Circuit unit, electronic device, and near field communication method

Abstract

This specification provides a circuit unit, an electronic device, and a near-field communication method. The solution includes: a circuit unit applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip, a first near-field communication antenna, a second near-field communication chip, a second near-field communication antenna, a tuning capacitor, a first switch module, a second switch module, and a control module; the control module is configured to: in the first near-field communication mode, control the first switch module to connect the first near-field communication antenna to the first near-field communication chip, and control the second switch module to disconnect; in the second near-field communication mode, control the second switch module to connect the second near-field communication antenna to the second near-field communication chip, and control the first switch module to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit, the tuning circuit being used to enhance the magnetic field generated by the second near-field communication antenna.

Description

Technical Field

[0001] This specification relates to one or more embodiments in the field of near-field communication technology, and particularly to a circuit unit. This specification also relates to an electronic device and a near-field communication method. Background Technology

[0002] Near Field Communication (NFC) technology is widely used in electronic devices, and many devices need to support both reader mode and tag mode simultaneously. To achieve these two functions, devices typically have separate reader antennas and tag antennas, and use time-division multiplexing to avoid signal interference between the two modes.

[0003] However, in compact electronic devices (such as payment terminals and smartphones), two antennas often need to be arranged close together, leading to electromagnetic coupling between them. Optimizing the performance of the two antennas within a limited space is a persistent concern in this field. Therefore, a solution is needed that can flexibly switch between two modes and improve near-field communication performance. Summary of the Invention

[0004] In view of this, one or more embodiments of this specification provide a circuit unit, an electronic device, and a near-field communication method, providing a solution that can flexibly switch between two modes and improve near-field communication performance.

[0005] According to a first aspect of one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a tuning capacitor, a first switching module, a second switching module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to disconnect. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit. The tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0006] According to a second aspect of one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a tuning capacitor, a first switching module, a second switching module, and a control module; The first switch module is configured to selectively connect the first near-field communication antenna to the first near-field communication chip or the tuning capacitor; The second switch module is configured to selectively connect or disconnect the second near-field communication antenna from the second near-field communication chip. The control module is configured to: when the electronic device is operating in the second near-field communication mode, control the second switch module to connect the second near-field communication antenna to the second near-field communication chip, and control the first switch module to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit, wherein the tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0007] According to a third aspect of one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first switch module, a second switch module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to disconnect. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to disconnect.

[0008] According to a fourth aspect of one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first tuning capacitor, a second tuning capacitor, a first switching module, a second switching module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to connect the second near-field communication antenna to the second tuning capacitor to form a first tuning circuit. The first tuning circuit is used to enhance the magnetic field generated by the first near-field communication antenna. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to connect the first near-field communication antenna to the first tuning capacitor to form a second tuning circuit. The second tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0009] According to a fifth aspect of the embodiments of this specification, an electronic device is provided, including circuit units as provided in the embodiments of this specification.

[0010] According to a sixth aspect of the embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, and a tuning capacitor; the method includes: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the connection between the second near-field communication chip and the second near-field communication antenna is disconnected. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the tuning capacitor to form a tuning circuit to enhance the magnetic field generated by the second near-field communication antenna.

[0011] According to a seventh aspect of the embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, and a tuning capacitor; the method includes: When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the tuning capacitor to form a tuning circuit, which is used to enhance the magnetic field generated by the second near-field communication antenna.

[0012] According to an eighth aspect of the embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first switch module, a second switch module, and a control module; the method includes: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the connection between the second near-field communication chip and the second near-field communication antenna is disconnected. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the connection between the first near-field communication chip and the first near-field communication antenna is disconnected.

[0013] According to a ninth aspect of the embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first tuning capacitor, and a second tuning capacitor; comprising: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the second near-field communication antenna is connected to the second tuning capacitor to form a first tuning circuit. The first tuning circuit is used to enhance the magnetic field generated by the first near-field communication antenna. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the first tuning capacitor to form a second tuning circuit. The second tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0014] One embodiment of this specification achieves at least the following beneficial effects: In the first mode, the control module in the circuit unit connects the first antenna to the first chip and disconnects the second antenna; in the second mode, it connects the second antenna to the second chip and simultaneously connects the first antenna to a tuning capacitor to form a tuning circuit to enhance the magnetic field of the second antenna. Because the second antenna is physically disconnected in the first mode, parasitic coupling interference to the working antenna is avoided, allowing the two antennas to coexist in a compact space without requiring a large distance between them. In the second mode, the non-working first antenna is not simply suspended, but forms an LC resonant circuit through the tuning capacitor. This circuit resonates under the excitation of the alternating magnetic field of the working antenna, and the secondary magnetic field generated by its internal circulating current is superimposed in phase with the original magnetic field of the working antenna, thereby transforming the coupling that might otherwise cause interference into a beneficial enhancement for the working antenna, improving communication distance and reliability. Simultaneously, because the physical disconnection of the switch replaces the chip being powered off, the non-working chip can maintain power supply without generating RF output, simplifying power management and shortening the response time for mode switching. Overall, this scheme achieves interference suppression and enhanced directional performance in a dual-antenna system through a mode-specific, role-specific antenna connection strategy. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a circuit unit provided in an embodiment of this specification; Figure 2 This is a schematic diagram of another circuit unit provided in the embodiments of this specification; Figure 3 The embodiments provided in this specification correspond to Figure 2 A schematic diagram of the structural configuration of a circuit unit in a practical application scenario; Figure 4 The embodiments provided in this specification correspond to Figure 2 A schematic diagram of the structural configuration of a circuit unit in another practical application scenario; Figure 5 This is a schematic diagram of the structural configuration of another circuit unit provided in the embodiments of this specification in a practical application scenario. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0018] This specification uses specific terms to describe embodiments thereof. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples, without contradiction.

[0019] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the one or more embodiments of this specification. The singular forms “a,” “an,” “an,” “the,” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in one or more embodiments of this specification includes any or all possible combinations of one or more associated listed items.

[0020] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitation, the presence of additional identical or equivalent elements in the process, method, product, or apparatus that includes said elements is not excluded.

[0021] Although the terms "first," "second," etc., may be used to describe various information in one or more embodiments of this specification, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, "first" may also be referred to as "second," and similarly, "second" may also be referred to as "first," without departing from the scope of one or more embodiments of this specification. Ordinal numbers such as "first," "second," etc., do not necessarily indicate order; often they are used to facilitate the distinction of objects. For example, "first server" and "second server" usually refer to two servers. To distinguish these two servers, they are described as "first server" and "second server." Of course, sometimes these two servers may be the same server.

[0022] Depending on the context, the word "if" as used here can be interpreted as "when," "when," or "in response to determination."

[0023] In this specification, unless explicitly stated otherwise, "receiving and sending data" does not necessarily mean direct receiving and sending; it can also mean indirect receiving and sending. For example, A receiving data sent by B can be understood as A directly receiving the data sent by B, or it can be understood as A indirectly receiving the data sent by B through other entities such as C. Similarly, B sending data to A can be understood as B sending the data directly to A, or it can be understood as B indirectly sending the data to A through other entities such as C. Here, C can be one entity, or it can be two or more entities.

[0024] In this specification, unless explicitly stated otherwise, the relationships between structures can be direct or indirect. For example, when describing "A is connected to B," unless it is explicitly stated that A and B are directly connected, it should be understood that A can be directly connected to B or indirectly connected to B. Similarly, when describing "A is on top of B," unless it is explicitly stated that A is directly above B (AB is adjacent and A is above B), it should be understood that A can be directly above B or indirectly above B (AB is separated by other elements, and A is above B). And so on.

[0025] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in one or more embodiments of this specification are all information and data authorized by the user or fully authorized by all parties. The collection, use and processing of related data shall comply with the relevant laws, regulations and standards of the relevant regions, and corresponding operation entry points shall be provided for users to choose to authorize or refuse.

[0026] Near Field Communication (NFC) technology is widely used in various electronic devices, many of which need to support both reader mode and tag mode simultaneously. To achieve this, a common approach is to use a dedicated chip that supports both modes, but this chip is expensive. To reduce costs, the industry generally uses two separate chips—a reader chip and a tag chip—to handle the reader and tag functions respectively.

[0027] When using two chips, there are two main antenna configuration options.

[0028] One approach is to have two chips share a single antenna. In this case, if the two chips are configured with the same matching circuit, the single matching circuit cannot simultaneously meet the different impedance matching requirements of the two chips, resulting in the chip performance not being fully utilized. If the two chips are configured with two independent matching circuits and connected to the same antenna, the two matching circuits will affect each other. Even if one chip is not working, its matching circuit will still have a parasitic effect on the radio frequency path of the working chip, interfering with normal operation.

[0029] Another approach is to configure separate antennas for the two chips, with the Reader chip connected to the Reader antenna and the Tag chip connected to the Tag antenna. This dual-antenna, dual-chip solution requires the two antennas to be arranged separately inside the device to reduce electromagnetic coupling interference between them. Specifically, to prevent the Reader antenna from erroneously reading the Tag antenna's signal (forming a loop) or the Tag antenna from being interfered with by the Reader antenna, it is necessary to increase the spatial distance between the two antennas, placing them at opposite ends of the device. Furthermore, the two chips need to operate in a time-sharing manner; that is, when one chip is working, the other chip must be powered off or enter a silent state.

[0030] However, this dual-antenna, dual-chip solution places high demands on the internal space layout of the device. In compact devices (such as some electronic payment terminals), it is difficult to space the two antennas sufficiently, resulting in mutual interference between them and affecting communication performance. Furthermore, even when the non-operating chip is powered off, the physical conductors of its antenna still form a closed or near-closed loop. Under the influence of the alternating magnetic field of the operating antenna, an induced current is generated, causing detuning and energy absorption in the operating antenna, reducing communication distance and reliability.

[0031] Therefore, existing solutions struggle to achieve an ideal balance between cost, space requirements, and antenna performance.

[0032] To address the deficiencies in related technologies, an embodiment of this specification proposes a circuit unit for use in electronic devices that support two near-field communication modes: reader mode and card emulation mode. This circuit unit dynamically switches between two antennas via an RF switch and connects a tuning capacitor to the non-working antenna, transforming it into a passive enhancement coil for the working antenna.

[0033] Specifically, in this embodiment of the solution, radio frequency switches are respectively installed between the first near-field communication antenna and the first near-field communication chip, and between the second near-field communication antenna and the second near-field communication chip. When a chip is working, the corresponding switch connects its antenna to that chip; simultaneously, the switch on the other side completely disconnects the electrical connection between the non-working antenna and its chip, making the non-working antenna a non-closed conductive loop. Compared to the traditional solution that only de-energizes the non-working chip (the antenna remains a closed loop), this solution effectively suppresses parasitic coupling interference from the non-working antenna to the working antenna through the physical disconnection of the switches.

[0034] Building upon the physical disconnection, this embodiment of the solution also includes a tuning capacitor for at least one of the antennas, selectively connecting the antenna to this capacitor via a switch. When the antenna is in a non-operating state, the switch switches it to the tuning capacitor, forming an LC resonant circuit with it. The resonant frequency of this circuit is configured to be close to the NFC operating frequency (e.g., 13.56MHz), causing it to resonate under the excitation of the alternating magnetic field generated by the operating antenna. This generates a secondary magnetic field in phase, superimposed on the operating antenna's magnetic field, thus enhancing it. In this way, the non-operating antenna, which might otherwise cause interference, is transformed into a beneficial passive enhancement coil, achieving the technical effect of "turning interference into gain."

[0035] This specification provides a circuit unit, an electronic device, and a near-field communication method, which will be described in detail in the following embodiments.

[0036] The technical solutions provided in the various embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0037] In one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first switch module, a second switch module, and a control module; The control module is configured as follows: When the electronic device operates in the first near-field communication mode, control the first switch module to connect the first near-field communication antenna to the first near-field communication chip, and control the second switch module to disconnect; When the electronic device operates in the second near-field communication mode, control the second switch module to connect the second near-field communication antenna to the second near-field communication chip, and control the first switch module to disconnect.

[0038] Among them, the near-field communication chip: refers to an integrated circuit that can perform NFC reader functions or card emulation functions. In the embodiments of this specification, the first near-field communication chip (hereinafter also referred to as the first chip) and the second near-field communication chip (hereinafter also referred to as the second chip) respectively support different near-field communication modes. For example, one of the chips can be a reader chip, which is used to communicate with external NFC tags or cards in the reader mode; the other chip can be a tag chip, which is used to emulate an NFC tag or card in the card emulation mode and communicate with external readers (such as smartphones, etc.). Both chips need to be connected to their respective antennas to transmit or receive radio frequency signals.

