to a lower frequency in the frequency domain, thereby enabling the resonance generated by the first coil to cover the operating frequency.

[0272] In some embodiments, the resonant circuit may include tuning devices connected in series and / or in parallel with the first coil. In some implementations, the resonant circuit may include one or more devices such as capacitors.

[0273] In the following example, one or more capacitors are connected in series with the first coil to adjust the antenna resonance to cover the operating frequency. It should be noted that in the embodiments of this application, any one of the one or more capacitors can include a lumped capacitor or a distributed capacitor. The distributed capacitor can correspond to a capacitor structure formed by two closely spaced metal plates. Further details will not be elaborated below.

[0274] Similar to the first coil, the natural resonance of the second coil is generally much higher than the operating frequency. Therefore, when adjusting the resonant position (i.e., the position of resonance in the frequency domain) of the second coil according to the examples above, a resonant circuit can be incorporated into the second coil. For example, this resonant circuit may include one or more capacitors connected in series.

[0275] The size of the capacitor connected in series with the first coil and / or the second coil can be flexibly adjusted according to the operating frequency and the resonant frequency position of the second coil. This application does not impose any limitations on this.

[0276] Understandably, when the NFC antenna is actually installed in an electronic device, the positional relationship between the first and second coils is relatively fixed due to spatial constraints. Therefore, based on the correspondence shown in Table 2 above, a configuration method corresponding to the current actual positional relationship can be selected for targeted configuration of the first and / or second coils. For example, according to the required configuration method, the capacitance value of the capacitor connected in series with the first and / or second coils can be adjusted so that the relationship between the resonant frequency and the operating frequency of the second coil matches the current positional relationship.

[0277] The following, with reference to the accompanying drawings, provides specific examples of the structural features in the electronic device that realize the aforementioned positional relationships. All examples assume the electronic device has a metal frame architecture, and the first and second coils are configured by reusing the metal frame.

[0278] For example, referring to Figure 18, there are several structural examples of implementing positional relationship 1 in an electronic device.

[0279] In the various examples shown in Figure 18, this scheme reuses two adjacent metal frames in the electronic device to implement the configuration of the first and second coils. For example, the metal frame on the left of the figure is used to implement the first coil, and the metal frame on the right is used to implement the second coil. In other embodiments, in any of the possible implementations shown in Figure 18, the positions of the first and second coils can also be interchanged.

[0280] In this system, one end of the first coil can be grounded. The other end of the first coil can be provided with a feed point for feeding in NFC signals. Thus, the first coil can radiate NFC communication through a single-port power supply system. It is understood that in some embodiments, when the first coil is used to implement a dual-port power supply system, the grounded end of the first coil may no longer be grounded, and a different feed point may be provided instead. For specific implementation details, refer to the aforementioned examples, which will not be repeated here.

[0281] One end of the second coil is grounded. The other end of the second coil is provided with a grounding point, which can be grounded through a matching device or directly grounded.

[0282] One or more capacitors can be placed on both the first and second coils, and there are no restrictions on the number or location of the capacitors.

[0283] In some embodiments, the first coil is taken as an example. The capacitor on the first coil may be located at the feed point, or in the path between the feed point of the first coil and the NFC chip (not shown in FIG18).

[0284] In other embodiments, a second coil is used as an example. The capacitor on the second coil can be located between the ground point and the reference ground.

[0285] In the examples shown in Figure 18, for any logic coil (such as the first coil or the second coil), the metal frame is directly connected to the reference ground at one end, thus forming a U-shaped structure. A feed point or ground point is set at the opening of the U-shaped structure. This allows a closed current loop to be formed through the U-shaped structure and the signal transmission path via the feed or ground, thus constructing the logic coil. In this example, the open end of the U-shaped structure can also be called the open terminal. For example, the end of the first coil where the feed point is set can be called the open terminal of the first coil, or the opening of the first coil. Similarly, the end of the second coil where the ground point is set can be called the open terminal of the second coil, or the opening of the second coil.

[0286] Refer to 1501 in Figure 18. In this example, the end of the first coil that is directly grounded is positioned away from the second coil. The end of the second coil that is directly grounded is positioned away from the first coil.

[0287] That is, the end of the first coil with the feed point is placed close to the end of the second coil with the ground point. This forms a "mouth-to-mouth" structure.

[0288] Refer to 1502 in Figure 18. In this example, the end of the first coil that is directly grounded is positioned close to the second coil. The end of the second coil that is directly grounded is positioned away from the first coil.

[0289] That is, the end of the first coil with the feed point is located away from the second coil, while the end of the second coil with the ground point is located close to the first coil. This forms a "mouth-to-back" structure.

[0290] Refer to 1503 in Figure 18. In this example, the end of the first coil that is directly grounded is positioned close to the second coil. The end of the second coil that is directly grounded is positioned close to the first coil.

[0291] That is, the end of the first coil with the feed point is located away from the second coil, and the end of the second coil with the ground point is located away from the first coil. This forms a T-shaped structure. This structure can also be called a "back-to-back" structure.

[0292] Referring to the foregoing description of positional relationship 1, in some embodiments, as shown in FIG18, the structural examples 1501 to 1503 can be implemented on a plane of an electronic device. For example, the electronic device can be a non-folding candybar phone, tablet computer, or similar device.

[0293] In other embodiments, the various structural examples shown in FIG18 can also be the logical result of projecting a first coil and a second coil disposed in different planes onto the same plane. For example, the electronic device is a foldable device. The electronic device includes at least two surfaces (such as surface A and surface B) that can be unfolded or folded. Thus, the first coil can be disposed on surface A. The second coil can be disposed on surface B. When the electronic device is in the folded state, surface A and surface B are snapped together, so that after the second coil on surface B is projected onto surface A, the projection of the second coil onto surface A and the first coil can have the structure shown in any of the examples in FIG18.

[0294] Furthermore, in the example shown in Figure 18, the effective magnetic flux regions (i.e., the gap between the metal frame and the reference ground) of the first and second coils are the same or nearly the same. In other embodiments, the effective magnetic flux regions of the first and second coils may also be different. Thus, the frequency domain positions of the natural resonances of the first and second coils may also be different. Correspondingly, the frequency domain relationship between the resonant frequency and the operating frequency of the second coil can be matched to the current positional relationship by adjusting the number or value of the capacitors on the first and / or second coils.

[0295] For any of the structures shown in Figure 18, by adjusting the capacitance on the first coil, the resonant frequency of the first coil is made to cover the operating frequency. By adjusting the capacitance on the second coil, the resonant frequency of the second coil is made to be lower than the operating frequency. This significantly improves the performance of NFC.

[0296] Referring to Figure 19, several specific implementation examples of positional relationship 2 are provided. Taking the electronic device as a foldable device, the first coil and the second coil are respectively located on surface A and surface B. For example, the first coil is located on surface A, and the second coil is located on surface B.

[0297] Referring to the description in Figure 18, in this example, the settings of the feed point, grounding point, and capacitor on the first and second coils are the same as in the example in Figure 18, and can be used as a reference for each other.

[0298] Referring to 1601 in Figure 19. When the electronic device is in the deployed state, the opening of the first coil (i.e., the end where the feed point is located) is away from the second coil. The opening of the second coil (i.e., the end where the ground point is located) is away from the first coil.

[0299] When the electronic device is in the closed state, the second coil and the first coil are close to each other. Thus, in the z-direction (e.g., a direction perpendicular to plane A), when the second coil is projected onto plane A, the projection of the second coil completely coincides with the first coil. In other embodiments, where the effective magnetic flux regions of the first and second coils are different, in the closed state, the projection of the second coil onto plane A may include the entire first coil, or the first coil may include the entire projection of the second coil. This also corresponds to positional relationship 2, similar to the configuration shown in 1601.

[0300] This creates a z-shaped structure with the top and bottom openings facing each other.

[0301] Referring to 1602 in Figure 19. When the electronic device is in the deployed state, the opening of the first coil (i.e., the end where the feed point is located) is close to the second coil. The opening of the second coil (i.e., the end where the ground point is located) is close to the first coil.

[0302] When the electronic device is in the closed state, the second coil and the first coil are close to each other. Thus, in the z-direction (such as the direction perpendicular to plane A), when the second coil is projected onto plane A, the projection of the second coil is completely included by the first coil.

[0303] This can also form a top-to-bottom mouth-to-mouth structure in the z-direction.

[0304] Referring to 1603 in Figure 19. When the electronic device is in the deployed state, the opening of the first coil (i.e., the end where the feed point is located) is away from the second coil. The opening of the second coil (i.e., the end where the ground point is located) is close to the first coil.

[0305] When the electronic device is in the closed state, the second coil and the first coil are close to each other. Thus, in the z-direction (e.g., a direction perpendicular to plane A), when the second coil is projected onto plane A, the projection of the second coil completely coincides with the first coil. In other embodiments, where the effective magnetic flux regions of the first and second coils are different, in the closed state, the projection of the second coil onto plane A may include the entire first coil, or the first coil may include the entire projection of the second coil. This also corresponds to positional relationship 2, similar to the configuration shown in 1603.

[0306] This can also form a z-shaped structure with the top and bottom openings facing each other.

[0307] Referring to 1604 in Figure 19. When the electronic device is in the deployed state, the opening of the first coil (i.e., the end where the feed point is located) is away from the second coil. The opening of the second coil (i.e., the end where the ground point is located) is close to the first coil.

[0308] When the electronic device is in the closed state, the second coil and the first coil are close to each other. Thus, in the z-direction (such as the direction perpendicular to plane A), when the second coil is projected onto plane A, the projection of the second coil is completely included by the first coil.

[0309] This can also form a z-shaped structure with the top and bottom openings facing each other.

[0310] It is understood that the examples shown in Figure 19 above are merely examples of several specific implementations of positional relationship 2. In other embodiments, the top-to-bottom, bottom-to-back, and top-to-bottom-back structures in the z-direction can also be implemented according to the configuration of positional relationship 2 to set up the NFC antenna in this application.

[0311] For any of the structures shown in Figure 19, by adjusting the capacitance of the first coil, the resonant frequency of the first coil can be made to cover the operating frequency. By adjusting the capacitance of the second coil, the resonant frequency of the second coil can be made higher than the operating frequency. This significantly improves the performance of NFC.

[0312] Figures 18 and 19 above provide possible structural implementations for positional relationship 1 and positional relationship 2, respectively. It is understood that the structures shown in Figures 18 and 19 do not constitute a limitation on positional relationship 1 and / or positional relationship 2. In other embodiments, other structural compositions conforming to the above-described features of positional relationship 1 and / or positional relationship 2 should also be included in the solutions provided in this application. Correspondingly, for different positional relationships, the above solutions can be implemented to configure the relationship between the resonant frequency and operating frequency of the second coil to match the positional relationship, thereby improving the performance of the NFC antenna.

[0313] In this embodiment, a structural example corresponding to positional relationship 5 is also provided. In this example, the first coil is configured as an FPC coil (as shown in Figure 2). This allows the first coil to be mounted on the upper half of the back cover of the electronic device.

