Card reading circuit and near field communication equipment

Abstract

The utility model discloses a card reading circuit and near field communication equipment. The card reading circuit comprises a near field communication module, a plurality of matching modules, a selection module and a plurality of antenna modules. The plurality of matching modules and the selection module are connected between the near field communication module and the plurality of antenna modules. The plurality of matching modules are respectively corresponding to the plurality of antenna modules. The selection module is used for controlling the working states of the plurality of antenna modules. According to the card reading circuit and the near field communication equipment, the selection module is additionally arranged in an original circuit, each antenna module is provided with the independent matching module, flexible selection of antennas can be achieved, the card reading distance can be optimized, and when the antenna module is additionally arranged on a single near field communication module, the card reading distance is basically kept unchanged.

Description

Technical Field

[0001] This application relates to the field of near-field communication technology, and in particular to a card reader circuit and a near-field communication device. Background Technology

[0002] Near Field Communication (NFC) technology, as an emerging wireless communication technology, has been widely used in mobile payment, identity verification and other scenarios in recent years.

[0003] NFC card reader technology is essentially a radio frequency identification (RFID) technology. It works by transmitting radio frequency signals at a specific frequency (typically 13.56MHz) to identify information on the card. The communication distance of this technology is generally around 10 centimeters, and the greater the transmission power, the farther the communication distance. In practical applications, to meet wider coverage requirements, it is sometimes necessary to add antennas to NFC card readers. However, when adding antennas, the transmission power is evenly distributed among the parallel antennas, resulting in a decrease in the transmission power of each antenna, thus shortening the reading distance. Utility Model Content

[0004] This application provides a card reader circuit and a near-field communication device to solve at least one of the aforementioned technical problems.

[0005] The card reader circuit of this application includes a near-field communication module, multiple matching modules, a selection module, and multiple antenna modules. The multiple matching modules and the selection modules are connected between the near-field communication module and the multiple antenna modules. The multiple matching modules correspond to the multiple antenna modules respectively. The selection module is used to control the working state of the multiple antenna modules.

[0006] In some embodiments, the card reader circuit further includes a filtering module, the near-field communication module is connected to the filtering module, and the plurality of matching modules and the selection module are connected between the filtering module and the plurality of antenna modules.

[0007] In some embodiments, there are multiple selection modules, each filtering module is connected to multiple matching modules, each matching module is connected to a corresponding multiple selection module, and each selection module is connected to a corresponding multiple antenna modules.

[0008] Each selection module is used to control the operating state of a corresponding antenna module.

[0009] In some implementations, each selection module includes a first transistor and a second transistor, wherein a first terminal of the first transistor is connected between the matching module and the antenna module, a second terminal of the first transistor is connected to a control port, and a third terminal of the first transistor is grounded; a first terminal of the second transistor is connected between the matching module and the antenna module, a second terminal of the second transistor is connected to the control port, and a third terminal of the second transistor is grounded.

[0010] The high or low level of the control port is used to control the conduction state of the selection module, thereby controlling the working state of the antenna module.

[0011] In some embodiments, the number of selection modules is one, the filtering module is connected to the selection module, the selection module is connected to multiple matching modules, and the multiple matching modules are connected to multiple antenna modules respectively.

[0012] The selection module is used to select and control one of the multiple antenna modules to operate.

[0013] In some embodiments, the selection module includes a first single-pole multi-throw switch and a second single-pole multi-throw switch, the filtering module is connected to the first single-pole multi-throw switch and the second single-pole multi-throw switch respectively, the first single-pole multi-throw switch is connected to a plurality of matching modules respectively, the second single-pole multi-throw switch is connected to a plurality of matching modules respectively, and the first single-pole multi-throw switch and the second single-pole multi-throw switch are also connected to a control port respectively.

[0014] The high or low level of the control port is used to control the switching state of the selection module, so as to select and control one of the multiple antenna modules to work.