[0039] It should be noted that although the reader chip and the tag chip are clearly defined in the embodiments of the specification, in actual applications, the reader chip can use a chip that only has reader functions, or can sample a chip that has both reader functions and card emulation functions; the tag chip can use a chip that only has card emulation functions, or can use a chip that has both card emulation functions and reader functions.

[0040] The near-field communication antenna: refers to a coil antenna used in conjunction with the NFC chip, usually composed of traces on a printed circuit board (PCB) or coils on a flexible circuit board. In the embodiments of this specification, the first near-field communication antenna (hereinafter also referred to as the first antenna) is a supporting antenna for the first near-field communication chip, and the second near-field communication antenna (hereinafter also referred to as the second antenna) is a supporting antenna for the second near-field communication chip. The antenna has two endpoints, which are used to connect to the radio frequency input and output terminals of the chip to form a current loop. When an alternating current flows through the antenna coil, an alternating magnetic field is generated to achieve electromagnetic coupling with external NFC devices.

[0041] Switching module: refers to an electronic device capable of changing the electrical connection path according to a control signal, such as a single-pole single-throw (SPST) switch or a single-pole double-throw (SPDT) switch. In this disclosure, a first switching module and a second switching module are used to connect or disconnect the antenna and the corresponding chip. Controlling the second switching module to disconnect means controlling the second switching module to be in an off state. Controlling the first switching module to disconnect means controlling the first switching module to be in an off state. When the switching module is in the "connected" state, a low-impedance path is formed between the antenna and the chip; when it is in the "disconnected" state, the electrical connection between the antenna and the chip is physically severed, and the antenna endpoint is in a high-impedance floating state.

[0042] The implementation of the switch module can include, but is not limited to, single-pole double-throw switches, double-pole double-throw switches, and dual-channel integrated switches. It should be noted that the first and second switch modules are logically distinct; in practical applications, both the first and second switch modules may be implemented using an integrated switch network or chip.

[0043] Control module: This refers to a logic unit capable of generating control signals, such as a microcontroller (MCU) or a dedicated control circuit. The control module outputs corresponding switching control signals based on the current operating mode required by the electronic device (card reader mode or card emulation mode).

[0044] Figure 1 This is a schematic diagram of the structure of a circuit unit 100 provided in an embodiment of this specification.

[0045] like Figure 1 The circuit unit shown includes a first near-field communication chip 101 and a second near-field communication chip 102, a first near-field communication antenna 103 and a second near-field communication antenna 104, a first switch module 105, a second switch module 106, and a control module 107.

[0046] like Figure 1 In the circuit unit shown, the first switch module 105 is configured to selectively connect the first near-field communication antenna 103 to the first near-field communication chip 101 or disconnect it; the second switch module 106 is configured to selectively connect the second near-field communication antenna 104 to the second near-field communication chip 102 or disconnect it.

[0047] Specifically, the control module 107 outputs a first control signal, which turns on the switch inside the first switch module 105, and the two ends of the first near-field communication antenna 103 are electrically connected to the radio frequency input / output terminals of the first near-field communication chip 101, respectively. At this time, the first near-field communication chip 101 can transmit or receive radio frequency signals through the first near-field communication antenna 103.

[0048] The control module 107 outputs a second control signal, causing the switch inside the second switch module to be in a non-conducting state, completely cutting off the electrical connection between the two endpoints of the second near-field communication antenna 104 and the second near-field communication chip 102. At this time, the two ends of the second near-field communication antenna 104 are in a high-impedance floating state, and the conductor loop it forms is no longer a closed loop (because neither end is connected to other circuits). Compared with simply de-energizing the chip but still forming a weak loop at both ends of the antenna through the chip's internal circuitry (such as ESD diodes and parasitic capacitances), physical disconnection can more effectively suppress the induced current on the antenna.

[0049] The working process of the above circuit unit is described below in conjunction with specific application scenarios.

[0050] Taking payment terminal equipment as an example, the equipment needs to support both card reader mode (such as reading the user's physical card, mobile phone emulation card, etc.) and card emulation mode (such as emulating a card so that the tag information it carries can be read by an external card reader).

[0051] In practical applications, the first near-field communication mode (hereinafter also referred to as the first mode) is one of a reader mode and a card emulation mode, and the second near-field communication mode (hereinafter also referred to as the second mode) is the other of the reader mode and card emulation mode. In one scenario, the first near-field communication mode is a reader mode, and the first near-field communication chip is a reader / writer chip; the second near-field communication mode is a card emulation mode, and the second near-field communication chip is a tag chip. In another scenario, the second near-field communication mode is a reader mode, and the second near-field communication chip is a reader / writer chip; the first near-field communication mode is a card emulation mode, and the first near-field communication chip is a tag chip. The following description uses one scenario as an example to illustrate the specific working process; it is understood that this working process can also be applied to the other scenario.

[0052] In some embodiments, the device includes a first near-field communication chip as a reader chip and a first near-field communication antenna as its matching antenna; a second near-field communication chip as a tag chip and a second near-field communication antenna as its matching antenna. A first switch module is connected between the first near-field communication antenna and the first near-field communication chip, and a second switch module is connected between the second near-field communication antenna and the second near-field communication chip. The control module is implemented by a microcontroller.

[0053] When the device enters card reader mode (e.g., when a cashier initiates a transaction and needs to read the customer's physical card or mobile SIM card), the microcontroller outputs a control signal: It controls the first switch module to turn on, connecting the first near-field communication antenna to the first near-field communication chip (Reader chip). The first near-field communication chip then drives the antenna to emit a magnetic field to read the external card. Simultaneously, the microcontroller controls the second switch module to turn off, completely severing the electrical connection between the second near-field communication antenna and the second near-field communication chip (Tag chip). At this time, although the second near-field communication antenna still exists inside the device as a metallic conductor, because both ends are in a high-resistance floating state, the circuit it forms is not closed. Therefore, under the influence of the alternating magnetic field generated by the first near-field communication antenna, only a very weak current (mainly from parasitic capacitance) can be induced in the second near-field communication antenna, and the interference to the working antenna is suppressed to a negligible level.

[0054] When the device enters card emulation mode (e.g., when the device needs to be recognized by an external card reader to provide its tag information), the microcontroller outputs a control signal: It controls the second switch module to turn on, connecting the second near-field communication antenna to the second near-field communication chip (Tag chip), which then simulates a card and communicates with the external card reader. Simultaneously, the microcontroller controls the first switch module to turn off, completely severing the electrical connection between the first near-field communication antenna and the first near-field communication chip (Reader chip). Similarly, the first near-field communication antenna is also in a high-impedance floating state to avoid interference with the operating antenna.

[0055] In other embodiments, the first near-field communication chip is a tag chip, and the second near-field communication chip is a reader chip, with the control logic interchanged accordingly. That is, in card emulation mode, the tag chip is connected to its antenna, and the reader chip's antenna is disconnected; in card reader mode, the reader chip is connected to its antenna, and the tag chip's antenna is disconnected.

[0056] In the above embodiments, for example, the switching module can be implemented using a single-pole single-throw switch. When both antennas are differential antennas, each switching module can include two single-pole single-throw switches, connected in series between the two ends of the antenna and the two RF terminals of the chip, respectively, to ensure that both ends of the antenna can be physically disconnected. The control signal output by the control module can be transmitted through a level conversion circuit or directly drive the control pin of the switch.

[0057] Based on some embodiments of this specification, the above-described circuit unit, by setting disconnectable switch modules between the two near-field communication antennas and their respective chips, and under the unified scheduling of the control module, ensures that when the working chip drives its antenna, the electrical connection between the non-working antenna and its chip is physically severed, thus making the non-working antenna appear as a non-closed conductor with high impedance at both ends. Compared to the traditional solution of simply de-energizing the non-working chip (in which case the antenna ends still form a closed loop through the low impedance path or parasitic loop inside the chip), physical disconnection can significantly reduce the induced current generated by the magnetic field excitation of the working antenna in the non-working antenna, thereby reducing the detuning and energy absorption effects caused by the induced current acting back on the working antenna. This feature allows the two antennas to be arranged in a relatively close spatial distance without causing serious mutual interference, reducing the space requirements for antenna layout in electronic devices and facilitating device miniaturization. At the same time, since the physical disconnection of the switch replaces the chip de-energization as an isolation means, the non-working chip itself can maintain power supply without generating RF output, simplifying the power management logic and avoiding the initialization delay when the chip is powered on again. Furthermore, the logic of the control module switching the switch state according to the operating mode is compatible with the chip time-sharing control in existing technologies, making it easy to implement on existing hardware architectures. In summary, in some embodiments, this circuit unit effectively suppresses inter-antenna coupling interference in a dual-antenna, dual-chip system at a lower hardware cost (adding two switch modules), and also brings optimizations in terms of space layout and power management.

[0058] In one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a tuning capacitor, a first switching module, a second switching module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to disconnect. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit. The tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0059] Here, a tuning capacitor refers to one or more capacitors whose capacitance value is configured to, together with the inductance of a specific antenna, determine a resonant frequency. This capacitor, connected in parallel or series with the antenna, forms an LC resonant circuit. In this embodiment, the tuning capacitor is connected to a first near-field communication antenna to form a tuning circuit in a second near-field communication mode.

[0060] The control module can be a microcontroller, which outputs control signals to the control terminals of the first switch module and the second switch module.

[0061] In practical applications, for the working antenna and the working chip, after the near-field communication antenna is connected to the near-field communication chip, the chip drives the antenna to generate an alternating magnetic field (actively transmitting in card reader mode) or respond to an external magnetic field (generating a reflected magnetic field through load modulation in card emulation mode). For the non-working antenna and the non-working chip, in some embodiments, the influence on the alternating magnetic field generated by the working antenna and the working chip or the response to the external magnetic field can be reduced by disconnecting the non-working antenna and the non-working chip. Alternatively, in other embodiments, the alternating magnetic field generated by the working antenna and the working chip or the response to the external magnetic field can be enhanced by connecting the non-working antenna to a tuning capacitor to form a tuning circuit.

[0062] Specifically, when the second near-field communication antenna is connected to the second near-field communication chip, the second near-field communication chip drives the antenna to generate an alternating magnetic field (in card reader mode) or to generate a modulated magnetic field in response to an external magnetic field (in card emulation mode). This magnetic field is used to communicate with external NFC devices. The tuning circuit generates an in-phase secondary magnetic field through resonance, enhancing the strength of this operating magnetic field.

[0063] Figure 2 This is a schematic diagram of another circuit unit 200 provided in the embodiments of this specification.

[0064] like Figure 2 The circuit unit shown includes a first near-field communication chip 201 and a second near-field communication chip 202, a first near-field communication antenna 203 and a second near-field communication antenna 204, a first switch module 205, a second switch module 206, a control module 207, and a tuning capacitor 208.

[0065] like Figure 2In the circuit unit shown, the first switch module 205 is configured to selectively connect the first near-field communication antenna 203 to the first near-field communication chip 201 or the tuning capacitor 208; the second switch module 206 is configured to selectively connect the second near-field communication antenna 204 to the second near-field communication chip 202 or disconnect it. In practical applications, the implementation of the switch modules includes, but is not limited to, using a single-pole double-throw switch (SPDT) for the first switch module 205 and a single-pole single-throw switch (SPST) for the second switch module 206.

[0066] Specifically, when the electronic device operates in the first near-field communication mode (or, when the electronic device needs to operate in the first near-field communication mode), on the one hand, the control module 207 outputs a first control signal, causing the first switch module 205 to switch to the first path, and the two ends of the first near-field communication antenna 203 form an electrical connection with the radio frequency terminal of the first near-field communication chip 201. At this time, the first near-field communication chip 201 can transmit or receive radio frequency signals through the first near-field communication antenna 203.

[0067] On the other hand, the control module 207 outputs a second control signal, causing the second switch module 206 to be in a non-conducting state, and the electrical connection between the two ends of the second near-field communication antenna 204 and the second near-field communication chip 202 is completely cut off. At this time, the two ends of the second near-field communication antenna 204 are in a high-impedance floating state, forming an unclosed conductor loop.

[0068] When the electronic device is operating in the second near-field communication mode (or when the electronic device needs to operate in the second near-field communication mode), the control module 207 outputs a third control signal, which turns on the second switch module 206, and the second near-field communication antenna 204 is connected to the second near-field communication chip 202, and the second near-field communication chip 202 operates through the second near-field communication antenna 204.

