Magnetic communication passive interface and NFC communication device

Abstract

The present invention discloses a magnetic communication passive interface and an NFC communication device. The magnetic communication passive interface communicates with a magnetic communication active interface. The magnetic communication passive interface includes a communication antenna, a plurality of energy harvesting antennas, and an energy harvesting matching and rectifying unit corresponding to the energy harvesting antennas. The energy harvesting matching and rectifying unit is used to set the output impedance of the energy harvesting antenna to a preset value; each of the energy harvesting antennas is set to a different working position, and by setting the output impedance of the energy harvesting antenna, the energy harvesting antenna reaches resonance with the antenna of the magnetic communication active interface at the working position, and the working position is the position of the magnetic communication passive interface relative to the magnetic communication active interface. The magnetic communication passive interface in the technical solution of the present invention can effectively receive energy at different working positions, improves the adaptability in different application scenarios, and enhances the user experience.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication, and particularly to a magnetic communication passive interface and an NFC communication device. Background Art

[0002] Magnetic communication technology, especially NFC (Near Field Communication) technology, uses a magnetic field as an information carrier, achieving a much shorter communication distance (e.g., a few centimeters) compared to traditional wireless communication, and has advantages such as high security and convenience. An important feature of magnetic communication technology is that while the magnetic communication interface transmits information, it allows relatively high energy to be transferred from one device to another through the magnetic communication interface, i.e., wireless energy transfer. As Figure 1 shown, the radio frequency signal 101 sent by the magnetic communication interface A is given to the magnetic communication interface B. Through the radio frequency signal 101, the magnetic communication interface A and the magnetic communication interface B can achieve two-way half-duplex communication 103 and one-way wireless energy transfer 102. The magnetic communication interface B receives the radio frequency energy from the magnetic communication interface A to power itself or an external device to maintain internal operation and external communication of the device. This feature is widely used in NFC technology and is widely applied to applications such as wireless payment, Bluetooth pairing, peer-to-peer transmission, passive tags, etc., and has a broad application prospect in the future Internet of Things.

[0003] With the rapid development of magnetic communication technology, in recent years, some designs of magnetic communication passive interfaces optimized for energy transfer have emerged, which greatly improve the energy acquisition efficiency without affecting the communication performance. As Figure 2 shown, due to the design of separating the energy harvesting antenna 201 from the communication antenna 202, it becomes possible to optimize the antenna separately for the energy harvesting process or the communication process. The passive interface can obtain a large amount of energy to power the system. In Figure 2 , the communication antenna 202 and the communication antenna matching circuit 204 cooperate to form a low-Q (quality factor) antenna loop optimized for communication, which has a relatively high bandwidth and is suitable for receiving and transmitting NFC data. The energy harvesting antenna 201 and the energy harvesting matching and rectifying circuit 203 cooperate to form a high-Q antenna loop optimized for energy harvesting, which has extremely low loss around the communication frequency (such as 13.56Mhz used for NFC) and is suitable for energy harvesting. The energy harvesting matching and rectifying circuit 203 simultaneously converts the radio frequency signal into a direct current signal. Due to the high Q value of the energy harvesting antenna, the passive interface is very sensitive to the relative position and distance of the two magnetic interfaces for communication, and can only achieve ideal energy harvesting performance within a very narrow range and distance. However, most magnetic communication usage methods require users to only place the device within a reasonable range to complete communication. Therefore, even if such magnetic communication interfaces achieve high energy harvesting efficiency in specific situations, the narrow energy harvesting range seriously affects the interface performance and user experience.

[0004] Existing solutions adjust the parameters of the matching circuit dynamically to adapt to various distances and ensure the energy harvesting efficiency. However, such solutions require the tunable matching circuit to have extremely low losses to ensure a high Q value of the antenna, which usually results in a large volume of tunable devices (such as low-loss RF switches, low-loss tunable capacitors, micro relays, etc.) and high costs, affecting the market promotion of magnetic communication devices and users' experience of cost performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that the manufacturing cost of the magnetic communication interface is relatively high by improving the structure and working mode of the electronic devices related to the magnetic communication interface to increase the energy reception intensity and efficiency of the passive interface, and to provide a magnetic communication passive interface and an NFC communication device.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention provides a magnetic communication passive interface, which communicates with a magnetic communication active interface. The magnetic communication passive interface includes a plurality of antennas, and the antennas include communication antennas only for communication and a plurality of energy harvesting antennas only for energy harvesting;

