Electronic devices

Abstract

The present application relates to an electronic device. The electronic device includes: a conductive frame, a near field communication unit, an antenna coil and a tuning switch circuit. Among them, a break is provided on the conductive frame, and a first free end and a second free end of the conductive frame are formed at the break position; the near field communication unit is used to provide an excitation current; the antenna coil and the conductive frame are used to transmit the excitation current together; the tuning switch circuit is connected in series between the first free end and the second free end at the break position; and the tuning switch circuit is used to block the excitation current at the working frequency point of the near field communication unit, and transmit the feeding current at a preset resonant frequency point; the feeding current is used to excite the conductive frame to radiate a preset radio frequency signal, and the preset resonant frequency point is higher than the working frequency point. The electronic device provided in this embodiment improves the NFC communication performance of the electronic device by reusing the conductive frame and setting a tuning switch circuit for the feeding current to pass through, and is conducive to realizing miniaturized design and reducing the volume of the electronic device.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an electronic device. Background Art

[0002] With the development of communication technology and wearable technology, wearable devices such as smart watches and bracelets have been increasingly widely used due to their portability and increasingly powerful communication functions. For example, wearable devices can connect to mobile phones, measure physiological parameters, record movement trajectories, etc. They can also support mobile payments such as subways and buses, as well as electronic ticketing, access control, mobile identity recognition and anti-counterfeiting. These communication functions rely on Near Field Communication (NFC).

[0003] However, the applicant found in the implementation process that the NFC communication effect of electronic devices such as wearable devices in traditional technologies is poor. For example, when a user uses a wearable device to swipe a card near a subway gate, the card swiping often fails. Summary of the invention

[0004] The embodiment of the present application provides an electronic device with high communication reliability.

[0005] An electronic device, comprising:

[0006] A conductive frame, wherein a fracture is formed on the conductive frame, and a first free end and a second free end of the conductive frame are formed at the fracture position;

[0007] A near field communication unit, used for providing an excitation current;

[0008] The antenna coil and the conductive frame are used to transmit the excitation current together;

[0009] A tuning switch circuit, the tuning switch circuit is connected in series between the first free end and the second free end of the break position;

[0010] The tuning switch circuit is used to block the excitation current at the operating frequency point of the near-field communication unit and transmit the feeding current at a preset resonant frequency point; wherein the feeding current is used to excite the conductive frame to radiate a preset radio frequency signal, and the preset resonant frequency point is higher than the operating frequency point.

[0011] The above-mentioned electronic device has a break in the conductive frame, and a tuning switch circuit is connected in series at the break position. The feed current fed from any point on the conductive frame is transmitted on the conductive frame through the tuning switch circuit, and the radiation of the preset radio frequency signal corresponding to the feed point current is realized at both the conductive frame and the break position, which is conducive to realizing the miniaturization design of the electronic device while meeting the size requirements of the antenna radiator required for the preset radio frequency signal transmission. In addition, the excitation current provided by the near-field communication unit cannot pass through the tuning switch circuit, so that the excitation current is transmitted on the conductive path formed by the antenna coil and the conductive frame, realizing the NFC signal radiation on the conductive path, and the preset radio frequency signal radiation and NFC signal radiation are multiplexed by the conductive frame, which is conducive to improving the NFC communication performance and miniaturization design of the electronic device.

[0012] In addition, whether the conductive frame is used for excitation current transmission or feeding current transmission is realized based on the tuning switch circuit, and there is no need to add control devices to achieve the reuse of the conductive frame, which is conducive to reducing the cost of electronic equipment and miniaturization design. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 is one of the structural schematic diagrams of an electronic device in one embodiment;

[0015] Figure 2 This is a second structural diagram of an electronic device in an embodiment;

[0016] Figure 3 A schematic diagram of the structure of an antenna coil, a tuning switch circuit and a conductive frame in an electronic device in one embodiment;

[0017] Figure 4 This is a third structural diagram of an electronic device in an embodiment;

[0018] Figure 5 This is a fourth structural diagram of an electronic device in an embodiment;

[0019] Figure 6 Schematic diagram of magnetic field intensity distribution of a large-sized coil in one embodiment. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first break may be referred to as a second break, and similarly, a second break may be referred to as a first break. Both the first break and the second break are breaks, but they are not the same break.