[0015] In some embodiments, the filtering module includes a first inductor, a second inductor, a first capacitor, and a second capacitor. One end of the first inductor and one end of the second inductor serve as the input terminals of the filtering module, and the other ends of the first inductor and the second inductor serve as the output terminals of the filtering module. One end of the first capacitor is connected to the other end of the first inductor, and the other end of the first capacitor is grounded. One end of the second capacitor is connected to the other end of the second inductor, and the other end of the second capacitor is grounded.

[0016] In some embodiments, each of the matching modules includes a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. One end of the third capacitor and one end of the fifth capacitor serve as the input terminals of the matching module, and the other ends of the third capacitor and the fifth capacitor serve as the output terminals of the matching module. One end of the fourth capacitor is connected to the other end of the third capacitor, and the other end of the fourth capacitor is grounded. One end of the sixth capacitor is connected to the other end of the fifth capacitor, and the other end of the sixth capacitor is grounded.

[0017] In some embodiments, the card reader circuit further includes a seventh capacitor and a first resistor. One end of the seventh capacitor is connected to the near-field communication module, and the other end of the seventh capacitor is connected to one end of the first resistor, and the other end of the first resistor is connected to the filtering module.

[0018] The near-field communication device according to the embodiments of this application includes the card reader circuit of any of the above embodiments.

[0019] The card reader circuit and near-field communication device of this application, by adding a selection module to the original circuit and equipping each antenna module with an independent matching module, can realize flexible antenna selection, optimize the card reading distance, and make the card reading distance basically unchanged when an antenna module is added to a single near-field communication module.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort. Among them:

[0022] Figure 1 This is one of the schematic diagrams of a card reader circuit according to certain embodiments of this application;

[0023] Figure 2 This is a second schematic diagram of a card reader circuit according to certain embodiments of this application;

[0024] Figure 3 This is one of the structural schematic diagrams of the card reader circuit according to certain embodiments of this application;

[0025] Figure 4 This is a second schematic diagram of the card reader circuit according to certain embodiments of this application;

[0026] Figure 5 This is the third schematic diagram of the card reader circuit according to certain embodiments of this application;

[0027] Figure 6 This is a schematic diagram of a near-field communication device according to certain embodiments of this application.

[0028] Explanation of reference numerals in the attached figures:

[0029] Card reader circuit 100, near-field communication module 10, matching module 20, selection module 30, antenna module 40, filtering module 50, near-field communication device 1000;

[0030] First transistor Q1, second transistor Q2, first single-pole multi-throw switch U1, second single-pole multi-throw switch U2, first inductor L1, second inductor L2, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, fifth capacitor C5, sixth capacitor C6, seventh capacitor C7, first resistor R1. Detailed Implementation

[0031] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0032] Please see Figure 1 and Figure 2 The card reader circuit 100 of this application includes a near-field communication module 10, multiple matching modules 20, a selection module 30, and multiple antenna modules 40. The multiple matching modules 20 and the selection module 30 are connected between the near-field communication module 10 and the multiple antenna modules 40. Each of the multiple matching modules 20 corresponds to one of the multiple antenna modules 40. The selection module 30 is used to control the operating state of the multiple antenna modules 40.

[0033] The card reader circuit 100 of this application can achieve flexible antenna selection and optimize the card reading distance by adding a selection module 30 to the original circuit and equipping each antenna module 40 with an independent matching module 20, so that the card reading distance remains basically unchanged when an antenna module 40 is added to a single near-field communication module 10.

[0034] Specifically, the near-field communication module 10 can be an NFC chip. The near-field communication module 10 is capable of generating and detecting 13.56MHz radio frequency signals for near-field communication.

[0035] Antenna module 40 can be an antenna chip. Antenna module 40 is used to transmit and receive radio frequency signals to achieve communication with the card. In this embodiment, the number of antenna modules 40 is multiple to meet requirements such as wider coverage, more flexible card reading direction, or higher card reading reliability. Multiple antenna modules 40 can be the same antenna module 40 for better compatibility.