[0008] The magnetic communication passive interface includes a plurality of energy harvesting matching and rectifying units corresponding to the energy harvesting antennas. The input end of each energy harvesting matching and rectifying unit is connected to the port of the corresponding energy harvesting antenna, and the energy harvesting matching and rectifying unit is used to set the output impedance of the energy harvesting antenna to a preset value;

[0009] Each energy harvesting antenna is set at a different working position, and by setting the output impedance of the energy harvesting antenna, the energy harvesting antenna resonates with the antenna of the magnetic communication active interface at the working position, and the working position is the position of the magnetic communication passive interface relative to the magnetic communication active interface.

[0010] Preferably, the plurality of energy harvesting antennas are concentrically nested and / or partially overlapped;

[0011] and / or,

[0012] The communication antenna and the energy harvesting antenna are concentrically nested and / or partially overlapped.

[0013] Preferably, the magnetic communication passive interface further includes a microcontroller, the microcontroller has a data interface, and the data interface is connected to an external device of the magnetic communication passive interface and communicates with the external device.

[0014] Preferably, the energy harvesting matching and rectifying unit is further configured to receive the radio frequency signal collected by the energy harvesting antenna and convert the radio frequency signal into a direct current signal.

[0015] Preferably, the magnetic communication passive interface further includes a selection unit configured to receive the direct current signals of multiple energy harvesting matching and rectifying units and select the direct current signal of one of the energy harvesting matching and rectifying units according to the instruction of the microcontroller for output to the external device.

[0016] Preferably, the magnetic communication passive interface further includes a power combining unit, and the power combining unit includes a plurality of input ends and one output end;

[0017] The output end of each energy harvesting matching and rectifying unit is respectively connected to one input end of the power combining unit, and the power combining unit is configured to superimpose the direct current signals output by multiple energy harvesting matching and rectifying units and output the superimposed direct current signal to the external device.

[0018] Preferably, the magnetic communication passive interface further includes an energy management unit, and the energy management unit receives the direct current signal output from the selection unit and transmits the direct current signal to the external device.

[0019] Preferably, the magnetic communication passive interface further includes an energy management unit, and the energy management unit receives the direct current signal output from the power combining unit and transmits the direct current signal to the external device.

[0020] Preferably, the microcontroller is also communicatively connected to the energy management unit, and the microcontroller controls the energy management unit to send the direct current signal to the external device, or the microcontroller controls the energy management unit to stop sending the direct current signal to the external device.

[0021] Preferably, the magnetic communication interface further includes a communication matching unit, and the communication matching unit is connected to the communication antenna and is configured to adjust the output impedance of the communication antenna.

[0022] Preferably, the microcontroller is also connected to the communication matching unit, receives the signal from the communication matching unit and demodulates to obtain data, and the microcontroller provides the demodulated data to the external device of the magnetic communication passive interface through the data interface;

[0023] The microcontroller also receives the data transmitted from the external device, modulates the data transmitted from the external device and then transmits it to the communication antenna through the communication matching unit for external transmission.

[0024] Preferably, the power combining unit includes a plurality of diodes. An anode of each diode is respectively connected to an input terminal of the energy harvesting matching and rectifying unit, and a cathode of each diode is connected to an output terminal of the energy harvesting matching and rectifying unit.

[0025] The present invention also provides an NFC communication device, which includes the aforementioned magnetic communication passive interface.

[0026] Based on common knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0027] The positive and progressive effects of the present invention are as follows: The magnetic communication passive interface and the NFC communication device provided by the present invention are provided with a communication antenna, a plurality of energy harvesting antennas, and an energy harvesting matching and rectifying unit corresponding to the energy harvesting antennas. The energy harvesting matching and rectifying unit is used to set the output impedance of the energy harvesting antenna to a preset value, so that the energy harvesting antenna and the antenna of the magnetic communication active interface achieve resonance at the working position. Thus, the magnetic communication passive interface can effectively receive energy at different working positions, improving its adaptability in different application scenarios and enhancing the user experience.

[0028] In addition, by providing a power combining unit to cooperate with the energy harvesting matching and rectifying unit to aggregate and process the energy collected by the energy harvesting antenna and supply it to an external device, when the relative position between the magnetic communication active interface and the magnetic communication passive interface changes, the passive interface can maintain a good energy reception power, expanding the energy harvesting range and further enhancing the user experience.