[0314] The second coil can be constructed using metal parts or materials in different planes within the electronic device. For example, this second coil can be configured by coupling a metal decorative element (metal deco) to a copper-clad PCB in the electronic device. The metal deco can be made of metal. This metal deco can be used to fix and protect the rear camera module of the electronic device.

[0315] As an example, refer to Figure 20. Figures 1701 and 1702 in Figure 20 show the rear view of the electronic device under two different rear camera IDs.

[0316] As shown in 1701 of Figure 20, in this example, the rear camera module of the electronic device can be positioned at the upper left of the device. Correspondingly, the first coil can be mounted on the inside of the back cover (e.g., on the positive z-direction side of the back cover). In some implementations, the first coil can be positioned in the middle of the upper half of the electronic device. This allows for better NFC communication near the middle of the upper half of the electronic device when the first coil is in operation.

[0317] As shown in 1702 of Figure 20, in this example, the rear camera module of the electronic device can be centrally located on the upper half of the electronic device. This is exemplified by the first coil also being mounted on the back cover, positioned in the middle of the upper half of the electronic device. In some implementations, the first coil can be arranged around the rear camera module. In this case, the metal deco can be included within the effective magnetic flux region of the first coil.

[0318] It is understood that 1701 and 1702 in Figure 20 are merely examples of two different metal Deco settings and do not constitute a structural limitation on this example.

[0319] Based on the structure of 1701 or 1702, the first coil is mounted on the back cover. In this way, the magnetic field direction of the first coil can diverge along the z-axis.

[0320] In this example, a logic coil (i.e., a second coil) can be constructed in the yoz plane or xoz plane by electrically connecting the metal deco to the copper-clad PCB under the back cover.

[0321] For example, as shown at 1703 in Figure 20, at least two electrical connection points may be provided on the metal Deco. For example, the at least two electrical connection points may include electrical connection point 1 and electrical connection point 2.

[0322] In some embodiments, electrical connection point 1 and electrical connection point 2 may be electrically connected to a reference ground on the PCB, respectively.

[0323] In this way, the metal Deco and PCB between electrical connection point 1 and electrical connection point 2 can form a complete current loop, constituting a logic coil as the second coil.

[0324] In the example of 1703 in Figure 20, electrical connection point 1 and electrical connection point 2 can be located at different positions along the y-axis on the metal deco. This allows the induced current of the second coil to be distributed within the yoz plane. Consequently, when the first coil is operating, an induced current can be generated in the second coil, producing a magnetic field along the x-axis. This extends the radiation performance of the first coil along the x-axis.

[0325] Electrical connection point 1 and electrical connection point 2 can be located at different positions along the x-axis on the metal Deco. This allows the induced current of the second coil to be distributed within the xoz plane. Consequently, when the first coil is operating, an induced current can be generated in the second coil, producing a magnetic field along the y-axis. This extends the radiation performance of the first coil along the y-axis.

[0326] In other embodiments, electrical connection point 1 and / or electrical connection point 2 can be capacitively coupled to a reference ground on the PCB. The resonant frequency of the second coil can be adjusted by setting this capacitor.

[0327] In other embodiments, a metal conductor, not connected to the reference ground, can be provided on the PCB below the metal deco (e.g., in the negative z-axis direction). The metal deco can be coupled to both ends of the metal conductor via electrical connection point 1 and electrical connection point 2. This constitutes a second coil in the xoz or yoz plane. It also enables extended radiation performance in directions other than the z-axis.

[0328] Thus, in the example shown in Figure 20, by reusing the metal Deco and other metal components (such as copper-clad PCBs) on different height planes, the configuration of the second coil in the thickness direction of the electronic device is realized, thereby ensuring the NFC performance of the electronic device in the screen or back cover area while improving the NFC radiation performance in other directions.

[0329] It is understood that in other embodiments, unlike the example in FIG20, the first coil may also be configured in the xoy plane using any other form (such as multiplexing or partially multiplexing the metal frame). In other embodiments, the configuration of the second coil may also reuse other metal components besides the metal deco. This application does not limit this.

[0330] Figures 18-20 above illustrate specific structural implementations of different positional relationships provided in the embodiments of this application. The following electromagnetic simulation of one of the structural implementations is performed with reference to the accompanying drawings. Through simulation and card reading results, the beneficial effects of the solution provided in the embodiments of this application are demonstrated.

[0331] For example, referring to Figure 21, a structural schematic of an NFC antenna scheme provided in an embodiment of this application is shown. The example uses an electronic device with a metal frame architecture.

[0332] In this example, a portion of the metal frame can be connected to the metal mid-frame via one or more structural connection points. These connection points provide structural support for the metal frame. Furthermore, the metal mid-frame, as a large-area metal component in the electronic device, can provide a zero-potential reference. Thus, the metal frame can be grounded through these connection points.

[0333] In the example shown in Figure 21, the metal frame corresponding to the first coil can be located in the upper right corner of the electronic device. For example, the metal frame multiplexing the first coil can be L-shaped. One side of the L-shaped metal frame is located on the short side (such as the top edge) of the electronic device, and the other side of the L-shaped metal frame is located on the long side (such as the side edge) of the electronic device.

[0334] In this example, the first coil corresponds to an NFC power supply system coupled to one end of the long side of the metal frame. The first coil corresponds to a reference ground coupled to one end of the short side of the metal frame.

[0335] The second coil is positioned close to the first coil.

[0336] For example, one end of the metal frame of the second coil (such as the right end) is separated from the grounded end of the first coil by a gap.

[0337] The other end of the metal frame of the second coil multiplexing is connected to the metal middle frame through a structural connection point. This achieves grounding at that end.

[0338] Thus, the effective magnetic flux region of the first coil is the L-shaped gap between the multiplexed metal frame of the first coil and the reference ground (i.e., the metal middle frame). The effective magnetic flux region of the second coil is the U-shaped gap between the multiplexed metal frame of the second coil and the reference ground (i.e., the metal middle frame).

[0339] The effective magnetic flux regions of the first and second coils do not overlap, corresponding to positional relationship 1 in Figure 15, forming a back-to-back structure.

[0340] Based on the foregoing description of the effective magnetic flux region, in the implementation of the scheme for constructing the first and second coils using a multiplexed metal frame provided in this example, the effective magnetic flux region of the corresponding coil can also be formed by the metal frame and the reference ground edge near the metal frame.

[0341] Taking the first coil as an example. The enclosing area of ​​the first coil (i.e., the effective magnetic flux area of ​​the first coil) is shown in Figure 21, which may include an L-shaped gap between the L-shaped metal frame in the upper right corner and the nearby middle frame (i.e., the reference ground). When the first coil radiates, NFC signals can be radiated outward through this L-shaped gap.

[0342] Taking the second coil as an example, the enclosing region of the second coil (i.e., the effective magnetic flux region of the second coil), as shown in Figure 21, can include a straight-line gap between the metal frame of the multiplexed second coil and the adjacent middle frame (i.e., reference ground). When the first coil radiates, the second coil can acquire energy through coupling and radiate NFC signals outward through this straight-line gap. This straight-line gap corresponds to the effective magnetic flux region of the second coil.

[0343] Other solutions in this application, such as reused metal frames and semi-common reused metal frames, achieve the corresponding enclosing regions and effective magnetic flux regions in a similar manner to the example shown in Figure 21, and will not be described in detail here.

[0344] In this example, the effective radiation areas of the first and second coils are in the same plane and do not overlap. Based on the above description, the resonant frequency of the second coil can be configured to be lower than the operating frequency so that the induced current in the second coil is in the same direction as the current in the first coil, thereby improving the NFC radiation performance.

[0345] In some embodiments, an electrical connection point 1801 may be provided at one end of the second coil near the first coil. One or more capacitors may be grounded at this electrical connection point 1801. This adjusts the resonant frequency of the second coil to be lower than the operating frequency.

[0346] As an example, the electrical connection point 1801 can be equipped with a capacitor of 29nF. Therefore, the return loss (S11) of the second coil is shown in Figure 22.

[0347] As shown in Figure 22, after adding a capacitor (such as a 29nF capacitor) to the second coil, the resonant frequency is tuned to 12.75MHz. This resonant frequency is lower than the operating frequency (13.56MHz), enabling the second coil to generate a current in the same direction as the first coil.

[0348] Refer to Figure 23 for a simulation comparison of the current before and after adding a capacitor (e.g., a 29nF capacitor). The figure shows the state after adding the capacitor (after tuning) and the state before adding the capacitor (before tuning).

[0349] As can be seen, before adding the capacitor, there is a relatively significant current distribution on the metal frame of the first coil. At the moment shown in Figure 23, the current direction can be from bottom to top on the long side and from right to left on the short side. Correspondingly, there is no significant current distribution on the metal frame corresponding to the second coil.

[0350] Even after adding the capacitor, a significant current is still distributed on the metal frame of the first coil. At the moment shown in Figure 23, the current direction can be from bottom to top on the long side and from right to left on the short side. Correspondingly, a significant right-to-left current distribution also appears on the metal frame of the second coil. This proves that by adding the capacitor and adjusting the resonant frequency of the second coil to below the operating frequency, it is possible to excite a current in the second coil that is in the same direction as that in the first coil.

[0351] Based on the analysis in Figure 14, since the second coil is excited to obtain a current in the same direction as the first coil, the magnetic field radiated by the induced current of the second coil can be superimposed in the same direction as the magnetic field generated by the first coil, thereby improving the radiation performance of the NFC antenna.

[0352] In some embodiments of this application, after adjusting the resonant frequency of the second coil to be lower than the operating frequency, other capacitors can be set to optimize the impedance of the second coil near the operating frequency, thereby improving the efficiency of the induced current in the second coil when radiating near the operating frequency.

[0353] For example, referring to Figure 24, a comparative schematic diagram of the original Smith chart before and after capacitor tuning is provided; as shown in Figure 24, after a 29nF capacitor is placed at electrical connection point 1801, the second coil is inductive relative to the first coil at 13.56MHz. The equivalent inductance value is 16.679nH as shown in Figure 24.

[0354] In this case, the impedance of the second coil at 13.56MHz is 1.421Ω.

[0355] Correspondingly, by adding a capacitor for tuning at the electrical connection point 1801, the impedance of the second coil at 13.56MHz can be effectively reduced.

[0356] For example, consider adding a 10nF capacitor at electrical connection point 1801. After adding the capacitor, the second coil becomes inductive relative to the first coil at 13.56MHz. The equivalent inductance is 3.1485nH, as shown in Figure 24.

[0357] In this case, the impedance of the second coil at 13.56MHz is 268.25mΩ.

[0358] As can be seen, adding more capacitors makes the second coil more inductive than the first coil, thus ensuring a unidirectional induced current. Furthermore, adding more capacitors (e.g., a 10nF capacitor) significantly reduces the impedance of the second coil at the operating frequency. This reduces port losses when the second coil radiates the induced current near the operating frequency, improving its radiation performance. Since the magnetic field radiated by the second coil is in the same direction as that radiated by the first coil, they can be superimposed. Therefore, the improved radiation performance of the second coil can further enhance the overall performance of the NFC antenna.