[0069] The control module 207 outputs a fourth control signal, causing the first switch module 205 to switch to the second path. The two ends of the first near-field communication antenna 203 are connected to the two ends of the tuning capacitor 208, forming an LC parallel resonant circuit (tuning circuit). This tuning circuit will resonate under the excitation of an alternating magnetic field, generating a large internal circulating current, which in turn generates a secondary magnetic field.

[0070] In one or more embodiments of this specification, the first near-field communication mode is one of a reader mode and a card emulation mode, and the second near-field communication mode is the other of the reader mode and the card emulation mode.

[0071] The following describes the operation of the circuit unit in a specific application scenario. Taking a payment terminal device as an example, this device needs to support both reader mode (e.g., reading physical cards) and card emulation mode (e.g., being recognized by an external card reader).

[0072] In an optional embodiment, the first near-field communication mode is a reader mode, the second near-field communication mode is a card emulation mode, the first near-field communication chip is a reader / writer chip, and the second near-field communication chip is a tag chip. In the first mode, reader mode, the device needs to actively read external physical cards or emulated cards; therefore, the first chip is a reader / writer chip (e.g., a certain type of NFC reader chip), and the first near-field communication antenna works in conjunction with it. In the second mode, card emulation mode, the device needs to simulate a card being recognized by an external reader; therefore, the second chip is a tag chip (e.g., a certain type of NFC tag chip), and the second near-field communication antenna works in conjunction with it. A tuning capacitor is connected to the first antenna.

[0073] Figure 3 The embodiments provided in this specification correspond to Figure 2 A schematic diagram of the structural configuration of circuit unit 200 in a practical application scenario.

[0074] In such Figure 3 In the configuration shown, the device contains: a first near-field communication chip, which is a reader chip (NFC1_Reader), and a first near-field communication antenna, which is its matching antenna (NFC antenna 1); a second near-field communication chip, which is a tag chip (NFC1_Tag), and a second near-field communication antenna, which is its matching antenna (NFC antenna 2); a tuning capacitor (CAP1), whose capacitance is pre-adjusted to match the inductance of the first near-field communication antenna, so that the resonant frequency of the LC circuit formed by the antenna and the capacitor is close to 13.56MHz; a first switching module using single-pole double-throw switches (SPDT1 and SPDT2), and a second switching module using single-pole single-throw switches (SPST1 and SPST2); and a control module, which is a microcontroller (MCU).

[0075] When the device enters reader mode (first near-field communication mode, such as when a cashier initiates a card transaction), the microcontroller outputs a control signal: This causes the first switching module to connect the first near-field communication antenna to the reader chip, which then drives the antenna to emit a magnetic field to read external physical or analog cards. Simultaneously, the second switching module is disconnected, cutting off the connection between the second near-field communication antenna and the tag chip. At this time, the two ends of the second near-field communication antenna are suspended, suppressing interference to the working antenna.

[0076] When the device enters card emulation mode (second near-field communication mode, for example, when the device needs to be identified by an external card reader to provide its carried tag information), the microcontroller outputs a control signal: This turns on the second switch module, connecting the second near-field communication antenna to the tag chip, which then simulates a card and communicates with the external card reader. Simultaneously, the first switch module switches the first near-field communication antenna to the tuning capacitor, forming an LC resonant circuit with the tuning capacitor. Under the influence of the alternating magnetic field generated by the second working antenna (second near-field communication antenna), this LC resonant circuit resonates. The secondary magnetic field generated by its internal circulating current is superimposed on the magnetic field of the second near-field communication antenna, thereby enhancing the magnetic field generated by the second near-field communication antenna and improving the distance and reliability at which the device can be identified by the external card reader.

[0077] based on Figure 3 In the configuration described, the tuning capacitor is associated with the reader antenna. Therefore, in card emulation mode, the reader antenna (non-operating) becomes an enhancement coil for the tag antenna, helping to increase the distance at which the device can be identified as a card. That is, based on the embodiments of this specification, the non-operating antenna is transformed into a tuning coil in the corresponding mode, turning the original source of interference into an enhancement source, thereby improving communication performance in the target direction without increasing the antenna spacing.

[0078] In an optional embodiment, the first near-field communication mode is a card emulation mode, the second near-field communication mode is a card reader mode, the first near-field communication chip is a tag chip, and the second near-field communication chip is a reader chip. The tuning capacitor remains connected to the first antenna. When the device needs to emulate a card (first mode), the tag chip operates through the first antenna, and the second antenna is disconnected; when the device needs to read an external card (second mode), the reader chip operates through the second antenna, and the first antenna is switched to the tuning capacitor to form a resonant circuit, enhancing the magnetic field of the second antenna.

[0079] Figure 4 The embodiments provided in this specification correspond to Figure 2 A schematic diagram of the structural configuration of circuit unit 200 in another practical application scenario.

[0080] In such Figure 4In the configuration shown, the first near-field communication chip is a tag chip (NFC2_Tag), and the second near-field communication chip is a reader chip (NFC1_Reader). The tuning capacitor is still connected to the antenna corresponding to the first near-field communication chip. In reader mode, the reader chip (NFC1_Reader) is connected to its antenna (NFC antenna 1), and the antenna (NFC antenna 2) of the tag chip (NFC2_Tag) is connected to the tuning capacitor (CAP2) to become an enhancement coil. In card emulation mode, the tag chip (NFC2_Tag) is connected to its antenna (NFC antenna 2), and the antenna (NFC antenna 1) of the reader chip (NFC1_Reader) is disconnected. Figure 4 and Figure 3 The difference in configuration lies in which antenna has a tuning capacitor. Figure 4 In the diagram, the part with the tuning capacitor is the tag antenna; that is, in reader mode, this antenna becomes the enhancement coil. The specific operating logic is... Figure 3 The example is symmetrical, so I will not repeat it further.

[0081] based on Figure 4 In the configuration described above, the tuning capacitor is associated with the tag antenna. Therefore, in reader mode, the tag antenna (non-operating) becomes an enhancement coil for the reader antenna, which helps to improve the distance at which the device can read external cards. That is, based on the embodiments in this specification, the non-operating antenna is transformed into a tuning coil in the corresponding mode, turning the original source of interference into a source of enhancement, thereby improving the communication performance in the target direction without increasing the antenna spacing.

[0082] Based on some embodiments of this specification, the above-described circuit unit, by setting a switchable switching module between the two near-field communication antennas and their respective chips, and introducing a tuning capacitor associated with the first antenna, allows the control module to perform the following operations according to the device's operating mode: In the first mode, the first antenna is connected to the first chip to become the operating antenna, and the second antenna is disconnected to avoid interference; in the second mode, the second antenna is connected to the second chip to become the operating antenna, while the first antenna is switched to form an LC resonant circuit using the tuning capacitor. Since the resonant frequency of this LC resonant circuit is configured to be close to the operating frequency (e.g., 13.56MHz), when the second antenna generates an alternating magnetic field, the resonant circuit is excited and resonates. The secondary magnetic field formed by its internal circulating current is superimposed in phase with the original magnetic field of the second antenna, thereby enhancing the magnetic field generated by the second antenna. This mechanism transforms the coupling interference that might have been caused by the non-operating antenna (the first antenna) into a beneficial enhancement for the operating antenna, improving the effective radiation capability and communication distance of the operating antenna. Simultaneously, in the second mode, when the second antenna acts as the operating antenna, the first antenna is physically disconnected from the first chip via a switch, avoiding the influence of the first chip's static circuitry on the resonant circuit; the second antenna being disconnected in the first mode also avoids its interference with the first antenna. Therefore, this circuit unit, while enabling switching between two modes, transforms the non-working antenna from a passively isolated element into a passive enhancement coil for the working antenna, converting interference into gain. Furthermore, since power-off of the non-working chip is unnecessary (its antenna is physically disconnected by a switch), power management is simplified; and the internal layout of the two antennas does not require deliberate spacing, reducing space requirements and facilitating device miniaturization. This solution, with lower cost and smaller footprint, simultaneously solves the problems of antenna interference and limited space layout in dual-antenna, dual-chip solutions, while significantly improving the performance of the working antenna.

[0083] In one or more embodiments of this specification, the tuning circuit is configured to electromagnetically couple with the second near-field communication antenna when the second near-field communication antenna is in operation, thereby enhancing the magnetic field generated by the second near-field communication antenna. Specifically, the tuning circuit is configured to match the operating frequency of the second near-field communication chip, so that the tuning circuit resonates at the operating frequency, generating the maximum induced current.

[0084] Furthermore, the resonant frequency of the tuning circuit is configured such that the difference between it and the operating frequency of the second near-field communication chip is less than a preset threshold.

[0085] The resonant frequency refers to the inherent oscillation frequency of the LC resonant circuit (composed of an antenna inductor and a tuning capacitor), and the calculation formula is as follows: When the frequency of the external alternating magnetic field approaches the resonant frequency, a large resonant current will be generated in the circuit.

[0086] The operating frequency of the second near-field communication chip, i.e. the operating frequency of near-field communication, is typically 13.56MHz.

[0087] The preset threshold refers to the maximum allowable deviation between the resonant frequency and the operating frequency. This preset threshold can be a relative value (e.g., ±5% of the operating frequency) or an absolute value (e.g., ±1MHz). The specific value of the preset threshold can be determined based on the actual antenna Q-value and application scenario.

[0088] For example, the resonant frequency of the tuning circuit can be configured to be between 13 and 14 MHz according to the preset threshold.

[0089] Furthermore, the resonant frequency of the tuning circuit can be adjusted by adjusting the capacitance value of the tuning capacitor.

[0090] Optionally, the tuning capacitor is an adjustable capacitor, the value of which is configured to be adjustable to change the resonant frequency of the tuning circuit. Here, an adjustable capacitor refers to a capacitor whose capacitance can be adjusted by external mechanical or electrical means, such as a trimmer capacitor or a varactor diode.

[0091] Optionally, the tuning capacitor includes multiple fixed capacitors connected in parallel, and the resonant frequency of the tuning circuit is adjusted by selecting different numbers of fixed capacitors to connect. Here, the capacitor array refers to a circuit composed of multiple fixed capacitors connected in parallel, where the total capacitance is changed by selecting different numbers of capacitors to connect via a switch.

[0092] In practical applications, during the equipment debugging phase, the first switch module can be switched to the tuning capacitor path. The resonant frequency of the LC circuit formed by the first near-field communication antenna and the tuning capacitor can be measured using a network analyzer or the induced voltage method. Then, the capacitance value can be changed (e.g., rotating the adjustable capacitor, welding fixed capacitors with different capacitance values, or selecting different combinations in the capacitor array by switching) until the deviation between the resonant frequency and the operating frequency of the second chip (e.g., 13.56MHz) is less than a preset threshold.

[0093] Based on some embodiments of this specification, by configuring the resonant frequency of the tuning circuit to have a difference from the operating frequency of the second chip less than a preset threshold, when the second antenna generates an alternating magnetic field as a working antenna, the LC circuit formed by the first antenna and the tuning capacitor can reach near-resonance under the excitation of this magnetic field, thereby generating a large resonant current and a secondary magnetic field. The closer the resonance is to the operating frequency, the stronger the secondary magnetic field, and the more significant the enhancement effect on the working antenna. Simultaneously, the existence of the preset threshold allows for a certain amount of engineering error, reducing the difficulty of debugging. By adjusting the capacitance of the tuning capacitor (e.g., using an adjustable capacitor or capacitor array), designers can flexibly calibrate the resonant frequency to the target range, adapting to frequency shifts caused by different antenna inductances and actual environments (such as PCB parasitic capacitance, nearby metal objects, etc.). This adjustability ensures that the circuit unit can achieve better enhancement effects under different devices and different antenna layout conditions.

[0094] In one or more embodiments of this specification, a differential structure of the first near-field communication antenna and an implementation of the first switching module are further provided.

[0095] Specifically, the first near-field communication antenna has a first antenna end and a second antenna end; the first switch module is configured to simultaneously connect the first antenna end and the second antenna end to the two radio frequency ends of the first near-field communication chip or to the two ends of the tuning capacitor.

[0096] More specifically, the first near-field communication antenna has a first antenna end and a second antenna end; the first switching module includes a first switching unit and a second switching unit, the first switching unit being connected between the first antenna end and a first differential terminal of the first near-field communication chip and a first terminal of the tuning capacitor, and the second switching unit being connected between the second antenna end and a second differential terminal of the first near-field communication chip and a second terminal of the tuning capacitor; the first switching unit and the second switching unit are configured to synchronously connect the first antenna end and the second antenna end to the corresponding differential terminal of the first near-field communication chip or synchronously connect them to the corresponding terminal of the tuning capacitor.

[0097] Optionally, the first switching module includes two single-pole double-throw (SPDT) switches, which are respectively connected to the two ends of the antenna and the two radio frequency terminals of the chip and the two ends of the tuning capacitor.