[0036] The matching module 20 is used to adjust the impedance to achieve impedance matching between the antenna module 40 and the near-field communication module 10, thereby achieving the optimal card reading distance. It can be understood that when the impedance between the antenna module 40 and the near-field communication module 10 is matched, the signal transmission efficiency is highest and the energy loss is minimal, allowing more signal energy to be transmitted to the card and increasing the card reading distance. In this embodiment, multiple matching modules 20 correspond to multiple antenna modules 40, meaning that each antenna module 40 is equipped with an independent matching module 20, which can independently adjust the impedance, optimize the circuit, and increase the card reading distance.

[0037] The selection module 30 is used to control the operating state of multiple antenna modules 40. That is, the selection module 30 can control the multiple antenna modules 40 to operate or not operate. The control of the operating state of each antenna module 40 by the selection module 30 can be independent. For example, when the card reader circuit 100 includes two antenna modules 40 (represented as antenna 1 and antenna 2 respectively), the selection module 30 can control antenna 1 to operate and antenna 2 to operate; or, the selection module 30 can control antenna 2 to operate and antenna 1 to operate; or, the selection module 30 can control antenna 1 and antenna 2 to operate simultaneously.

[0038] When the selection module 30 controls one of the antenna modules 40 to operate, that antenna module 40 is active, while the other antenna modules 40 are inactive. This prevents the other antenna modules 40 from sharing the transmission power, thus avoiding a reduction in transmission power and consequently a shorter reading distance. When the selection module 30 controls multiple antenna modules 40 to operate simultaneously, parallel operation of multiple antennas is possible. Although this shortens the reading distance, each antenna module 40 is equipped with an independent matching module 20, which can adjust the impedance to achieve the optimal reading distance. Therefore, in both scenarios, the reading distance remains essentially unchanged even when an additional antenna module 40 is added to a single near-field communication module 10.

[0039] In this embodiment, multiple matching modules 20 and selection modules 30 are connected between the near-field communication module 10 and multiple antenna modules 40. Specifically, multiple matching modules 20 and selection modules 30 are sequentially connected between the near-field communication module 10 and multiple antenna modules 40 (e.g., ...). Figure 1(as shown); or, the selection module 30 and multiple matching modules 20 are sequentially connected between the near-field communication module 10 and multiple antenna modules 40 (as shown). Figure 2 As shown in the figure, no restrictions are imposed here.

[0040] Please see Figure 1 and Figure 2 In some embodiments, the card reader circuit 100 further includes a filtering module 50. The near-field communication module 10 is connected to the filtering module 50. Multiple matching modules 20 and selection modules 30 are connected between the filtering module 50 and multiple antenna modules 40.

[0041] Specifically, the filtering module 50 may employ an electromagnetic compatibility (EMC) circuit to ensure that the card reader circuit 100 operates stably in complex electromagnetic environments.

[0042] In some embodiments, the filtering module 50 can be an LC filter circuit, which can selectively pass through or filter out signals of a specific frequency. For example, the LC filter circuit can be designed to selectively pass through signals of 13.56MHz while filtering out signals higher than 13.56MHz to reduce electromagnetic interference and improve the stability and accuracy of the card reader circuit 100.

[0043] In this embodiment, multiple matching modules 20 and selection modules 30 are connected between the filtering module 50 and multiple antenna modules 40. Specifically, multiple matching modules 20 and selection modules 30 are sequentially connected between the filtering module 50 and multiple antenna modules 40. In this case, the filtering module 50 is connected to multiple matching modules 20 respectively (e.g., ...). Figure 1 (as shown); or, the selection module 30 and multiple matching modules 20 are sequentially connected between the filter module 50 and multiple antenna modules 40. In this case, the filter module 50 is connected to the selection module 30 (as shown). Figure 2 (As shown).

[0044] Please see Figure 1 and Figure 3 In some embodiments, there are multiple selection modules 30. The filtering module 50 is connected to multiple matching modules 20, the multiple matching modules 20 are connected to multiple selection modules 30, and the multiple selection modules 30 are connected to multiple antenna modules 40. Each selection module 30 controls the operating state of a corresponding antenna module 40.