[0359] In practical implementation, the number and capacitance of capacitors coupled to the first and / or second coils can be flexibly selected according to the actual situation. This allows the second coil to be excited with the same direction current as the first coil while reducing the port impedance of the second coil near the operating frequency. This, in turn, more effectively improves the performance of the NFC antenna.

[0360] Table 3 below provides a comparison of the reading distance gains of this solution compared to the solution without a coupling coil. T2, T3T, T4, T4A, and ID cards are all common card types used to measure reader performance.

[0361] Table 3

[0362] As shown in Table 3, after adding the coupling coil, the NFC antenna effectively improves the reading distance of various cards in the card reader scenario. Conversely, in the card reader mode, the reading distance is also significantly improved when the NFC antenna is used as a card.

[0363] It is understood that in the above embodiments, by coupling the second coil with the first coil, a current in the same direction can be excited in the second coil, thereby improving the performance of the NFC antenna. This performance optimization can be reflected in the enhancement of the magnetic field and the expansion of the magnetic field coverage.

[0364] For example, when only the first coil is operating, the effective magnetic flux region is relatively limited. For instance, taking the implementation shown in Figure 21 as an example, when only the first coil is operating, the effective magnetic flux region includes the L-shaped gap region between the L-shaped metal frame and the metal middle frame of the first coil.

[0365] The effective magnetic flux region of the NFC antenna can be expanded by configuring the second coil. For example, if the second coil is configured with a resonant frequency lower than the operating frequency, the effective magnetic flux region of the NFC antenna can include the L-shaped gap corresponding to the first coil, as well as the U-shaped gap between the metal frame and the metal middle frame of the second coil.

[0366] In this way, good NFC communication quality can be obtained within the expanded effective magnetic flux area.

[0367] It should be noted that in all the above embodiments, the example is that a second coil is added as a coupling coil on the basis of the main coil corresponding to the first coil.

[0368] In other embodiments of this application, the NFC antenna scheme may include more coupling coils. The configuration of each coupling coil can refer to the configuration of the second coil described above.

[0369] For example, let's continue with the metal frame structure shown in Figure 21.

[0370] For ease of explanation, referring to Figure 25, the multiple electrical connection points on the metal frame are simplified. As shown in Figure 25, two electrical connection points, such as #1 and #2, can be provided on the frame 221 (i.e., the metal frame for the first antenna multiplexing in the above example). The #1 electrical connection point is located at one end of the short side of the frame 221, and the #2 electrical connection point is located at one end of the long side of the frame 221.

[0371] On the frame 222 (i.e., the metal frame for the second antenna reuse in the above example), a #3 electrical connection point can be provided at one end near the frame 221.

[0372] Border 223 is the border adjacent to border 222 on its shorter side. In this example, the end of border 223 closest to border 222 can be directly connected to the metal frame via a structural connection point. The end of border 223 furthest from border 222 can be provided with an electrical connection point #4.

[0373] Border 224 is the border adjacent to border 223 on its short side. In this example, the end of border 224 furthest from border 223 can be directly connected to the metal frame via a structural connection point. For example, border 224 can be connected to the frame at the upper left corner of the electronic device. The end of border 224 closest to border 223 is separated from border 223 by a gap. A #5 electrical connection point can be provided at the end of border 224 closest to border 223.

[0374] Referring to Figure 26, in some embodiments, electrical connection point #1 can be coupled to the NFC feed source. Electrical connection point #2 can be grounded. This allows current to be energized on frame 221, enabling NFC communication radiation from the first coil described above.

[0375] In other embodiments, electrical connection point #1 can be coupled to the NFC feed source. Electrical connection point #2 can be grounded. This allows current to be energized on frame 221, enabling NFC communication radiation from the first coil described above. Furthermore, electrical connection point #3 is grounded via capacitor C1. The presence of capacitor C1 ensures that the resonant frequency of the second coil in the multiplexed frame 222 is lower than the operating frequency, thereby energizing a current in the same direction on frame 222 as on frame 221, thus improving NFC radiation performance.

[0376] This corresponds to the scheme example in Figure 21 above. Furthermore, corresponding configurations can be made at other electrical connection points to excite currents in the same direction as the first coil on other nearby coupled coils, further improving NFC radiation performance.

[0377] Referring, as exemplarily to FIG. 27, in some embodiments, electrical connection point #1 can be coupled to the NFC feed. Electrical connection point #2 can be grounded. Electrical connection point #3 is grounded via capacitor C1. Furthermore, electrical connection point #4 is configured to be grounded via capacitor C2. The setting of capacitor C2 enables the coil of multiplexed frame 223 (such as the logic coil formed between frame 223 and the metal frame) to be energized with a current in the same direction as frame 221 or frame 222. Thus, the coil of multiplexed frame 223 can also serve as a coupling coil, further improving the radiation performance of the NFC antenna.

[0378] In other embodiments, electrical connection point #1 can be coupled to the NFC feed. Electrical connection point #2 can be grounded. Electrical connection point #3 is grounded via capacitor C1. Electrical connection point #4 is configured to be grounded via capacitor C2. Furthermore, electrical connection point #5 is configured to be grounded via capacitor C3. The setting of capacitor C3 enables the coil of the multiplexed frame 224 (such as the logic coil formed between frame 224 and the metal frame) to be energized with a current in the same direction as frame 221, frame 222, or frame 223. Thus, the coil of the multiplexed frame 224 can also serve as a coupling coil, further improving the radiation performance of the NFC antenna.

[0379] Therefore, through the solutions and simulation examples provided in Figures 26 and 27, in some embodiments of this application, one or more coupling coils near the main coil can be configured accordingly, so that the NFC coverage area and magnetic field strength are effectively improved.

[0380] It should be noted that in the examples provided in Figures 21 to 27 above, frame 221 is used as the metal frame of the main coil. In other embodiments, the main coil can reuse any other frame configuration. For example, the NFC feed signal can be coupled at electrical connection point #3 on frame 222, so that frame 222 radiates corresponding to the main coil. In this way, frames 221, 223, and 224 can be configured as coupling coils to optimize and improve NFC performance. Other similar configurations will not be elaborated further.

[0381] This allows for more flexible configuration of the main coil, avoiding the limitations of NFC antenna reuse frames caused by the configuration of devices in the path (such as SAR sensors) or space constraints on the PCB board when some frames are reused as antennas for other wireless communication systems.

[0382] The above examples, with specific illustrations, demonstrate the implementation and effects of the NFC antenna schemes provided in this application. The first coil in each NFC antenna scheme provided in this application can be applied to any of the aforementioned schemes. For example, it can be applied to the WPC sharing scheme shown in Figure 3, the metal frame multiplexing scheme shown in Figure 5, and the cellular multiplexing scheme shown in Figure 6, etc.

[0383] It is understandable that when the first coil is implemented using a common or semi-common scheme, the metal frame therein can also be used as a radiator in other wireless communication systems.

[0384] For example, referring to Figure 6, the metal frame can serve as an NFC antenna (such as the first coil of an NFC antenna) and can also be reused as part or all of the radiators of a cellular antenna.

[0385] Therefore, in order to ensure the normal operation of different wireless communication systems, appropriate settings can be made at the power supply end, grounding end, and other locations.

[0386] Taking a single-port system radiating NFC communication by reusing a metal frame in the form of a shared structure for the first coil in an NFC antenna as an example; the metal frame also serves as the radiator for a cellular communication system.

[0387] Referring to Figure 6 and Figure 28, an example of a metal frame reuse scheme compatible with both cellular and NFC communication systems is provided. In this example, the metal frame enables the function of the main coil (or first coil) in the NFC antenna of the various embodiments described above.

[0388] As shown in Figure 28, at least two electrical connection points can be provided on the metal frame. For example, electrical connection points P1 and P2. Electrical connection point P1 can be coupled to the feed signals of both the first and second systems. For example, the first system can be an NFC communication system, and its feed signal can be an NFC signal. The second system can be another communication system different from the NFC communication system, such as a cellular communication system, a Wi-Fi communication system, or a GPS communication system. In this example, the second communication system is a cellular communication system, and the corresponding feed signal is a cellular signal. Electrical connection point P2 can be grounded.

[0389] In this example, electrical connection point P1 and electrical connection point P2 can be set at both ends of the metal frame, respectively.

[0390] Referring to the explanation in Figure 6, in order to achieve isolation of the power supply signals of different systems, in the example shown in Figure 28, the power supply signals of different systems can be isolated by an isolation network before the power supply connection point P1.

[0391] Referring to Figure 29, a schematic diagram of an isolated network is provided. As shown in Figure 29, an inductor L2 can be set between the power supply signal of the NFC system (i.e., the first system power supply signal) and the electrical connection point P1 to achieve isolation from the second system. A capacitor C5 can be set between the power supply signal of the cellular system (i.e., the second system power supply signal) and the electrical connection point P1 to achieve isolation from the first system.

[0392] In some implementations, taking the cellular communication system corresponding to the second system operating at a frequency of less than 900MHz as an example, inductor L2 can be configured as 47nH or an inductance of 47nH plus or minus 20%. Capacitor C5 can be configured as 100pF or a capacitor of 100pF plus or minus 20%.

[0393] In other implementations, taking the cellular communication system corresponding to the second system operating at a frequency greater than 900MHz and less than 3GHz as an example, inductor L2 can be configured as 27nH or an inductance of 27nH plus or minus 20%. Capacitor C5 can be configured as a 33pF capacitor or a capacitor of 33pF plus or minus 20%.

[0394] In other implementations, taking the second system's corresponding cellular communication system operating at a frequency greater than 3GHz as an example, inductor L2 can be configured as 18nH or 18nH plus or minus 20%. Capacitor C5 can be configured as 22pF or 22pF plus or minus 20%.

[0395] Figure 29 provides an example of the isolation network setup at the feed end. In some implementations, when the second system reuses the metal frame, additional grounding points can be set on the metal frame to achieve functions such as frequency switching.

[0396] Referring again to Figure 28, an electrical connection point P3 may also be provided on the metal frame in this example. This electrical connection point P3 can be used for frequency switching in a cellular communication system. For example, the electrical connection point P3 may be coupled to a tuning component. The tuning component may include two or more tuning paths. Different inductors or capacitors may be provided on different tuning paths. Thus, the electronic device can control the different paths in the tuning component to be turned on or off in different scenarios, thereby realizing frequency band switching in cellular communication.

[0397] In this example, one or more capacitors / inductors can be placed between the electrical connection point P3 and the tuning component used for cellular handover to isolate the NFC signal from the cellular signal.

[0398] For example, as shown in Figure 28, in some implementations, a capacitor C4 may be connected in series between the electrical connection point P3 and the tuning component for cellular switching; or, while providing the series capacitor C4, an inductor L1 may be connected in parallel between the capacitor C4 and the tuning component. In some embodiments, the value of capacitor C4 may include between 33pF and 100pF.