[0098] Specifically, in the circuit unit, the first near-field communication antenna has a first antenna end and a second antenna end; the first switch module includes a first single-pole double-throw switch and a second single-pole double-throw switch; the common terminal of the first single-pole double-throw switch is connected to the first antenna end of the first near-field communication antenna, the first throw is connected to the first differential terminal of the first near-field communication chip, and the second throw is connected to the first terminal of the tuning capacitor; the common terminal of the second single-pole double-throw switch is connected to the second antenna end of the first near-field communication antenna, the first throw is connected to the second differential terminal of the first near-field communication chip, and the second throw is connected to the second terminal of the tuning capacitor.

[0099] The differential antenna has two independent radio frequency terminals (a first antenna terminal and a second antenna terminal), with opposite signal phases relative to ground. The differential structure helps suppress common-mode interference.

[0100] A single-pole double-throw (SPDT) switch is a three-terminal device consisting of a common terminal (pole) and two throws (first throw and second throw). The common terminal can be switched to either the first throw or the second throw, but cannot be connected to both simultaneously. In this embodiment, the common terminal of each SPDT is connected to one end of the antenna, the first throw is connected to the corresponding differential terminal of the chip, and the second throw is connected to the corresponding terminal of the tuning capacitor.

[0101] Return to reference Figure 3 or Figure 4 In practical applications, the common terminal of the first single-pole double-throw switch is connected to the first antenna terminal of the first near-field communication antenna. When the control signal switches the common terminal to the first throw, the first antenna terminal is connected to the first differential terminal of the first chip; when switched to the second throw, the first antenna terminal is connected to the first terminal of the tuning capacitor. Similarly, the second single-pole double-throw switch controls the connection between the second antenna terminal of the first near-field communication antenna and the second differential terminal of the first chip or the second terminal of the tuning capacitor. The first and second single-pole double-throw switches operate synchronously, ensuring that both ends of the antenna are simultaneously connected to the chip or simultaneously connected to the tuning capacitor.

[0102] Continue to refer to Figure 3Example. The first near-field communication antenna is a differential antenna, with its two endpoints denoted as the first antenna terminal ANT1 and the second antenna terminal ANT2. The first switch module uses two single-pole double-throw switches—the first single-pole double-throw switch SPDT1 and the second single-pole double-throw switch SPDT2. The common terminal of the first single-pole double-throw switch SPDT1 is connected to the first antenna terminal ANT1, the first throw is connected to the first differential terminal NFC1_ANT1 of the first chip (reader chip NFC1_Reader), and the second throw is connected to the first terminal CAP1_ANT1 of the tuning capacitor; the common terminal of the second single-pole double-throw switch SPDT2 is connected to the second antenna terminal ANT2, the first throw is connected to the second differential terminal NFC1_ANT2 of the first chip (reader chip NFC1_Reader), and the second throw is connected to the second terminal CAP1_ANT2 of the tuning capacitor.

[0103] The two control signals of the control module are respectively connected to the control terminals of the two SPDTs. When the control signal is high, the common terminal of both switches is switched to the first throw (chip side); when the control signal is low, both are switched to the second throw (tuning capacitor side). Thus, in the second mode (card emulation mode), the control signal is low, and the two terminals of the first near-field communication antenna are connected to the two ends of the tuning capacitor through the second throws of the two SPDTs, forming a complete parallel LC loop.

[0104] Figures 3 to 5 The "SW_CTRL" designation indicates a switch control signal output by a control module (e.g., a microcontroller MCU). This control signal can be one or more level signals, connected to the control terminals of the first and second switch modules respectively. Based on the current operating mode required by the electronic device (first near-field communication mode or second near-field communication mode), the control module outputs corresponding control logic (e.g., high or low level) through the SW_CTRL signal line to drive the RF switches inside the first and second switch modules to switch to the target state. Specifically, as shown... Figure 3 and Figure 4 As shown, when the control signal is at the first level, the first switch module connects the first near-field communication antenna to the first near-field communication chip, while the second switch module is in the off state. When the control signal is at the second level, the second switch module connects the second near-field communication antenna to the second near-field communication chip, while the first switch module connects the first near-field communication antenna to the tuning capacitor. In the implementation of the differential antenna, SW_CTRL can simultaneously control two single-pole double-throw switches or one double-pole double-throw switch to ensure synchronous switching of the two ends of the antenna. Those skilled in the art will understand that the naming of SW_CTRL is only for ease of illustration and does not constitute a limitation on the form or number of control signals. In actual design, multiple control lines or coded signals can be used to implement more complex switching logic.

[0105] Based on some embodiments in this specification, two single-pole double-throw (SPDT) switches are used to control the two ends of the differential antenna respectively, enabling completely symmetrical switching of the differential antenna. Compared to controlling only one end, this symmetrical structure ensures the consistency of path length and impedance from both ends of the antenna to the chip or capacitor, thereby maintaining the differential characteristics of the antenna and avoiding the generation of common-mode signals. Simultaneously, the two switches switch synchronously, ensuring that both ends of the antenna are either connected to the chip or the tuning capacitor simultaneously, avoiding the chaotic state of one end connected to the chip and the other to the capacitor. This ensures that the LC resonant circuit is composed of a complete antenna coil and capacitor connected in parallel, producing the expected resonance enhancement effect. Furthermore, the SPDT itself has low insertion loss and high isolation. When switching to the tuning capacitor, the isolation between the RF port of the first chip and the antenna is effectively guaranteed, reducing the influence of chip parasitic parameters on the resonant circuit.

[0106] In practical applications, the first switch module can not only be implemented as follows: Figure 3 or Figure 4 The two SPDTs shown can still be implemented with other configurations.

[0107] Optionally, the first switching module can employ a double-pole double-throw (DPDT) switch. The DPDT has two independent common terminals and two sets of throws, enabling synchronous switching of two signals. Specifically: the first common terminal of the DPDT is connected to the first antenna terminal of the first near-field communication antenna, and the second common terminal is connected to the second antenna terminal of the first near-field communication antenna; the two output terminals of the first set of throws are respectively connected to the first differential terminal and the second differential terminal of the first near-field communication chip; the two output terminals of the second set of throws are respectively connected to the first terminal and the second terminal of the tuning capacitor. The control module outputs a control signal to the control terminal of the DPDT. When the control signal is at a first level (e.g., high level), both common terminals are simultaneously connected to the first set of throws (chip side); when the control signal is at a second level (low level), both common terminals are simultaneously connected to the second set of throws (tuning capacitor side). This implementation reduces the number of control signals and ensures synchronous switching of the two antenna terminals.

[0108] Alternatively, a chip that integrates two independent SPDTs within a single package and shares control logic can be used.

[0109] In one or more embodiments of this specification, a differential structure of the second near-field communication antenna and an implementation of the second switching module are further provided.

[0110] Specifically, the second near-field communication antenna has a first antenna end and a second antenna end; the second switch module is configured to simultaneously connect the first antenna end and the second antenna end to the two radio frequency ends of the second near-field communication chip or simultaneously disconnect them.

[0111] More specifically, the second near-field communication antenna has a first antenna end and a second antenna end; the second switching module includes a third switching unit and a fourth switching unit, the third switching unit being connected in series between the first antenna end and the first differential terminal of the second near-field communication chip, and the fourth switching unit being connected in series between the second antenna end and the second differential terminal of the second near-field communication chip; the third switching unit and the fourth switching unit are configured to be synchronously turned on to connect the two antenna ends to the two radio frequency terminals of the second near-field communication chip, or synchronously turned off to leave the two antenna ends in a floating state.

[0112] Optionally, the second switching module includes two single-pole single-throw (SPST) switches, which are connected in series between the two ends of the second antenna and the two radio frequency terminals of the second chip.

[0113] Specifically, in the circuit unit, the second near-field communication antenna has a first antenna terminal and a second antenna terminal; the second switch module includes a first single-pole single-throw switch and a second single-pole single-throw switch; the first single-pole single-throw switch is connected in series between the first antenna terminal of the second near-field communication antenna and the first differential terminal of the second near-field communication chip; the second single-pole single-throw switch is connected in series between the second antenna terminal of the second near-field communication antenna and the second differential terminal of the second near-field communication chip; the disconnection means that both the first single-pole single-throw switch and the second single-pole single-throw switch are in the disconnected state.

[0114] A single-pole single-throw (SPST) switch is a two-terminal device with both on and off states. Series connection refers to inserting the switch into a wire; that is, one end of the antenna is first connected to one end of the switch, and the other end of the switch is then connected to the corresponding differential terminal of the chip.

[0115] Return to reference Figure 3 or Figure 4 In practical applications, the first single-pole single-throw switch is connected in series between the first antenna terminal of the second antenna and the first differential terminal of the second chip: when the switch is closed, the antenna terminal and the corresponding terminal of the chip are connected; when the switch is open, the connection between them is broken. The second single-pole single-throw switch is connected in series between the second antenna terminal of the second antenna and the second differential terminal of the second chip: similarly, it controls the connection or disconnection. The open state means that both SPSTs are in the open position, at which time neither of the two terminals of the second antenna is electrically connected to the second chip, and both ends are in a high-impedance floating state.

[0116] Continue to refer to Figure 3Example. The second near-field communication antenna is a differential antenna, with its two endpoints denoted as the first antenna terminal ANT1 and the second antenna terminal ANT2. The second switch module uses two single-pole single-throw switches—the first single-pole single-throw switch SPST1 and the second single-pole single-throw switch SPST2. One end of the first single-pole single-throw switch SPST1 is connected to the first antenna terminal ANT1, and the other end is connected to the first differential terminal NFC2_ANT1 of the second chip (tag chip NFC2_Tag); one end of the second single-pole single-throw switch SPST2 is connected to the second antenna terminal ANT2, and the other end is connected to the second differential terminal NFC2_ANT2 of the second chip.

[0117] The control module has two control signals connected to the control terminals of the two SPSTs respectively. When the device is operating in card reader mode (first mode), the control signals disconnect both SPSTs, leaving the two ends of the second antenna floating and not connected to the tag chip at all. When the device is operating in card emulation mode (second mode), the control signals close both SPSTs, connecting the second antenna to the tag chip, which then communicates with the external card reader through this antenna.

[0118] Based on some embodiments in this specification, two single-pole single-throw (SPST) switches are connected in series between the two ends of the differential antenna and the chip, respectively, to achieve complete physical disconnection of the second antenna. When both SPST switches are disconnected, the two ends of the second antenna are in a high-impedance floating state, no longer forming a closed conductor loop. Compared to simply de-energizing the chip (in which case the two ends of the antenna still form a weak loop through the chip's internal ESD diodes, parasitic capacitances, etc.), this physical disconnection can more effectively suppress the induced current in the antenna, thereby further reducing the detuning and energy absorption caused by the non-operating antenna to the operating antenna. At the same time, the dual-switch structure ensures symmetrical disconnection of the differential antenna, avoiding the unbalanced interference that may be introduced by single-end disconnection. In addition, the SPST switch has a simple structure and low cost, making it suitable for scenarios that only require on / off control and do not require switching multiple signals.

[0119] In practical applications, the second switch module can not only be implemented as follows: Figure 3 or Figure 4 The two SPSTs shown can still be implemented in other configurations.

[0120] Optionally, the second switch module can employ a dual-channel single-pole single-throw (DPST) RF switch chip, or a chip integrating two independent SPSTs within a package and sharing control logic (e.g., a dual-channel analog switch or a dual-channel RF switch). This chip has four RF ports (two inputs, two outputs) and one common control pin. Specifically, the first channel of the chip is connected in series between the first antenna terminal of the second near-field communication antenna and the first differential terminal of the second chip; the second channel is connected in series between the second antenna terminal and the second differential terminal of the second chip. The control module outputs a control signal to the chip's control pin: when the control signal is at an on level (e.g., high level), both channels are closed simultaneously, and both ends of the antenna are simultaneously connected to the chip's differential terminal; when the control signal is at an off level, both channels are disconnected simultaneously, and both ends of the antenna are in a high-impedance floating state. Compared to two independent SPSTs, using the above-mentioned chip offers better synchronization, a smaller board area, simpler control, and better matching of parasitic parameters, but the cost is relatively higher.

[0121] Alternatively, in practical applications, a first switching module and / or a switching network of the first switching module can be constructed using PIN diodes or field-effect transistors (FETs).

[0122] In another alternative embodiment, the first switch module and the second switch module may not be discrete SPDTs or SPSTs, but rather configured as multi-channel integrated RF switch chips.