[0029] In addition, by providing a selection unit, different DC signals can be selected for the external device, so as to meet the power supply needs of various different types of external devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a communication schematic diagram between magnetic communication interfaces in the prior art.

[0031] Figure 2 It is a schematic diagram of the antenna distribution of the magnetic communication interface in the prior art.

[0032] Figure 3 It is a received power curve of the energy harvesting antenna of the magnetic communication interface under different matching schemes in the prior art.

[0033] Figure 4 It is a schematic structural diagram of the magnetic communication passive interface according to Embodiment 1 of the present invention.

[0034] Figure 5Schematic diagram of the magnetic communication passive interface according to Embodiment 2 of the present invention.

[0035] Figure 6 Schematic diagram of the power combining unit according to Embodiment 2 of the present invention.

[0036] Figure 7 Schematic diagram of the position distribution of multiple energy harvesting antennas in a specific implementation manner according to Embodiment 2 of the present invention.

[0037] Figure 8 Schematic diagram of the relative distance between the active interface and the passive interface in a specific implementation manner according to Embodiment 2 of the present invention.

[0038] Figure 9 Receiving power curve of multiple energy harvesting antennas in a specific implementation manner according to Embodiment 2 of the present invention.

[0039] Figure 10 Schematic diagram of the position distribution of multiple energy harvesting antennas in another specific implementation manner according to Embodiment 2 of the present invention.

[0040] Figure 11 Schematic diagram of the relative position between the active interface and the passive interface in another specific implementation manner according to Embodiment 2 of the present invention.

[0041] Figure 12 Receiving power curve of multiple energy harvesting antennas in another specific implementation manner according to Embodiment 2 of the present invention.

[0042] Figure 13 Schematic diagram of the magnetic communication passive interface according to Embodiment 3 of the present invention. Specific implementation manner

[0043] Those skilled in the art can understand that although the prior art has achieved the separation of the communication antenna and the energy harvesting antenna, the narrow energy harvesting range seriously affects the interface performance and user experience. Please continue to refer to Figure 2 , the most fundamental reason for the narrow optimal energy range of the magnetic communication interface in the prior art is the high Q value adopted to improve the energy harvesting efficiency. The high Q value is a necessary condition for improving the energy harvesting efficiency. However, a major drawback after the Q value is high is the sensitivity to changes in the antenna inductance value and capacitance value. The inductance value of the magnetic communication passive interface antenna includes not only its own inductance but also the mutual inductance between two magnetic communication interface antennas, and the mutual inductance changes with the distance and orientation between the two antennas. Therefore, adopting Figure 2 's structure is doomed that the antenna can only reach the highest efficiency at certain specific distances and orientations.

[0044] Generally speaking, for Figure 2 's structure, there are approximately three types of antenna matching schemes for different applications. Figure 3Shows a schematic diagram of the received power of these three matching schemes varying with the distance between the antennas of the magnetic communication interface. For the first scheme, the reference curve 301, the optimal matching point is set at the closest distance between the two antennas, that is, point 304. The optimal matching point means that for a given position of the passive interface relative to the active interface, by adjusting the parameters of each device (such as capacitors, inductors, resistors, etc.) in the matching circuit, the passive interface antenna and the active interface antenna can achieve resonance at this specific relative position and reach the maximum energy reception power. For the first matching scheme, at point 304, since the distance between the passive interface antenna and the active interface antenna is very close, the common magnetic flux of the two antennas is very large, so the power that can be received at point 304 is very large. However, as the distance increases, the common magnetic flux of the two antennas decreases, and the passive interface deviates from the optimal matching point, and the receivable power drops sharply.

[0045] For the second scheme, the reference curve 302, the optimal matching point is set at a slightly farther position, that is, point 305. Under this matching scheme, the common magnetic flux between the two antennas at point 305 is not as large as that at point 304. Although it is at the optimal matching point, the received power is larger than that at point 304 in matching scheme 1. As the distance between the antennas approaches, although the common magnetic flux increases, since it has deviated from the optimal matching point, the received power does not increase much or may even decrease slightly. But at point 305 and farther distances, the received power of matching scheme 2 is greater than that of matching scheme 1.