[0399] Thus, by configuring capacitor C4 and inductor L1, a reference path can be provided for the NFC signal to return to the reference ground. Furthermore, by configuring capacitor C4 and inductor L1, it can be ensured that when the state of the cellular communication tuning component changes (such as switching between different conduction paths), the impedance of the NFC signal relative to the reference ground remains unchanged or changes within an acceptable range. This avoids the impact of cellular handover on NFC communication. In some implementations, the configuration of capacitor C4 and inductor L1 can ensure that in extreme scenarios (such as when the conduction path in the tuning component is grounded through an inductor, or when the conduction path in the tuning component is left floating and not grounded), NFC communication will not wake up from a low-power state, causing excessive power consumption.

[0400] The isolation network setup for multiplexing with other systems during the configuration of the first coil has been described above. In some cases, the second coil can also be configured to share a radiator (such as a metal frame) with other systems.

[0401] For example, consider a configuration where the second coil and the third system share a metal frame. The third system can be a different communication system than the NFC communication system, such as a cellular communication system, a Wi-Fi communication system, or a GPS communication system.

[0402] Referring to Figure 30, in some embodiments, when the third system reuses the metal frame, the metal frame can be configured such that one end of the metal frame is grounded and the other end is connected to the third system power supply signal through capacitor C6.

[0403] In this configuration, an isolation network M1 can be configured between the third system power supply signal and the metal frame. This isolation network M1 can be configured as a large capacitor in the NFC band. For the third system operating frequency band, the isolation network M1 can be equivalent to a small capacitor (such as capacitor C6). This allows the second coil to be grounded via the metal frame through a capacitor, while maintaining compatibility with the third system's communication.

[0404] As shown in Figure 30, in different implementations, the isolation network M1 can sample any of the following configurations: capacitor and inductor connected in parallel and then in series with the capacitor; capacitor and inductor connected in series and then in parallel with the capacitor.

[0405] Referring to Figure 31, in some other embodiments, when the third system reuses the metal frame, the metal frame can be configured such that one end of the metal frame is grounded and the other end is connected to the third system power supply signal through inductor L3.

[0406] In this configuration, an isolation network M2 can be configured between the third system's power supply signal and the metal frame. This isolation network M2 can be configured as a large capacitor in the NFC band. For the third system's operating frequency band, the isolation network M2 can be equivalent to an inductor (such as inductor L3). This allows the second coil to be grounded via the metal frame through a capacitor, while maintaining compatibility with the third system's communication.

[0407] As shown in Figure 31, in different implementations, the isolation network M2 can sample any of the following configurations: capacitor and inductor connected in parallel and then in series with the inductor; capacitor and inductor connected in series and then in parallel with the inductor; capacitor and inductor connected in series.

[0408] In practical implementation, as shown in Figure 30 or Figure 31, the values ​​of inductance and capacitance in isolation networks M1 and M2 can be flexibly configured according to actual conditions, so that isolation network M1 or isolation network M2 is equivalent to a large capacitor relative to the NFC operating frequency (e.g., 13.56MHz). This large capacitor enables the relationship between the resonant frequency and the operating frequency of the second coil to match the current positional relationship between the first and second coils.

[0409] In the above embodiments, the configuration methods and conditions of the main coil and coupling coils, as well as the setting of the isolation network, are specifically described in the NFC antenna scheme provided in this application. Several possible implementations of the NFC antenna are provided below. Based on the above analysis, the NFC antennas in various subsequent specific scenarios can improve NFC performance by exciting induced currents in one or more coupling coils in the same direction as the main coil.

[0410] Referring to Figure 32, a logic diagram of an NFC antenna is shown.

[0411] In this example, we continue to use an electronic device with a metal frame architecture as an example. As shown in Figure 32, the electronic device may include multiple metal frames, wherein any one or more metal frames can be electrically connected to the metal frame at one end through a structural connection point (such as a metal reinforcing rib) to achieve grounding at that end. In some embodiments, the multiple metal frames may also include metal frames that are not grounded at either end through a structural connection point.

[0412] For example, in this example, the metal frame may include MF1, MF2, MF3 on the top of the electronic device and MF4 partially located on the top of the electronic device. A metal frame included on one side of the electronic device may include a portion of MF4 and MF5. Other metal frames included on the electronic device may include MF6, MF7, and MF8.

[0413] Taking MF1 through MF8, each with one end grounded, as an example. As shown in Figure 32, the ends of MF1 and MF6 that are close together are connected to each other and grounded. The ends of MF2 and MF3 that are close together are connected to each other and grounded. The ends of MF4 and MF5 that are close together are connected to each other and grounded. The ends of MF7 and MF8 that are close together are connected to each other and grounded.

[0414] In this scenario, based on any two or more metal frames from MF1 to MF8, and with targeted configuration based on the above description, the configuration of the first coil and the second coil can be achieved, thereby obtaining the effect of improved NFC performance.

[0415] In this example, the relative positions of any two metal frames from MF1 to MF8 can correspond to positional relationship 1 in Figure 13 or Figure 15. This allows the resonant frequency of the second coil to be adjusted below the operating frequency, enabling the configuration of the coupling coil and improving the performance of the NFC antenna.

[0416] The following example demonstrates how to configure an NFC antenna by reusing all the metal frames from MF1 to MF8.

[0417] In this example, the configuration of the first and second coils (i.e., the main coil and the coupling coil) can be achieved through targeted settings of MF1 to MF8. Multiple coupling coils can be included. This improves the radiation performance of NFC.

[0418] For example, the end of MF1 away from the grounding point can be provided with an electrical connection point EP1; the end of MF2 away from the grounding point can be provided with an electrical connection point EP2; the end of MF3 away from the grounding point can be provided with an electrical connection point EP3; the end of MF4 away from the grounding point can be provided with an electrical connection point EP4; the end of MF5 away from the grounding point can be provided with an electrical connection point EP5; the end of MF6 away from the grounding point can be provided with an electrical connection point EP6; the end of MF7 away from the grounding point can be provided with an electrical connection point EP7; and the end of MF8 away from the grounding point can be provided with an electrical connection point EP8.

[0419] Refer to the explanations of the NFC system in Figures 9 and 10.

[0420] Taking the NFC antenna configuration via a dual-port feeding system as an example, EP1 to EP8 can include any two electrical connection points coupled to the two output ports of the matching circuit, so that the signal output by the NFC chip, after being processed by the matching circuit, is fed into the metal frame in a differential feeding manner to excite the first coil. Correspondingly, for the setting of the second coil, one or more capacitors can be grounded at the electrical connection points of the metal frame. Through the tuning of these capacitors, the resonant frequency of any second coil (i.e., any coupled coil) is made lower than the operating frequency.

[0421] Taking the configuration of an NFC antenna through a single-port feeding system as an example, EP1 to EP8 can include any electrical connection point coupled to an output port of the matching circuit. This allows the signal output from the NFC chip to be processed by the matching circuit and then fed into the metal frame to excite the first coil. The other electrical connection point corresponding to the first coil is grounded. Correspondingly, for the configuration of the second coil, one or more capacitors can be grounded at the electrical connection point of the metal frame. By tuning these capacitors, the resonant frequency of any second coil (i.e., any coupled coil) is made lower than the operating frequency.

[0422] In the example shown in Figure 32, the NFC antenna configuration is implemented using a dual-port feeding system. The two feeding signals that feed the NFC signal can correspond to F1 and F2, respectively.

[0423] In this example, MF1 and MF4 can each form the first coil. For example, the electrical connection point EP1 of MF1 can be coupled to F1. Thus, one end of MF1 is coupled to F1, and the other end is coupled to reference ground. The electrical connection point EP4 of MF4 can be coupled to F2. Thus, one end of MF4 is coupled to F2, and the other end is coupled to reference ground.

[0424] Therefore, after the differential mode feed enters MF1 from F1, it can enter MF4 through the edge of the reference ground, and then return to the matching circuit and NFC chip through the electrical connection point EP4 of MF4, thus forming a complete current loop for the first coil.

[0425] In this example, MF2, MF3, MF5, and MF6 are adjacent to the metal frame of the first coil, and can be used to construct four first-stage coupling coils respectively. MF7 is adjacent to MF6, and MF7 can be used to construct the second-stage coupling coil. MF8 is adjacent to MF7, and MF8 can be used to construct the third-stage coupling coil.

[0426] In this application, each coupling coil can be considered a second coil. The first-stage coupling coil is positioned adjacent to the first coil (e.g., separated by a gap), resulting in the largest induced current and the most significant improvement in NFC performance. Conversely, the second-stage coupling coil, positioned adjacent to the first-stage coupling coil, receives a smaller induced current, also showing a relatively significant improvement in NFC performance. The third-stage coupling coil, positioned adjacent to the second-stage coupling coil, receives a smaller induced current, providing some improvement in NFC performance. In other words, the farther away from the first coil, the weaker the induced current of the coupling coil, and the worse the improvement in NFC performance.

[0427] In this example, because the first coil uses separate MF1 and MF4 configurations, the second-stage coupling coils can be constructed using MF2, MF3, MF5, MF6, etc. Compared to using one or two adjacent metal frames to construct the first coil, this approach allows for more configurations of the second-stage coupling coils, further improving NFC performance.

[0428] For example, a capacitor can be grounded at the electrical connection point EP2 of MF2. This allows MF2 to form a complete current loop with the reference ground. The capacitor also ensures that the resonant frequency of the second coil formed by MF2 and the reference ground is lower than the operating frequency, thus allowing a current in MF2 to flow in the same direction as that in MF1 when the first coil corresponding to MF1 is operating. This improves NFC radiation performance.

[0429] Similar to MF2, capacitors can be grounded at electrical connection points EP3 of MF3, EP5 of MF5, EP6 of MF6, EP7 of MF7, and EP8 of MF8. This allows the resonant frequencies of the second coils formed by MF3 and reference ground, MF4 and reference ground, MF5 and reference ground, MF6 and reference ground, MF7 and reference ground, and MF8 and reference ground to be lower than the operating frequency. Furthermore, the current direction from MF2 to MF8 is the same as the current direction from MF1 to MF4. This significantly improves NFC radiation performance compared to using only MF1 and MF4 to construct the first coil. Moreover, the use of the metal frame on the sides of MF6 and MF5 to construct the second coil also enhances NFC radiation performance in the side direction of the electronic device, increasing the coverage area of ​​NFC communication within the device.

[0430] It is understandable that Figure 32 is merely an example of NFC antenna configuration in a multi-bezel scenario. In other cases, due to other components located on the top of the electronic device (such as a receiver, audio components such as a speaker box, or front / rear cameras), the configuration shown in Figure 32 may not be feasible, or the coupling strength between MF1, MF2, MF3, and MF4 may be weak. In such cases, the construction of the first and second coils can be adjusted to obtain better NFC radiation performance under the current conditions.

[0431] For example, referring to Figure 33, another schematic diagram of an NFC antenna configuration is shown. In this example, an electronic device with a metal frame as shown in Figure 32 is used.