[0022] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0023] like Figure 1-3 As shown, in one of the embodiments, the electronic device provided in the embodiment of the present application includes: a conductive frame 200, a near field communication unit 400, an antenna coil 600 and a tuning switch circuit 800.

[0024] In this embodiment, a fracture DF is formed on the conductive frame 200, and the first free end and the second free end of the conductive frame 200 are formed at the position of the fracture DF. The fracture DF divides the conductive frame 200 into at least one disconnected conductor. It should be understood that when the fracture DF is not unique, the first free end and the second free end of the conductive frame 200 are multiple groups, for example, Figure 2 There are two sets of first free ends and second free ends at the positions DF1 and DF2 shown in FIG.

[0025] The near field communication (NFC) unit 400 is used to provide an excitation current to achieve the radiation of an NFC signal (near field communication signal) on the transmission path of the excitation current. Optionally, the near field communication unit 400 can adopt a two-end feeding method, and the excitation current is fed in and out through the NFC_P terminal and the NFC_N terminal as shown in the figure. The near field communication unit 400 is used to provide a differential excitation current. Compared with the single-end communication, the two-end communication method can subtract the same interference signal based on the difference when subjected to the same interference, thereby improving the anti-interference performance of the excitation current, and then improving the stability of the NFC communication.

[0026] The antenna coil 600 is connected to the conductive frame 200 to transmit the excitation current together. As a part of the excitation current transmission path, the conductive frame 200 can enhance the radiation area of ​​the NFC signal and improve the near-field communication performance of the electronic device. There are many ways to connect the antenna coil 600 and the conductive frame 200. The general connection principle is that the induced current of the antenna coil 600 and the conductive frame 200 is in the same direction in the radio frequency field emitted by other devices, and the radiation field of the antenna coil 600 and the radiation field of the conductive frame 200 enhance each other, thereby improving the NFC communication performance.

[0027] The antenna coil 600 can be implemented by FPC (Flexible Printed Circuit) or PCB (Printed circuit boards) printed wire or LDS (Laser-Direct-structuring) metal, or a combination of the above methods. In addition, the antenna coil 600 can also be made of a new material with radiation performance equivalent to that of metal.

[0028] The number of turns of the antenna coil 600 may be determined based on the layout space of the electronic device, and the intervals between the turns of the coils are set on the principle of not affecting each other.

[0029] The tuning switch circuit 800 is connected in series between the first free end and the second free end of the fracture DF. The tuning switch circuit 800 is used to block the excitation current at the working frequency point of the near field communication unit 400, and transmit the feeding current at the preset resonant frequency point; wherein the feeding current is used to excite the conductive frame 200 to radiate the preset radio frequency signal, and the preset resonant frequency point is higher than the working frequency point.

[0030] The operating frequency point of the near field communication unit 400 can be 13.56MHz, which is a low frequency signal. The preset radio frequency signal may include but is not limited to a cellular network signal, a wireless fidelity signal (Wireless Fidelity, WiFi), a global positioning system (Global Positioning System, GPS) signal, a Bluetooth (Bluetooth, BT) signal, etc. The operating frequencies of these preset radio frequency signals are all above 850MHz, which is higher than 13.56MHz, that is, the preset resonant frequency point of the preset radio frequency signal is higher than the operating frequency point of the near field communication unit 400. Based on this difference, a suitable tuning switch circuit 800 can be set so that the tuning switch circuit 800 is in a high impedance state at the operating frequency point, and the excitation current is not allowed to pass through the gap DF. At this time, the excitation current of the near field communication unit 400 is transmitted through the antenna coil 600 and the conductive frame 200, and the conductive frame 200 acts on the radiation of the near field communication signal to improve the NFC communication performance.

[0031] The tuning switch circuit 800 is in a low-impedance state at the preset resonant frequency point of non-near field communication, and the feeding current can be transmitted in the conductive frame 200 through the break DF. When a tuning switch circuit 800 is connected in series between the first free end and the second free end of each break DF position, the size of the conductive frame 200 acting on the feeding current transmission is equivalent to the size of the conductive frame 200 without the break DF, which can avoid the problem of insufficient size of the antenna radiator used for radiating the preset radio frequency signal due to the setting of the break DF, which is conducive to reducing the volume of the electronic device. And under the adaptation selection of the tuning switch circuit 800, automatic switching between NFC signal transmission and preset radio frequency signal transmission can be realized, without the need to introduce a control device to control the multiplexing process of the conductive frame 200, and the cost is low.