[0046] For the third scheme, the reference curve 303, the optimal matching point is set at an even farther position, that is, point 306. Under this matching scheme, the received power at points 304 and 305 is lower than that of the first two matching schemes. However, at point 306 and farther distances, the received power of matching scheme 3 is better than the first two schemes.

[0047] It should be noted that the above discussion is made under the assumption that the two magnetic communication interface antennas are facing each other and parallel. Whether it is the distance or the relative orientation, the influence on the two antennas can be calculated and described by mutual inductance. When the two antennas are not facing each other or parallel, according to the magnitude of the mutual inductance between the two antennas, these situations can be equivalent to the situation where the two magnetic communication interface antennas are facing each other and parallel but at different distances. Therefore, the above discussion still applies to the situation where the antennas are not facing each other or parallel.

[0048] From the above analysis, it can be seen that for various matching schemes such as Figure 2 shown, in actual applications, due to hardware limitations, only one matching scheme can be selected, so it is impossible to take into account the received power at each different relative position.

[0049] The present invention proposes a method using a multi-energy harvesting antenna and a corresponding matching circuit to solve the problem of optimal antenna matching. To make the above objects, features, and beneficial effects of the present invention more obvious and understandable, the following detailed description of specific embodiments of the present invention will be given in conjunction with the accompanying drawings.

[0050] Embodiment 1

[0051] This embodiment provides a magnetic communication interface, as Figure 4 shown, the present invention provides a magnetic communication passive interface, the magnetic communication passive interface communicates with a magnetic communication active interface, the magnetic communication passive interface includes a plurality of antennas, and the antennas include a communication antenna 401 only for communication and a plurality of energy harvesting antennas 402 only for energy harvesting.

[0052] The magnetic communication passive interface includes a plurality of energy harvesting matching and rectifying units 4041 corresponding to the energy harvesting antennas 402. The input end of each energy harvesting matching and rectifying unit 4041 is connected to the port of the corresponding energy harvesting antenna 401. The energy harvesting matching and rectifying unit 4041 is used to set the output impedance of the energy harvesting antenna 402 to a preset value; each energy harvesting antenna 402 is set at a different working position, and by setting the output impedance of the energy harvesting antenna 402, the energy harvesting antenna 402 resonates with the antenna of the magnetic communication active interface at the working position, and the working position is the position of the magnetic communication passive interface relative to the magnetic communication active interface.

[0053] The energy harvesting matching and rectifying unit 4041 is further used to receive the radio frequency signal collected by the energy harvesting antenna 401 and convert the radio frequency signal into a direct current signal.

[0054] In this embodiment, the relative position between the magnetic communication passive interface and the magnetic communication active interface includes a relative distance and a relative orientation.

[0055] Each energy harvesting antenna 401 can be in the form of one or more turns, and its shape can be the same or different, but the plurality of energy harvesting antennas 401 need to cover a substantially same area.

[0056] Specifically, the plurality of energy harvesting antennas 401 are concentrically nested and / or partially overlapped with each other. The communication antenna 402 is concentrically nested and / or partially overlapped with the energy harvesting antennas 401.

[0057] If the energy harvesting space is equivalent to a three-dimensional (XYZ) coordinate system, when it is necessary to expand the area of the energy harvesting region, that is, the X-Y plane expands and the depth in the Z direction remains unchanged, the antennas can be arranged in an overlapping form. When it is necessary to extend the energy harvesting distance, that is, the X-Y plane remains unchanged and the depth in the Z direction increases, the antennas can be arranged in a concentric nested form. In addition, a combination of the two forms (both overlapping and concentric) can also be adopted, so as to achieve both the expansion of the area and the extension of the depth during energy harvesting, and improve the energy harvesting intensity and efficiency.

[0058] In this embodiment, the magnetic communication passive interface can be used for NFC communication devices to implement functions such as wireless payment, Bluetooth pairing, peer-to-peer transmission, and passive tags.

[0059] The magnetic communication interface further includes a communication matching unit 403. The communication matching unit 403 is connected to the communication antenna 402 and is used to adjust the output impedance of the communication antenna 402.

[0060] In addition, due to the coupling relationship between the communication antenna 402 and the energy harvesting antenna 401, the signal strength of the communication antenna 402 may be affected by the coupling degree. Based on this, the communication signal received by the communication antenna 402 can also be amplified additionally before transmission.