[0432] Unlike the example in Figure 32, in the implementation shown in Figure 33, the first coil can be constructed using MF2 and MF3. For example, the electrical connection point EP2 of MF2 and the electrical connection point EP3 of MF3 can be coupled to the two output ports of the matching circuit respectively to implement a two-port power supply system. This achieves the configuration of the first coil.

[0433] Correspondingly, MF1 and MF4 can be used to construct the first-stage coupling coil, and the corresponding electrical connection points EP1 and EP4 can be grounded through capacitors. MF6 and MF5 can be used to construct the second-stage coupling coil, and the corresponding electrical connection points EP6 and EP5 can be grounded through capacitors. MF7, adjacent to MF6, is used to construct the third-stage coupling coil, and MF8 is used to construct the fourth-stage coupling coil. The corresponding electrical connection points EP7 and EP8 are grounded through capacitors. Thus, by tuning the capacitors on each coupling coil, the resonant frequency of each coupling coil is made lower than the operating frequency, thereby exciting an induced current in each coupling coil in the same direction as that in the first coil, improving NFC performance.

[0434] Figures 32 and 33 above provide two examples of NFC antenna configurations based on dual-port feeding. It is understood that when the first coil is configured with single-port feeding, either feed point F1 or F2 can be replaced with a ground setting, thereby energizing the first coil.

[0435] In some other embodiments of this application, unlike the technical implementation shown in FIG32 or FIG33 where both the first coil and the second coil are completely reused by a metal frame, the first coil and / or the second coil can also be configured as a semi-common structure, using a metal frame and other metal components to achieve a complete current loop.

[0436] For example, the first coil is configured in a semi-integrated manner, while the second coil is configured in a completely integrated manner with the metal frame.

[0437] Referring to Figure 34, two possible logic examples of NFC antennas are provided. In each scheme shown in Figure 34, the first coil is constructed using MF1 and MF4, similar to the method shown in Figure 32.

[0438] As shown in 3401 of Figure 34, the first coil may include MF1, MF4, and an FPC trace coupled to MF1. The FPC trace may be L-shaped, with one end coupled to the electrical connection point EP1 of MF1 and the other end coupled to the feed source F1 corresponding to the NFC signal. Correspondingly, the electrical connection point EP4 of MF4 is coupled to another feed source F2 corresponding to the NFC signal. In this example, if MF1 and MF4 are also multiplexed by other communication systems (such as cellular communication systems), an isolation network M3 may be provided between feed source F1 and MF1, and an isolation network M4 may be provided between feed source F1 and MF4. The specific configuration of isolation networks M3 and M4 can be flexibly set according to the design of the other multiplexed communication systems. Refer to Figures 28-32 for details.

[0439] In some implementations, the isolation network M3 between feed F1 and MF1 can be set between the FPC trace and the electrical connection point EP1, as shown in 3401. In other implementations, the isolation network M3 can be set in other locations, such as in series on the FPC trace, or between the FPC trace and feed F1.

[0440] In the implementation shown in 3401, the first coil is configured using a metal frame and an FPC. The configuration of the second coil can be referenced from the implementation in Figure 32 above, thereby improving the NFC radiation performance.

[0441] Figure 34, 3402, provides another implementation. In this implementation, the FPC trace can be positioned between MF4 and the feed source F2. For example, in the example of 3402, one end of the FPC trace is coupled to the electrical connection point EP4 of MF4, and the other end of the FPC trace is coupled to the feed source F2 corresponding to the NFC signal. Similar to 3401, if MF1 and MF4 are also multiplexed by other communication systems (such as cellular communication systems), an isolation network M5 can be provided between MF1 and the feed source F1, and an isolation network M6 can be provided between MF4 and the feed source F2. The isolation network configuration in this example is consistent with the configuration shown in 3401 and will not be described further.

[0442] Understandably, as shown in Figure 34, in both implementations, adding FPC traces to the first coil extends the effective magnetic flux region of the NFC antenna towards the center of the electronic device. For example, in the implementation shown in Figure 32, the effective magnetic flux regions of the first and second coils can include the gaps formed between the various metal frames and the reference ground. In the implementation shown in Figure 34, the effective magnetic flux region of the first coil extends to MF1, MF4, and the area between the FPC traces via FPC traces. This further increases the coverage area of ​​the NFC antenna, thereby improving NFC radiation performance.

[0443] In addition, based on the scheme shown in Figure 33, the construction of the first coil and / or the second coil can also be achieved by using FPC traces. Continuing with the example of constructing the first coil using a metal frame and FPC traces.

[0444] Referring to Figure 35, as shown in 3501, in this example, the metal frame for the first coil multiplexing may include MF2 and MF3. In this example, MF2 and MF3 can also be multiplexed by other wireless communication systems for signal transmission and reception. Thus, in the example of 3501, the electrical connection point EP2 of MF2 can be coupled to one end of the FPC trace through the isolation network M7, and the other end of the FPC trace can be coupled to the feed source F1. The electrical connection point EP3 of MF3 can be coupled to the feed source F2 through the isolation network M8.

[0445] In this way, when the first coil is working, the NFC signal can flow back from feed source F1 through FPC traces, MF2 and MF3 to feed source F2, thus realizing a complete current loop.

[0446] In this example of 3501, similar to the implementation in Figure 33, the second coil can be constructed using MF1, MF4, MF6, MF7, MF8, and MF5 to achieve the effect of a multi-stage coupled coil.

[0447] In this way, by configuring FPC traces in the first coil, the NFC signal coverage area of ​​the first coil can be extended towards the center of the electronic device. By configuring multiple stages of second coils, the magnetic field strength of NFC at the top of the electronic device can be increased, as well as the signal coverage capability of NFC on the sides of the electronic device, thereby improving the performance of the NFC antenna.

[0448] In Figure 35, 3502, another example of the construction of the first coil is provided. In this example, the FPC trace can be positioned between the electrical connection point EP3 of the feed F2 and MF3.

[0449] In this example, the electrical connection point EP2 of MF2 can be coupled to the feed F1 via the isolation network M9. The electrical connection point EP3 of MF3 can be coupled to one end of the FPC trace via the isolation network M10, and the other end of the FPC trace can be coupled to the feed F2. The construction and setup of the second coil are similar to those of 3501.

[0450] In this way, when constructing the first coil through MF2, MF3 and FPC, the configuration of FPC traces in 3501 or 3502 can be flexibly selected according to the actual height requirements of each position in the electronic device.

[0451] Understandably, for the same reason, the NFC antenna solution shown in 3502 can also achieve similar technical effects as 3501. Further details will not be elaborated here.

[0452] In other embodiments, the semi-common multiplexing construction of the first coil shown in Figure 34 or Figure 35 can also be applied to the construction of any second coil, and will not be described in detail here.

[0453] It should be noted that the FPC traces designed in the above embodiments are all illustrated using an L-shaped trace as an example. This does not constitute a limitation on the construction of the first coil and / or the second coil. In other embodiments, the FPC traces can also be replaced with other metal materials. In other embodiments, the structural shape of the FPC traces can also be different from the L-shape, such as U-shape, straight line, or square shape.

[0454] Based on the aforementioned correspondence between positional relationships and resonant frequencies, in the examples provided in Figures 32-35, since each coil corresponds to positional relationship 1, the magnetic field directions are opposite. Therefore, by setting capacitors on each second coil, the resonant frequency can be adjusted to a low-frequency position of the operating frequency, thereby exciting a current in the same direction on each second coil. The capacitors of each second coil can be set between the electrical connection point and the reference ground. In other embodiments, the specific location for setting the capacitors can also include other electrical components, such as inductors and resistors. Each electrical component can be equivalent to a capacitor in the NFC operating frequency band.

[0455] In the following explanation, we take setting a capacitor to adjust the resonant frequency so that the excitation current on the second coil is in the same direction as that on the first coil as an example.

[0456] In the examples shown in Figures 32-35 above, the first coil is fed with NFC signals via dual-port power supply. Specific examples of feeding the first coil via single-port power supply are also provided below.

[0457] It is understandable that, in conjunction with the foregoing descriptions of single-port and dual-port power supply systems, in the specific implementation process, based on a dual-port power supply system, the electrical connection relationship of one of the electrical connection points coupled to the two feed sources can be replaced by grounding instead of coupling to the feed source.

[0458] In the single-port feeding implementation provided in this application, the frame structure shown in Figure 36 is taken as an example. It is understood that in other embodiments, in the NFC antenna design with this port feeding, the fully reused metal frame setting in the following example can also be replaced with other implementations (such as FPC, semi-coherent, etc.).

[0459] The metal frame shown in Figure 36 is just an example. In other implementations, the shape of the first coil and / or the second coil in the NFC antenna can also be different, such as a straight line, a U-shape, etc.

[0460] As shown in Figure 36, in this example, the metal frame of the electronic device may include MF9 to MF12. MF9 is left floating at both ends. MF10 is left floating at one end and grounded at the other. MF11 is left floating at one end and grounded at the other. MF10 and MF11 may be grounded together at their closest points. MF12 is left floating at the end closest to MF11, and the other end of MF12 is grounded.

[0461] Similar to the aforementioned dual-port power supply system, in this example, for any metal frame, its ungrounded end can be provided with an electrical connection point.

[0462] For example, electrical connection points EP91 and EP92 can be respectively set at the two ends of MF9. Electrical connection point EP10 can be set at the ungrounded end of MF10. Electrical connection point EP11 can be set at the ungrounded end of MF11. Electrical connection point EP12 can be set at the ungrounded end of MF12.

[0463] For the aforementioned multiple electrical connection points, at least one electrical connection point may be coupled to a single-port fed source. For example, consider configuring the first coil by multiplexing MF9.

[0464] The EP91 can be configured as an NFC feed source. Referring to the configuration example of the single-port feed system in Figure 9, in this example, the EP91 can be configured to be coupled to an NFC feed source by being coupled to the end of the matching circuit that outputs the NFC signal. It can be understood that when the EP91 is configured to be coupled to an NFC feed source, the EP91 can also serve as the feed point for the first coil.

[0465] Correspondingly, EP92 can be grounded. This allows the NFC signal to flow from EP91 into MF9, out of EP92 into MF2, and back to ground. This forms a complete current loop for NFC signal radiation.

[0466] Correspondingly, other metal frames can be configured as coupling coils. For example, MF10, adjacent to MF9, can be configured as a first-stage coupling coil. MF11, not adjacent to MF9 but adjacent to MF10, can be configured as a second-stage coupling coil. MF12, not adjacent to either MF9 or MF10 but adjacent to MF11, can be configured as a third-stage coupling coil.

[0467] In this case, the positional relationship between each logic coil in MF10 to MF12 and the first coil corresponding to MF9 is positional relationship 1. In this way, by adjusting the resonant frequency of each logic coil in MF10 to MF12 to be lower than the operating frequency, the current on the coupling coil is excited in the same direction as the main coil, thereby improving the NFC performance.