[0032] Optionally, a tuning switch circuit 800 may be connected in series between the first free end and the second free end of each fracture DF position.

[0033] The electronic device provided by the implementation of the present application is provided with a break DF on the conductive frame 200, and a tuning switch circuit 800 is provided at the break DF. The feeding current fed from a point on the conductive frame 200 is transmitted on the conductive frame 200 through the tuning switch circuit 800, avoiding the break setting, reducing the length of the antenna radiator used to radiate the preset radio frequency signal, which is conducive to miniaturization of the electronic device, and the tuning switch circuit 800 does not allow the excitation current to pass, so that the excitation current is transmitted on the conductive path formed by the antenna coil 600 and the conductive frame 200. By reusing the conductive frame 200, not only the NFC communication performance of the electronic device can be improved, but also the space occupied by the antenna can be saved. That is, the solution provided by the embodiment of the present application is conducive to improving the NFC communication performance of the electronic device and miniaturization design.

[0034] In addition, by reusing the conductive frame 200, the interference between the turns of the antenna coil 600 and between the antenna coil 600 and the conductive frame 200 is reduced within a limited space.

[0035] In the embodiments of the present application, Figure 1 As shown, the first end of the antenna coil 600 is connected to the first free end of the break position. The first signal terminal NFC_P of the near field communication unit 400 is connected to the second free end of the break position, and the second signal terminal NFC_N of the near field communication unit 400 is connected to the second end of the antenna coil 600. When the break is not unique, the first free end of the break position here refers to the first free end of the conductive frame 200 at one of the break positions, and the second free end here refers to the second free end of the same break position as the above-mentioned first free end, so as to ensure that the conductive frame 200 is fully connected to the antenna coil 600 for NFC signal enhancement. The first signal end of the near field communication unit 400 can be as follows Figure 1 and Figure 2 The second signal terminal can be as shown in NFC_P. Figure 1 and Figure 2 NFC_N as shown. Figure 1 and Figure 2 As shown, the excitation current is fed into the conductive frame 200 through the second free end, passes through the conductive frame 200 and the antenna coil 600, and flows back to the near field communication unit 400 through the second end of the antenna coil 600.

[0036] like Figure 1 As shown, in one embodiment, the first signal terminal NFC_P of the near field communication unit 400 provides an excitation current, which is fed into the conductive frame 200 from the second free end of the break DF. The current is transmitted in the conductive frame 200 in a clockwise direction. When it flows to the first free end of the break DF, it flows to the first end of the antenna coil 600 through the connection between the first free end and the first end of the antenna coil 600, and starts from the first end. It is transmitted in the antenna coil 600 in a clockwise direction and flows back to the second signal terminal NFC_N of the near field communication unit at the second end of the antenna coil 600. As can be seen from the figure, the direction of the current in the antenna coil 600 is consistent with the direction of the current in the conductive frame 200. Based on the right-hand rule, the direction of the magnetic field generated by the conductive frame 200 is the same as the direction of the magnetic field provided by the antenna coil 600, so that the magnetic field strength of the electronic device for NFC signal communication is the sum of the magnetic field strength of the conductive frame 200 and the magnetic field strength of the antenna coil 600, which helps to improve the NFC communication performance.

[0037] In the embodiments of the present application, Figure 2 and Figure 3 As shown, the fracture DF includes at least a first fracture DF1 and a second fracture DF2. There is one first fracture DF1 and one second fracture DF2, that is, there are at least two fractures on the conductive frame 200.

[0038] For the scheme with at least two breaks, except for Figure 2 In the connection mode of the conductive frame 200 and the antenna coil 600, the connection can also be achieved as follows Figure 3As shown, the first end of the antenna coil 600 is connected to the first free end at the first break DF1, and the second end of the antenna coil 600 is connected to the second free end at the first break DF1, that is, the connection with the antenna coil 600 is realized at the two free ends of the same break DF1. To ensure that the conductive frame 200 can fully act on the radiation of the NFC signal, the first free end at the second break DF2 is connected to the first signal end of the near field communication unit 400, and the second free end at the second break DF2 is connected to the second signal end of the near field communication unit 400. The excitation current provided by the near field communication unit 400 is fed to the conductive frame 200 through the first free end at the second break DF2, and after being transmitted through the conductive frame 200 and the antenna coil 600, it flows back to the near field communication unit 400 through the second free end at the second break DF2. The conductive frame 200 acts on the enhancement of the NFC signal.