[0045] In this embodiment, the matching module 20, selection module 30, and antenna module 40 have a one-to-one correspondence. One near-field communication module 10 is connected to one filtering module 50, and each filtering module 50 is connected to multiple matching modules 20 (the two output terminals of the filtering module 50 are common terminal 1 and common terminal 2, respectively, and each matching module 20 is connected to both common terminal 1 and common terminal 2). Then, each matching module 20 is connected to a corresponding antenna module 40 through a corresponding selection module 30. Each selection module 30 is used to control the operating state of its corresponding antenna module 40.

[0046] by Figure 3 For example, when the card reader circuit 100 includes two antenna modules 40 (referred to as antenna 1 and antenna 2 respectively), the first selection module 30 is used to control the working state of antenna 1, and the second selection module 30 is used to control the working state of antenna 2. The control of the working states of the two antenna modules 40 by the two selection modules 30 is independent of each other, which can realize flexible selection of antennas. As analyzed above, regardless of whether the selection module 30 controls one antenna module 40 to work or controls multiple antenna modules 40 to work simultaneously, the card reading distance remains basically unchanged when an antenna module 40 is added to a single near-field communication module 10.

[0047] Please see Figure 3 In some embodiments, each selection module 30 includes a first transistor Q1 and a second transistor Q2. The first terminal of the first transistor Q1 is connected between the matching module 20 and the antenna module 40, the second terminal of the first transistor Q1 is connected to a control port, and the third terminal of the first transistor Q1 is grounded. The first terminal of the second transistor Q2 is connected between the matching module 20 and the antenna module 40, the second terminal of the second transistor Q2 is connected to the control port, and the third terminal of the second transistor Q2 is grounded. The high or low voltage level of the control port is used to control the conduction state of the selection module 30, thereby controlling the operating state of the antenna module 40.

[0048] In this embodiment, each selection module 30 can be constructed using two N-channel enhancement-mode field-effect transistors (NFETs). The first terminal, second terminal, and third terminal correspond to the drain, gate, and source of the transistor, respectively.

[0049] The gates of both the first transistor Q1 and the second transistor Q2 are connected to the control port. The control port can be a general purpose input / output (GPIO) port. The control port can read the state of external control signals (high or low level), thereby enabling or disabling the selection module 30 to control the operating state of the antenna module 40 and achieve flexible antenna selection.

[0050] In some embodiments, when the control port is high, the selection module 30 is turned on and the antenna module 40 is not working; when the control port is low, the selection module 30 is not turned on and the antenna module 40 is working.

[0051] It should be noted that each selection module 30 is connected to an independent control port to independently control the operating state of the antenna module 40. For example, the first selection module 30 is connected to GPIO1, the second selection module 30 is connected to GPIO2, the third selection module 30 is connected to GPIO3, and so on. When only antenna 1 needs to be used, GPIO1 is set to low, the first selection module 30 is not turned on, and antenna 1 is working (i.e., active); GPIO2 is set to high, the second selection module 30 is turned on, and antenna 2 is not working (i.e., disabled), thus ensuring the reading distance of a single antenna. The equivalent circuit at this time is as follows: Figure 4 As shown. When multiple antennas need to work in parallel, GPIO1, GPIO2, GPIO3... can be made low at the same time. Although this will shorten the reading distance, since each antenna module 40 is equipped with an independent matching module 20, the impedance can be adjusted, the circuit can be optimized, and the reading distance can be increased.

[0052] Please see Figure 2 and Figure 5 In some embodiments, the number of selection modules 30 is one. A filtering module 50 is connected to the selection module 30, and the selection module 30 is connected to multiple matching modules 20, which in turn are connected to multiple antenna modules 40. The selection module 30 is used to select and control one of the multiple antenna modules 40 to operate.

[0053] In this embodiment, a near-field communication module 10 is connected to a filtering module 50, the filtering module 50 is connected to a selection module 30, the selection module 30 is connected to multiple matching modules 20, and each matching module 20 is connected to a corresponding antenna module 40. The selection module 30 is used to select and control one of the multiple antenna modules 40 to operate.