[0468] For example, each of EP10 on MF10, EP11 on MF11, and EP12 on MF12 can be configured to be grounded via a capacitor. The capacitance value can be used to adjust the resonant frequency of each logic coil. Furthermore, when multiplexing other communication systems is included in the coupling coil and / or main coil, an isolation network can be configured on the path, as described in the foregoing examples, to achieve isolated multiplexing of the same radiator for different antenna systems. Further details will not be elaborated further.

[0469] In other embodiments of this application, the radiator of the NFC antenna in this single-port feeding scheme can also be implemented in a semi-coherent manner. For example, the radiator of the main coil reuses MF9, and additional FPC traces are used.

[0470] Referring to Figure 37, two specific examples are provided. In this implementation as shown in Figure 37, the configuration of the coupling coils can be referred to the relevant description in Figure 36 above.

[0471] In Figure 37, 3701, EP92 of MF9 can be coupled to the NFC feed source, and EP91 of MF9 can be coupled to the FPC trace. The other end of the FPC trace can be grounded. Thus, the area enclosed by the FPC trace and MF9 corresponds to the effective magnetic flux area of ​​the main coil. It can be understood that by setting up the FPC trace, the effective magnetic flux area of ​​the main coil can be effectively increased, improving NFC radiation performance and also effectively increasing the NFC coverage area.

[0472] In the example shown in Figure 37, the MF9, which is multiplexed with the main coil, can also be used as a radiator for other systems. Thus, an isolation network M5 can be configured between the FPC and the MF9 to isolate the NFC signal from signals from other systems. Specific configurations can be found in the examples in Figures 28 to 31.

[0473] Figure 37, 3702, provides another example of a main coil configuration in an NFC antenna. In this configuration, the NFC signal can be fed into the MF9 via an FPC. For example, one end of the FPC can be coupled to the NFC feed signal, and the other end of the FPC can be coupled to the EP91 of the MF9 via an isolation network M5, with the EP92 of the MF9 grounded.

[0474] It is understandable that both solutions provided in Figure 37 can achieve the goal of improving NFC performance. Specifically, the NFC feed needs to be coupled to the metal frame as shown in 3701, or to the FPC as shown in 3702. This can be flexibly configured according to the actual situation (such as space on the PCB board) to achieve the configuration of the main coil.

[0475] The above examples illustrate the implementation and configuration of positional relationship 1 in the aforementioned examples on electronic devices.

[0476] Figure 38 provides an example of constructing an NFC antenna in another scenario. In this example, the electronic device is a foldable device. The foldable device can include a side A and a side B, which are connected by a hinge. In the unfolded state, side A and side B are adjacent and in the same plane; in the closed state, side A and side B are interlocked.

[0477] Taking the metal frame structure on both sides A and B as an example, which is similar to the structure in Figure 37.

[0478] As shown in Figure 38, in the unfolded state, on surface A, the metal frame extending from away from the rotation axis to near the rotation axis can include: MF13a, MF14a, MF15a, MF16a, etc. MF13a can be L-shaped, with one end of the L-shape positioned on the side of the electronic device and the other end positioned on the top edge. The metal frame adjacent to the top edge end of MF13a can be MF14a. MF14a and MF13a are separated by a gap. The end of MF14a away from MF13a is grounded. The ends of MF14a and MF15a close to each other are grounded together. The end of MF15a away from MF14a is separated from MF16a by a gap. The end of MF16a away from MF15a is grounded.

[0479] Correspondingly, on surface B, the metal borders extending from away from the rotation axis to closer to the rotation axis can include: MF13b, MF14b, MF15b, MF16b, etc. Taking the symmetrical relationship between the positions of each metal border on surface B with respect to the rotation axis as an example, with respect to the positional relationship of each metal border on surface A.

[0480] Taking the main coil configured with a single-port feed on surface A as an example, this main coil can be constructed using a metal frame MF13a to form a logic coil. For instance, one end of MF13a on the side can be coupled to an NFC feed source to receive the NFC feed signal F1. The other end of MF13a is grounded. Therefore, the L-shaped gap formed by MF13a and the reference ground corresponds to the effective magnetic flux region of the main coil.

[0481] Based on the implementations in the aforementioned examples, in some implementations, multi-stage coupled coils can be constructed using MF14a, MF15a, and MF16a. For example, an electrical connection point can be set at the ungrounded end of MF14a, MF15a, and MF16a, and grounded through a capacitor, so that the resonant frequency of each coupled coil is lower than the operating frequency.

[0482] Therefore, in the unfolded state, the performance of NFC can be improved by setting up various metal frames on the A-side.

[0483] In the closed state, the metal frame on surface B is close to the metal frame on surface A. In this way, the metal frame on surface B can be used to construct logic coils that partially or completely overlap with the main coil and / or coupling coil on surface A.

[0484] In some embodiments, in the closed state, the projections of the main coil formed by MF13b and MF13a on plane A or plane B coincide. This corresponds to the aforementioned positional relationship 2. Thus, MF13b can be configured with its two ends grounded via capacitors, making the resonant frequency of the logic coil formed between MF13b and the reference ground higher than the operating frequency. This allows a current in the same direction as the main coil to be energized on MF13b in the closed state, improving NFC performance.

[0485] In other embodiments, in the closed state, the projections of the main coil formed by MF14b and MF14a on plane A or plane B coincide. This corresponds to the aforementioned positional relationship 2. Thus, MF14b can be configured with its two ends grounded via capacitors, causing the resonant frequency of the logic coil formed between MF14b and the reference ground to be higher than the operating frequency or higher than the resonant frequency of the corresponding logic coil of MF14a. This allows, in the closed state, a current in the same direction as MF14a to be excited on MF14b, serving as the next-stage coupling coil (e.g., the second-stage coupling coil) of the coupling coil (e.g., the first-stage coupling coil) corresponding to MF14a, thereby improving NFC radiation performance.

[0486] The configuration of other metal frames on the B side can be referenced in the above example and will not be repeated here.

[0487] It is understood that the examples shown in Figure 38 all exemplify the configuration of the main coil and coupling coil using a fully reused metal frame. In other implementations, the main coil and / or coupling coil may also be configured using a semi-combined configuration, reuse of other metal materials, etc. This application does not impose any limitations on this.

[0488] Furthermore, in the example shown in Figure 38, the metal borders on surfaces A and B are symmetrically arranged with respect to the rotation axis, so the projections of the corresponding logic coils in the closed state can completely overlap. In other implementations, the length, number, and slot type of the metal borders on surfaces A and B can also be different. In this case, the projections of the logic coils on the two surfaces can partially overlap in the closed state. The configuration of the coupling coils in this case can be referred to the illustration in Figure 16, and will not be specifically illustrated here.

[0489] In other embodiments, the capacitors used to adjust the resonant frequency of the coupling coil in the various embodiments described above can also be replaced with other circuit components that are equivalent to inductors at the NFC operating frequency.

[0490] The solutions provided in Figures 32-38 above illustrate various positional relationships where the planes containing the main coil and the coupling coil coincide or are parallel. The following examples, using specific cases, illustrate the configuration of the NFC antenna in positional relationships where the planes containing the main coil and the coupling coil are perpendicular or partially perpendicular.

[0491] The NFC antenna may include at least two coils, such as coil S1 and coil S2. Of these at least two coils, two may be located in planes that are not parallel or overlap.

[0492] For example, the planes containing coil S1 and coil S2 intersect. Alternatively, the plane containing coil S1 can be perpendicular to the plane containing coil S2. It should be noted that in some implementations, the traces of coil S1 or coil S2 can be distributed in three-dimensional space. For example, coil S1 may include a portion within the xoy plane, with a z-axis coordinate of z1. Coil S1 may also include another portion distributed within the xoy plane, with a z-axis coordinate of z2. z1 and z2 are different. The traces in these planes with different z-axis coordinates are coupled via communication connections.

[0493] In different implementations, coil S1 can be the main coil, and coil S2 can be the coupling coil. Alternatively, coil S1 can be the coupling coil, and coil S2 can be the main coil.

[0494] As shown in the example in Figure 20 above, in some embodiments, logic coils perpendicular to the xoy plane can be constructed by reusing metal components in different planes. For example, logic coils can be constructed using the metal Deco on the back cover and the steel sheet / FPC / PDS / LDS traces embedded under the Deco. Alternatively, logic coils can be constructed by drilling holes inside existing metal materials including xoz or yoz planes.

[0495] In a practical implementation, the corresponding part or all of the traces in the logic coil formed by the xoz or yoz plane or its projection within the two planes can be configured on areas such as the battery cover, protective shell, and motherboard bracket.

[0496] It should be noted that in the implementation of the scheme corresponding to positional relationship 5, the planes where the coupling coil and the main coil are located are not limited to being perpendicular to each other. A complete current loop formed between the coupling coil and the main coil, including when the planes where some traces are located are perpendicular to each other, or when the projections of some traces onto mutually perpendicular planes form a complete current loop, can extend the NFC radiation direction of the main coil and improve radiation performance.

[0497] Furthermore, in some cases, the NFC antenna traces are separated and their planes are not perpendicular to each other. However, the magnetic materials (such as nanocrystals) used under the NFC antennas are interconnected, which can also enable the magnetic field of the main coil to couple with the coupling coil, forming a form similar to position relationship 5, thereby improving NFC performance.

[0498] Referring to Figure 39, a schematic diagram of an NFC antenna configuration is shown. In this example, coil S1 is used as the coupling coil, and coil S2 is used as the main coil.

[0499] In some embodiments, the coil S2 can be implemented using FPC traces mounted on the back cover. The number of feed points on the coil S2 can be configured as needed using a single-port or dual-port feed system, as described above.

[0500] In this embodiment, coil S1 can be constructed in the z-direction via metal deco and PCB, and the main coil is set in the xoy plane via FPC traces.

[0501] In this embodiment, the electronic device also includes a WPC coil. Thus, through the overlapping relationship between the metal traces, projected traces, and / or magnetic materials between the WPC coil and / or the coupling coil and the main coil, current can be excited on the coupling coil, enhancing the NFC radiation capability along the z-axis perpendicular to the xoy plane where the main coil is located.

[0502] As shown in 391 of Figure 39, in some implementations, the metal deco is rectangular. Referring to the example in Figure 20, taking the case where both the metal deco and the main coil are located in the xoy plane, the z-axis coordinate of the metal deco in the xoy plane can be z1. The z-axis coordinate of the metal material used to construct the coupling coil, such as the PCB, in the xoy plane can be z2. z1 and z2 are different.

[0503] In this example, one or more electrical connection points can be provided on the coil S1. Taking the coil S1 multiplexed with a metal deco as an example, these one or more electrical connection points can be provided on the metal deco.

[0504] Thus, the metal Deco can be coupled to the traces on the PCB through one or more electrical connection points, thereby realizing the construction of logic coils with projected coils in the xoz plane or yoz plane or into these two planes.

[0505] Taking a coil S1 with two electrical connection points as an example.

[0506] As shown in Figure 40, in some embodiments, such as Form 1, the two electrical connection points can be connected by capacitor C4.