[0039] For small-volume wearable devices, the space for setting up antenna radiators is limited, but the functional requirements of such electronic devices are becoming more and more diverse. Users use such electronic devices not only for LTE (Long Term Evolution) signal communication, but also for measuring physiological parameters such as blood oxygen, swiping subway cards, etc. Under different functional requirements, there are differences in the size requirements for antenna radiators used for RF signal radiation in electronic devices. In the embodiments of the present application, Figure 3 As shown, the break also includes at least one third break DF3, and a tuning switch circuit 800 is serially connected between the first free end and the second free end of each third break DF3.

[0040] In the embodiment of the present application, the tuning switch circuit 800 includes: a capacitor (for example, Figure 3 The capacitor is connected in series between the first free end and the second free end of the fracture DF. The tuning switch circuit 800 may only include a capacitor, such as a 30pF capacitor. The capacitor implementation is simple, feasible and low-cost.

[0041] When a 30pF capacitor is used to implement the tuning switch circuit 800, according to the impedance calculation formula of the capacitor, the impedance of the 30pF capacitor at the working frequency point of 13.56MHz of the near field communication unit 400 is 391.236j, which is in a high impedance state; and the impedance of the 30pF capacitor at the frequency point of 850MHz is 6.241j, which is in a low impedance state, and it is in a low impedance state at frequencies greater than 850MHz. By connecting a 30pF capacitor in series at the break position, the NFC signal at a frequency of 13.56MHz is equivalent to an open circuit state, which meets the need for a break to prevent the conductive frame 200 from suppressing the NFC signal; and for a preset resonant frequency point with an working frequency point greater than 850MHz, the capacitor is equivalent to a short circuit state, and the preset radio frequency signal can be transmitted on the conductive frame 200 through the capacitor. In actual application, the capacitance of the capacitor can be adjusted according to demand, for example, Figure 3 The capacitance values ​​of C1 and C2 can be different.

[0042] Of course, the tuning switch circuit 800 may also be implemented in other circuit ways, as long as it satisfies the requirement of being in a high impedance state at the operating frequency of the near field communication unit 400 and being in a low impedance state at a preset resonant frequency.

[0043] In an embodiment of the present application, the first signal terminal NFC_P and the second signal terminal NFC_N of the near field communication unit 400 are connected to the antenna coil 600 and the conductive frame 200 through a matching circuit. The matching circuit is used to match the impedance during the transmission of the excitation current. Optionally, a filter circuit may be connected in series between the matching circuit and the near field communication unit 400 to filter out other interference signals other than the excitation current. The filter circuit may use an LC filter circuit. The matching circuit may be implemented using a capacitor device.

[0044] In the embodiment of the present application, a feeding point is also provided on the conductive frame 200, and the electronic device also includes a feed source for providing a feeding current, and the feeding current is fed into the conductive frame 200 through the feeding point to stimulate the conductive frame 200 to radiate a preset radio frequency signal. For electronic devices with multiple types of preset radio frequency signal communication requirements, the feeding point can be set to multiple, and the feed sources are set one by one with the feeding points, and each feed source can provide a feeding current to the conductive frame 200 to stimulate the conductive frame 200 to radiate the preset radio frequency signal corresponding to the feed source. Thereby, the transmission of multiple types of preset radio frequency signals such as LTE signals, GPS signals, WiFi signals and BT signals of the electronic device is realized.

[0045] The feeding point may be a contact feeding point or a coupling feeding point. Similarly, the connection between the antenna coil 600 and the conductive frame 200 may be achieved through a contact connection or a coupling connection.

[0046] Each tuning switch circuit 800 can block the excitation current provided by the near field communication unit 400. The parameters of the tuning switch circuits 800 at different break positions can be determined according to the preset resonant frequencies of various preset RF signals and the size of the antenna radiator required to transmit the preset RF signal.