[0054] by Figure 5For example, when the card reader circuit 100 includes two antenna modules 40 (referred to as antenna 1 and antenna 2 respectively), the selection module 30 is used to select and control either antenna 1 or antenna 2 to operate. When the selection module 30 selects to control one of the antenna modules 40 to operate, that antenna module 40 is in an active state, while the other antenna modules 40 are in an inactive state. This avoids the other antenna modules 40 from diverting transmission power, thus preventing a reduction in transmission power and solving the problem of shortened card reading distance. Furthermore, since each antenna module 40 is equipped with an independent matching module 20, impedance can be adjusted to achieve the optimal card reading distance.

[0055] Please see Figure 5 In some embodiments, the selection module 30 includes a first single-pole multi-throw switch U1 and a second single-pole multi-throw switch U2. The filtering module 50 is connected to both the first single-pole multi-throw switch U1 and the second single-pole multi-throw switch U2. The first single-pole multi-throw switch U1 is connected to multiple matching modules 20, and the second single-pole multi-throw switch U2 is also connected to multiple matching modules 20. The first single-pole multi-throw switch U1 and the second single-pole multi-throw switch U2 are also connected to a control port. The high or low voltage level of the control port is used to control the switching state of the selection module 30, thereby selecting one of the multiple antenna modules 40 to operate.

[0056] Specifically, both the first single-pole multi-throw (SPMD) switch U1 and the second SPMD switch U2 include one input terminal and multiple output terminals. The two output terminals of the filter module 50 are a common terminal 1 and a common terminal 2, respectively. The input terminal of the first SPMD switch U1 is connected to the common terminal 1, and the input terminal of the second SPMD switch U2 is connected to the common terminal 2. The multiple output terminals of the first SPMD switch U1 are each connected to one input terminal of a plurality of matching modules 20, and the multiple output terminals of the second SPMD switch U2 are each connected to another input terminal of a plurality of matching modules 20.

[0057] by Figure 5 For example, when the card reader circuit 100 includes two antenna modules 40 (represented as antenna 1 and antenna 2 respectively), both the first single-pole multi-throw switch U1 and the second single-pole multi-throw switch U2 are single-pole double-throw switches SP2T. Both the first single-pole multi-throw switch U1 and the second single-pole multi-throw switch U2 include one input terminal and two output terminals. The input terminal of the first single-pole multi-throw switch U1 is connected to common terminal 1, and the input terminal of the second single-pole multi-throw switch U2 is connected to common terminal 2. The two output terminals of the first single-pole multi-throw switch U1 are each connected to one input terminal of one of the two matching modules 20, and the two output terminals of the second single-pole multi-throw switch U2 are each connected to the other input terminal of one of the two matching modules 20.

[0058] The first single-pole multi-throw (SPMD) switch U1 and the second SPMD switch U2 are also connected to control ports. For example, the first SPMD switch U1 is connected to GPIO1, and the second SPMD switch U2 is connected to GPIO2. The high and low levels of GPIO1 and GPIO2 are used to control the switching states of the first SPMD switch U1 and the second SPMD switch U2 to select one of the multiple antenna modules 40 to operate. For example, when GPIO1 and GPIO2 are low, the first SPMD switch U1 and the second SPMD switch U2 switch to select antenna 1 to operate; when GPIO1 and GPIO2 are high, the first SPMD switch U1 and the second SPMD switch U2 switch to select antenna 2 to operate.

[0059] It is understandable that when the card reader circuit 100 includes more antenna modules 40, the first single-pole multi-throw switch U1 and the second single-pole multi-throw switch U2 can be a single-pole four-throw switch SP4T, a single-pole eight-throw switch SP8T, etc. In this case, each single-pole multi-throw switch can be connected to more control ports, so that the single-pole multi-throw switch can have more switching states, thereby flexibly selecting one of the antenna modules 40 to work.

[0060] Please see Figure 3 and Figure 5 In some embodiments, the filter module 50 includes a first inductor L1, a second inductor L2, a first capacitor C1, and a second capacitor C2. One end of the first inductor L1 and one end of the second inductor L2 serve as the input terminals of the filter module 50, and the other ends of the first inductor L1 and the second inductor L2 serve as the output terminals of the filter module 50. One end of the first capacitor C1 is connected to the other end of the first inductor L1, and the other end of the first capacitor C1 is grounded. One end of the second capacitor C2 is connected to the other end of the second inductor L2, and the other end of the second capacitor C2 is grounded.