[0507] In other embodiments, as shown in Form 2 of FIG40, the two electrical connection points can be grounded separately via capacitors. For example, they can be grounded via capacitor C5 and capacitor C6 respectively.

[0508] In the various forms shown in Figure 40 above, the capacitor can be used to tune the resonant frequency of the coupling coil to be higher than, lower than, or close to the operating frequency.

[0509] In this way, by adjusting the resonant frequency of the coupling coil to near the NFC operating frequency, the energy on the main coil can be coupled to configure the logic coil in the xoz or yoz plane, thereby improving the radiation capability in the x-axis or y-axis.

[0510] In some implementations, the greater the distance between the two electrical connection points on the coupling coil, the larger the projection area of ​​the coupling coil in the xoz or yoz plane, and the more significant the improvement in NFC radiation performance in the x-axis or y-axis.

[0511] In specific implementations, the location of the electrical connection point can be flexibly set according to the actual situation. In this embodiment, the location of the electrical connection point on the coil S1 is not limited.

[0512] Furthermore, when two or more electrical connection points are configured on coil S1, these two or more electrical connection points can be positioned as far away from coil S2 as possible, thereby reducing the impact of coil S1 on the radiation of coil S2 when it is reused for other wireless communications.

[0513] It should be noted that in different implementations, the shape, position, and implementation form of coil S1 and / or coil S2 may differ from the example in 391.

[0514] As shown in Figure 392, coil S1 can be circular. The configuration of the two electrical connection points on the coupling coil can be referred to the illustration in Figure 40.

[0515] As shown in 393, coil S1 can be circular. The configuration of the two electrical connection points on the coupling coil can be referred to the illustration in Figure 40. In this example of 393, the main coil (coil S2) and the coupling coil can also overlap at least partially with the WPC coil, thereby achieving a multi-level coupling coil configuration via the WPC coil. It is understood that when performing this multi-level coil configuration, the resonant frequency of the coupling coil can be flexibly adjusted according to the positional relationship between the logic coil formed by the specific electrical connections and the main coil, thereby improving NFC radiation performance.

[0516] In some other embodiments of this application, the main coil (such as coil S2) can also be implemented in a semi-common form. In this semi-common implementation, some traces of coil S2 can reuse the metal frame, and coil S2 may also include some traces implemented through FPC traces, etc. Communication connections are established between different parts.

[0517] Therefore, NFC signal radiation through a metal frame can effectively utilize the good radiation space at the top of the electronic device to obtain better radiation performance.

[0518] For example, referring to Figure 41, three NFC antenna schemes for configuring coil S2 using a semi-common approach are provided. The implementation of coil S1 and the setting of the electrical connection points can be referred to the example in Figure 39, and will not be repeated here.

[0519] As shown in 411 of 41, coil S2 may include a portion of the traces multiplexed by the top metal frame, and may also include a portion of the traces implemented via FPC traces. The two ends of the FPC traces are electrically connected to the two ends of the metal frame, respectively. In some implementations, the projections of the FPC traces and the WPC coil in the xoy plane may at least partially overlap. Thus, the WPC coil can also be configured as a coupled coil of coil S2 by capacitor tuning similar to that of the aforementioned coupled coil.

[0520] As shown in 412 of Figure 41, in some embodiments, the projections of coil S2 and WPC coil in the xoy plane may not coincide.

[0521] As shown in 413 of Figure 43, in some embodiments, both coil S1 and coil S2 may include partial traces that at least partially overlap with the projection of the WPC coil in the xoy plane.

[0522] It should be noted that in this example, coil S2 is configured as the main coil. Thus, at least one feed point can be provided on coil S2. In some implementations, coil S2 can be coupled to a matching circuit through the feed point, thereby enabling communication with the NFC chip. In this way, coil S2, the matching circuit, and the NFC chip can constitute a complete NFC signal loop.

[0523] Taking the example in 411 as an example, when setting coil S2 using a multiplexed metal frame, the FPC trace can be set to be non-closed. The openings (i.e., both ends) of the FPC trace are electrically connected to the metal frame respectively.

[0524] In some other embodiments of this application, the coupling coil can be configured using a metal frame. This allows for the radiation of the coupling coil through the metal frame, thus achieving the goal of improving NFC performance.

[0525] For example, referring to Figure 42, several NFC antenna schemes provided in embodiments of this application are illustrated. In this example, the configuration of coil S2 as the main coil can be referred to the description in Figure 39. Coil S1 can be configured as a coupling coil.

[0526] As shown in 421 of Figure 42, coil S1 can be configured as shown in 391 of Figure 39. Furthermore, coil S1 may also include a metal frame portion. For example, coil S1 can be coupled to the metal frame via two communication connection lines. Thus, coil S1 can include a closed current loop 1 formed by the metal deco and PCB traces. Coil S1 may also include a metal frame and a closed current loop 2 formed by the metal portion on the metal deco and between the two communication connection lines on the metal frame. Therefore, the closed current loop 2 formed by the metal deco and PCB traces can be used to provide NFC signal radiation capability in the x-axis or y-axis. The current loop 1 including the metal frame can serve as the coupling coil for current loop 2, further improving NFC radiation performance.

[0527] As shown in Figure 422, a specific implementation is provided where coil S1 is circular and configured with a multiplexed metal frame. Figure 423 in Figure 42 provides a configuration where coil S1 is circular, and both coil S1 and coil S2 have partial projections overlapping with the WPC coil. Specific implementations can be found in the aforementioned implementations and will not be repeated here.

[0528] It is understood that, in the examples shown in Figures 41 and 42, the reused metal border may include a top border. In other embodiments, the reused metal border may include a side border. This application does not limit this.

[0529] In the above implementation, coil S1 is used as the coupling coil and coil S2 is used as the main coil for illustration. In other embodiments, coil S1 can also be configured as the main coil and coil S2 can be configured as the coupling coil.

[0530] Referring to Figure 43, several NFC antenna schemes provided in embodiments of this application are illustrated. In this example, coil S1 can function as the main coil, and coil S2 can function as the coupling coil.

[0531] In conjunction with the foregoing description, in some embodiments, coil S1 can be constructed using logic coils within the xoz or yoz plane formed by the metal deco and traces on the PCB. Thus, in the following implementation, in addition to the two electrical connection points coupled between the metal deco and the PCB, coil S1 can also have at least one feed point (not shown in Figure 43) for feeding in NFC signals via single-port or dual-port power.

[0532] As shown in 431 of Figure 43, the projection of coil S1 in the xoy plane may intersect with or at least partially overlap with the WPC coil, and coil S2 may also include a projection that overlaps with the WPC coil.

[0533] Similar to the description of the aforementioned scheme where coil S1 is the coupling coil, in this example, where coil S2 is the coupling coil, in some embodiments, coil S2 may have one or more electrical connection points. Taking two electrical connection points on coil S2 as an example, the configuration of these two connection points can be referred to the description in Figure 40. Thus, by adjusting the capacitor, the frequency relationship between the resonant frequency and the operating frequency of coil S2 in the frequency domain can be adjusted.

[0534] In this embodiment, a coil placement point may be provided on the coil S1. This coil placement point may be located on the side of the coil S1 near the coil S2.

[0535] In some implementations, the coil configuration point can be configured to be open. Thus, coil S1 is configured as a non-closed coil. Consequently, when coil S1 is operating, the magnetic field can be radiated more efficiently to the effective magnetic flux region of coil S2 through the opening of the coil configuration point, thereby improving the effectiveness of the coupling coil setup and further optimizing NFC performance.

[0536] In other implementations, similar to the one described above, the coil configuration point can also be configured as directly connected / conductive.

[0537] As shown in 432 of Figure 43, the coil S1 can also be circular and positioned in the middle of the upper half of the electronic device. At least one electrical connection point can be provided on the coil S1. For example, one or two feed points can be provided on the coil S1. Alternatively, one or more grounding points or electrical connection points coupled to ground via capacitors can be provided on the coil S1.

[0538] In this example 432, the projection of coil S2 in the xoy plane may not coincide with that of the WPC coil. In some implementations, the WPC coil may be configured as the first-stage coupling coil of coil S1, thereby enhancing the radiation capability along the z-axis. Specific configuration methods can be found in the foregoing description.

[0539] As shown in 433 of Figure 43, coil S1 can also be positioned in the middle of the electronic device. After projection onto the xoy plane, coil S1 can intersect with or at least partially overlap with the WPC coil, and coil S2 can also intersect with or at least partially overlap with the WPC coil.

[0540] Referring to Figure 44, a semi-common implementation scheme for coil S2 is provided. The implementations of the various schemes provided in Figure 44 can be referred to the positional descriptions in Figure 43.

[0541] For example, as shown at 441 in Figure 44, coil S1 operates as the main coil. The position and electrical connection settings of coil S1 can be referenced at 431 in Figure 43. In this example, coil S2 can be constructed as a corresponding logic coil by coupling it to the top metal frame via FPC traces. The FPC traces of coil S2 projected onto the xoy plane can intersect with the WPC coil projected onto the same plane.

[0542] As shown in 442 of Figure 44, the position and electrical connection settings of coil S1 can be referenced in 432 of Figure 43. In this example, coil S2 can be constructed as a corresponding logic coil by coupling it to the top metal frame via FPC traces. The FPC traces of coil S2 projected onto the xoy plane can be identical to the WPC coils projected onto the same plane without intersecting.

[0543] As shown in 443 of Figure 44, the position and electrical connection settings of coil S1 can be referenced in 433 of Figure 43. In this example, coil S2 can be constructed as a corresponding logic coil by coupling it to the top metal frame via FPC traces. The FPC traces of coil S2 projected onto the xoy plane can intersect with the WPC coil projected onto the same plane. In this example, by reusing the metal frame for coil S2, the effective magnetic flux area of ​​the coupled coil can be significantly expanded. For example, the effective magnetic flux area of ​​coil S2 can include the effective magnetic flux area of ​​coil S1. In this way, while improving the top NFC radiation capability, the contribution of the coupled coil to NFC radiation can be further increased.

[0544] Referring to Figure 45, a semi-common implementation scheme for coil S1 is provided. The implementations of the various schemes provided in Figure 45 can be referred to the position descriptions in Figures 43 and 44, respectively.

[0545] As shown at 451 in Figure 45, coil S1 may include the z-axis portion formed by the aforementioned metal deco and PCB. Furthermore, both ends of the metal frame can be coupled to two electrical connection points of the metal deco via communication connection lines. Thus, coil S1 can extend onto the metal frame for radiation.

[0546] That is, in this example, the metal deco corresponding to coil S1 may include one or two feed points. The metal deco may also include a coil configuration point. This coil configuration point can be set to be disconnected or connected. The metal deco may also have at least two electrical connection points. These may include connection points that are electrically connected to the metal frame respectively.