[0047] For example, Figure 3 As shown, a tuning switch circuit C1 is connected in series at the position of the first break DF1, and a first feed source KY1 is connected to the conductive frame between the first break DF1 and the second break DF2. The first feed current provided by the first feed source KY1 flows from the first feed point a in a counterclockwise direction to NFC_N. The conductive frame 200 between a and NFC_N acts on the transmission of the first feed current to achieve the radiation of the first preset RF signal corresponding to the first feed current. The second feed source KY2 is connected to the conductive frame between the second break DF2 and the third break DF3. If the antenna radiator size required by the second preset RF signal corresponding to the second feed current is a length between b and c, a tuning switch circuit C2 can be set. The tuning switch circuit C2 is in a high impedance state at the preset resonant frequency of the second preset RF signal, and does not allow the second feed current to pass.

[0048] If the size of the antenna radiator required by the second preset radio frequency signal is the length from b to e, a tuning switch circuit C2 is configured, and the tuning switch circuit C2 is in a low impedance state at the preset resonant frequency of the second preset radio frequency signal, and the second feed current is transmitted from b in a counterclockwise direction, flows through the tuning switch circuit C2 and is transmitted to e. By configuring the tuning switch circuit C1 to be in a high impedance state at the preset resonant frequency of the second preset radio frequency signal, the conductive frame 200 between be and is implemented to radiate the second preset radio frequency signal.

[0049] In an embodiment of the present application, a high-frequency short-circuit filter circuit, such as a high-frequency short-circuit capacitor, can be connected in series between each feed source and its corresponding feed point. This can not only realize that the feed current provided by the feed source is fed into the conductive frame 200, but also avoid interference between the feed current and the excitation current. The high-frequency short-circuit filter circuit here refers to a filter circuit that allows the feed current provided by the feed source to pass through, but does not allow the excitation current to pass through. The parameter selection of the filter circuit can be determined according to the feed current parameters provided by the feed source.

[0050] In an embodiment of the present application, the electronic device may further include a non-near field communication unit, and a preset radio frequency signal is provided based on the non-near field communication unit. The non-near field communication unit may be an IC, which may be integrated on a circuit board of the electronic device. Based on the type of the preset radio frequency signal, the non-near field communication unit may be a chip that matches it. For example, corresponding to a cellular network signal, the non-near field communication unit may be a cellular communication chip for providing the cellular network signal. When the preset radio frequency signal is a GPS signal, the non-near field communication unit may be a GPS chip. When the preset radio frequency signal is a WiFi signal, the non-near field communication unit may be a WiFi chip. When the preset radio frequency signal is a BT signal, the non-near field communication unit may be a BT chip.

[0051] The conductive frame 200 can be used to radiate the preset radio frequency signal at the preset resonant frequency, for example, a WiFi signal operating in the 5 GHz frequency band, or for example, a WiFi signal in the 2.4 GHz frequency band.

[0052] In the embodiment of the present application, the antenna coil 600 and the conductive frame 200 are connected by a spring to transmit the excitation current together. Figure 1-3 In the electronic device shown in , each connection point between the antenna coil 600 and the conductive frame 200 can be connected by a spring. The connection between the near field communication unit 400 and the antenna coil 600 or the conductive frame 200 can also be achieved by a spring.

[0053] In order to ensure the effectiveness of the setting of the break and to disconnect the transmission path of the NFC signal on the conductive frame 200, in the embodiment of the present application, the gap of the break is greater than the first distance, and the first distance is the distance between the spring connected to the first free end and the spring connected to the second free end of the break. That is, the gap of the break should be greater than the distance between two adjacent springs to avoid coupling of NFC signals on two adjacent springs due to the small size of the break.

[0054] In the embodiment of the present application, the electrical connection between the various parts can also be achieved through conductors, flexible circuit boards, etc.

[0055] In the embodiments of the present application, Figure 4 and Figure 5 As shown, the electronic device also includes: a middle frame. The middle frame includes a conductive frame 200 and a middle plate, and the antenna coil 600 is arranged in the middle area of ​​the middle plate. At this time, the distribution uniformity of the NFC signal is better, which is more conducive to improving the coupling of the user's electronic device with the radio frequency field of other devices at various positions when using the electronic device. The position of the break can be set at any position of the conductive frame 200, for example, it can be as follows Figure 4 and Figure 5The position shown can be determined based on the spatial arrangement requirements of other modules mounted on the electronic device. For example, it can be set at a position that can ensure the stability of the middle frame and will not affect the spatial arrangement requirements of the buttons on electronic devices such as watches. The shape of the conductive frame 200 can be rectangular, circular, etc., depending on the overall structural design of the electronic device and is not limited. It should be understood that Figure 3 and Figure 5 In the embodiment, NFC_P and NFC_N are connected to a near field communication unit not shown. Figure 4 and Figure 5 As shown, the conductive frame 200 can be arranged on the side of the middle frame. For small electronic devices, the conductive frame 200 and the antenna coil 600 are arranged close to each other, and the magnetic field is enhanced better.