[0061] The magnetic communication passive interface provided by the present invention is provided with a communication antenna, a plurality of energy harvesting antennas, and an energy harvesting matching and rectifying unit corresponding to the energy harvesting antenna. The energy harvesting matching and rectifying unit is used to adjust the output impedance of the energy harvesting antenna, so that the energy harvesting antenna reaches the maximum energy receiving power at the working position. Thus, the magnetic communication passive interface can effectively receive energy at different working positions, improves the adaptability in different application scenarios, and enhances the user experience.

[0062] Embodiment 2

[0063] This embodiment provides a magnetic communication passive interface. Please refer to Figure 5 , which is a further improvement based on Embodiment 1.

[0064] In this embodiment, the magnetic communication passive interface further includes a power combining unit 4042. The power combining unit 4042 includes a plurality of input terminals and one output terminal; the output terminal of each energy harvesting matching and rectifying unit 4041 is respectively connected to an input terminal of the power combining unit 4042, and the power combining unit 4042 is used to superimpose the DC signals output by the plurality of energy harvesting matching and rectifying units 4041.

[0065] The magnetic communication passive interface further includes an energy management unit 4043, and the energy management unit 4043 receives a DC signal output from the power combining unit 4042.

[0066] The magnetic communication passive interface further includes a microcontroller 405. The microcontroller 405 has a data interface, and the data interface is connected to an external device 406 of the magnetic communication passive interface and communicates with the external device 406.

[0067] The microcontroller 405 can also receive a signal from the communication matching unit 403 and demodulate the signal to obtain data. The microcontroller 405 provides the demodulated data to the external device 406 of the magnetic communication passive interface through the data interface; the microcontroller 405 also receives data transmitted from the external device 406, modulates the data transmitted from the external device 406, and then transmits the data to the communication antenna 402 through the communication matching unit 403 for external transmission.

[0068] The microcontroller 405 is also communicatively connected to the energy management unit 4043. The microcontroller 405 controls the energy management unit 4043 to send the DC signal to the external device 406, or the microcontroller 405 controls the energy management unit 4043 to stop sending the DC signal to the external device 406.

[0069] In this embodiment, the microcontroller 405 can also control the energy management unit 4043 to adjust the magnitude of the DC signal so that the DC signal connected to the external device 406 can meet the working requirements of the external device 406. Or, when there are multiple external devices 406, the microcontroller 405 can also control the energy management unit 4043 to adjust the DC signals supplied to each different external device 406.

[0070] Preferably, please refer to Figure 6 , the power combining unit 4042 may include a plurality of diodes VD. An anode of each diode VD is respectively connected to an input end of the energy harvesting matching and rectifying unit 4041, and cathodes of each diode VD are all connected to an output end of the energy harvesting matching and rectifying unit 4041.

[0071] Please refer to Figures 7 - 9 , in a specific embodiment, for example, the magnetic communication passive interface may include three energy harvesting antennas 401, and the three energy harvesting antennas 401 are concentrically nested. As Figure 7 shown, the three energy harvesting antennas 401 are respectively Figure 8The antennas A1, B1, and C1 shown in the figure, and each of the three antennas is connected to one of the energy harvesting matching and rectifying units 4041.

[0072] In Figure 9 When the distance between the magnetic communication active interface and the magnetic communication passive interface is the first distance, by pre-designing the parameters of each electronic device in the matching circuit, the parameters of each electronic device are made to achieve the best match, so that the antenna A1 can achieve the maximum energy reception power at the first distance. When the magnetic communication active interface antenna moves along the moving direction, the distance between the active interface and the passive interface is no longer the first distance. Therefore, the best matching method at the first distance can no longer maintain the maximum energy reception power of the antenna A1.

[0073] When the distance between the magnetic communication active interface and the magnetic communication passive interface is the second distance, by pre-designing the parameters of each electronic device in the matching circuit, the parameters of each electronic device are made to achieve the best match, so that the antenna B1 can achieve the maximum energy reception power at the second distance. When the magnetic communication active interface antenna moves along the moving direction, the distance between the active interface and the passive interface is no longer the second distance. Therefore, the best matching method at the second distance can no longer maintain the maximum energy reception power of the antenna B1.