[0123] The above provides an example of a differential antenna for near-field communication. A differential antenna has two RF terminals, each with opposite signal phases relative to ground. When connected to a chip, the differential antenna can be directly connected to the chip's differential RF pins without requiring additional components. When connected to a capacitor, the capacitor bridges the two antenna terminals, forming a closed loop with the antenna coil. Overall, differential antennas offer better performance, simpler design, and lower cost.

[0124] It is understood that, in other embodiments, the near-field communication antenna can also be implemented as a single-ended antenna. A single-ended antenna has only one RF signal terminal, with the other end grounded. When connected to a chip, since the RF output of most NFC chips is differential, the single-ended antenna needs to be connected to the differential pin of the chip via a balun or LC matching network. When connected to a capacitor, the capacitor is connected across the signal terminal and ground, and the antenna coil and capacitor form a closed loop (through ground).

[0125] Specifically, in some embodiments, the first near-field communication antenna has a first end; the first switching module is configured to connect the first end to a radio frequency terminal of the first near-field communication chip or to a terminal of the tuning capacitor; and the second end of the first near-field communication antenna is grounded.

[0126] In one or more embodiments of this specification, in the circuit unit, optionally, when the electronic device is operating in the first near-field communication mode, the second near-field communication chip remains powered and is in a non-transmitting state; when the electronic device is operating in the second near-field communication mode, the first near-field communication chip remains powered and is in a non-transmitting state.

[0127] "Keep power supply" means that the chip's DC power supply (VCC) is always on, and some circuits inside the chip (such as registers, oscillators, etc.) can continue to work, but its radio frequency transmission function is disabled.

[0128] Non-transmitting state means that the chip does not output radio frequency carrier signals and does not actively drive the antenna. In practical applications, this can be achieved by pulling the chip's transmit enable pin low or by disabling its transmit channel via software commands.

[0129] A chip power failure means that the power supply to the chip is completely cut off. All circuits inside the chip stop working, and an initialization process needs to be executed after power is restored.

[0130] In practical applications, under the first near-field communication mode (e.g., card reader mode), the first chip operates normally, and the second chip remains powered on but is controlled not to generate radio frequency output. Since the second switch module physically disconnects the second antenna from the second chip, even if the second chip remains powered, its radio frequency port does not drive the antenna and therefore does not generate a signal. Under the second near-field communication mode (e.g., card emulation mode), the second chip operates normally, and the first chip remains powered but is in a non-transmitting state.

[0131] In an alternative embodiment, if there are strict requirements for power consumption, the non-working chip can be completely powered off, but in this case, switching from one mode to another requires additional time for chip power-on initialization.

[0132] Based on some embodiments of this specification, by physically disconnecting the non-working antenna from the corresponding chip using the switch module, further controlling the non-working chip to maintain power supply and a non-transmitting state brings two benefits. Firstly, since the physical disconnection cuts off the radio frequency path between the antenna and the chip, even if the chip maintains power supply, its radio frequency output cannot reach the antenna, thus avoiding interference with the working antenna. Secondly, maintaining power supply means that its internal registers and states are preserved. When switching from the current mode to another mode, the wake-up or enable time is much shorter than the power-on time after a complete power outage, resulting in a faster mode switching response. Furthermore, the current consumed in the power-on but non-transmitting state is typically much smaller than the normal operating current, resulting in limited power consumption increase for battery-powered devices. In some embodiments, if the device is power-sensitive or has a long standby time, the non-working chip can be completely powered off; this implementation is not excluded by the embodiments of this specification. By combining physical isolation of the switch with chip power supply state control, a trade-off between fast switching and low power consumption can be struck in practical applications.

[0133] In one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a tuning capacitor, a first switching module, a second switching module, and a control module; The first switch module is configured to selectively connect the first near-field communication antenna to the first near-field communication chip or the tuning capacitor; The second switch module is configured to selectively connect or disconnect the second near-field communication antenna from the second near-field communication chip. The control module is configured to: when the electronic device is operating in the second near-field communication mode, control the second switch module to connect the second near-field communication antenna to the second near-field communication chip, and control the first switch module to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit, wherein the tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0134] In practical applications, on the one hand, the control module outputs a first control signal, which puts the second switch module into a conducting state, and the two ends of the second near-field communication antenna are electrically connected to the radio frequency terminal of the second near-field communication chip. At this time, the second chip can transmit or receive radio frequency signals through the antenna, thus becoming a working antenna.

[0135] On the other hand, the control module outputs a second control signal, causing the first switch module to switch to the tuning capacitor path. The two ends of the first near-field communication antenna are electrically connected to the two ends of the tuning capacitor, forming an LC resonant circuit (tuning circuit). This tuning circuit itself does not actively transmit signals, but it will resonate under the excitation of an external alternating magnetic field, generating an induced current and a secondary magnetic field.

[0136] Specifically, when the second near-field communication antenna generates an alternating magnetic field as a working antenna, this magnetic field passes through the LC resonant circuit formed by the first near-field communication antenna. Since the resonant frequency of this circuit is configured to be close to the working frequency (e.g., 13.56MHz), a large resonant current is generated in the circuit. The secondary magnetic field generated by this current is superimposed in phase with the original magnetic field of the working antenna, thereby enhancing the total magnetic field strength around the working antenna and improving its effective communication distance or signal strength.

[0137] Take payment terminal equipment as an example.

[0138] In one configuration, the device includes: a first near-field communication chip, which is a tag chip, and a first near-field communication antenna, which is its matching antenna; a second near-field communication chip, which is a reader chip, and a second near-field communication antenna, which is its matching antenna; a tuning capacitor, the capacitance of which is pre-adjusted to match the inductance of the first near-field communication antenna, so that the resonant frequency of the LC circuit formed by the antenna and the capacitor is close to 13.56MHz; a first switching module using a single-pole double-throw switch, and a second switching module using a single-pole single-throw switch; and a control module, which is a microcontroller.

[0139] In one application scenario, the device needs to perform card reader functions (e.g., reading bank cards). In this case, the microcontroller outputs a control signal: turning on the second switching module, connecting the second near-field communication antenna to the reader chip, which then drives the antenna to emit a magnetic field to read external cards. Simultaneously, the first switching module switches the first near-field communication antenna to the tuning capacitor, meaning the tag antenna and the tuning capacitor form an LC resonant circuit. When the alternating magnetic field generated by the reader antenna passes through this resonant circuit, the circuit resonates, and the secondary magnetic field generated by the internal circulating current is superimposed on the magnetic field of the reader antenna, thereby enhancing the effective magnetic field of the reader antenna and increasing the reading distance and reliability.

[0140] In another configuration, the first chip is a reader chip, the second chip is a tag chip, and the tuning capacitor is associated with the reader antenna. In this case, the aforementioned control operation connects the tag antenna to the tag chip, while the reader antenna switches to the tuning capacitor as an enhancement coil to amplify the magnetic field response when the tag antenna is recognized by an external card reader.

[0141] Based on some embodiments of this specification, the control module connects the second antenna to the second chip via a second switch module, while simultaneously connecting the first antenna to a tuning capacitor via a first switch module, enabling the two antennas to work collaboratively in different roles. Since the LC circuit formed by the tuning capacitor and the first antenna is configured to resonate near the operating frequency of the second chip, when the second antenna transmits an alternating magnetic field as a working antenna, this resonant circuit is excited by the magnetic field, generating a large resonant current. The secondary magnetic field generated is superimposed in phase with the original magnetic field of the working antenna, thereby enhancing the effective radiation capability of the working antenna. This mechanism transforms the first antenna, which might otherwise be idle, into a passive magnetic field enhancement coil, improving the communication distance and reliability of the second antenna. Simultaneously, since the first antenna is physically disconnected from the first chip via a switch, the parasitic parameters of the first chip are avoided from affecting the resonant circuit, and there is no need to power off the first chip, facilitating rapid mode switching. Furthermore, this circuit unit does not require a large space distance between the two antennas, reducing the requirements for device layout.

[0142] In one or more embodiments of this specification, a circuit unit is provided for use in an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first tuning capacitor, a second tuning capacitor, a first switching module, a second switching module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to connect the second near-field communication antenna to the second tuning capacitor to form a first tuning circuit. The first tuning circuit is used to enhance the magnetic field generated by the first near-field communication antenna. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to connect the first near-field communication antenna to the first tuning capacitor to form a second tuning circuit. The second tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0143] The first switch module is configured to selectively connect the first near-field communication antenna to the first near-field communication chip or the first tuning capacitor; the second switch module is configured to selectively connect the second near-field communication antenna to the second near-field communication chip or the second tuning capacitor.

[0144] In practical applications, the operation in the first near-field communication mode includes: the control module causing the first switch module to connect the first near-field communication antenna to the first near-field communication chip, enabling the first chip to operate through the antenna; simultaneously, the second switch module causes the second near-field communication antenna to connect to the second tuning capacitor, forming a first tuning circuit. This tuning circuit is used to enhance the magnetic field generated by the first operating antenna.

[0145] Operation in the second near-field communication mode includes: the control module causing the second switch module to connect the second near-field communication antenna to the second near-field communication chip, enabling the second chip to operate through the antenna; simultaneously, the first switch module connecting the first near-field communication antenna to the first tuning capacitor, forming a second tuning circuit. This tuning circuit is used to enhance the magnetic field generated by the second operating antenna.

[0146] Taking a payment terminal device as an example, the device is configured as follows: the first chip is a reader / writer chip, and the first antenna is its matching antenna; the second chip is a tag chip, and the second antenna is its matching antenna; a first tuning capacitor (matching the first antenna) and a second tuning capacitor (matching the second antenna) are configured respectively; both the first and second switch modules use SPDT or DPDT switches; the control module is a microcontroller.

[0147] When the device enters reader mode (first mode), the microcontroller controls the first switching module to connect the first antenna to the reader chip, and the reader chip drives the antenna to emit a magnetic field. Simultaneously, it controls the second switching module to connect the second antenna to the second tuning capacitor, making the second antenna a resonant circuit. This resonant circuit generates an in-phase secondary magnetic field under the magnetic field excitation of the working antenna, enhancing the card reading distance.

[0148] When the device enters card emulation mode (second mode), the microcontroller controls the second switch module to connect the second antenna to the tag chip, and the tag chip emulates the card; at the same time, it controls the first switch module to connect the first antenna to the first tuning capacitor, so that the first antenna becomes a resonant circuit and enhances the response magnetic field of the tag antenna.

[0149] In both modes, the non-working antenna is converted into a passive enhancement coil of the working antenna.

[0150] Based on some embodiments of this specification, the control module connects the working antenna to the corresponding chip in two modes, while simultaneously connecting the non-working antenna to the corresponding tuning capacitor, forming an LC resonant circuit with the tuning capacitor. Since the two tuning capacitors are configured to match the inductance of their respective antennas, their resonant frequencies are close to the operating frequencies. When the working antenna generates an alternating magnetic field, the resonant circuit formed by the non-working antenna is excited to resonate, and its secondary magnetic field is superimposed on the magnetic field of the working antenna, thereby enhancing the effective radiation of the working antenna. This mechanism achieves mutual enhancement in two directions: in reader mode, the tag antenna becomes the tuning coil of the reader antenna, and in card emulation mode, the reader antenna becomes the tuning coil of the tag antenna. Compared to a scheme that only sets a tuning capacitor on one side, this circuit unit can achieve magnetic field enhancement in both modes, and the two antennas do not need to be placed at a large distance within the device. Furthermore, since the switch physically disconnects the connection between the chip and the antenna, the non-working chip can maintain power supply without interference, simplifying power management.

[0151] In one or more embodiments of this specification, the first near-field communication mode is one of a reader mode and a card emulation mode, and the second near-field communication mode is the other of the reader mode and the card emulation mode.

[0152] Optionally, the first near-field communication mode is a reader mode, the second near-field communication mode is a card emulation mode, the first near-field communication chip is a reader chip, and the second near-field communication chip is a tag chip. In this mode, the first tuning capacitor is associated with the reader antenna, and the second tuning capacitor is associated with the tag antenna. In card emulation mode, the reader antenna connected to the first tuning capacitor becomes the enhancement coil of the tag antenna; in reader mode, the tag antenna connected to the second tuning capacitor becomes the enhancement coil of the reader antenna.

[0153] Alternatively, the first near-field communication mode is a card emulation mode, and the second near-field communication mode is a reader mode. The first near-field communication chip is a tag chip, and the second near-field communication chip is a reader chip. In this case, the first tuning capacitor is associated with the tag antenna, and the second tuning capacitor is associated with the reader antenna. In card emulation mode, the reader antenna connected to the second tuning capacitor becomes the enhancement coil of the tag antenna; in reader mode, the tag antenna connected to the first tuning capacitor becomes the enhancement coil of the reader antenna.