[0056] In the embodiment of the present application, the fracture position can be filled with a plastic material of the same color as the conductive frame 200, which is beneficial to improving the appearance of the electronic device. The above-mentioned tuning switch circuit can be encapsulated in the plastic material, which is beneficial to the stability of the connection between the tuning switch circuit 800 and the conductive frame 200, and can also save the layout space on the frame of the electronic device.

[0057] In an embodiment of the present application, one side of the middle plate is metal, forming a metal area. When other electronic components on the electronic device transmit alternating current, the metal area will generate high-frequency interference signals, which interfere with the above-mentioned excitation current. Based on this, the electronic device also includes a filter circuit (not shown). The filter circuit establishes an electrical connection between the metal area and the ground. Due to the characteristics of the filter circuit passing high frequency and blocking low frequency, the high-frequency interference signal is filtered out, and the transmission of the NFC low-frequency signal is not affected, thereby further improving the communication performance of the electronic device. The filter circuit may include capacitors, inductors, and a combination of the two.

[0058] In the embodiments of the present application, the electronic device may be a smart phone, a tablet computer, or other device, and may also be a gaming device, an augmented reality (AR) device, an automotive device, a data storage device, an audio playback device, a video playback device, a laptop computer, a desktop computing device, etc.

[0059] In the embodiment of the present application, the electronic device may be specifically a wearable device. Wearable devices include but are not limited to smart watches, smart bracelets, etc. For example, smart watches with call functions, smart watches and sports watches without call functions, and bracelets with NFC functions, etc. The wearable device provided in the embodiment of the present application, based on the setting of the tuning switch circuit 800 and the setting of the seam on the conductive frame 200, improves the NFC communication performance without increasing the size of the device, and is compatible with the communication of preset radio frequency signals such as LTE signals, GPS signals, WiFi signals and BT signals.

[0060] In the embodiment of the present application, the length of the conductive frame 200 for radiating the preset radio frequency signal is less than one quarter of the sum of the lengths of the conductive frame 200 and the antenna coil 600 for radiating the NFC signal.

[0061] In order to better help those skilled in the art understand the implementation process of the embodiment scheme of the present application, the electronic device is a smart watch and the application scenario is passing through a subway gate as an example for explanation. However, it should be emphasized that the examples given here do not limit the actual protection scope of the present application.

[0062] like Figure 6 As shown in the figure, the relationship between the magnetic field strength and the distance X (mm) to the center point under a large-size coil test case. As can be seen from the figure, the magnetic field strength at the center point of large-size coils such as subway gates is weak, which results in the weakest coupling performance between the watch and the gate at the center point. Traditional wearable devices use a fully conductive frame 200, on which a reverse current will be formed to reduce the magnetic field of the NFC signal, further attenuating the NFC signal received by the watch from the gate. As shown in Table 1, in a test example, when the frame of the watch is a conductive frame 200, the coupling coefficient between the watch and the gate will be attenuated by about 2 / 3. As a result, when the watch swipes the card at the center of the subway gate, it may not receive the gate signal, resulting in a card swiping failure, affecting the card swiping success rate and user experience.

[0063] Table 1

[0064] Gate center point Coupling coefficient No conductive frame 0.043 Plastic conductive frame 0.042 Conductive frame 0.016

[0065] By Figure 1-3 Under the structure of the electronic device shown in , the conductive frame 200 that would originally weaken the NFC signal is converted into a part that enhances the signal, which can improve the signal received when the subway gate center swipes the card and increase the card swiping success rate. And by connecting a 30pF capacitor in series at the break position of the conductive frame 200, the conductive frame 200 is still disconnected for the 13.56MHz NFC signal, and for other higher frequency preset radio frequency signals, the 30pF capacitor is equivalent to a short circuit, and the size of the antenna radiator used to transmit the preset radio frequency signal can be equivalent to a complete closed conductive frame 200.