[0547] As shown in 452 of Figure 45, coil S1 may include a circular metal deco. The metal deco can be electrically connected to the PCB traces below (z-axis) through two electrical connection points to form a logic coil along the z-axis. The metal deco can also be coupled to the metal frame through two electrical connection points, so that when coil S1 is working, the NFC feed signal can also be transmitted to the metal frame for radiation.

[0548] The electrical connection configuration of coil S1 in 453 of Figure 45 is similar to that in 451 and 452 above.

[0549] It should be noted that, in the various examples shown in Figure 45, the positions of coil S1 and coil S2 can be referred to the descriptions in Figures 39 to 44 above, and will not be repeated here.

[0550] Thus, the scheme example shown in Figure 45 provides a solution for configuring the main coil using a metal Deco.

[0551] It is understandable that the solutions provided in Figures 39 to 45 can correspond to various specific implementations of the aforementioned positional relationship 5, all of which can extend the communication capabilities of the NFC antenna in different directions.

[0552] Furthermore, in the above embodiments, the example given is that coil S1 is constructed as a logic coil via a metal deco and PCB traces. It is understood that in other embodiments, coil S1 can also be constructed as a logic coil in the xoz or yoz plane using other methods. The specific configuration of the coils can be referenced interchangeably during implementation and will not be elaborated further.

[0553] It should be noted that the electronic device 100 in this application embodiment may include at least one of the following: mobile phone, foldable electronic device, tablet computer, desktop computer, laptop computer, handheld computer, laptop, ultra-mobile personal computer (UMPC), netbook, cellular phone, personal digital assistant (PDA), augmented reality (AR) device, virtual reality (VR) device, artificial intelligence (AI) device, wearable device, in-vehicle device, smart home device, or smart city device. This application embodiment does not impose any special limitations on the specific type of the electronic device 100.

[0554] The NFC antenna solution provided in this application embodiment can be applied to electronic devices. Taking an electronic device as a terminal device as an example, this NFC antenna can also be called a terminal antenna in the terminal device. The terminal antenna may include at least one main coil (such as the first coil described above) and at least one coupling coil (such as the second coil). The first coil includes one or two feed points for implementing single-port feeding or dual-port feeding configuration. The second coil includes one or more capacitor components. The capacitor component can be a lumped capacitor and / or a distributed capacitor, or the capacitor component may include multiple capacitor / inductor devices, which can be equivalent to a capacitor in the NFC frequency band (such as 13.65MHz). The capacitor component can be used to adjust the relationship between the resonant frequency and the operating frequency (such as 13.56MHz) of the coupling coil. This makes the relationship between the resonant frequency and the operating frequency correspond to the positional relationship between the first coil and the second coil. As shown in Table 2 above, the positional relationship between the first coil and the second coil has a definite correspondence with the net magnetic flux direction of the effective magnetic flux region of the first coil and the second coil. Therefore, from another perspective, by tuning the capacitor assembly on the coupling coil, the relationship between the resonant frequency and the operating frequency can be made to correspond to the relationship between the net magnetic flux directions of the first and second coils. Specific details are as described in Table 2 above and in the descriptions of the various embodiments, and will not be repeated here.

[0555] It should be understood that although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Obviously, those skilled in the art can make various alterations and modifications to this application without departing from the scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and modifications.

Claims

1. A terminal antenna, characterized in that, The terminal antenna is applied to an electronic device, and the terminal antenna includes at least a first coil and a second coil; The first coil includes at least one feed point, which is used to access the near-field communication (NFC) feed signal; The second coil includes at least one tuning device, which is used to adjust the resonant frequency corresponding to the second coil; The current flow direction in the first coil includes a first direction, and the current flow direction in the second coil includes a second direction, wherein both the first direction and the second direction are either clockwise or counterclockwise; or... The first direction and the second direction are opposite, and the planes containing the first coil and the second coil intersect.

2. The terminal antenna according to claim 1, characterized in that, The relationship between the resonant frequency of the second coil and the operating frequency of the first coil corresponds to the positional relationship between the first coil and the second coil.

3. The terminal antenna according to claim 1 or 2, characterized in that, The positional relationship between the first coil and the second coil is the first positional relationship; The at least one tuning device is used to adjust the resonant frequency to be lower than the operating frequency.

4. The terminal antenna according to claim 3, characterized in that, The first positional relationship includes at least one of the following: The planes containing the first coil and the second coil do not intersect; and the projections of the first coil and the second coil in the first plane do not coincide. The planes containing the first coil and the second coil do not intersect; and the projections of the first coil and the second coil in the first plane include an overlapping first region, the area of ​​the first region is smaller than the area of ​​the second region, and the second region is the portion of the projection area of ​​the second coil in the first plane that is different from the first region. The planes containing the first coil and the second coil intersect; The first plane is the plane where the first coil or the second coil is located.

5. The terminal antenna according to claim 3 or 4, characterized in that, When the positional relationship between the first coil and the second coil is the same as the first positional relationship, the net magnetic flux direction of the area surrounded by the first coil is opposite to the net magnetic flux direction of the area surrounded by the second coil.

6. The terminal antenna according to claim 1 or 2, characterized in that, The positional relationship between the first coil and the second coil is the second positional relationship; The at least one tuning device is used to adjust the resonant frequency to be higher than the operating frequency.

7. The terminal antenna according to claim 6, characterized in that, The second positional relationship includes at least one of the following: The planes containing the first coil and the second coil do not intersect; and the projection of the first coil in the first plane covers the projection of the second coil in the first plane. The planes containing the first coil and the second coil do not intersect; Furthermore, the projection of the second coil in the first plane covers the projection of the first coil in the first plane; The planes containing the first coil and the second coil do not intersect; and the projections of the first coil and the second coil in the first plane include an overlapping third region, the area of ​​which is larger than that of a fourth region, which is a region of the projection area of ​​the second coil in the first plane that is different from the third region. The planes containing the first coil and the second coil intersect; The first plane is the plane where the first coil or the second coil is located.

8. The terminal antenna according to claim 6 or 7, characterized in that, When the positional relationship between the first coil and the second coil is the same as the second positional relationship, the net magnetic flux direction of the region surrounded by the first coil is the same as the net magnetic flux direction of the region surrounded by the second coil.

9. The terminal antenna according to any one of claims 1-8, characterized in that, The second coil includes a first electrical connection point; At least one tuning device on the second coil includes the first tuning device; One end of the first tuning device is coupled to the first electrical connection point, and the other end of the first tuning device is grounded.

10. The terminal antenna according to any one of claims 1-8, characterized in that, The second coil includes a second electrical connection point and a third electrical connection point. At least one tuning device on the second coil includes a second tuning device; One end of the second tuning device is coupled to the second electrical connection point, and the other end of the second tuning device is coupled to the third electrical connection point.

11. The terminal antenna according to claim 9 or 10, characterized in that, The tuning device includes at least one of the following: Lumped capacitance; Distributed capacitance; A tuning circuit, comprising inductors and / or capacitors, wherein the tuning circuit is equivalent to a capacitor at the operating frequency of the first coil.

12. The terminal antenna according to any one of claims 1-11, characterized in that, The electronic device is also equipped with an NFC chip, which is coupled to at least one feed point of the first coil.

13. The terminal antenna according to claim 12, characterized in that, The electronic device is also equipped with a matching circuit, which includes an input port and a first output port; The NFC chip is coupled to the input terminal of the matching circuit, and the first output port of the matching circuit is coupled to a first power supply point, which is included in the at least one power supply point.

14. The terminal antenna according to claim 13, characterized in that, The first coil is also provided with a first grounding point, which is grounded.

15. The terminal antenna according to claim 12, characterized in that, The at least one feed point includes a second feed point and a third feed point; The NFC chip is coupled to the second power supply point and the third power supply point, respectively.

16. The terminal antenna according to claim 15, characterized in that, The signals input to the first feed point and the second feed point are differential mode signals.

17. The terminal antenna according to any one of claims 1-16, characterized in that, The first coil and / or the second coil are disposed in the electronic device by at least one of the following forms: FPC metal coil; The metal frame of electronic devices; Deco metal decorative pieces.

18. The terminal antenna according to any one of claims 1-17, characterized in that, The first coil and the second coil are arranged adjacent to each other.

19. The terminal antenna according to claim 18, characterized in that, The electronic device is provided with a first metal frame and a second metal frame. The first metal frame and the second metal frame are separated by a gap, or, The first metal frame and the second metal frame are connected to the metal middle frame at their closest points; the metal middle frame is disposed in the electronic device, and the first metal frame and the second metal frame are disposed around the metal middle frame; The first metal frame is reused as at least a portion of the first radiating coil, and the second metal frame is reused as at least a portion of the second radiating coil; The first radiation coil is the first coil, and the second radiation coil is the second coil; or, The first radiating coil is the second coil, and the second radiating coil is the first coil.

20. The terminal antenna according to claim 19, characterized in that, The first radiating coil is disposed at one of the two apex corners of the electronic device; the second radiating coil is disposed at the top edge of the electronic device.

21. The terminal antenna according to claim 19 or 20, characterized in that, The first metal frame is L-shaped and is located at the top corner of the electronic device; the first metal frame and the metal middle frame form an L-shaped gap; The second metal frame is in the shape of a straight line and is located on the top edge of the electronic device; the second metal frame and the metal middle frame form a straight line gap; One end of the second metal frame is separated from the end of the first metal frame located at the top edge by a gap, or... One end of the second metal frame and the end of the first metal frame located at the top edge are both connected to the metal middle frame.

22. The terminal antenna according to any one of claims 19-21, characterized in that, The terminal antenna also includes a third coil; At least one tuning device is configured on the third coil, and the at least one tuning device is used to adjust the resonant frequency corresponding to the third coil. When the terminal antenna is working, the current flow direction in the third coil includes a third direction, and the first direction and the third direction are the same.

23. The terminal antenna according to claim 21, characterized in that, The third coil and the second coil are arranged adjacent to each other.

24. The terminal antenna according to claim 23, characterized in that, The electronic device is provided with a third metal frame, and the third metal frame, the second metal frame and the first metal frame are sequentially arranged around the metal frame. The third metal frame is separated from the second metal frame by a gap, or, The third metal frame and the second metal frame are both connected to the metal middle frame at their closest points; The third metal frame is reused as at least a part of the third coil.

25. The terminal antenna according to any one of claims 1-24, characterized in that, At least a portion of the radiating coil included in the terminal antenna is also used for a second wireless communication, which is different from NFC communication; The radiating coil includes a fourth electrical connection point; the fourth electrical connection point is coupled to an isolation network; The radiating coil includes a first coil and / or a second coil, and the fourth electrical connection point includes a feed point and / or a ground point and / or an electrical connection point coupled to the tuning device.

26. The terminal antenna according to claim 25, characterized in that, The second wireless communication includes at least one of the following: cellular communication, WIFI communication, and GPS communication.

27. The terminal antenna according to any one of claims 1-26, characterized in that, The terminal antenna is an NFC antenna, and the operating frequency of the first coil includes 13.56MHz.

28. An electronic device, characterized in that, The electronic device is equipped with a terminal antenna as described in any one of claims 1-27.

Images