[0154] Based on some embodiments in this specification, both correspondences can achieve bidirectional enhancement. The difference lies in which antenna the tuning capacitor is associated with, which affects the resonant characteristics of that antenna when acting as an enhancement coil (because different antenna inductances require different tuning capacitor values). In practical applications, the control module can correctly switch between the two modes, allowing a non-operating antenna to become the tuning coil of an operating antenna in the corresponding mode, thereby improving the communication performance of the device in both directions.

[0155] In one or more embodiments of this specification, the first tuning circuit is configured to: when the first near-field communication antenna is in operation, the first tuning circuit electromagnetically couples with the first near-field communication antenna to enhance the magnetic field generated by the first near-field communication antenna; the second tuning circuit is configured to: when the second near-field communication antenna is in operation, the second tuning circuit electromagnetically couples with the second near-field communication antenna to enhance the magnetic field generated by the second near-field communication antenna.

[0156] More specifically, the resonant frequency of the first tuning circuit is configured such that the difference between it and the operating frequency of the first near-field communication chip is less than a first preset threshold; the resonant frequency of the second tuning circuit is configured such that the difference between it and the operating frequency of the second near-field communication chip is less than a second preset threshold.

[0157] The first preset threshold and the second preset threshold can be the maximum allowable deviation between the resonant frequency and the corresponding chip operating frequency. The threshold can be a relative value (e.g., ±5% of the operating frequency) or an absolute value (e.g., ±1MHz). The first preset threshold and the second preset threshold can be the same or different.

[0158] In practical applications, during the equipment debugging phase, the capacitance of the first tuning capacitor can be adjusted so that the difference between the resonant frequency of the LC circuit formed by the first near-field communication antenna and the first tuning capacitor and the operating frequency of the first chip is less than a first preset threshold. Similarly, the second tuning capacitor can be adjusted so that the difference between the resonant frequency of the second circuit and the operating frequency of the second chip is less than a second preset threshold.

[0159] For example, the first chip operates at 13.56MHz, with a first preset threshold set to ±5% (i.e., ±0.678MHz). After measuring the inductance of the first antenna using an LCR bridge, the initial capacitance value is calculated. Then, an adjustable capacitor or capacitor array is used for fine-tuning, ensuring the resonant frequency falls within the range of 13.56MHz ±0.678MHz (e.g., 13.0MHz to 14.2MHz). The second chip also operates at 13.56MHz, with a second preset threshold set to ±1MHz. After tuning, the resonant frequency falls within the range of 12.56MHz to 14.56MHz. In practical applications, the threshold can be adjusted according to the required enhancement effect.

[0160] Based on some embodiments of this specification, the resonant frequencies of the two tuning circuits are configured such that the difference between them and the operating frequencies of their respective chips is less than a preset threshold. This allows the LC circuit formed by the non-operating antenna on the other side and the tuning capacitor to resonate near the operating frequency when one chip drives its antenna to operate, thereby generating a large resonant current and a secondary magnetic field. The preset threshold ensures the effectiveness of the resonance enhancement while allowing for certain engineering errors and mass production tolerances. By setting two thresholds separately, the enhancement intensity in both directions can be independently controlled, providing a certain degree of design flexibility.

[0161] In one or more embodiments of this specification, a differential structure of the first near-field communication antenna and an implementation of the first switching module are further provided.

[0162] Specifically, in the circuit unit, the first near-field communication antenna has a first antenna end and a second antenna end; the first switch module is configured to synchronously connect the first antenna end and the second antenna end to the two radio frequency ends of the first near-field communication chip or synchronously connect them to the two ends of the first tuning capacitor.

[0163] Optionally, the first near-field communication antenna has a first antenna end and a second antenna end; the first switch module includes a first single-pole double-throw switch and a second single-pole double-throw switch; the common terminal of the first single-pole double-throw switch is connected to the first antenna end of the first near-field communication antenna, the first throw is connected to the first differential terminal of the first near-field communication chip, and the second throw is connected to the first terminal of the first tuning capacitor; the common terminal of the second single-pole double-throw switch is connected to the second antenna end of the first near-field communication antenna, the first throw is connected to the second differential terminal of the first near-field communication chip, and the second throw is connected to the second terminal of the first tuning capacitor.

[0164] In practical applications, the control module can output one control signal (or two synchronization signals) to the control terminals of the two SPDTs. When it is necessary to connect the antenna to the chip, the common terminals of the two SPDTs are simultaneously switched to the first throw; when it is necessary to connect the antenna to the tuning capacitor, they are simultaneously switched to the second throw. The switching actions are kept synchronized.

[0165] Alternatively, similar to the description of circuit unit 200 above, the first switching module can also be implemented using a double-pole double-throw switch (DPDT). Alternatively, a chip integrating two independent SPDTs within a single package and sharing control logic can be used. Alternatively, a first switching module composed of PIN diodes or field-effect transistors (FETs) can be used.

[0166] Based on some embodiments of this specification, by configuring the first switch module to synchronously connect the two endpoints of the first near-field communication antenna to the differential terminals of the chip or the tuning capacitor, the symmetrical operation of the differential antenna is ensured. Synchronous switching avoids differential signal imbalance caused by asynchrony between the two endpoints, thereby maintaining the antenna's radiation efficiency and the Q value of the resonant circuit. The specific implementation using two single-pole double-throw switches features universal components and simple control, and the two switches can be independently arranged to adapt to different PCB designs. The synchronous switching function ensures that in any operating mode, both ends of the antenna are always in the same connection state (either both connected to the chip or both connected to the capacitor), thereby ensuring the integrity of the LC resonant circuit.

[0167] In one or more embodiments of this specification, a differential structure of the second near-field communication antenna and an implementation of the second switching module are further provided.

[0168] Specifically, in the circuit unit, the second near-field communication antenna has a first antenna end and a second antenna end; the second switch module is configured to synchronously connect the first antenna end and the second antenna end to the two radio frequency ends of the second near-field communication chip or synchronously connect them to the two ends of the second tuning capacitor.

[0169] Optionally, the second near-field communication antenna has a first antenna end and a second antenna end; the second switching module includes a third single-pole double-throw switch and a fourth single-pole double-throw switch; the common terminal of the third single-pole double-throw switch is connected to the first antenna end of the second near-field communication antenna, the first throw is connected to the first differential terminal of the second near-field communication chip, and the second throw is connected to the first terminal of the second tuning capacitor; the common terminal of the fourth single-pole double-throw switch is connected to the second antenna end of the second near-field communication antenna, the first throw is connected to the second differential terminal of the second near-field communication chip, and the second throw is connected to the second terminal of the second tuning capacitor.

[0170] In practical applications, the control module can output one control signal (or two synchronization signals) to the control terminals of the two SPDTs. When it is necessary to connect the antenna to the chip, the common terminals of the two SPDTs are simultaneously switched to the first throw; when it is necessary to connect the antenna to the tuning capacitor, they are simultaneously switched to the second throw. The switching actions are kept synchronized.

[0171] Alternatively, similar to the description of circuit unit 200 above, the second switching module can also be implemented using a double-pole double-throw (DPDT) switch. Alternatively, a chip integrating two independent SPDTs within a single package and sharing control logic can be used. Alternatively, a second switching module composed of PIN diodes or field-effect transistors (FETs) can be used.

[0172] Based on some embodiments of this specification, the second switching module adopts a synchronous switching structure similar to the first switching module, ensuring that the differential characteristics of the second antenna are maintained in both modes. When the second antenna is used as a working antenna, symmetrical connection to the chip helps to output a balanced differential signal and reduce common-mode radiation; when the second antenna is used as a booster coil (connected to the second tuning capacitor), symmetrical connection ensures the symmetry of the LC resonant circuit, making the resonant current uniformly distributed and generating the expected in-phase booster magnetic field. Through the synchronous switching of the two switching modules, the entire circuit unit can achieve a balanced connection between the differential antenna and the chip or tuning capacitor in both operating modes, thereby obtaining better electromagnetic compatibility performance and enhancement effect.

[0173] Figure 5 This is a schematic diagram of the structural configuration of another circuit unit 300 provided in the embodiments of this specification in a practical application scenario.

[0174] In such Figure 5 In the configuration shown, the device supporting both reader mode (e.g., reading physical cards) and card emulation mode (e.g., being recognized by an external card reader) includes: a first near-field communication chip (NFC1_Reader) and a first near-field communication antenna (NFC antenna 1) as its matching antenna; a second near-field communication chip (NFC2_Tag) and a second near-field communication antenna (NFC antenna 2) as its matching antenna; a first tuning capacitor (CAP1), whose capacitance is pre-adjusted to match the inductance of the first near-field communication antenna, so that the resonant frequency of the LC circuit formed by the antenna and the capacitor is close to 13.56MHz; a second tuning capacitor (CAP2), whose capacitance is pre-adjusted to match the inductance of the second near-field communication antenna, so that the resonant frequency of the LC circuit formed by the antenna and the capacitor is close to 13.56MHz; a first switching module using two single-pole double-throw switches (SPDT1, SPDT2), and a second switching module using two single-pole double-throw switches (SPDT3, SPDT4); and a control module being a microcontroller (MCU).

[0175] The first near-field communication antenna is a differential antenna, having a first antenna terminal ANT1 and a second antenna terminal ANT2. The common terminal of SPDT1 is connected to ANT1, the first throw is connected to the first differential terminal NFC1_ANT1 of the first chip, and the second throw is connected to the first terminal CAP1_ANT1 of the first tuning capacitor CAP1. The common terminal of SPDT2 is connected to ANT2, the first throw is connected to the second differential terminal NFC1_ANT2 of the first chip, and the second throw is connected to the second terminal CAP1_ANT2 of the first tuning capacitor CAP1.

[0176] The second near-field communication antenna is also a differential antenna, with a first antenna terminal ANT3 and a second antenna terminal ANT4. The common terminal of SPDT3 is connected to ANT3, the first throw is connected to the first differential terminal NFC2_ANT1 of the second chip, and the second throw is connected to the first terminal CAP2_ANT1 of the second tuning capacitor CAP2. The common terminal of SPDT4 is connected to ANT4, the first throw is connected to the second differential terminal NFC2_ANT2 of the second chip, and the second throw is connected to the second terminal CAP2_ANT2 of the second tuning capacitor CAP2.

[0177] The microcontroller's control signals are connected to the control terminals of the four SPDTs. Two SPDTs (SPDT1 and SPDT2) are configured to operate synchronously: when the control signal is high, their common terminal is switched to the first throw (chip side); when the control signal is low, they are switched to the second throw (tuning capacitor side). Similarly, SPDT3 and SPDT4 also operate synchronously, and can be controlled by independent signals or associated with the aforementioned signals.

[0178] In practical applications, when the device enters reader mode (first near-field communication mode): the microcontroller outputs a control signal, causing SPDT1 and SPDT2 to connect the first near-field communication antenna to the reader chip. The reader chip drives the antenna to emit a magnetic field to read external physical or analog cards. Simultaneously, SPDT3 and SPDT4 connect the second near-field communication antenna to the second tuning capacitor CAP2. At this time, the second near-field communication antenna and CAP2 form an LC resonant circuit, resonating under the action of the alternating magnetic field generated by the first working antenna. The secondary magnetic field generated by its internal circulating current is superimposed in phase with the magnetic field of the first working antenna, thereby enhancing the magnetic field generated by the first near-field communication antenna and improving the card reading distance and reliability.

[0179] When the device enters card emulation mode (second near-field communication mode): the microcontroller outputs control signals, causing SPDT3 and SPDT4 to connect the second near-field communication antenna to the tag chip, which then emulates a card and communicates with an external card reader. Simultaneously, SPDT1 and SPDT2 connect the first near-field communication antenna to the first tuning capacitor CAP1. The first near-field communication antenna and CAP1 form an LC resonant circuit, resonating under the alternating magnetic field generated by the second working antenna. Its secondary magnetic field is in phase with the magnetic field of the second antenna, enhancing the magnetic field generated by the second antenna and improving the distance and reliability at which the device can be identified by an external card reader.

[0180] In this embodiment, bidirectional magnetic field enhancement is achieved by configuring a tuning capacitor for each antenna and having the control module switch the non-working antenna to the corresponding tuning capacitor according to the operating mode. In reader mode, the tag antenna becomes the tuning coil of the reader antenna, increasing the transmitted magnetic field strength; in card emulation mode, the reader antenna becomes the tuning coil of the tag antenna, increasing the response magnetic field strength. This mechanism transforms the potential inter-antenna coupling interference into a beneficial bidirectional enhancement, while allowing the two antennas to be compactly arranged within the device, reducing space requirements. Four SPDT switches are used to control the two endpoints of the differential antenna respectively, ensuring the symmetry of the differential signal and the reliability of the switching.