[0066] The back cover of the wearable device is often a metal back cover. In the embodiment of the present application, the wearable device also includes a display screen. In order to better realize the near-field communication of the wearable device, the antenna coil 600 can be arranged between the display screen and the back, for example, it can be attached to the non-display surface of the display screen. On the one hand, it is conducive to improving the integration of the wearable device and reducing the volume of the wearable device. On the other hand, when the wearable device is used to communicate with other devices for NFC, the influence of the metal back cover on the NFC communication performance is avoided. As described in the above embodiment, the metal area of ​​the metal back cover can be grounded through a filter circuit to avoid the influence of high-frequency interference signals on the NFC signal, thereby improving the NFC communication performance. The electronic device has a circuit board, and the ground can be mainly arranged on the surface of the circuit board. The circuit board is also provided with electrical connection devices such as spring feet, screws, springs, conductive cloth, conductive foam or conductive glue, which are used to establish the connection between the antenna coil 600, the conductive frame 200 and the near-field communication unit 400, or to establish the connection between the ground and the filter circuit. In addition, air, plastic, ceramic or other dielectric materials can be filled between the ground and the components connected to it.

[0067] In an embodiment of the present application, the wearable device may also include other types of components, such as one or more of the following components: a power button, a volume button, a battery, and a camera.

[0068] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0069] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An electronic device, characterized in that: include: A conductive frame, wherein a fracture is formed on the conductive frame, and a first free end and a second free end of the conductive frame are formed at the position of the fracture; A near field communication unit, used for providing an excitation current; An antenna coil, wherein the antenna coil is connected to the conductive frame and is used to transmit the excitation current together; A tuning switch circuit, the tuning switch circuit is connected in series between the first free end and the second free end of the break position; The tuning switch circuit is used to block the excitation current at the operating frequency point of the near field communication unit, and transmit the feeding current at a preset resonant frequency point; wherein the feeding current is used to excite the conductive frame to radiate a preset radio frequency signal, and the preset resonant frequency point is higher than the operating frequency point; in: The first end of the antenna coil is connected to the first free end of the break position; the first signal end of the near field communication unit is connected to the second free end of the break position, and the second signal end of the near field communication unit is connected to the second end of the antenna coil; wherein the excitation current is fed into the conductive frame through the second free end, and flows back to the near field communication unit through the second end of the antenna coil; or, The fracture comprises at least a first fracture and a second fracture; The first end of the antenna coil is connected to the first free end of the first break position, and the second end of the antenna coil is connected to the second free end of the first break position; The first free end of the second break position is connected to the first signal end of the near field communication unit, and the second free end of the second break position is connected to the second signal end of the near field communication unit; The excitation current is fed into the conductive frame through the first free end of the second break position, and flows back to the near field communication unit through the second free end of the second break position.

2. The electronic device according to claim 1, characterized in that: The break also includes at least one third break, and a tuning switch circuit is connected in series between the first free end and the second free end of each third break.

3. The electronic device according to any one of claims 1 to 2, characterized in that: A tuning switch circuit is serially connected between the first free end and the second free end of each of the break positions.

4. The electronic device according to claim 1, characterized in that: The tuning switch circuit comprises: A capacitor is connected in series between the first free end and the second free end of the fracture position.

5. The electronic device according to claim 1, characterized in that: A feeding point is also provided on the conductive frame, and the electronic device also includes a feeding source for providing the feeding current. The feeding current is fed into the conductive frame through the feeding point to stimulate the conductive frame to radiate the preset radio frequency signal.

6. The electronic device according to claim 1, characterized in that: Also includes: The middle frame includes the conductive frame and a middle plate, and the antenna coil is arranged in the middle area of ​​the middle plate.

7. The electronic device according to claim 1, characterized in that: The electronic device is a wearable device.

8. The electronic device according to claim 1, characterized in that: The antenna coil and the conductive frame are connected via a spring sheet and transmit the excitation current together.

9. The electronic device according to claim 8, characterized in that: The gap of the break is larger than a first distance, and the first distance is the distance between the spring piece connected to the first free end and the spring piece connected to the second free end at the break position.

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