[0061] One end of the first inductor L1 can be connected to the first transmitter TX1 of the near-field communication module 10, and one end of the second inductor L2 can be connected to the second transmitter TX2 of the near-field communication module 10.

[0062] When multiple matching modules 20 and selection modules 30 are sequentially connected between the filter module 50 and multiple antenna modules 40 (e.g.) Figure 3 As shown), the other end of the first inductor L1 serves as common terminal 1 and is connected to one input terminal of the matching module 20; the other end of the second inductor L2 serves as common terminal 2 and is connected to the other input terminal of the matching module 20. When the selection module 30 and multiple matching modules 20 are sequentially connected between the filter module 50 and multiple antenna modules 40 (as shown), Figure 5As shown, the other end of the first inductor L1 serves as common terminal 1 and is connected to the input terminal of the first single-pole multi-throw switch U1; the other end of the second inductor L2 serves as common terminal 2 and is connected to the input terminal of the second single-pole multi-throw switch U2.

[0063] In this embodiment, the filtering module 50 uses the above-described circuit, which can selectively pass through or filter out signals of a specific frequency to reduce electromagnetic interference and improve the stability and accuracy of the card reader circuit 100.

[0064] Please see Figure 3 and Figure 5 In some embodiments, each matching module 20 includes a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6. One end of the third capacitor C3 and one end of the fifth capacitor C5 serve as the input terminals of the matching module 20, and the other ends of the third capacitor C3 and the fifth capacitor C5 serve as the output terminals of the matching module 20. One end of the fourth capacitor C4 is connected to the other end of the third capacitor C3, and the other end of the fourth capacitor C4 is grounded. One end of the sixth capacitor C6 is connected to the other end of the fifth capacitor C5, and the other end of the sixth capacitor C6 is grounded.

[0065] When multiple matching modules 20 and selection modules 30 are sequentially connected between the filtering module 50 and multiple antenna modules 40 (e.g.) Figure 3 As shown in the figure, one end of the third capacitor C3 is connected to the common terminal 1, one end of the fifth capacitor C5 is connected to the common terminal 2, the other end of the third capacitor C3 is connected to one input terminal of the selection module 30, and the other end of the fifth capacitor C5 is connected to the other input terminal of the selection module 30.

[0066] When the selection module 30 and multiple matching modules 20 are sequentially connected between the filter module 50 and multiple antenna modules 40 (e.g.) Figure 5 As shown, one end of the third capacitor C3 is connected to one output terminal of the first single-pole multi-throw switch U1, one end of the fifth capacitor C5 is connected to one output terminal of the second single-pole multi-throw switch U2, the other end of the third capacitor C3 is connected to one end of the antenna module 40, and the other end of the fifth capacitor C5 is connected to the other end of the antenna module 40.

[0067] Please see Figure 3 and Figure 5 In some embodiments, the card reader circuit 100 further includes a seventh capacitor C7 and a first resistor R1. One end of the seventh capacitor C7 is connected to the near-field communication module 10, and the other end of the seventh capacitor C7 is connected to one end of the first resistor R1, which in turn is connected to the filter module 50.

[0068] One end of the seventh capacitor C7 can be connected to the receiver RX of the near-field communication module 10, and the other end of the first resistor R1 is connected to the other end of the first inductor L1. The arrangement of the seventh capacitor C7 and the first resistor R1 helps the card reader circuit 100 to achieve stable signal reception.

[0069] Please see Figure 6 The near-field communication device 1000 of this application includes the card reader circuit 100 of any of the above embodiments. The near-field communication device 1000 can be used in scenarios such as mobile payment, identity verification, and data transmission, and performs short-range wireless communication through electromagnetic induction.