[0074] When the distance between the magnetic communication active interface and the magnetic communication passive interface is the third distance, by pre-designing the parameters of each electronic device in the matching circuit, the parameters of each electronic device are made to achieve the best match, so that the antenna C1 can achieve the maximum energy reception power at the third distance. When the magnetic communication active interface antenna moves along the moving direction, the distance between the active interface and the passive interface is no longer the third distance. Therefore, the best matching method at the third distance can no longer maintain the maximum energy reception power of the antenna C1.

[0075] The received power curve of the antenna A1 is LA1, the received power curve of the antenna B1 is LB1, and the received power curve of the antenna C1 is LC1. As the relative distance between the active interface and the passive interface changes, all three curves have a relatively obvious power change trend. L1 is the composite curve after the curves LA1, LB1, and LC1 are superimposed. It can be seen from the curve L1 that when three energy harvesting antennas 401 are set, within the entire working range where the active interface and the passive interface can be changed, it can maintain a relatively high energy reception power.

[0076] Please refer to Figures 10 - 12 , in a specific embodiment, for example, the magnetic communication passive interface antenna includes three partially overlapping energy harvesting antennas 401, which are respectively Figure 11The antennas A2, B2, and C2 shown in [Figure 0] are magnetic communication passive interfaces each containing three energy harvesting antennas 401, which obtain energy from the magnetic communication active interface antenna. Part of the antenna A2 overlaps with the antenna B2, and part of the antenna B2 overlaps with the antenna C2. Each of the three antennas is connected to one of the energy harvesting matching and rectifying units 4041.

[0077] In Figure 12 when the magnetic communication active interface antenna is directly facing the antenna A2, by pre-designing the parameters of each electronic device in the matching circuit, the parameters of each electronic device are optimized to achieve the maximum energy reception power of the antenna A2 at the directly facing position. When the magnetic communication active interface antenna is translated away from the position directly facing the antenna A2, the energy reception power of the antenna A2 decreases, but the active interface antenna gradually approaches the antenna B2, causing the power received by the antenna B2 to gradually increase. By pre-designing the parameters of each electronic device in the matching circuit, the parameters of each electronic device are optimized when the magnetic communication active interface antenna is directly facing the antenna B2 to achieve the maximum energy reception power of the antenna B2 at the directly facing position. When the magnetic communication active interface antenna is translated away from the position directly facing the antenna B2, the energy reception power of the antenna B2 decreases, but the active interface antenna gradually approaches the antenna C2, causing the power received by the antenna C2 to gradually increase. By pre-designing the parameters of each electronic device in the matching circuit, the parameters of each electronic device are optimized when the magnetic communication active interface antenna is directly facing the antenna C2 to achieve the maximum energy reception power of the antenna C2 at the directly facing position.

[0078] In Figure 12 the received power curve of the antenna A2 is LA2, the received power curve of the antenna B2 is LB2, and the received power curve of the antenna C2 is LC2. As the relative position between the active interface and the passive interface changes, all three curves have a relatively obvious power change trend. L2 is the composite curve after the curves LA2, LB2, and LC2 are superimposed. From the curve L2, it can be seen that within the entire working range where the active interface and the passive interface can be changed, it can maintain a relatively high energy reception power.

[0079] It should be noted that those skilled in the art can adaptively select the number of energy harvesting antennas 401 and the relative cooperation positions between the antennas according to the requirements of specific application scenarios. This embodiment does not limit this.

[0080] Each unit in this embodiment can be implemented in the form of an ordinary circuit or an integrated chip.

[0081] The magnetic communication passive interface provided in this embodiment can maintain good energy reception power when the relative position between the magnetic communication active interface and the magnetic communication passive interface changes, expanding the range of energy harvesting and further enhancing the user experience.

[0082] Embodiment 3

[0083] This embodiment provides a magnetic communication passive interface. Please refer to Figure 13 This magnetic communication passive interface is a further improvement based on Embodiment 1.

[0084] The microcontroller 405 has a data interface, which is connected to the external device 406 of the magnetic communication passive interface and communicates with the external device 406.

[0085] The magnetic communication passive interface may further include a selection unit 4044, which is configured to receive the DC signals of multiple energy harvesting matching and rectifying units 4041 and select one of the DC signals of the energy harvesting matching and rectifying units 4041 according to the instruction of the microcontroller 405 and output it to the external device 406.

[0086] In this embodiment, the magnetic communication passive interface further includes an energy management unit 4043, which receives the DC signal output from the selection unit 4044 and transmits the DC signal to the external device 406.