[0181] In one or more embodiments of this specification, an electronic device is provided that may include circuit units as described in any of the above embodiments.

[0182] Taking a payment terminal device as an example, this device can be a handheld or desktop payment terminal used to process contactless payment transactions. The device internally houses the aforementioned circuit unit, including a first near-field communication chip (e.g., a reader / writer chip), a first near-field communication antenna, a second near-field communication chip (e.g., a tag chip), a second near-field communication antenna, and one or two tuning capacitors and corresponding switching and control modules. One or more sensing areas can be provided on the device's casing, corresponding to the positions of the two antennas. Due to the aforementioned circuit unit, the spacing between the two antennas inside the device can be relatively small; for example, the closest distance between them can be within a few millimeters to one or two centimeters, without needing to deliberately increase the distance to avoid interference. Of course, even if the spacing between the two antennas inside the device is relatively large, it does not affect the implementation of the embodiments described in this specification.

[0183] In some embodiments, the electronic device can also be a vending machine, an access control panel, a vehicle-mounted NFC module, an identity recognition terminal, or a smartphone supporting dual-mode NFC functionality. Taking a vending machine as an example, the reader antenna within the device can be used to read the user's payment card or mobile phone to complete the transaction; the tag antenna within the device can be identified by the management terminal to download product prices or update inventory information. If a circuit unit with bidirectional enhancement capabilities (such as...) is used... Figure 4 (Example), both operations can achieve a longer effective communication distance and a higher success rate.

[0184] In other embodiments, the electronic device may require only unidirectional enhancement, such as a certain type of access control card reader where the reader mode is used frequently and the card emulation mode is used only occasionally for configuration. In this case, a more suitable approach can be adopted. Figure 2 or Figure 3The asymmetric circuit unit shown in the diagram is where the tuning capacitor is associated with only one side of the antenna. The control module switches the antenna to the tuning capacitor or disconnects it based on the operating mode. This reduces component costs while maintaining core functionality.

[0185] The operation of the electronic device is automatically executed by its internal microcontroller (as a control module) based on the required function (e.g., the device receiving a business instruction or sensing a trigger condition). The microcontroller outputs control signals, causing the switching module to switch the antenna connection state according to preset logic. In the bidirectional enhancement scheme, regardless of whether the device is in reader mode or card emulation mode, the non-working antenna is switched to the corresponding tuning capacitor, forming a resonant circuit, thereby enhancing the magnetic field of the working antenna. This process is imperceptible to the user; the user only experiences a more stable communication distance and faster transaction response speed.

[0186] Based on the above configuration, this electronic device can accommodate a dual-antenna, dual-chip system within a limited internal space, ensuring communication performance in both NFC operating modes while avoiding signal interference caused by excessively close antenna spacing. For battery-powered portable devices, since there is no need to frequently power off inactive chips, mode switching latency is lower, which helps improve the user experience. Furthermore, the number of components in the circuit unit is relatively small (mainly increasing switches and capacitors), limiting the impact on overall cost and reliability.

[0187] In Near Field Communication (NFC) applications, some electronic devices need to support both reader mode and card emulation mode simultaneously. For example, in financial payment terminals, access control devices, and vehicle control terminals, the device needs to actively read information from external NFC cards or mobile terminals, and also passively be identified by external card readers to provide its own tag information. In traditional solutions, these two modes often require separate antennas and chips, and the antennas are prone to interference, affecting communication performance. Therefore, a method is needed that can flexibly switch between the two modes and improve antenna performance.

[0188] Based on the same ideas as the circuit units and electronic devices provided above, embodiments of this specification also provide near-field communication methods corresponding to the electronic devices of the circuit units described above.

[0189] In one or more embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, and a tuning capacitor; the method includes: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the connection between the second near-field communication chip and the second near-field communication antenna is disconnected. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the tuning capacitor to form a tuning circuit to enhance the magnetic field generated by the second near-field communication antenna.

[0190] In some embodiments, the first near-field communication mode is a card reader mode, the second near-field communication mode is a card emulation mode, the first near-field communication chip is a reader / writer chip, and the second near-field communication chip is a tag chip; or, the first near-field communication mode is a card emulation mode, the second near-field communication mode is a card reader mode, the first near-field communication chip is a tag chip, and the second near-field communication chip is a reader / writer chip.

[0191] In some embodiments, the method further includes a step of pre-adjusting the capacitance value of the tuning capacitor so that the difference between the resonant frequency of the tuning circuit and the operating frequency of the second near-field communication chip is less than a preset threshold (for example, at an operating frequency of 13.56MHz, the preset threshold can be set to ±5% or ±1MHz).

[0192] Taking a payment terminal device as an example, the device contains: a first chip, a reader chip, and a first antenna, which is its matching antenna; a second chip, a tag chip, and a second antenna, which is its matching antenna; and a tuning capacitor, the capacitance of which is pre-adjusted to match the inductance of the first antenna, so that the resonant frequency of the LC circuit formed by the first antenna and the capacitor is close to 13.56MHz. The device can default to reader mode (first mode). When a user approaches with a physical NFC card or a mobile terminal simulating an NFC card, the device connects the first antenna to the reader chip and simultaneously disconnects the second antenna (e.g., physically disconnecting it via a series switch) to prevent the second antenna from interfering with the working antenna. The reader chip then transmits a radio frequency field through the first antenna to read information from the external card.

[0193] When the device needs to switch to card emulation mode (second mode), for example, when it needs to be recognized by an external card reader terminal, the device connects the second antenna to the tag chip and simultaneously switches the first antenna to the tuning capacitor. At this time, the first antenna and the tuning capacitor form an LC resonant circuit. When the radio frequency field emitted by the external card reader (e.g., a maintenance terminal) acts on the second antenna, the second antenna acts as a working antenna to communicate with the external card reader; simultaneously, this radio frequency field also excites the resonant circuit formed by the first antenna, causing it to generate a resonant current and a secondary magnetic field. This secondary magnetic field is superimposed in phase with the original magnetic field of the second antenna, thereby enhancing the effective radiation of the second antenna and improving the distance and reliability at which the device is recognized by the external card reader.

[0194] In some embodiments, the electronic device may default to card emulation mode. Alternatively, the electronic device may default to card reader mode and continuously monitor preset types of wireless signals in the surrounding environment (e.g., Bluetooth signals, cellular network signals, or satellite navigation signals). When the wireless signal is detected, it can be determined that a mobile communication terminal is approaching, and the device automatically switches from card reader mode to card emulation mode. Alternatively, the electronic device may default to card reader mode and can switch to card emulation mode in response to a user's trigger operation. In card emulation mode, the second mode operation in the above method can be performed—connecting the second antenna to the tag chip and the first antenna to the tuning capacitor. In this way, when the user holds the mobile terminal close to the device, the mobile terminal can quickly read the tag information in the device, thereby waking up the application on the mobile terminal and realizing "tap-to-read" interaction. If the tag information is not successfully read for some reason and the timeout occurs, the device can also switch back to card reader mode to read the information of the simulated NFC card in the mobile terminal. In this scenario, the antenna switching and tuning enhancement mechanism in this embodiment can significantly improve the probability of successful reading of tag information and extend the effective sensing distance.

[0195] Based on some embodiments of this specification, the method performs different antenna connection operations in two operating modes: In the first mode, the working antenna is connected to the corresponding chip, and the non-working antenna is physically disconnected, reducing parasitic coupling interference from the non-working antenna to the working antenna; in the second mode, the working antenna is connected to the corresponding chip, and the non-working antenna is switched to a tuning capacitor to form an LC resonant circuit. Since the resonant frequency of this circuit is configured close to the operating frequency, when the working antenna emits an alternating magnetic field, the resonant circuit is excited to generate an in-phase secondary magnetic field, thereby enhancing the effective radiation of the working antenna. This mechanism transforms the non-working antenna, which might otherwise cause interference, into a beneficial passive enhancement coil, improving communication distance and reliability. Simultaneously, since the connection between the non-working antenna and the corresponding chip is physically disconnected, there is no need to power down the non-working chip, simplifying power management and mode switching response time. This method is particularly suitable for electronic devices that need to integrate a dual-antenna, dual-chip system in a compact space, such as financial payment terminals, access control card readers, and automotive NFC modules.

[0196] In one or more embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, and a tuning capacitor; the method includes: when the electronic device is operating in the second near-field communication mode, connecting the second near-field communication antenna to the second near-field communication chip, and connecting the first near-field communication antenna to the tuning capacitor to form a tuning circuit, the tuning circuit being used to enhance the magnetic field generated by the second near-field communication antenna.

[0197] In practical applications, this method is suitable for scenarios where only the second mode (e.g., card emulation mode) is relevant, or where the device only requires enhanced performance in a specific mode. Taking a vending machine as an example, the device is configured with: a first chip as a reader chip and a first antenna as its associated antenna; a second chip as a tag chip and a second antenna as its associated antenna; and a tuning capacitor connected to the first antenna. During normal operation, the device may spend most of its time in reader mode (first mode), at which point the tuning capacitor is not used. However, when the device needs to be configured or updated by a management terminal, it enters card emulation mode (second mode). At this time, the method executes: connecting the second antenna to the tag chip and simultaneously connecting the first antenna to the tuning capacitor. The resonant circuit formed by the first antenna and the tuning capacitor resonates under the excitation of the radio frequency field of the external management terminal, enhancing the response signal of the second antenna and ensuring that configuration data can be transmitted stably and quickly.

[0198] In some embodiments, the device may default to card emulation mode. Alternatively, the device may default to reader mode, and when an NFC-enabled mobile communication terminal approaches the device, the device can anticipate the user's intent by detecting non-NFC wireless signals such as Bluetooth signals and switch from reader mode to card emulation mode in advance. Alternatively, the device may default to reader mode and can switch modes in response to user triggering. After this switching is complete, the steps of this embodiment can be executed: connecting the antenna (second antenna) corresponding to the tag chip to the tag chip, and connecting the antenna (first antenna) corresponding to the reader chip to the tuning capacitor. In this way, the user only needs to bring the mobile terminal close to the device to quickly read the tag information and launch the application. The enhancement mechanism in this embodiment can extend the effective sensing distance and reduce reading failures caused by user placement deviations.

[0199] Based on some embodiments of this specification, when the electronic device is operating in the second near-field communication mode, this method switches the non-operating first antenna to a tuning capacitor, creating a magnetic field-enhanced coupling between it and the operating antenna (the second antenna). Since the capacitance of the tuning capacitor is configured to match the inductance of the first antenna, the resonant frequency is close to the operating frequency. The alternating magnetic field emitted by the operating antenna can excite a large in-phase secondary magnetic field in the resonant circuit, thereby enhancing the effective radiation of the operating antenna. This effect improves the response distance and reliability of the device in card emulation mode, making it particularly suitable for scenarios requiring passive identification by an external card reader, such as "tap-to-pay," access control, and payment terminal check-in. Furthermore, this method only requires specific operations in the second mode, making it simple to implement and requiring minimal hardware modifications.

[0200] In one or more embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, and a second near-field communication antenna; the method includes: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the connection between the second near-field communication chip and the second near-field communication antenna is disconnected. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the connection between the first near-field communication chip and the first near-field communication antenna is disconnected.

[0201] In this embodiment, interference is isolated by physically disconnecting the non-operating antenna. Taking a simple access control device that needs to support both reader mode and card emulation mode as an example, the device is configured with: a first chip (reader chip) and a first antenna; and a second chip (tag chip) and a second antenna. The device may not require a tuning capacitor. When the device operates in reader mode (first mode), the method executes as follows: the first antenna is connected to the reader chip, allowing the reader chip to transmit a radio frequency field to read external cards; simultaneously, the second antenna is disconnected (e.g., by disconnecting its connection to the tag chip via a series SPST switch), leaving both ends of the second antenna suspended to reduce its induced interference to the operating antenna. When the device operates in card emulation mode (second mode), the method executes as follows: the second antenna is connected to the tag chip, allowing the tag chip to emulate a card and communicate with the external reader; simultaneously, the first antenna is disconnected to prevent the first antenna from interfering with the second antenna.

[0202] This method can be used in some low-cost devices or devices with low performance requirements. For example, in some scenarios, the device defaults to card reader mode, continuously detecting Bluetooth signals. When a mobile terminal is detected approaching, the device switches to card emulation mode and performs the operation of connecting the second antenna to the tag chip and disconnecting the first antenna. Since the first antenna is physically disconnected, its metal conductor does not form a closed loop, thus suppressing coupling interference to the second antenna to a low level. This method is simple to implement in hardware, requiring only two sets of switches, and is inexpensive.