[0070] In summary, the card reader circuit 100 and near-field communication device 1000 of this application, by adding a selection module 30 to the original circuit and equipping each antenna module 40 with an independent matching module 20, can achieve flexible antenna selection, optimize the card reading distance, and ensure that the card reading distance remains basically unchanged when an antenna module 40 is added to a single near-field communication module 10.

[0071] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0073] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0074] The foregoing disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with an embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Although embodiments of this application have been shown and described above, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A card reader circuit, characterized in that, It includes a near-field communication module, multiple matching modules, a selection module, and multiple antenna modules. The multiple matching modules and the selection modules are connected between the near-field communication module and the multiple antenna modules. The multiple matching modules correspond to the multiple antenna modules respectively. The selection module is used to control the working state of the multiple antenna modules.

2. The card reader circuit according to claim 1, characterized in that, The card reader circuit also includes a filtering module, the near-field communication module is connected to the filtering module, and the multiple matching modules and the selection module are connected between the filtering module and the multiple antenna modules.

3. The card reader circuit according to claim 2, characterized in that, The number of selection modules is multiple, the filtering module is connected to multiple matching modules respectively, the multiple matching modules are connected to multiple selection modules respectively, and the multiple selection modules are connected to multiple antenna modules respectively. Each selection module is used to control the operating state of a corresponding antenna module.

4. The card reader circuit according to claim 3, characterized in that, Each selection module includes a first transistor and a second transistor. A first terminal of the first transistor is connected between the matching module and the antenna module, a second terminal of the first transistor is connected to a control port, and a third terminal of the first transistor is grounded. A first terminal of the second transistor is connected between the matching module and the antenna module, a second terminal of the second transistor is connected to the control port, and a third terminal of the second transistor is grounded. The high or low level of the control port is used to control the conduction state of the selection module, thereby controlling the working state of the antenna module.

5. The card reader circuit according to claim 2, characterized in that, The number of selection modules is one, the filtering module is connected to the selection module, the selection module is connected to multiple matching modules, and the multiple matching modules are connected to multiple antenna modules respectively. The selection module is used to select and control one of the multiple antenna modules to operate.

6. The card reader circuit according to claim 5, characterized in that, The selection module includes a first single-pole multi-throw switch and a second single-pole multi-throw switch. The filtering module is connected to the first single-pole multi-throw switch and the second single-pole multi-throw switch respectively. The first single-pole multi-throw switch is connected to a plurality of matching modules respectively. The second single-pole multi-throw switch is connected to a plurality of matching modules respectively. The first single-pole multi-throw switch and the second single-pole multi-throw switch are also connected to a control port respectively. The high or low level of the control port is used to control the switching state of the selection module, so as to select and control one of the multiple antenna modules to work.

7. The card reader circuit according to claim 2, characterized in that, The filtering module includes a first inductor, a second inductor, a first capacitor, and a second capacitor. One end of the first inductor and one end of the second inductor serve as the input terminals of the filtering module, and the other ends of the first inductor and the other ends of the second inductor serve as the output terminals of the filtering module. One end of the first capacitor is connected to the other end of the first inductor, and the other end of the first capacitor is grounded; one end of the second capacitor is connected to the other end of the second inductor, and the other end of the second capacitor is grounded.

8. The card reader circuit according to claim 1, characterized in that, Each of the matching modules includes a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. One end of the third capacitor and one end of the fifth capacitor serve as the input terminals of the matching module, and the other ends of the third capacitor and the fifth capacitor serve as the output terminals of the matching module. One end of the fourth capacitor is connected to the other end of the third capacitor, and the other end of the fourth capacitor is grounded. One end of the sixth capacitor is connected to the other end of the fifth capacitor, and the other end of the sixth capacitor is grounded.

9. The card reader circuit according to claim 2, characterized in that, The card reader circuit also includes a seventh capacitor and a first resistor. One end of the seventh capacitor is connected to the near-field communication module, and the other end of the seventh capacitor is connected to one end of the first resistor. The other end of the first resistor is connected to the filtering module.

10. A near-field communication device, characterized in that, Includes the card reader circuit as described in any one of claims 1-9.

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