[0087] Preferably, the selection unit 4044 can select to output the DC signal with the maximum power to the external device 406, or output the DC signal that best matches the external device 406 to the external device 406.

[0088] The magnetic communication passive interface provided in this embodiment can select different DC signals for the external device through the selection unit, so as to meet the power supply needs of various different types of external devices.

[0089] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example. The protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A magnetic communication passive interface, characterized in that The magnetic communication passive interface communicates with the magnetic communication active interface. The magnetic communication passive interface includes a plurality of antennas. The antennas include communication antennas for communication only and a plurality of energy harvesting antennas for energy harvesting only; A plurality of the energy harvesting antennas are concentrically nested and partially overlapped with each other; And / or, the communication antennas and the energy harvesting antennas are concentrically nested and partially overlapped with each other; The magnetic communication passive interface includes a plurality of energy harvesting matching and rectifying units corresponding to the energy harvesting antennas. The input end of each energy harvesting matching and rectifying unit is connected to the port of the corresponding energy harvesting antenna. The energy harvesting matching and rectifying unit is configured to set the output impedance of the energy harvesting antenna to a preset value; Each of the energy harvesting antennas is set to a different working position. By setting the output impedance of the energy harvesting antenna, the energy harvesting antenna and the antenna of the magnetic communication active interface are made to resonate at the working position. The working position is the relative distance and relative orientation of the magnetic communication passive interface with respect to the magnetic communication active interface.

2. The magnetic communication passive interface according to claim 1, wherein, The magnetic communication passive interface further includes a microcontroller. The microcontroller has a data interface. The data interface is connected to an external device of the magnetic communication passive interface and communicates with the external device.

3. The magnetic communication passive interface according to claim 2, characterized in that, The energy harvesting matching and rectifying unit is further configured to receive the radio frequency signal collected by the energy harvesting antenna and convert the radio frequency signal into a direct current signal.

4. The magnetic communication passive interface according to claim 3, wherein, The magnetic communication passive interface further includes a selection unit. The selection unit is configured to receive the direct current signals of the plurality of energy harvesting matching and rectifying units and select the direct current signal of one of the energy harvesting matching and rectifying units according to an instruction of the microcontroller and output the selected direct current signal to the external device.

5. The magnetic communication passive interface according to claim 3, wherein The magnetic communication passive interface further includes a power combining unit. The power combining unit includes a plurality of input ends and one output end; The output end of each energy harvesting matching and rectifying unit is respectively connected to an input end of the power combining unit. The power combining unit is configured to superimpose the direct current signals output by the plurality of energy harvesting matching and rectifying units and output the superimposed direct current signal to the external device.

6. The magnetic communication passive interface according to claim 4, wherein The magnetic communication passive interface further includes an energy management unit. The energy management unit receives the direct current signal output from the selection unit and transmits the direct current signal to the external device.

7. The magnetic communication passive interface according to claim 5, wherein The magnetic communication passive interface further includes an energy management unit. The energy management unit receives the direct current signal output from the power combining unit and transmits the direct current signal to the external device.

8. The passive magnetic communication interface according to claim 6 or 7, characterized in that, The microcontroller is further communicatively connected to the energy management unit. The microcontroller controls the energy management unit to send the direct current signal to the external device, or the microcontroller controls the energy management unit to stop sending the direct current signal to the external device.

9. The magnetic communication passive interface according to claim 2, wherein The magnetic communication passive interface further includes a communication matching unit. The communication matching unit is connected to the communication antenna and is configured to adjust the output impedance of the communication antenna.

10. The magnetic communication passive interface according to claim 9, characterized in that, The microcontroller is also connected to the communication matching unit, receives signals from the communication matching unit and demodulates them to obtain data, and the microcontroller provides the demodulated data to an external device of the magnetic communication passive interface through the data interface; The microcontroller also receives data transmitted from the external device, modulates the data transmitted from the external device, and then transmits it to the communication antenna for external transmission through the communication matching unit.

11. The magnetic communication passive interface according to claim 5, characterized in that, The power combining unit includes a plurality of diodes, the anode of each diode is respectively connected to an input end of the energy harvesting matching and rectifying unit, and the cathode of each diode is connected to the output end of the energy harvesting matching and rectifying unit.

12. An NFC communication device, characterized in that, The NFC communication device includes the magnetic communication passive interface according to any one of claims 1-11.

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