[0203] Based on some embodiments of this specification, this method physically disconnects the non-working antenna in both modes. Compared to simply powering off the non-working chip (whose antenna still forms a closed loop through the chip's internal circuitry), physical disconnection more effectively suppresses induced current in the non-working antenna, thereby reducing detuning effects and energy absorption on the working antenna. The two antennas can be arranged in close proximity without severe mutual interference, reducing the space requirements for antenna layout. Simultaneously, since powering off the non-working chip is not required, mode switching response is fast. This method is suitable for cost-sensitive scenarios that do not require magnetic field enhancement, such as simple access control card readers or check-in terminals.

[0204] In one or more embodiments of this specification, a near-field communication method is provided, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first tuning capacitor, and a second tuning capacitor; comprising: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the second near-field communication antenna is connected to the second tuning capacitor to form a first tuning circuit. The first tuning circuit is used to enhance the magnetic field generated by the first near-field communication antenna. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the first tuning capacitor to form a second tuning circuit. The second tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

[0205] Taking a payment terminal as an example, the device is equipped with: a first chip as a reader / writer chip and a first antenna; a second chip as a tag chip and a second antenna; and a first tuning capacitor (matched with the first antenna) and a second tuning capacitor (matched with the second antenna) are configured respectively. The device supports bidirectional enhancement in both reader mode and card emulation mode.

[0206] When the device is in card reader mode (first mode), the method is as follows: A first antenna is connected to the reader chip, which drives the first antenna to emit a radio frequency field to read external cards. Simultaneously, a second antenna is connected to a second tuning capacitor, forming a first tuning circuit. This tuning circuit resonates under the excitation of the alternating magnetic field generated by the first antenna, producing a secondary magnetic field of the same phase, thereby enhancing the magnetic field strength of the first antenna and improving the card reading distance and success rate.

[0207] When the device is in card emulation mode (second mode), the method executes as follows: a second antenna is connected to the tag chip, which emulates a card and communicates with an external card reader; simultaneously, a first antenna is connected to a first tuning capacitor, forming a second tuning circuit. This tuning circuit resonates under the excitation of the alternating magnetic field generated by the second antenna, enhancing the magnetic field of the second antenna and improving the distance and reliability at which the device can be identified by an external card reader.

[0208] In some scenarios, devices need to be compatible with multiple interaction methods, including physical NFC cards, mobile terminal "tap-to-read," and mobile terminal simulating NFC cards. This embodiment is particularly suitable for such scenarios requiring high bidirectional performance. For example, the device defaults to reader mode, continuously transmitting a card search signal to read physical NFC cards. Simultaneously, the device continuously monitors wireless signals such as Bluetooth. When a mobile terminal is detected approaching based on a wireless signal and the distance is less than a threshold, the device can temporarily switch to card simulating mode and execute a second mode operation (the second antenna is connected to the tag chip, and the first antenna is connected to the first tuning capacitor) so that the mobile terminal can read the tag information by "tap-to-read." If the tag information reading fails due to a timeout, the device can switch back to reader mode and execute the first mode operation (the first antenna is connected to the reader chip, and the second antenna is connected to the second tuning capacitor) to read the information of the simulated NFC card in the mobile terminal. During this process, the bidirectional enhancement mechanism of this embodiment can significantly improve the communication success rate under each interaction method.

[0209] Based on some embodiments of this specification, this method connects the working antenna to the corresponding chip in both operating modes, while simultaneously connecting the non-working antenna to a matching tuning capacitor, forming a resonant circuit. Since the two tuning capacitors are configured to match the inductance of their respective antennas, and the resonant frequency is close to the operating frequency, the non-working antenna can act as a passive enhancement coil for the working antenna, generating a co-phase secondary magnetic field and enhancing the effective radiation of the working antenna, regardless of whether the device is in reader mode or card emulation mode. This bidirectional enhancement mechanism improves the communication performance of the device in both directions, and the two antennas can be compactly arranged within the device without interfering with each other. Compared to a scheme that only sets a tuning capacitor on one side, this embodiment provides balanced performance optimization, suitable for scenarios that require simultaneous assurance of card reading distance and card emulation distance, such as high-end payment terminals and smart access control machines. Furthermore, since the switch physically disconnects the connection between the chip and the antenna, the non-working chip can maintain power supply without interference, which is beneficial for rapid mode switching.

[0210] From a procedural perspective, the execution entity of the near-field communication method provided in this specification can be the control module (e.g., microcontroller, MCU) and its controlled switch module and radio frequency front-end circuit in the electronic device (circuit unit). Specifically, the electronic device can be a financial payment terminal, access control device, vehicle NFC module, vending machine, smartphone, or any device supporting dual-mode NFC functionality. The control module, based on the device's current operating mode (reader mode or card emulation mode), drives the first and second switch modules to perform corresponding antenna connection or disconnection operations by outputting control signals. The switch module can be a single-pole double-throw switch, a single-pole single-throw switch, a double-pole double-throw switch, or an integrated radio frequency switch chip. When executing the method, the control module reads its internal state or receives external trigger signals (such as user operation, wireless signal detection results, etc.) to determine the currently required operating mode, and controls the switching module's conduction and switching according to the steps in the method, thereby achieving the selection of the connection path between the antenna and the chip or tuning capacitor. Those skilled in the art will understand that the various steps of the method can be executed by hardware circuits (such as logic controllers, application-specific integrated circuits) in the electronic device, or implemented by the microcontroller executing firmware or software instructions.

[0211] While one or more embodiments of this specification provide method steps as described in the embodiments or flowcharts, it is understood that the order of steps listed in the embodiments or flowcharts is merely one possible execution order among many steps and does not represent the only possible execution order. The order of some steps may be adjusted according to actual needs, or some steps may be omitted. When the claims involve method steps, changes in the order of such steps, or parallel execution between steps, are also within the scope of protection of the claims.

[0212] The various technical features in the above embodiments can be combined arbitrarily, as long as there is no conflict or contradiction between the combinations of features. However, due to space limitations, they have not been described one by one. Therefore, the arbitrary combination of various technical features in the above embodiments is also within the scope of this specification.

[0213] The above is an illustrative scheme of a near-field communication method according to this embodiment. It should be noted that the technical solution of this near-field communication method and the technical solution of the electronic unit described above belong to the same concept. For details not described in detail in the technical solution of the near-field communication method, please refer to the description of the technical solution of the electronic unit described above.

[0214] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and method embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The devices, methods and electronic units provided in the embodiments of this specification correspond to each other, and therefore the devices and methods also have similar beneficial technical effects as the corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the corresponding devices and methods will not be repeated here.

[0215] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0216] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A circuit unit applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a tuning capacitor, a first switching module, a second switching module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to disconnect. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit. The tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

2. The circuit unit as described in claim 1, wherein the first near-field communication mode is a card reader mode, the second near-field communication mode is a card emulation mode, the first near-field communication chip is a reader / writer chip, and the second near-field communication chip is a tag chip; or, The first near-field communication mode is a card emulation mode, the second near-field communication mode is a card reader mode, the first near-field communication chip is a tag chip, and the second near-field communication chip is a reader / writer chip.

3. The circuit unit as described in claim 1, wherein the resonant frequency of the tuning circuit is configured such that the difference between the resonant frequency and the operating frequency of the second near-field communication chip is less than a preset threshold.

4. The circuit unit as described in claim 1, wherein the first near-field communication antenna has a first antenna end and a second antenna end; the first switch module is configured to synchronously connect the first antenna end and the second antenna end to two radio frequency ends of the first near-field communication chip or synchronously connect them to two ends of the tuning capacitor.

5. The circuit unit as described in claim 1, wherein the second near-field communication antenna has a first antenna end and a second antenna end; the second switch module is configured to simultaneously connect the first antenna end and the second antenna end to the two radio frequency ends of the second near-field communication chip or to simultaneously disconnect them.

6. The circuit unit according to claim 1, wherein when the electronic device is operating in the first near-field communication mode, the second near-field communication chip is kept powered and in a non-transmitting state; and when the electronic device is operating in the second near-field communication mode, the first near-field communication chip is kept powered and in a non-transmitting state.

7. A circuit unit applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a tuning capacitor, a first switching module, a second switching module, and a control module; The first switch module is configured to selectively connect the first near-field communication antenna to the first near-field communication chip or the tuning capacitor; The second switch module is configured to selectively connect or disconnect the second near-field communication antenna from the second near-field communication chip. The control module is configured to: when the electronic device is operating in the second near-field communication mode, control the second switch module to connect the second near-field communication antenna to the second near-field communication chip, and control the first switch module to connect the first near-field communication antenna to the tuning capacitor to form a tuning circuit, wherein the tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

8. A circuit unit applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first switch module, a second switch module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to disconnect. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to disconnect.

9. A circuit unit applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the circuit unit includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first tuning capacitor, a second tuning capacitor, a first switching module, a second switching module, and a control module; The control module is configured as follows: When the electronic device is operating in the first near-field communication mode, the first switch module is controlled to connect the first near-field communication antenna to the first near-field communication chip, and the second switch module is controlled to connect the second near-field communication antenna to the second tuning capacitor to form a first tuning circuit. The first tuning circuit is used to enhance the magnetic field generated by the first near-field communication antenna. When the electronic device is operating in the second near-field communication mode, the second switch module is controlled to connect the second near-field communication antenna to the second near-field communication chip, and the first switch module is controlled to connect the first near-field communication antenna to the first tuning capacitor to form a second tuning circuit. The second tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

10. The circuit unit as described in claim 9, wherein the first near-field communication mode is a card reader mode, the second near-field communication mode is a card emulation mode, the first near-field communication chip is a reader / writer chip, and the second near-field communication chip is a tag chip; or, The first near-field communication mode is a card emulation mode, the second near-field communication mode is a card reader mode, the first near-field communication chip is a tag chip, and the second near-field communication chip is a reader / writer chip.

11. The circuit unit of claim 9, wherein the resonant frequency of the first tuning circuit is configured such that the difference between it and the operating frequency of the first near-field communication chip is less than a first preset threshold; and the resonant frequency of the second tuning circuit is configured such that the difference between it and the operating frequency of the second near-field communication chip is less than a second preset threshold.

12. The circuit unit of claim 9, wherein the first near-field communication antenna has a first antenna end and a second antenna end; the first switch module is configured to synchronously connect the first antenna end and the second antenna end to two radio frequency ends of the first near-field communication chip or synchronously connect them to two ends of the first tuning capacitor.

13. The circuit unit of claim 9, wherein the second near-field communication antenna has a first antenna end and a second antenna end; the second switch module is configured to synchronously connect the first antenna end and the second antenna end to two radio frequency ends of the second near-field communication chip or synchronously connect them to two ends of the second tuning capacitor.

14. An electronic device comprising the circuit unit according to any one of claims 1 to 13.

15. A near-field communication method applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device comprising a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, and a tuning capacitor; the method comprising: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the connection between the second near-field communication chip and the second near-field communication antenna is disconnected. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the tuning capacitor to form a tuning circuit to enhance the magnetic field generated by the second near-field communication antenna.

16. A near-field communication method applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device comprising a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, and a tuning capacitor; the method comprising: When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the tuning capacitor to form a tuning circuit, which is used to enhance the magnetic field generated by the second near-field communication antenna.

17. A near-field communication method, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, and a second near-field communication antenna; The method includes: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the connection between the second near-field communication chip and the second near-field communication antenna is disconnected. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the connection between the first near-field communication chip and the first near-field communication antenna is disconnected.

18. A near-field communication method, applied to an electronic device supporting a first near-field communication mode and a second near-field communication mode; the electronic device includes a first near-field communication chip supporting the first near-field communication mode, a first near-field communication antenna, a second near-field communication chip supporting the second near-field communication mode, a second near-field communication antenna, a first tuning capacitor, and a second tuning capacitor; comprising: When the electronic device is operating in the first near-field communication mode, the first near-field communication antenna is connected to the first near-field communication chip, and the second near-field communication antenna is connected to the second tuning capacitor to form a first tuning circuit. The first tuning circuit is used to enhance the magnetic field generated by the first near-field communication antenna. When the electronic device is operating in the second near-field communication mode, the second near-field communication antenna is connected to the second near-field communication chip, and the first near-field communication antenna is connected to the first tuning capacitor to form a second tuning circuit. The second tuning circuit is used to enhance the magnetic field generated by the second near-field communication antenna.

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